What Is Colorectal Cancer Screening?
Screening is an extremely important preventive method to catch cancer early before it advances to an incurable stage. Colorectal cancer (CRC) screening is useful among individuals who do not show symptoms. It can help detect polyps in the colon and rectum, which can develop into cancer if left untouched.
Understanding Your Risk of Developing CRC
Risk Factors You Can Control
Many lifestyle and environmental factors have been linked to an increased risk of developing CRC:
- Being overweight or obese
- Not being physically active
- Diet high in red and processed meats
- Eating meats cooked at very high temperatures
- Low blood levels of Vitamin D
- Alcohol consumption
Risk Factors You Cannot Control
- Ageing: those over 50 are more susceptible, although CRC is increasing in young adults
- Personal and/or family history of adenomatous polyps (adenomas) or CRC
- Personal history of inflammatory bowel disease, including Crohn’s disease or ulcerative colitis
- Inherited syndrome like Lynch Syndrome, FAP, Peutz-Jeghers syndrome or MUTYH-associated polyposis (MAP). Here’s more information on these inherited syndromes.
- African American or Ashkenazi Jewish ancestry
You can read more about these risk factors here.
If you have a family history of CRC, consult your doctor and/or a genetic counselor to understand your risk of developing the disease. The American Cancer Society provides valuable information on Understanding Genetic Testing for Cancer and What Happens During Genetic Testing for Cancer Risk.
Screening Test and How to Prepare for It
Two categories of screening options are available: stool-based testing and visual exam. Speak to your doctor to find out which test is right for you.
These tests require the patient to collect and mail-in a stool sample using an at-home kit. Currently, there are three types of stool tests approved by the FDA:
- Guaiac Fecal Occult Blood Test (gFOBT)
- Fecal Immunochemical Test (FIT)
- Multi-targeted Stool DNA Test (FIT-DNA)
Additional information on each test, preparing for sample collection, and frequency of getting the test done can be found here and here.
A visual exam allows your doctor to look inside your colon and rectum for any abnormal growth—either a polyp (non-cancerous) or a tumor—using a guided camera or a scanner. These tests need some extra preparation than stool-based tests:
- Sigmoidal colonoscopy
- CT colonoscopy
The American Cancer Society and the American Society for Clinical Oncology provide details on each test.