Analysis of Human DNA in Stool Samples as a Technique for Colorectal Cancer Screening
Detection of genetic abnormalities associated with colorectal cancer (CRC) in stool samples has been proposed as a screening test for CRC. This technology is another potential alternative to currently available screening approaches such as fecal occult blood testing, fecal immunochemical testing (FIT), or colonoscopy.
Several genetic alterations have been associated with colorectal cancer. In the proposed multistep model of carcinogenesis, the tumor suppressor gene p53 and the proto-oncogene K-ras are most frequently altered. Mutations in APC (adenomatous polyposis coli) genes and epigenetic markers (e.g., hypermethylation of specific genes) have also been detected. Colorectal cancer is also associated with DNA replication errors in microsatellite sequences (termed microsatellite instability) in patients with Lynch syndrome (formerly known as hereditary nonpolyposis colorectal cancer) and in subgroups of patients with sporadic colon carcinoma. Tumor-associated gene mutations and epigenetic markers can be detected in exfoliated intestinal cells in stool specimens. Since cancer cells are shed into stool, tests have been developed that detect these genetic alterations in the DNA from shed colorectal cancer cells isolated from stool samples.
On August 12, 2014, Exact Sciences received FDA premarket approval for its latest automated fecal DNA testing product, Cologuard™. Cologuard™ is intended for the qualitative detection of colorectal neoplasia associated DNA markers and for the presence of occult hemoglobin in human stool. A positive result may indicate the presence of CRC or advanced adenoma and should be followed by diagnostic colonoscopy. Cologuard™ is indicated to screen adults of either sex, 50 years or older, who are at average risk for CRC. Cologuard™ is not a replacement for diagnostic colonoscopy or surveillance colonoscopy in high-risk individuals.
Over the past several years, different stool DNA tests have been evaluated in studies and some have been marketed. One of previously marketed tests, PreGen-Plus™, tests for 21 different mutations in the p53, APC, and K-ras genes; the BAT-26 MSI marker; and incorporates the DNA Integrity Assay (DIA®). PreGen-Plus™ has not been cleared by FDA. On January 13, 2006, FDA sent correspondence to LabCorp indicating that PreGen-Plus™ may be subject to FDA regulation as a medical device. As a consequence, and as a result of studies showing better performance of other tests, this test is no longer offered. Another previously marketed test is called ColoSure™, developed by OncoMethylome Sciences, which detects aberrant methylation of the vimentin (hV) gene. This test was offered as a laboratory-developed test, not subject to FDA regulation.
POLICYDNA analysis of stool samples is considered investigational as a screening technique for colorectal cancer in patients at average-to-high risk of colorectal cancer.
POLICY EXCEPTIONSFederal Employee Program (FEP) may dictate that all FDA-approved devices, drugs or biologics may not be considered investigational and thus these devices may be assessed only on the basis of their medical necessity.
Investigative is defined as the use of any treatment procedure, facility, equipment, drug, device, or supply not yet recognized as a generally accepted standard of good medical practice for the treatment of the condition being treated and; therefore, is not considered medically necessary. For the definition of Investigative, “generally accepted standards of medical practice” means standards that are based on credible scientific evidence published in peer-reviewed medical literature generally recognized by the relevant medical community, and physician specialty society recommendations, and the views of medical practitioners practicing in relevant clinical areas and any other relevant factors. In order for equipment, devices, drugs or supplies [i.e, technologies], to be considered not investigative, the technology must have final approval from the appropriate governmental bodies, and scientific evidence must permit conclusions concerning the effect of the technology on health outcomes, and the technology must improve the net health outcome, and the technology must be as beneficial as any established alternative and the improvement must be attainable outside the testing/investigational setting.
The coverage guidelines outlined in the Medical Policy Manual should not be used in lieu of the Member's specific benefit plan language.
POLICY HISTORY8/2002: Approved by Medical Policy Advisory Committee (MPAC)
11/5/2003: Code Reference section completed
10/13/2004: Code Reference section updated, CPT code 87999 effective deletion date and note added, ICD-9 diagnosis code 154.0, 197.5, 230.4, V76.41, V76.51 deleted, HCPCS S3890 added
5/2/2006: Policy reviewed, no changes
9/25/2007: Policy reviewed, no changes
04/22/2010: Policy description updated regarding available tests. Policy statement unchanged. FEP verbiage added to the Policy Exceptions section. Deleted outdated references from the Sources section. Deleted CPT code 87999 from the codes table as HCPCS S3890 is the specific code for this test.
02/23/2011: Policy reviewed; no changes
01/17/2012: Policy reviewed; no changes
03/13/2013: Policy reviewed; no changes
03/07/2014: Policy reviewed; no changes
12/31/2014: Added the following new 2015 HCPCS code to the Code Reference section: G0464.
06/15/2015: Policy title changed from "Fecal DNA Testing for Colorectal Cancer Screening and Monitoring" to "Analysis of Human DNA in Stool Samples as a Technique for Colorectal Cancer Screening." Policy description updated regarding tests. Policy statement unchanged.
07/20/2015: Code Reference section updated for ICD-10.
12/31/2015: Policy description updated regarding tests. Policy statement re-worded to state that DNA analysis of stool samples is considered investigational as a screening for colorectal cancer in patients at average-to-high risk of colorectal cancer. It previously stated: DNA analysis of stool samples is considered investigational as a screening technique for colorectal cancer in both patients with average to moderate risk and in patients considered at high risk for colorectal cancer. Investigative definition updated in policy guidelines section. Code Reference section updated to add new 2016 CPT code 81528.
06/06/2016: Policy number added.
SOURCE(S)Blue Cross Blue Shield Association medical policy #2.04.29
CODE REFERENCEThis may not be a comprehensive list of procedure codes applicable to this policy.