The ABCs of Colon Cancer: Awareness, Barriers, and Choices

The death of 43-year-old “Black Panther” actor Chadwick Boseman in August 2020 had brought renewed attention to colon cancer and the need for regular screenings.

Colon cancer, a malignant growth in the large intestine, is the third leading cause of cancer - related mortality in the United States. However, the prognosis significantly improves when the disease is detected early.

One subtype of colon cancer is rectal cancer, which originates in the rectum, the terminal segment of the large intestine. Collectively, the term "colorectal cancer" refers to malignancies originating in either the colon or the rectum.

Symptomatology in colon cancer is variable. Some people may present with bloody stools, abdominal discomfort, or alterations in bowel habits, such as a change in stool size. However, it's important to note that a significant number of individuals may be asymptomatic. In such cases, the absence of symptoms may hinder early detection, allowing the tumor to progress. Routine screenings can detect not only cancer but also small growths called polyps, which hold the potential to become cancerous over time.

The recommended age to begin routine screening is 50 years, continuing until the age of 75. If an individual exhibits symptoms of colon cancer or possesses a higher risk, the medical practitioner may advise early screening. Risk factors include a family history of colon cancer or polyps and certain medical conditions like inflammatory bowel disease.

There are a variety of screening methods available for colon cancer, differing in their procedures, cost, and required preparation.

• The Fecal Immunochemical Test (FIT) is a simple at-home test conducted annually, requiring a single stool sample that remains unaffected by diet or medication. If results indicate abnormalities, a subsequent colonoscopy is necessary.

• Colonoscopy, performed every 10 years, involves the insertion of a thin tube affixed with a camera into the rectum to examine the entire colon. Polyps discovered during this procedure can often be removed immediately. However, this method is the costliest, carries a higher risk of injury, and may require a day of recovery and transportation assistance post-procedure.

• The Guaiac-based fecal occult blood test is another annual at-home test requiring three consecutive stool samples. Its effectiveness is contingent on yearly testing, and dietary or medicinal factors may result in false positives.

• The multitargeted stool DNA test (FIT-DNA), like the FIT, requires a single stool sample and is performed every one to three years.

• Flexible sigmoidoscopy, performed every five years, involves the insertion of a lit tube to examine the rectum and the lower part of the colon. Though it reduces mortality from colon cancer and is safer and more economical than a colonoscopy, it doesn't offer the same accuracy.

• CT colonography, also known as a virtual or x-ray colonoscopy, uses compressed air and imaging techniques to inspect the colon. This test, despite being less accurate overall, is almost as effective at detecting large polyps as a traditional colonoscopy.

Prevention of colon cancer primarily involves early detection and removal of polyps. Lifestyle modifications, such as a diet rich in calcium and dairy and low in red meat, regular physical activity, maintaining a healthy weight, and statin use, may reduce the risk of polyp formation and subsequent colon cancer. Aspirin or ibuprofen may also lower risk, but these should be used cautiously due to potential side effects. For postmenopausal women, hormone therapy may decrease risk, though it carries its own potential side effects. It is noteworthy that fiber, folic acid, or antioxidant supplementation does not seem to impact the risk of polyp development or colon cancer.

References

1. AAFP's Patient Information Resource

   • https://familydoctor.org/condition/colorectal-cancer/

2. American Cancer Society

   • https://www.cancer.org/cancer/colon-rectal-cancer.html

3. American College of Gastroenterology

   • http://gi.org/wp-content/uploads/2013/08/Colonoscopy_Payments_QandA_Guide.pdf

4. Centers for Disease Control and Prevention

   • https://www.cdc.gov/cancer/colorectal/index.htm

5. Screen for Life: National Colorectal Cancer Action Campaign

   • https://www.cdc.gov/cancer/colorectal/pdf/basic_fs_eng_color.pdf