Colorectal Cancer Screening

Colorectal cancer (CRC) is a common and potentially lethal cancer. Successful screening is very valuable since it can trigger removal of premalignant adenomas and localized cancer, aiding in prevention of CRC and CRC related deaths. Both the incidence and mortality rates from CRC have been declining in the United States, with death rates from CRC declining on average 2.7% each year between 2004 to 2013. One model suggests that screening may account for 53% of the observed reduction in CRC mortality. Most colorectal cancers arise from adenomas, many of which are polyps that progress from small to large polyps, and then to dysplasia and ultimately, cancer. Neoplastic changes result from both inherited and acquired genetic defects. The progression from adenoma to carcinoma, when it occurs, takes at least 10 years on average.

Currently recommended screening tests for CRC are either stool-based or those that visualize the colon. Screening tests can improve disease prognosis by detecting early-stage treatable cancers or even adenomas that can progress to cancers. Stool-based tests rely on detection of human hemoglobin and/or DNA, often released into the stool when adenomas or cancer are present. Endoscopic procedures can detect and even prevent cancer, when adenomatous polyps are removed prior to malignant transformation.

At the current time, several stool-based screening tests are commercially available and recommended by guideline groups, including the Fecal Immunochemical Test (FIT) and the Cologuard test. Both tests are clinically acceptable options, but have some key differences in their techniques, availability, convenience, comfort and cost (see reverse).

In considering which stool-based test to select, it is important to review these differences and understand their impact on the patient. The best test is the one that the patient is willing and able to do, after an informed shared decision-making process with the clinician. The decision must take into consideration the patient’s willingness to collect a stool specimen, particularly if the stool specimen needs to be a large sample as required by Cologuard. For this reason, the Fecal Immunochemical Test (FIT) test collection process is often more acceptable to patients. Furthermore, it is also important to note that the Fecal Immunochemical Test (FIT) is recommended to be performed every year and the Cologuard every 3 years. A positive result from either test will reflex to a colonoscopy.

RML recommends the use of the Fecal Immunochemical Test (FIT: RML test code 3510285) for routine screening for CRC. An in-depth comparison of both testing options can be found on the back of this document.

Please contact Gerald C. Miller, Ph.D., D(ABMLI) Chief of Microbiology and Immunology, Brittany Vaughn, MHA, MLS (ASCP)cmSM, or Mary (Kat) Herman, MLS(ASCP)cmSM at 918-744-2553 if you have questions.

Table I. Comparison of the FIT (Fecal Immunochemical Test) and Cologuard

  FIT (OC-Auto) Cologuard
Manufacturer Polymedco Exact Sciences
Pooled Sensitivity* 79% (73-88%) 92.30%
Pooled Specificity 94% (91-96%) 86.60%
False Positive Rate 3.60% 10.20%
Screening Interval 1 year; recent data demonstrates that 2 years would be appropriate 3 years; however, optimal time has not been determined
Test Principle Immunoassay; human stool Hgb Immunoassay & molecular; human stool Hgb and DNA
Specimen Collection** Dip the probe into the feces on the floating paper & insert into the cassette Place stool in bucket-like container, patient adds buffer; also place a sample into a bottle
Number samples required One Two: one bucket-like container and one bottle (same stool)
Sample volume required 0.01 gram ≤300 grams; lab will notify patient if volume is insufficient
Specimen Stability 15 days at room temp 30 days refrigerated Exact Sciences MUST receive the specimen within 72 hours of collection
Results Available 24-48 hours Results will come from Exact Sciences in 2 weeks


  FIT (OC-Auto) Cologuard
Commercial Payers Per the Affordable Care Act and as documented on; "Most health plans must cover a set of preventative services at no cost to the patient". Colorectal Screening for eligible patients (ages 50-75; average risk for colon cancer without symptoms) is included in the list of representative services for which a patient should not be charged a co-pay or deductible.1 Out of pocket payment can vary based on insurance company and benefit plan; however, on average most out of pocket expenses do not exceed $20.00.2 Covered by most private insurers with no co-pay or deductible for eligible patients (ages 50-75; average risk for colon cancer without symptoms). 
Medicare or Medicaid Covered with no co-pay or deductible for eligible patients (ages 50-75; average risk for colon cancer without symptoms). Covered with no co-pay or deductible for eligible patients (ages 50-75; average risk for colon cancer without symptoms).
Self Pay:    
Per Test (self-pay) Up to $37.48 *** Up to $649.00
Ten Year Cost (self-pay) Up to $374.80 *** Up to $1947.00

Fecal Immunochemical Test / FIT (OC-Auto) / (iFOBT) / Occult Blood
RML Test Code: 3510285
CPT Code: 82274

* Regarding effectiveness, it is often sited that Cologuard has a sensitivity of 92% compared with the FIT's sensitivity of 79%; however, it is important to recognize that FIT is performed yearly and Cologuard every three years. The increased frequency of the FIT test improves the "functional" sensitivity over the entire screening period (50-75 years of age). Also important to consider is that the Cologuard has a 10.2% false positive rate and a colonoscopy is recommended for all positive stool based tests. The FIT test has a 3.6% false positive rate.

**Regarding convenience, the Cologuard is every three years and FIT is yearly. FIT requires only a small fecal aliquot yearly whereby Cologuard requires collection of an entire bowel movement (requiring <300 g in a bucket container and a small aliquot into a bottle). ***Discounts applied for early payment or financial assistance.

1 Services must be ordered by a provider in the health plan's network.
2 Based on the most common insurance companies 2018 benefit plans.