Colonoscopy vs. At Home Colon Cancer Test: How to Choose?
Colorectal cancer is an ideal disease to screen for because it can be detected and treated during its earliest stages before any symptoms develop. A medical screening is often geared towards people who fall under a certain category (for example, over the age of 45) who are asked by medical providers to get a screening test for cancer regardless of whether or not they have any symptoms. Colorectal cancer can be deadly if not caught early. Widespread screening for this disease saves lives and reduces the suffering associated with intense cancer treatment methods.
Many physicians will tell their patients who hit the golden age of 50 that they need to get a colonoscopy to screen for colon cancer. A colonoscopy is often referred to as the gold standard for colon cancer screening because it is a procedure that allows the operating physician to detect and remove polyps (abnormal growths that may be precancerous) during the procedure. However, screening rates for colon cancer remain lower than ideal because many people are hesitant to get a colonoscopy due to its intense bowel preparation and the invasive nature of the procedure itself.
Studies have shown that people who are given a choice between taking an at home colon cancer test and a colonoscopy are more likely to complete their colorectal screening than those patients who are not offered a choice.
Studies have shown that people who are given a choice between taking an at home colon cancer test and a colonoscopy are more likely to complete their colorectal screening than those patients who are not offered a choice. If your doctor has offered you a choice between an at home cancer screening and a colonoscopy, you may wonder which is best for you. In this case, check with your physician and open up a discussion regarding the risks and benefits of both. This article was written to help you become more informed about your decision as to the best colon cancer screening method for you.
Is a Colonoscopy the Ideal Colorectal Cancer Screening Method?
Many healthcare professionals consider a colonoscopy the most effective method for detecting and preventing colon cancer for the following reasons:
- Early detection. A colonoscopy detects colorectal cancer at its earliest and most treatable stage.
- Polyp removal. During the procedure, polyps (abnormal tissue growths that may develop into cancerous tissue) are easily visualized and removed immediately.
- Reduced mortality rate. There is a 65%-88% reduction in mortality that is associated with screening colonoscopies.
- Reduced rate of incidence. Observational studies have shown a 31%-71 % reduction in colorectal cancer incidence in those who have had a colonoscopy screening..
A colonoscopy is considered a 1-step or direct test because it can be both diagnostic and therapeutic depending on what the physician finds during a colonoscopy. The majority of colorectal cancers develop from adenomas, abnormal precancerous lesions found in the intestinal lining of the colon and rectum. These lesions can be removed during a routine colonoscopy and stop the progression of the adenomas developing into cancer.
High-Risk Patients and Colonoscopies
The first question you should ask yourself when trying to decide which colon screening method to choose is:
Do I Have a Family History of Colon Cancer?
If you have a family member who has had colon cancer you are at a higher risk for developing colon cancer. In fact, 20% of people diagnosed with colorectal cancer have a family member who has had colon cancer. While having a family member, especially a first-degree relative (such as your mother or father), who has had colon cancer places you in a high-risk category for colon cancer, this does not mean you will definitely get colorectal cancer. Nonetheless, because your risk is much higher than someone with no familial history of colon cancer, you should consider getting a colonoscopy as any abnormal tissue found is immediately removed during the procedure.
Other Risk Factors
The following risk factors typically place you in this high-risk category for colorectal cancer:
- Family history of colorectal cancer
- Personal history of colorectal cancer or polyps
- Personal history of inflammatory bowel disease, including ulcerative colitis or Crohn’s disease
- Personal history of receiving radiation therapy to the abdomen or pelvic area for previous cancer treatment
- Confirmed or suspected history of colorectal cancer syndrome that is hereditary, such as familial adenomatous polyposis (FAP) or Lynch syndrome
Having one or more of these risk factors typically means that your physician will recommend colorectal cancer screening using a colonoscopy. Remember that if a polyp or adenoma is found during a colonoscopy, the gastroenterologist can immediately remove the abnormal tissue and test for malignant cells, whereas at home screening methods do not have this option.
If a polyp or adenoma is found during a colonoscopy, the gastroenterologist can immediately remove the abnormal tissue and test for malignant cells, whereas at home screening methods do not have this option.
As discussed previously, the main advantage of a colonoscopy is that the practicing physician can immediately excise or remove polyps and take a biopsy of abnormal tissue to test for cancerous cells. The main advantages of a colonoscopy include:
- Physicians can detect very small polyps and abnormalities that may be missed in an at home screening test
- Physicians can remove suspicious tissue growths and/or polyps during the procedure
- Other colon disorders, such as diverticulitis, can be identified and diagnosed during the procedure
- You receive immediate results after your colonoscopy
- If you are at an average risk for colon cancer and have a normal result, you typically will need another colonoscopy in ten years
At Home Colon Cancer Screening Tests Advantages
At home colon cancer screenings are often prescribed by physicians to patients who are at a low risk for developing colon cancer as an alternative to a colonoscopy. These tests are inexpensive, non-invasive, and usually done in the comfort of a person’s home. Among these choices are at-home cancer screening tests which require no bowel preparation nor invasive procedure. Your healthcare provider may recommend that you take an at-home CRC screening test if you have no personal or family history of polyps and colon cancer. Currently there are three at-home colorectal cancer screening options available to you by prescription:
- FIT test – The fecal immunochemical test (FIT) detects blood in the stool by using antibodies. The test is simple: you collect a small amount of fecal matter from a bowel movement, place it in a sterile container, and mail it to a lab for analysis.
- Multitarget stool DNA test (Cologuard™) – Like FIT, you collect a small amount of your stool and place it in sterile container to be shipped to a lab to analyse for cancer. This test detects not only blood in your stool, but also cellular changes to your DNA that indicate abnormal tissue growth.
- Guaiac-Based Fecal Occult Blood test (gFOBT) – This test uses the chemical guaiac to detect blood in the stool. It requires that you take three separate stool samples that are smeared on test cards to be mailed in for testing.
Your doctor may prescribe one of the three options mentioned above – all of which require you to take a sample of your stool from home without the uncomfortable bowel preparation that is required for an effective colonoscopy. Advantages of at home colon cancer tests include:
- No bowel preparation is required
- Tests are usually significantly less expensive than a colonoscopy
- Tests are simple and generally done in the comfort of your own bathroom
- At home colon cancer tests are comparably accurate in detecting colon cancer and precancerous abnormal tissues
Your Physician and You
The CDC affirms that at home colon cancer screening tests (such as FIT, FOBT, and Cologuard) should be offered as options to all patients in order to increase overall screening rates. The CDC also has recommended that physicians not only offer options but also inform patients in depth about each test and match their patients with the test they believe will complete. Ultimately, it is up to you and your doctor which test you will choose. Be open with your physician to discuss any questions or concerns you have about which test is best. Remember that following through with the colon cancer screening, whether it be a colonoscopy or an at home fecal blood stool test, can help save your life if you have an undetected case of colon cancer or small polyps unbeknownst to you.
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Cusumano, V. T., et., al. (2020, April 19). Patients without colonoscopic follow-up after abnormal fecal immunochemical tests are often unaware of the abnormal result and report several barriers to colonoscopy. BMC Gastroenterology, 20, 115. Retrieved from PMC: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7168865/
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