According to estimates by the National Cancer Institute, in 2020 over 147,000 new cases of colorectal cancer will be diagnosed in the U. S., and over 53,000 people will die of this cancer.^1, Five-year survival estimates are around 65%.

Colorectal cancer is classified as stage II (also called Dukes B) when it has spread outside the colon and/or rectum to nearby tissue but is not detectable in lymph nodes (stage III disease, also called Dukes C) and has not metastasized to distant sites (stage IV disease). Primary treatment is surgical resection of primary cancer and colonic anastomosis. After surgery, the prognosis is good, with survival rates of 75% to 80% at 5 years.^2, A Cochrane review by Figueredo et al (2008), assessing 50 studies of adjuvant therapy vs surgery alone in stage II patients, found a small though statistically significant absolute benefit of chemotherapy for disease-free survival but not for overall survival.^2, Therefore, adjuvant chemotherapy with 5-fluorouracil or capecitabine is recommended only for resected patients, with high-risk stage II disease (ie, those with poor prognostic features).^3,

Of patients with stage II colon cancer, 75% to 80% are cured by surgery alone, and the absolute benefit of chemotherapy for the overall patient population is small. Patients most likely to benefit from chemotherapy are difficult to identify by standard clinical and pathologic risk factors. Gene expression profiling and circulating tumor DNA tests are intended to facilitate identifying stage II patients most likely to experience recurrence after surgery and most likely to benefit from additional treatment.

However, the clinical and pathologic features used to identify high-risk disease are not well-established, and patients for whom benefits of adjuvant chemotherapy would most likely outweigh harms cannot be identified with certainty. The current diagnostic system relies on a variety of factors, including tumor substage IIB (T4A tumors that invade the muscularis propria and extend into pericolorectal tissues) or IIC (T4B tumors that invade or are adherent to other organs or structures), obstruction or bowel perforation at initial diagnosis, an inadequately low number of sampled lymph nodes at surgery (≤12), histologic features of aggressiveness, a high preoperative carcinoembryonic antigen level, and indeterminate or positive resection margins.^3,

Of interest, a review by Vilar and Gruber (2010) has noted that microsatellite instability and mismatch repair deficiency in colon cancer may represent confounding factors to be considered in treatment.^4, These factors may identify a minority (15%-20%) of the population with improved disease-free survival who may derive no benefit or may exhibit deleterious effects from adjuvant 5-fluorouracil plus leucovorin-based treatments. Patient microsatellite instability and mismatch repair status may be critically important in how to study, interpret, and use a particular gene expression profile test.

Regulatory Status

Clinical laboratories may develop and validate tests in-house and market them as a laboratory service; laboratory-developed tests must meet the general regulatory standards of the Clinical Laboratory Improvement Amendments. Multigene expression assay testing and circulating tumor DNA (ctDNA) for predicting recurrent colon cancer is available under the auspices of Clinical Laboratory Improvement Amendments. Laboratories that offer laboratory-developed tests must be licensed by the Clinical Laboratory Improvement Amendments for high-complexity testing. To date, the U.S. Food and Drug Administration has chosen not to require any regulatory review of this test.

Gene expression profile and ctDNA tests for colon cancer currently commercially available include:

• ColoPrint 18-Gene Colon Cancer Recurrence Assay (Agendia)
• GeneFx Colon (Helomics Therapeutics; also known as ColDx, Almac Diagnostics)
• OncoDefender-CRC (Everist Genomics)
• Oncotype DX Colon Recurrence Score (Genomic Health)
• Signatera ctDNA test (Natera)

• None

The Human Genome Variation Society nomenclature is used to report information on variants found in DNA and serves as an international standard in DNA diagnostics. It is being implemented for genetic testing medical policy updates starting in 2017 (see Table PG1). The Society's nomenclature is recommended by the Human Variome Project, the HUman Genome Organization, and by the Human Genome Variation Society itself.

The American College of Medical Genetics and Genomics and the Association for Molecular Pathology standards and guidelines for interpretation of sequence variants represent expert opinion from both organizations, in addition to the College of American Pathologists. These recommendations primarily apply to genetic tests used in clinical laboratories, including genotyping, single genes, panels, exomes, and genomes. Table PG2 shows the recommended standard terminology-"pathogenic," "likely pathogenic," "uncertain significance," "likely benign," and "benign"-to describe variants identified that cause Mendelian disorders.

Table PG1. Nomenclature to Report on Variants Found in DNA

Previous	Updated	Definition
Mutation	Disease-associated variant	Disease-associated change in the DNA sequence
	Variant	Change in the DNA sequence
	Familial variant	Disease-associated variant identified in a proband for use in subsequent targeted genetic testing in first-degree relatives

Table PG2. ACMG-AMP Standards and Guidelines for Variant Classification

Variant Classification	Definition
Pathogenic	Disease-causing change in the DNA sequence
Likely pathogenic	Likely disease-causing change in the DNA sequence
Variant of uncertain significance	Change in DNA sequence with uncertain effects on disease
Likely benign	Likely benign change in the DNA sequence
Benign	Benign change in the DNA sequence

ACMG: American College of Medical Genetics and Genomics; AMP: Association for Molecular Pathology.


Medicare Coverage:
There is no National Coverage Determination (NCD) for Gene Expression Profile Testing and Circulating Tumor DNA Testing for Predicting Recurrence in Colon Cancer. In the absence of an NCD, coverage decisions are left to the discretion of Local Medicare Carriers. Novitas Solutions, Inc, the Local Medicare Carrier for jurisdiction JL, has determined that CPT code 81525 has limited coverage for colorectal cancer MRNA gene expression profiling by real time RT-PCR of 12 genes testing. Please refer to Novitas Solutions Inc, LCD Biomarkers for Oncology (L35396). Available to be accessed at Novitas Solutions, Inc., Medical Policy Search page: https://www.novitas-solutions.com/webcenter/portal/MedicareJL/LcdSearch?_afrLoop=90769712476969#!%40%40%3F_afrLoop%3D90769712476969%26centerWidth%3D100%2525%26leftWidth%3D0%2525%26rightWidth%3D0%2525%26showFooter%3Dfalse%26showHeader%3Dfalse%26_adf.ctrl-state%3D63y7eftob_46.

PROPRIETARY LABS (Labs that are the sole source for the diagnostic lab test)
For labs which are proprietary (that is, the sole source for the diagnostic lab test involved), Medicare Advantage Products will follow the Medicare Local Coverage Determination of the State where the proprietary lab is located.


Medicaid Coverage:

For members enrolled in Medicaid and NJ FamilyCare plans, Horizon BCBSNJ applies the above medical policy.

FIDE SNP:

For members enrolled in a Fully Integrated Dual Eligible Special Needs Plan (FIDE-SNP): (1) to the extent the service is covered under the Medicare portion of the member’s benefit package, the above Medicare Coverage statement applies; and (2) to the extent the service is not covered under the Medicare portion of the member’s benefit package, the above Medicaid Coverage statement applies.

[RATIONALE: This policy was created in 2010 and has been updated regularly with searches of the PubMed database. The most recent literature update was performed through July 8, 2020.

Evidence reviews assess whether a medical test is clinically useful. A useful test provides information to make a clinical management decision that improves the net health outcome. That is, the balance of benefits and harms is better when the test is used to manage the condition than when another test or no test is used to manage the condition.

The first step in assessing a medical test is to formulate the clinical context and purpose of the test. The test must be technically reliable, clinically valid, and clinically useful for that purpose. Evidence reviews assess the evidence on whether a test is clinically valid and clinically useful. Technical reliability is outside the scope of these reviews, and credible information on technical reliability is available from other sources.

Gene Expression Profile Testing

Clinical Context and Test Purpose

The purpose of prognostic testing of diagnosed disease is to predict natural disease course (eg, aggressiveness, risk of recurrence, death). This type of testing uses gene expression of affected tissue to predict the course of the disease.

The question addressed in this policy is: Does prognostic testing using the gene expression profile (GEP) tests described below in individuals diagnosed with stage II or stage III colon cancer improve the net health outcome?

The specific clinical context of each test is described briefly in the following section. The following PICO was used to select literature to inform this review.

Patients

The relevant population of interest are patients who have undergone surgery for stage II or stage III colon cancer and are being evaluated for adjuvant chemotherapy.

Interventions

The interventions of interest are GEP testing with the ColoPrint 18-Gene Colon Cancer Recurrence Assay, GeneFx Colon (ColDx), OncoDefender-CRC, and Oncotype DX Colon Recurrence Score.

These tests are offered commercially through various manufacturers and would be performed on tumor tissue after surgical resection.

Comparator

The comparator of interest is standard care without prognostic testing. The current standard of care is not to provide adjuvant chemotherapy to patients with stage II colon cancer and to administer adjuvant chemotherapy routinely to patients with stage III colon cancer.

Outcomes

The outcomes of interest are recurrence risk, recurrence-free survival, and overall survival at follow-up in patients classified as low-risk, medium-risk, or high-risk by GEP.

The time of interest is 3 to 5 years after surgical resection to assess colon cancer recurrence, given that the majority of colon cancer recurrences occur within the first 3 years after surgical resection of the primary tumor and approximately 95% in the first 5 years.^5,.

Technically Reliable

Assessment of technical reliability focuses on specific tests and operators and requires a review of unpublished and often proprietary information. Review of specific tests, operators, and unpublished data are outside the scope of this policy and alternative sources exist. This policy focuses on the clinical validity and clinical utility.

Clinically Valid

A test must detect the presence or absence of a condition, the risk of developing a condition in the future, or treatment response (beneficial or adverse).

Review of Evidence

ColoPrint 18-Gene Colon Cancer Recurrence Assay

Salazar et al (2011) described the development of an 18-gene expression test called the ColoPrint 18-Gene Colon Cancer Recurrence Assay.^6, A total of 188 samples were prospectively collected from patients with colorectal cancer (CRC). RNA was isolated from fresh tissue frozen in liquid nitrogen, labeled and hybridized to customized whole-genome oligonucleotide high-density microarrays. A cross-validation procedure was performed on 33834 gene probes that showed variation across the training samples. They were scored for their association with 5 year distant metastasis-free survival. From this pool of genes, an optimal set of 18 nonredundant probes was identified and used to construct classification scores for the test. Results were dichotomized into a 2 category, low- and high-risk, scoring system.

In a small independent validation study, Salazar et al (2011) used a patient cohort of 206 patients. However, only 56% represented stage II tumors.^7, Risk classification and survival are shown in Table 1 for the patients with stage II disease in this study.

Maak et al (2013) conducted a subsequent validation study in fresh-frozen tumor samples from patients who had undergone curative resection for stage II colon cancer.^8, Mismatch repair status, clinical parameters, and follow-up data (median, 8.4 years) were collected. Five-year distant metastasis-free survival for patients classified as low-risk and high-risk is shown in Table 1. Information about net reclassification and clinical utility was not provided.

Table 1. RFS in Patients With Stage II Colon Cancer Assessed With ColoPrint

Study	N	Follow-Up, y	Low Risk, %	Mean RFS for Low Risk, %	High Risk, %	Mean RFS for High Risk, %
Salazar et al (2011)7,	115	5	63.2	90.9	36.8	73.9
Maak et al (2013)8,	135	8.4a		95		80

N: sample size; RFS: recurrence-free survival; y: years
^a Median.

Kopetz et al (2015) reported on a pooled analysis of 416 patients with stage II colon cancer from independent cohorts in the U. S., Spain, Italy, Austria, and Germany.^9, Investigators compared the prognostic ability of ColoPrint with National Comprehensive Cancer Network (NCCN) risk prediction based on clinicopathologic factors (T4; high-grade tumor; lymphovascular or perineural invasion; perforation or obstruction; <12 lymph nodes examined; positive margins). Recurrence risk at a mean 81 months (range, 56 to 178) is shown in Table 2. Statistical comparison of the risk models (eg, using a likelihood ratio test and/or receiver operating characteristic curves) and comparison of classifications by survival outcomes (ie, reclassification analysis) were not provided. Further, a 5-year recurrence risk as high as 14% in patients classified as low-risk by ColoPrint may be too high for some patients to consider forgoing chemotherapy.

Table 2. ColoPrint and NCCN Risk Prediction and RR in Patients With Stage II Colon Cancer

Study	Risk Prediction	Low Risk, n (%)	Mean RR for Low Risk (95% CI)	High Risk, n (%)	Mean RR for High Risk (95% CI)
Kopetz et al (2015)9,	ColoPrint	263 (63)	10 (7 to 14)	153 (37)	21 (14 to 28)
	NCCN	236 (57)	13 (9 to 18)	180 (43)	15 (10 to 20)

CI: confidence interval; n: sample size; NCCN: National Comprehensive Cancer Network; RR: recurrence risk.

GeneFx Colon

Kennedy et al (2011) reported on the development of a 634-probe set signature.^10, A training set of 215 patients (142 low-risk, 73 high-risk) was identified based on 5-year disease-free survival. The assay was performed using aDNA-microarray analysis of formalin-fixed, paraffin-embedded (FFPE) samples. Cross-validation studies were used to select an optimal transcript signature for prognostic classification. Independent validation was performed. Kennedy et al (2011) on 144 patients enriched for recurrence (85 low-risk, 59 high-risk) using the threshold score identified in the training set.^10, The signature in this convenience sample of patients predicted disease recurrence with a hazard ratio (HR) of 2.53 (p<0.001) in the high-risk group. The signature also predicted cancer-related death with an HR of 2.21 (p<0.001) in the high-risk group.

Niedzwiecki et al (2016) reported on the recurrence-free interval for 393 of 1738 patients treated in the Cancer and Leukemia Group B 9581 (CALGB 9581) trial.^11, Treatment in CALGB 9581 was with an experimental monoclonal antibody (edrecolomab) or observation; there was no significant survival benefit from the experimental treatment. Of 901 eligible patients with available tissue, a randomized sample of 514 patients was selected. The final analysis included 360 patients in the randomized cohort (58 events) and 33 nonrandomly selected events that had samples successfully analyzed. The investigators hypothesized that the high failure rate was due to the long interval between sample collection and analysis (mean, 13.2 years). Table 3 provides recurrence scores for patients categorized as low-risk and high-risk. After adjusting for prognostic variables that included mismatch repair deficiency, patients categorized as high-risk by GeneFx had a significantly worse recurrence-free interval in unadjusted analysis (HR=2.13; 95% CI, 1.3 to 3.5; p<0.01). However, in multivariate analysis, the GeneFx risk score was marginally associated with overall survival (HR=1.74; 95% CI, 0.97 to 3.1; p=0.06). For the 271 samples analyzed by both GeneFx and Oncotype DX (see below), there was a weak correlation in continuous scores (R=0.18).

Table 3. RFS in Patients With Stage II Colon Cancer Assessed With GeneFx

Study	N	Follow-Up, y	Low Risk, n (%)	Mean RFS for Low Risk (95% CI)	High Risk, n (%)	Mean RFS for High Risk (95% CI)
Niedzwecki et al (2016)11,	393	5	177 (45)	91 (89 to 93)	216 (55)	82 (79 to 85)

CI: confidence interval; n: sample size; RFS: recurrence-free survival; y: years.

OncoDefender-CRC

Lenehan et al (2012) reported on the development of a 5-gene test called OncoDefender.^12, A total of 417 cancer-associated genes were preselected for the study of archived FFPE primary adenocarcinoma tissues from 74 patients with CRC (15 with stage I disease, 59 with stage II disease; 60 withcolon cancer, 14 with rectal cancer). Patients were divided into a training set and a test set. Cross-validation was performed to estimate the ability of the classifier to generalize to unseen samples. The most important feature of gene fitness was the area under the receiver operating characteristic curve for each gene.

In addition, Lenehan et al (2012) performed external validation on 251 patients with stage I and II colon cancer obtained from an international study set. Patient dropout from the set of archived samples used was substantial; only 264 (55%) of 484 patients with lymph node-negative CRC satisfied the initial clinicopathologic screening. This included a mix of patients with both rectal and colon cancer (stages I and II). The test appeared to distinguish patients at high-vs low-risk of recurrence (HR=1.63; p=0.031). Sensitivity and specificity of OncoDefender were compared with NCCN guidelines and showed similar sensitivity (69% vs 73%), with improved specificity (48% vs 26%). However, the isolated performance of the test in patients with stage II colon cancer was not reported, and several NCCN high-risk findings (bowel obstruction or perforation and lymphovascular invasion) demonstrated higher HRs than observed with the molecular signature. The study alluded to but did not directly address clinical utility.

Oncotype DX Colon Recurrence Score

O'Connell et al (2010) described the development of a 12-gene expression test called Oncotype DX Colon Recurrence Score.¹² A total of 761 candidate genes of possible prognostic value for recurrence or of possible predictive value for treatment were examined by correlating the genes in tumor samples with clinical outcomes in 1851 patients who had surgery with or without adjuvant 5-fluorouracil-based chemotherapy. Gene expression was quantified from microdissected, FFPE primary colon cancer tissue. Of the 761 candidate genes, multivariate analysis (including disease severity, stage, and nodal involvement) reduced the gene set to a 7-gene prognostic signature and a separate 6-gene predictive signature. Five reference genes also are included in the assay.

Tables 4 and 5 summarize the characteristics and results of several validation studies. External validation of the algorithm was first reported by Gray et al (2011), who used FFPE primary tumor samples from patients with stage II colon cancer who had participated in the Quick and Simple and Reliable study.^13, The relation between the 7 gene recurrence score and risk of recurrence was statistically significant, with a 3 year risk of recurrence for predefined low-, intermediate-, and high-risk groups as shown in Table 5. In the surgery-alone group, the HR for recurrence in the high-risk group compared with the low-risk group was 1.47 (95% CI, 1.01 to 2.14, p=0.046).

Table 4. Oncotype DX Colon Validation Study Characteristics

Study; Trial	Design	N	Colon Cancer, n		Randomized Treatments
			Stage II	Stage III	Intervention	Comparator
Gray et al (2011)13,; QUASAR	RCT	3239	1436		Adjuvant chemotherapy	Surgery alone
Venook et al (2013)14,; CALGB 9581	RCT	1713	690		Edrecolomab	Observation
Yothers et al (2013)15,; NASBP C-07 R	RCT	2409	264		FULV with oxaliplatin	FULV without oxaliplatin
Reimers et al (2014)16,; TME	RCT	1861	130a	167a	Radiotherapy	No radiotherapy
Yamanaka et al (2016)17,; SUNRISE	Cohort	1487	247	350	Not applicable

CALGB 9581: Cancer and Leukemia Group B 9581 trial; FULV: 5-fluorouracil plus leucovorin; N: sample size; NASBP C-07: National Surgical Adjuvant Breast and Bowel Project; QUASAR: Quick and Simple and Reliable; RCT: randomized controlled trial; TME: Dutch total mesenteric excision trial.
^a Rectal.

Venook et al (2013) reported on a validation study using tumor tissue from patients with stage II colon cancer who had participated in the randomized CALGB 9581 trial.^14, The investigators selected samples stratified by treatment group from those who had tumor tissue available (40% of the original patient sample). They used recurrence score cut points of 29 and 39 to determine low-, intermediate-, and high-risk groups (see Table 5); these values differ from the cut points of 30 and 41 validated in the Quick and Simple and Reliable study (previously described). In multivariate analysis, every 25-unit change in recurrence score was associated with recurrence independent of tumor stage, tumor grade, mismatch repair status, presence or absence of lymphovascular invasion, and the number of nodes assessed.

Yothers et al (2013) conducted a validation study using tumor tissue from 264 patients with stage II colon cancer who had participated in the National Surgical Adjuvant Breast and Bowel Project C-07 trial.^15, The National Surgical Adjuvant Breast and Bowel Project C-07 randomized 2409 patients with stage II (28%) or stage III (72%) colon cancer to adjuvant chemotherapy with 5-fluorouracil plus leucovorin or oxaliplatin plus 5-fluorouracil plus leucovorin. For the randomly selected sample of 50% of patients with stage II colon cancer, estimated 5-year recurrence risks (adjusted for treatment) are shown in Table 5. Five-year recurrence risk, estimated by Kaplan-Meier analysis, was reduced in high-risk patients who received oxaliplatin (9%; 95% CI, 3% to 25%) compared with those who did not (23%; 95% CI, 12% to 42%) but this difference was not observed in low- or intermediate-risk patients. However, CIs for these estimates were wide due to small numbers of patients and events in each risk group. For all stage III patients in any risk class, adjusted 5-year recurrence risk estimates exceeded 15%.

Table 5. Recurrence Rates by Risk Category for the Oncotype DX Colon Recurrence Risk Score

Study	Trial	Risk Prediction, y	Mean Recurrence Rate (95% CI), %
			Low Risk	Medium Risk	High Risk
Gray et al (2011)13,	QUASAR	3	12	18	22
Venook et al (2013)14,	CALGB 9581	5	12 (10 to 15)	15 (12 to 17)	18 (14 to 22)
Yothers et al (2013)15,	NASBP C-07	5	9 (6 to 13)	13 (8 to 17)	18 (12 to 25)
Reimers et al (2014)16,	TME stage II cohort (rectal)	5	11 (6 to 22)	27 (16 to 46)	43 (29 to 65)
Yamanaka et al (2016)17,	SUNRISE stage II cohort	5	9 (7 to 12)	14 (11 to 17)	19 (13 to 24)
	SUNRISE stage III cohort	5	20 (14 to 25)	29 (23 to 35)	38 (29 to 47)

CALGB 9581: Cancer and Leukemia Group B 9581 trial; CI: confidence interval; N: sample size; NASBP C-07: National Surgical Adjuvant Breast and Bowel Project; QUASAR: Quick and Simple and Reliable; TME: Dutch total mesenteric excision trial; y: years.

Reimers et al (2014)^16, conducted a retrospective study using prospectively collected tumor specimens from the Dutch total mesenteric excision trial^18, in patients with resectable rectal cancer. Reimers et al (2014) used available tumor tissue from 569 stage II and III patients randomized to surgery alone. Among 130 patients with stage II rectal cancer, Oncotype DX Colon classified 63 (49%) patients as low-risk, 37 (28%) patients as intermediate-risk, and 30 (23%) patients as high-risk. Five-year Kaplan-Meier recurrence risk estimates in the low-, intermediate-, and high-risk groups are shown in Table 5. Oncotype DX Colon risk classification and estimated recurrence risks for patients with stage III rectal cancer were not reported.

The SUNRISE study, as reported by Yamanaka et al (2016), evaluated tissue samples from consecutive patients with stage II and stage III colon cancer who had been treated with surgery alone.^17, Surgery was the standard of care at hospitals in Japan during the study period 2000 to 2005. From the total cohort of 1,487 patients, samples were randomly selected from patients who had or did not have a recurrence, in a 1:2 ratio. The final number of patients studied was 597; 202 patients had disease recurrence, and 395 had no recurrence. As shown in Table 5, the risk of recurrence in patients with stage III colon cancer with a low-risk score was similar to patients with stage II disease and a high-risk score and exceeded 15%. When adjusted for disease stage, a 25-unit increase in the recurrence score had an HR of 2.05 (95% CI, 1.47 to 2.86; p<0.001).

Section Summary: Clinically Valid

Several validation studies of GEP testing for colon cancer have reported that testing provides prognostic information on the risk of recurrence. Some studies have reported that GEP testing offers prognostic information in a multivariate analysis. Other data have suggested that GEP testing may provide modest incremental prognostic information over the standard prognostic workup, including the NCCN risk prediction model. Patients with a low recurrence score have a lower risk of recurrence and patients with a high-risk score have a higher risk of recurrence. However, the increase in recurrence risk for a high-risk score is small, and it is uncertain whether the degree of increase is sufficient to intensify management.

Clinically Useful

A test is clinically useful if the use of the results informs management decisions that improve the net health outcome of care. The net health outcome can be improved if patients receive correct therapy, or more effective therapy, or avoid unnecessary therapy, or avoid unnecessary testing.

Review of Evidence

Direct Evidence

Direct evidence of clinical utility is provided by studies that have compared health outcomes for patients managed with and without the test. Because these are intervention studies, the preferred evidence would be from randomized controlled trials.

A technical brief by Black et al (2012), conducted for the Agency for Healthcare Research and Quality, reviewed the clinical evidence for GEP testing in predicting outcomes, including the benefit from adjuvant chemotherapy, in patients with stage II colon cancer.^19, The 4 commercially available assays reviewed herein were included in the brief. No prospective studies were identified that assessed change in the net health outcome with the use of a GEP assay, and no studies were identified that used a net reclassification analysis and subsequently evaluated the impact of the reclassification on the net health outcome. Additionally, evidence was limited on the reproducibility of test findings, indications for GEP testing in stage II patients, and whether results of GEP assays can stratify patients into groups with clinically meaningful differences in recurrence risk. No studies have been identified in subsequent literature updates that evaluated the impact of GEP testing on recurrence in patients with stage II or III colon cancer.

A more recent evidence report conducted for the Washington State Health Care Authority (2017) reviewed the clinical utility of gene expression profile tests for cancer, including ColoPrint and Oncotype DX for stage II or III colon cancer.^20, The researchers identified no clinical utility studies with mortality, morbidity, or harms outcomes.

Chain of Evidence

Indirect evidence on clinical utility rests on clinical validity. If the evidence is insufficient to demonstrate test performance, no inferences can be made about clinical utility. A chain of evidence may be developed, which addresses 2 key questions.

1. Does the use of GEP testing of colon cancer risk in individuals with stage II or stage III colon cancer lead to a change in management regarding the use of adjuvant chemotherapy?
2. Do those management changes improve health outcomes?

Cartwright et al (2014),^22, and Srivastava et al (2014),^23, have also published studies showing the effect of Oncotype DX Colon results on treatment recommendations made using traditional risk classifiers in patients with stage II colon cancer. Cartwright et al (2014) performed a retrospective study predicting that test results might lead to reductions in treatment intensity in a percentage of patients.^22, Srivastava et al (2014) performed a prospective study that directly demonstrated reductions in treatment intensity in a percentage of patients.^23,

This type of study does not determine whether patient outcomes are improved as a consequence of the changes in management, and there are no well-defined treatment protocols that differ according to the risk of recurrence within stage II or within stage III colon cancer.

Section Summary: Clinically Useful

Some studies have reported management changes following GEP testing. However, these studies did not report clinical outcomes, and there is no direct evidence to determine whether GEP testing improves health outcomes. A chain of evidence might be constructed if there was evidence that changes in management for patients with stage II colon cancer improved health outcomes. The intensity of surveillance and management may be impacted by results of GEP testing but the evidence to demonstrate that a change in management improved health outcomes is weak and not definitive. Therefore, the evidence does not demonstrate clinical utility.

Circulating Tumor DNA Testing

Clinical Context and Test Purpose

The purpose of prognostic testing of diagnosed disease is to predict natural disease course (eg, aggressiveness, risk of recurrence, death). This type of testing uses circulating tumor DNA (ctDNA) testing of blood to predict the course of the disease.

The question addressed in this policy is: Does prognostic testing using the ctDNA test described below in individuals diagnosed with stage II or stage III colon cancer improve the net health outcome?

The following PICO was used to select literature to inform this review.

Patients

The relevant populations of interest are:

1) patients with stage II colon cancer who have undergone surgery and are being evaluated for adjuvant chemotherapy

2) patients with stage III colon cancer who have undergone surgery and are being evaluated for adjuvant chemotherapy

3) patients who are being monitored for risk of relapse following treatment for stage II or II colon cancer

Interventions

The intervention of interest is ctDNA testing with the Signatera assay. Signatera is designed to detect molecular residual disease in the blood. Tumor tissue obtained from either a diagnostic biopsy or surgically resected tissue is used to identify 16 single nucleotide variants found in the tumor but not in normal tissue. Once the tumor has been definitively treated, a custom assay of 16 tumor-specific clonal, somatic variants is generated for the patient and the resulting tumor signature is monitored throughout the patient’s disease course.

Comparator

The comparator of interest is standard of care without ctDNA testing.

1) For patients with stage II colon cancer, the current standard of care is not to routinely administer adjuvant chemotherapy. However, current NCCN guidelines are that adjuvant chemotherapy can be considered in patients with stage II colon cancer, using clinicopathologic characteristics to identify patients who might benefit.^3,

2) For patients with stage III colon cancer, the current standard of care is to administer adjuvant chemotherapy routinely.^3,

3) For patients who are being monitored for risk of relapse following treatment for stage II or III colon cancer, guidelines suggest monitoring CEA every three to six months for at least two to three years, and annual imaging for three to five years.^3,

Outcomes

The outcomes of interest are recurrence risk, recurrence-free survival, and overall survival at follow-up.

Given that the majority of colon cancer recurrences occur within the first 3 years after surgical resection of the primary tumor and approximately 95% in the first 5 years, the timepoint of interest to assess recurrence is 3 to 5 years following surgical resection.^5,.

1) For patients with stage II colon cancer who are being evaluated for adjuvant chemotherapy, given that the test will be used to rule-in stage II patients for adjuvant chemotherapy, the performance characteristics of most interest are positive predictive value and specificity.

2) For patients with stage III colon cancer who are being evaluated for adjuvant chemotherapy, given that the test will be used to rule-out patients for adjuvant chemotherapy, the performance characteristics of most interest are negative predictive value and sensitivity. However, since the test would be used to select patients who would not receive category 1 recommended treatment, direct evidence of improvement in outcomes is required.

3) For patients who are being monitored for risk of relapse following treatment for stage II or III colon cancer, recurrence at 3 to 5 years should be assessed.

Technically Reliable

Assessment of technical reliability focuses on specific tests and operators and requires a review of unpublished and often proprietary information. Review of specific tests, operators, and unpublished data are outside the scope of this policy and alternative sources exist. This policy focuses on the clinical validity and clinical utility.

Clinically Valid

A test must detect the presence or absence of a condition, the risk of developing a condition in the future, or treatment response (beneficial or adverse).

Review of Evidence

Signatera Assay

Two cohort studies, one that used the Signatera assay, reported an association between positive ctDNA results and risk of recurrence of colon cancer (Tables 6 and 7).^24,25, Study limitations are described in Tables 8 and 9.

Reinert et al (2019) enrolled 125 patients with Stage I-III colon cancer in a validation study of the Signatera assay.^24, Plasma samples were collected before surgery, at 30 days following surgery, and every 3 months for up to 3 years. The recurrence rate at 3 years was 70% in patients with a positive ctDNA test (7 of 10) compared to 11.9% (10 of 84) of those with a negative ctDNA test. In multivariate analyses, ctDNA status was associated with recurrence after adjusting for clinicopathological risk factors including stage, lymphovascular invasion, and microradical resection status.

Wang et al (2019) enrolled patients with stage I, II, or II colon cancer and collected samples for ctDNA analyses at 1 month following surgery and then every 3 to 6 months; samples were available for 58 patients.^25, The recurrence rate among patients with positive ctDNA levels after surgery was 77% (10 of 13 patients). Of the 45 patients who had negative ctDNA results (16 of whom received adjuvant chemotherapy and 29 who did not), none had a recurrence during a median followup of 49 months (range 11-70 months). Three of 48 patients (6%) who had a positive ctDNA test did not experience recurrence; however these patients eventually had undetectable ctDNA levels during followup.

Table 6. Circulating Tumor DNA Study Characteristics

Study; Trial	Design	Detection Method	N	Data Collection	Colon Cancer, n
					Stage I	Stage II	Stage III
Reinert et al (2019)24,	Cohort	Signatera Assay	125	Day 30 following surgery, up to 3 years	5	39	81
Wang et al (2019)25,	Cohort	Safe-Sequencing System	58	Median 49 months (range 11-70 months)	9	21	28

N: sample size

Table 7. Recurrence Rates by Risk Category for Circulating Tumor DNA

Study	Mean Recurrence Rate (95% CI)
	ctDNA Positive	ctDNA Negative
Reinert et al (2019)24,	7/10 70% (34.2% - 93.1%)	10/8411.9% (6.3% - 20.1%)
Hazard Ratio for RFS (95% CI)	7.2 (2.7-19.0); P <.001
Wang et al (2019)25,	10/13 (77%)	0/45 0% (95% CI 0%-7.9%)

CI: confidence interval; ctDNA: circulating tumor DNA; RFS: recurrence-free survival

Table 8. Study Relevance Limitations

Study	Populationa	Interventionb	Comparatorc	Outcomesd	Duration of Follow-Upe
Reinert et al (2019)24,	1. included patients with type I-III colon cancer		3. No comparator	1. Overall survival not assessed
Wang et al (2019)25,	1. included patients with type I-III colon cancer	3. Safe-Sequencing System	3. No comparator	1. Overall survival not assessed

The study limitations stated in this table are those notable in the current review; this is not a comprehensive gaps assessment.
^a Population key: 1. Intended use population unclear; 2. Clinical context is unclear; 3. Study population is unclear; 4. Study population not representative of intended use.
^bIntervention key: 1. Classification thresholds not defined; 2. Version used unclear; 3. Not intervention of interest.
^c Comparator key: 1. Classification thresholds not defined; 2. Not compared to credible reference standard; 3. Not compared to other tests in use for same purpose.
^d Outcomes key: 1. Study does not directly assess a key health outcome; 2. Evidence chain or decision model not explicated; 3. Key clinical validity outcomes not reported (sensitivity, specificity and predictive values); 4. Reclassification of diagnostic or risk categories not reported; 5. Adverse events of the test not described (excluding minor discomforts and inconvenience of venipuncture or noninvasive tests).

^e Follow-Up key: 1. Follow-up duration not sufficient with respect to natural history of disease (true positives, true negatives, false positives, false negatives cannot be determined).

Table 9. Study Design and Conduct Limitations

Study	Selectiona	Blindingb	Delivery of Testc	Selective Reportingd	Data Completenesse	Statisticalf
Reinert et al (2019)24,	1. Patient selection not described					Multiple subgroup analyses, small numbers of patients with positive ctDNA tests.
Wang et al (2019)25,	1. Patient selection not described					Small numbers of patients with postive ctDNA tests.

The study limitations stated in this table are those notable in the current review; this is not a comprehensive gaps assessment.
^a Selection key: 1. Selection not described; 2. Selection not random or consecutive (ie, convenience).
^bBlinding key: 1. Not blinded to results of reference or other comparator tests.
^cTest Delivery key: 1. Timing of delivery of index or reference test not described; 2. Timing of index and comparator tests not same; 3. Procedure for interpreting tests not described; 4. Expertise of evaluators not described.
^d Selective Reporting key: 1. Not registered; 2. Evidence of selective reporting; 3. Evidence of selective publication.
^e Data Completeness key: 1. Inadequate description of indeterminate and missing samples; 2. High number of samples excluded; 3. High loss to follow-up or missing data.
^f Statistical key: 1. Confidence intervals and/or p values not reported; 2. Comparison to other tests not reported.

Clinically Useful

A test is clinically useful if the use of the results informs management decisions that improve the net health outcome of care. The net health outcome can be improved if patients receive correct therapy, or more effective therapy, or avoid unnecessary therapy, or avoid unnecessary testing.No studies of the clinical utility of ctDNA were identified.

Review of Evidence

Direct Evidence

There is no direct evidence of the clinical utility of ctDNA testing in patients with colon cancer.

Chain of Evidence

Indirect evidence on clinical utility rests on clinical validity. If the evidence is insufficient to demonstrate test performance, no inferences can be made about clinical utility. A chain of evidence may be developed, which addresses 2 key questions.

1. Does the use of ctDNA testing of colon cancer risk in individuals with stage II or stage III colon cancer lead to a change in management regarding the use of adjuvant chemotherapy?
2. Do those management changes improve health outcomes?

Section Summary

Two cohort studies reported an association between positive ctDNA results using the Signatera assay and risk of recurrence of colon cancer. While these studies showed an association between ctDNA results and risk of recurrence, they are limited by their observational design and relatively small numbers of patients with positive results. Management decisions were not based on ctDNA test results. There are no controlled studies of management changes made in response to ctDNA test results compared to other risk factors, and no studies showing whether testing improved outcomes.

SUMMARY OF EVIDENCE

For individuals who have stage II or III colon cancer who receive GEP testing, the evidence includes development and validation studies and decision-impact studies. Relevant outcomes are disease-specific survival, test accuracy and validity, and change in disease status. The available evidence has shown that GEP testing for colon cancer can improve risk prediction, particularly the risk of recurrence in patients with stage II or III colon cancer. However, the degree of difference in risk conferred by the test is small. Evidence to date does not permit conclusions on whether GEP classification is sufficient to modify treatment decisions in stage II or III patients. Studies showing management changes as a consequence of testing have not demonstrated whether such changes improve outcomes. The evidence is insufficient to determine the effects of the technology on health outcomes.

For individuals who have stage II or III colon cancer who receive circulating tumor DNA (ctDNA) testing, the evidence includes cohort studies. Relevant outcomes are disease-specific survival, test accuracy and validity, and change in disease status. Two cohort studies reported an association between positive ctDNA results and risk of recurrence of colon cancer. In one study, the recurrence rate among patients with positive ctDNA levels was 77% (10 of 13 patients); no patients with negative ctDNA experienced a relapse over a median followup of 49 months (range 11-70 months). In the other, the recurrence rate at 3 years was 70% in patients with a positive ctDNA test compared to 11.9% of those with a negative ctDNA test. While these studies showed an association between ctDNA results and risk of recurrence, they are limited by their observational design and relatively small numbers of patients with positive results. Management decisions were not based on ctDNA test results.There are no controlled studies of management changes made in response to ctDNA test results compared to other risk factors, and no studies showing whether testing improved outcomes.The evidence is insufficient to determine the effects of the technology on health outcomes.

SUPPLEMENTAL INFORMATION

Practice Guidelines and Position Statements

National Comprehensive Cancer Network

Current clinical practice guidelines from the National Comprehensive Cancer Network ( v.4.2020) on colon cancer state that "there is insufficient data to recommend the use of multigene assays to determine adjuvant therapy" in patients with stage II or III colon cancer.^3,

The guidelines do not comment on circulating tumor DNA testing to guide decision about adjuvant chemotherapy, but state, "Research into additional possible predictive markers may allow for more informed decision-making in the future."

U.S. Preventive Services Task Force Recommendations

Not applicable.

Ongoing and Unpublished Clinical Trials

Some unpublished trials that might influence this review are listed in Table 10.

Table 10. Summary of Key Trials

NCT No.	Trial Name	Planned Enrollment	Completion Date
Unpublished
NCT00903565a	A Prospective Study for the Assessment of Recurrence Risk in Stage II Colon Cancer Patients Using ColoPrint (PARSC)7,	1,200	Dec 2019
Ongoing
NCT04264702a	BESPOKE Study of ctDNA Guided Therapy in Colorectal Cancer	1,000	Jun 2024

NCT: national clinical trial.
^a Denotes industry-sponsored or cosponsored trial.]
________________________________________________________________________________________

Horizon BCBSNJ Medical Policy Development Process:

This Horizon BCBSNJ Medical Policy (the “Medical Policy”) has been developed by Horizon BCBSNJ’s Medical Policy Committee (the “Committee”) consistent with generally accepted standards of medical practice, and reflects Horizon BCBSNJ’s view of the subject health care services, supplies or procedures, and in what circumstances they are deemed to be medically necessary or experimental/ investigational in nature. This Medical Policy also considers whether and to what degree the subject health care services, supplies or procedures are clinically appropriate, in terms of type, frequency, extent, site and duration and if they are considered effective for the illnesses, injuries or diseases discussed. Where relevant, this Medical Policy considers whether the subject health care services, supplies or procedures are being requested primarily for the convenience of the covered person or the health care provider. It may also consider whether the services, supplies or procedures are more costly than an alternative service or sequence of services, supplies or procedures that are at least as likely to produce equivalent therapeutic or diagnostic results as to the diagnosis or treatment of the relevant illness, injury or disease. In reaching its conclusion regarding what it considers to be the generally accepted standards of medical practice, the Committee reviews and considers the following: all credible scientific evidence published in peer-reviewed medical literature generally recognized by the relevant medical community, physician and health care provider specialty society recommendations, the views of physicians and health care providers practicing in relevant clinical areas (including, but not limited to, the prevailing opinion within the appropriate specialty) and any other relevant factor as determined by applicable State and Federal laws and regulations.

___________________________________________________________________________________________________________________________

Index:
Gene Expression Profile Testing and Circulating Tumor DNA Testing for Predicting Recurrence in Colon Cancer
Multigene Expression Assay for Predicting Recurrence in Colon Cancer
Gene Expression Profile Testing for Predicting Recurrence in Colon Cancer
Cicrulating Tumor DNA Testing for Predicting Recurrence in Colon Cancer
ColonPRS®
ColoPrint®
GeneFx Colon®
OncoDefender™-CRC (Colon and Rectal Cancer)
Oncotype DX® - Colon Cancer Test
Microchip Array, Tumor Gene Expression, Colon Cancer
Tumor Gene Expression, Colon Cancer
Oncotype DX® Colon Recurrence Score
Signatera ctDNA Test

References:
1. National Cancer Institute, Surveillance Epidemiology and End Results Program. Cancer Stat Facts: Colorectal Cancer. n.d.; https://seer.cancer.gov/statfacts/html/colorect.html. Accessed Juy 21, 2020.

2. Figueredo A, Coombes ME, Mukherjee S. Adjuvant therapy for completely resected stage II colon cancer. Cochrane Database Syst Rev. Jul 16 2008; (3): CD005390. PMID 18646127

3. National Comprehensive Cancer Network (NCCN). Clinical practice guidelines in oncology: colon cancer. Version 4.2020. https://www.nccn.org/professionals/physician_gls/pdf/colon.pdf. Accessed July 21, 2020.

4. Vilar E, Gruber SB. Microsatellite instability in colorectal cancer-the stable evidence. Nat Rev Clin Oncol. Mar 2010; 7(3): 153-62. PMID 20142816

5. Makhoul R, Alva S, Wilkins KB. Surveillance and Survivorship after Treatment for Colon Cancer. Clin Colon Rectal Surg. Dec 2015; 28(4): 262-70. PMID 26648797

6. Salazar R, Roepman P, Capella G, et al. Gene expression signature to improve prognosis prediction of stage II and III colorectal cancer. J Clin Oncol. Jan 01 2011; 29(1): 17-24. PMID 21098318

7. Salazar R, Rosenberg R, Lutke Holzik M, et al. The PARSC trial, a prospective study for the assessment of recurrence risk in stage II colon cancer (CC) patients using ColoPrint [abstract]. J Clin Oncol. 2011;29(Suppl):TPS167.

8. Maak M, Simon I, Nitsche U, et al. Independent validation of a prognostic genomic signature (ColoPrint) for patients with stage II colon cancer. Ann Surg. Jun 2013; 257(6): 1053-8. PMID 23295318

9. Kopetz S, Tabernero J, Rosenberg R, et al. Genomic classifier ColoPrint predicts recurrence in stage II colorectal cancer patients more accurately than clinical factors. Oncologist. Feb 2015; 20(2): 127-33. PMID 25561511

10. Kennedy RD, Bylesjo M, Kerr P, et al. Development and independent validation of a prognostic assay for stage II colon cancer using formalin-fixed paraffin-embedded tissue. J Clin Oncol. Dec 10 2011; 29(35): 4620-6. PMID 22067406

11. Niedzwiecki D, Frankel WL, Venook AP, et al. Association Between Results of a Gene Expression Signature Assay and Recurrence-Free Interval in Patients With Stage II Colon Cancer in Cancer and Leukemia Group B 9581 (Alliance). J Clin Oncol. Sep 01 2016; 34(25): 3047-53. PMID 27432924

12. Lenehan PF, Boardman LA, Riegert-Johnson D, et al. Generation and external validation of a tumor-derived 5-gene prognostic signature for recurrence of lymph node-negative, invasive colorectal carcinoma. Cancer. Nov 01 2012; 118(21): 5234-44. PMID 22605513

13. Gray RG, Quirke P, Handley K, et al. Validation study of a quantitative multigene reverse transcriptase-polymerase chain reaction assay for assessment of recurrence risk in patients with stage II colon cancer. J Clin Oncol. Dec 10 2011; 29(35): 4611-9. PMID 22067390

14. Venook AP, Niedzwiecki D, Lopatin M, et al. Biologic determinants of tumor recurrence in stage II colon cancer: validation study of the 12-gene recurrence score in cancer and leukemia group B (CALGB) 9581. J Clin Oncol. May 10 2013; 31(14): 1775-81. PMID 23530100

15. Yothers G, O'Connell MJ, Lee M, et al. Validation of the 12-gene colon cancer recurrence score in NSABP C-07 as a predictor of recurrence in patients with stage II and III colon cancer treated with fluorouracil and leucovorin (FU/LV) and FU/LV plus oxaliplatin. J Clin Oncol. Dec 20 2013; 31(36): 4512-9. PMID 24220557

16. Reimers MS, Kuppen PJ, Lee M, et al. Validation of the 12-gene colon cancer recurrence score as a predictor of recurrence risk in stage II and III rectal cancer patients. J Natl Cancer Inst. Nov 2014; 106(11). PMID 25261968

17. Yamanaka T, Oki E, Yamazaki K, et al. 12-Gene Recurrence Score Assay Stratifies the Recurrence Risk in Stage II/III Colon Cancer With Surgery Alone: The SUNRISE Study. J Clin Oncol. Aug 20 2016; 34(24): 2906-13. PMID 27325854

18. Kapiteijn E, Marijnen CA, Nagtegaal ID, et al. Preoperative radiotherapy combined with total mesorectal excision for resectable rectal cancer. N Engl J Med. Aug 30 2001; 345(9): 638-46. PMID 11547717

19. Black ER, Falzon L, Aronson N. Gene Expression Profiling for Predicting Outcomes in Stage II Colon Cancer (Technical Brief. No. 13). Rockville, MD: Agency for Healthcare Research and Quality; 2012.

20. Washington State Health Care Authority. Gene Expression Profile Testing of Cancer Tissue: Final Evidence Report. 2018. https://www.hca.wa.gov/assets/program/gene-expression-final-rpt-20180220_0.pdf. Accessed July 21, 2020.

21. Brenner B, Geva R, Rothney M, et al. Impact of the 12-Gene Colon Cancer Assay on Clinical Decision Making for Adjuvant Therapy in Stage II Colon Cancer Patients. Value Health. Jan 2016; 19(1): 82-7. PMID 26797240

22. Cartwright T, Chao C, Lee M, et al. Effect of the 12-gene colon cancer assay results on adjuvant treatment recommendations in patients with stage II colon cancer. Curr Med Res Opin. Feb 2014; 30(2): 321-8. PMID 24127781

23. Srivastava G, Renfro LA, Behrens RJ, et al. Prospective multicenter study of the impact of oncotype DX colon cancer assay results on treatment recommendations in stage II colon cancer patients. Oncologist. May 2014; 19(5): 492-7. PMID 24710310

24. Reinert T, Henriksen TV, Christensen E, et al. Analysis of Plasma Cell-Free DNA by Ultradeep Sequencing in Patients With Stages I to III Colorectal Cancer. JAMA Oncol. May 09 2019. PMID 31070691

25. Wang Y, Li L, Cohen JD, et al. Prognostic Potential of Circulating Tumor DNA Measurement in Postoperative Surveillance of Nonmetastatic Colorectal Cancer. JAMA Oncol. May 09 2019. PMID 31070668

Codes:
(The list of codes is not intended to be all-inclusive and is included below for informational purposes only. Inclusion or exclusion of a procedure, diagnosis, drug or device code(s) does not constitute or imply authorization, certification, approval, offer of coverage or guarantee of payment.)

CPT*

81525
81599
84999
88299