Advance with MUSC Health

Colorectal Cancer Awareness Month

Advance With MUSC Health
March 11, 2024
Erika Blank, M.D.

When some people think of March, they think of March Madness or St. Patrick's Day. Dr. Erika Blank thinks of colorectal cancer.

With colorectal cancer ranking as the third most common cancer and the second leading cause of cancer-related deaths in the United States, timely screening and early detection play pivotal roles in combating its growing prevalence. Here, Dr. Blank addresses the importance of proactive measures in preventing, detecting and treating colorectal cancer.

Colon cancer statistics

Colorectal cancer is the third most common cancer in the United States and the second leading cause of cancer death in men and women combined. The lifetime risk of developing colorectal cancer is about 1 in 23 for men and 1 in 25 for women.

Over the last five decades, colorectal cancer cases and deaths have declined in older adults in large part due to an increased uptake of screening and better treatments. In people under 55, however, cases have been growing by about 1 to 2 percent per year since the mid-1990s and death rates have been increasing by about 1 percent per year since the mid-2000s.

This rise in colorectal cancer cases and deaths in young and middle-aged people has led to a recent change in screening recommendations, lowering the starting age to 45.

Why screen for colon cancer?

Screening saves lives. The majority of colorectal cancers arise from pre-cancerous polyps, which progress to cancer over many years.

The evolution from a polyp to cancer is a slow process, on average requiring 10 years. Colorectal cancer is preventable if pre-cancerous polyps can be detected and removed before they become malignant.

Also, if a polyp has progressed to cancer, early detection leads to a better prognosis as the cancer can be treated more effectively at an earlier stage. The five-year survival rate of localized colorectal cancer is 88 percent. In comparison, the five-year survival rate when the cancer has already spread to distant parts of the body is only 16 percent, highlighting the utility of early detection through screening.

Who should be screened?

Adults who are at average risk for colorectal cancer used to start screening when they turned 50, but now most guidelines recommend beginning screening at age 45.

Screening is recommended to continue through age 75 for healthy people.

For people between 76 and 85, we make decisions based on personal preferences, life expectancy, health status and prior screening history.

Screening is discouraged after age 85 as the risks outweigh the benefits.

People at high risk for colorectal cancer should begin screening earlier. A family history of colorectal cancer or an advanced adenoma in a first-degree relative, a history of inflammatory bowel disease (ulcerative colitis or Crohn's disease) and specific genetic syndromes (e.g., Lynch syndrome, familial adenomatous polyposis (FAP), peuzt-jeghers syndrome) all place a person at higher risk of developing colorectal cancer.

A diagnostic colonoscopy should be performed immediately if a person has symptoms such as blood in the stool, rectal bleeding, change in bowel habits, abdominal pain, anemia or unintentional weight loss. In this case, we are no longer screening since symptoms must be evaluated.

What are colon cancer screening options?

The most common options for colorectal cancer screening range from stool-based tests to direct visualization with a colonoscopy. If a stool-based test is positive, a follow-up colonoscopy must be performed. Deciding which screening test to perform is personal and depends on one's preferences regarding the convenience, the risk and the sensitivity and specificity of the test. Most importantly, you choose a screening test and get it done.

Fecal immunochemical test for blood (FIT) - Tests for blood in a stool sample. Performed at home by placing a small stool sample on the collection kit and performed yearly. If positive, a colonoscopy is performed.

  • Sensitivity (the ability to detect cancer) 74 percent.
  • Sensitivity for detecting adenomas (pre-cancerous polyps) is lower at 23.8 percent, 7.6 percent and 7.6 percent for adenomas ≥10mm, 6-9mm, ≤5mm.
  • Specificity (the ability to correctly diagnose those without cancer) 96.4 percent.
  • No risks.

Multitarget stool DNA test with FIT (Cologuard) - Checks DNA in stool cells for genetic changes that may be a sign of colorectal cancer. A FIT test, checking for blood in the stool, is performed at the same time. An entire stool is collected in the kit provided. The test is conducted every three years. If positive, a colonoscopy is performed.

  • Sensitivity (the ability to detect cancer) 92 percent.
  • Sensitivity for detecting adenomas (pre-cancerous polyps) is lower at 42.2 percent, 17.2 percent 17.2 percent for adenomas ≥10mm, 6-9mm, ≤5mm.
  • Specificity (the ability to correctly diagnose those without cancer) is 89.8 percent.
  • No risks.

Colonoscopy - Colonoscopy is the most common screening test in the United States. A gastroenterologist uses a flexible fiberoptic endoscope to directly visualize the inside of the rectum, colon and a portion of the end of the small intestine. If lesions are detected, they may be biopsied and/or removed. A colonoscopy is performed every 10 years if the initial result is normal in average-risk people.

Before the exam, diet adjustments, certain medications rigorous bowel preparation are performed to clean the colon. Sedation is also usually used during the procedure, requiring the patient to be accompanied by another person and to avoid activities that require mental alertness until the sedative effect wears off.

  • Sensitivity (the ability to detect cancer) 95 percent.
  • Sensitivity for detecting adenomas (pre-cancerous polyps) is much better at 95 percent, 85 percent 75 percent for adenomas >10mm, 6-9mm, <5mm.
  • Specificity (the ability to correctly diagnose those without cancer) 86 percent.
  • Risks include a small risk of perforation (0.01 to 0.1 percent), major bleeding and infection.
  • Risks depend on the patient's age, comorbidities and endoscopist's experience. There is also a risk of dehydration and electrolyte abnormalities from the bowel preparation.

Can I prevent colorectal cancer?

There is no way to prevent colorectal cancer completely, but we can lower the risk of developing it. Research shows that habits related to diet, weight and exercise are strongly linked to colorectal cancer risk. In addition to regular screening, following these healthy lifestyle behaviors will reduce the risk of colorectal cancer:

  • Eat lots of vegetables, fruits and whole grains! Diets that include a variety of vegetables, fruits and whole grains have been linked with a decreased risk of colorectal cancer. Also, eat less red meat (beef, pork, or lamb) and processed meats (hot dogs and some luncheon meats), which have been linked with an increased risk of colorectal cancer.
  • Get regular exercise! If you are not physically active, you may have a greater chance of developing colorectal cancer. Being more active may help reduce your risk. Aim for a minimum of 150 minutes of moderate physical activity each week or 30 minutes, five days a week.
  • Maintain a healthy weight! Being overweight or obese increases your risk of getting and dying from colorectal cancer.
  • Quit smoking! People who have been smoking for a long time are more likely than people who don’t smoke to develop and die from colorectal cancer. Ask your doctor for help if you want to quit smoking, call 1-800-QUIT-NOW for help.
  • Avoid alcohol! Alcohol use has been linked with a higher risk of colorectal cancer. It is best not to drink alcohol. But if you do drink, limit the amount to no more than one drink a day if you are a woman and no more than two drinks a day if you are a man.

With screening, early detection and prevention of colorectal cancer being so beneficial, it is March madness not to stay on top of your screening and remind your friends and families to get their screening tests done as well.

About the Author:

Dr. Erika Blank blends her expertise in building healthier lifestyles into her internal medicine practice to provide the most successful outcomes and create long-term health benefits for her patients. If you are interested in personalized medical care customized to your unique needs, please visit Accel Health and join the waitlist today.