How Effective Are Home Screening Kits at Detecting Colon Cancer?

You may have seen the recent coverage regarding individuals who had to pay a medical co-payment bill from a colonoscopy performed following a positive Cologuard® test. In the event you haven't, we've provided several links to the report in a number of publications.

CBS News: Woman hit with nearly $2,000 unexpected bill for colon cancer screening

U.S. News & World Report: Could Home Test for Colon Cancer Mean a Big Medical Bill to Come?

People: Missouri Woman Billed $1,900 for Colonoscopy After Previously Taking an At-Home Cancer Test

A concern not mentioned in the article is that a large quantity of these screening results may be false-positive, compelling individuals to worry about having colon polyps or cancer and being charged a possible medical co-payment even though the colonoscopy produced a negative result.

A recent research study of 450 people, presented at Digestive Disease Week in May 2021, found that only two percent of patients who had a positive stool test had colon cancer. In addition, two-thirds of the patients received a false-positive outcome, which could have caused additional personal costs for a diagnostic colonoscopy to confirm the findings of the home test, as explained by the media reports. Additionally, most insurance policies may provide benefits for a simple colonoscopy screening that detects and reduces the risk of colon cancer as a preventive means.

Understanding colon cancer

Colon cancer claims the lives of more than 50,000 individuals every year. Though it is the second most likely cause of cancer fatality among people in the United States, colorectal cancer can be prevented, treated, and overcome, but only with accurate and early detection. Since this form of cancer commonly emerges as growths in the colon, known as polyps, finding and eliminating these tissue growths is the most effective option to prevent colorectal cancer. Following are three types of tests utilized to conduct colorectal cancer (CRC) screenings:

  1. Colonoscopy – 95% of large polyps are found
  2. Stool DNA (Cologuard testing) – 42% of large polyps are identified
  3. Fecal Immunochemical Test (FIT) – 30% of large colon polyps are detected

Colonoscopy exams continue to be the gold standard for finding polyps in the colon (large intestine). Moreover, polyps found throughout the course of a colonoscopy screening are eradicated during the process, often reducing the need to receive additional treatments.

When potential polyps are discovered from a Cologuard or positive FIT test, a colonoscopy procedure is required to excise the intestinal polyps. Bigger colon polyps might not be found with Cologuard and Fit screenings. In the event that polyps are not discovered and eliminated, the risk of developing colon cancer increases.

Recently, the U.S. Preventive Services Task Force (USPSTF) recommended that screenings for colorectal cancer starting at age 45 rather than 50. As a result, an additional 22 million adults age 45 – 49 should be assessed for colorectal cancer within this year alone. While home colorectal cancer screening tests may appear to be a more convenient, less expensive means, the fact remains that a colonoscopy is the only screening method that has the ability to detect and prevent colorectal cancer.

Colorectal cancer detection vs. prevention

Home colon cancer screenings (such as Cologuard) are intended to detect cancerous factors (including DNA) in the fecal specimen sent in. But in 58% of cases, perilous precancerous polyps are not identified at all with Cologuard kits. As a screening test, Cologuard should be repeated every 36 months if the beginning test outcomes provide a negative outcome. Cologuard is known to deliver a considerable number of false-negative and false-positive conclusions. According to a recent survey, two out of three of the patients who underwent a Cologuard home screening presented with false-positive results. Positive test outcomes following a blood or stool screening must be followed up by a colonoscopy to validate the results. Because the blood or fecal test is deemed to be the "screening" evaluation, the follow-up colonoscopy is regarded as a "diagnostic" colonoscopy.

A colonoscopy procedure is conducted to detect and prevent colon and rectal cancer, as it detects over 95% of harmful, premalignant polyps and gets rid of them at the procedure time. This procedure can also permit the physician to take tissue specimens for pathology testing to discover with greater precision if colorectal cancer is prevailing. Furthermore, colonoscopies are (by and large) more definitive and offer preventive factors by eliminating any polyps or abnormal cells identified in the large intestine.

Three primary specifications of colonoscopy procedures are:

Screening/preventive colonoscopies are carried out most often for asymptomatic individuals (no digestive diseases either previous or present) who are age 45 or more and need to establish a baseline screening to ascertain if they are likely to develop colon cancer. This type of colonoscopy lets the physician visualize any concerning tissues in the colon and rectum, such as abnormal cells and polyps. During a screening colonoscopy, polyps (which can grow into cancerous areas) can be removed and biopsies can be obtained to ascertain if cancerous tissue is occurring in the large intestine. A preventive colonoscopy is advised every ten years for patients without symptoms who are between the ages of 45 – 75 and who have no personal or family history of gastrointestinal diseases, colon cancer, or colon polyps. Most insurance companies provide benefits for screening colonoscopies as a preventative measure. It is essential to consult with the insurance carrier first before undergoing any procedure to learn of coverage limits and any expected out-of-pocket fees associated with this exam under the individual's plan.

Surveillance colonoscopies are performed when an individual has a health history of GI disease, colon polyps, or cancer but might be exhibiting no GI symptoms (either past or present). The recommendation for a surveillance colonoscopy might vary based on the person's health history. Patients with a history of colon polyps would undergo a surveillance colonoscopy and likely receive further surveillance exams at shortened timeframes (like on a 2 to 5-year basis). Contacting the insurance provider ahead of having any procedure to ascertain coverage limits and any potential remaining costs associated with this examination according to the person's benefits.

Follow-up/diagnostic colonoscopies are recommended if a patient presents with or has a history of anemias, polyps, GI symptoms, or GI diagnoses. A person's health history and findings from any previous colonoscopy determine the need for a diagnostic colonoscopy. For example, if a person conducts a non-invasive colon cancer screening test, like FIT or Cologuard, and receives any type of positive result, a diagnostic colonoscopy would generally be needed to verify the findings of the screening evaluation. Follow-up colonoscopy exams are likely to require out-of-pocket fees, making it critical to contact the insurance provider prior to undergoing any service to gain an understanding of coverage and any estimated personal payments for this procedure.

Individuals age 45 or older should receive a colon cancer screening as a baseline and preventive approach to care that can foster long-term colon health. It is also imperative to realize the disparities between available colon cancer screenings and how each type works. Colonoscopy is still the most effective type of identifying cancer and the sole method of colon cancer prevention.

Hear more about colon and rectal cancer screenings in Dallas, TX

Colonoscopy exams are efficient procedures that can safeguard your digestive and general wellness. If you have additional inquiries regarding home screenings or want to arrange for a colonoscopy, reach out to Digestive Health Associates of Texas today. Our Dallas, TX gastroenterologists are here to provide the assistance you need for long-term colon health.