Some people with long-standing Inflammatory Bowel Disease (IBD), including Crohn’s Disease and Ulcerative Colitis, are at increased risk for colorectal cancer. Colorectal cancer and colon cancer are often used interchangeably because the colon and rectum have many features in common. The rectum is the passageway connecting the colon to the anus.
The association of IBD and colorectal cancer depends on the duration and activity of the disease, and extent of digestive tract that is involved. The incidence of colorectal cancer has declined over the past 30 years, due to successful surveillance programs and improved control of mucosal inflammation.
What is colorectal cancer?
Colorectal cancer is a cancer of the large intestine and rectum. Cancer occurs when cells in the body act improperly, and keep dividing and growing in an uncontrolled way.
What are symptoms of colorectal cancer?
Symptoms of colorectal, which can be similar to Crohn’s Disease and Ulcerative Colitis, include:
- Change in bowel habits (diarrhea or constipation)
- Stomach pain
- Blood in bowel movements
- Black or dark colored stools
- Feeling weak or tired
- Unexplained weight loss
What is the link between inflammatory bowel disease and colorectal cancer?
Inflammation of the colon, as seen in IBD, can cause continuous turnover of cells and increased risk of irregularities.
Ulcerative colitis, which affects the lining of the colon and the rectum, and a type of Crohn’s disease, called Crohn’s Colitis, which affects all or much of the large colon, may lead to colorectal cancer.
The risk of developing cancer is linked to three main factors:
- Duration of the colitis. The risk of developing cancer usually begins to increase approximately 8-10 years after the start of symptoms.
- Extent of involvement of the large bowel. The risk of cancer is highest if all or most of the colon is affected.
- Severity of inflammation
What is the risk?
A recent study showed that the overall risk of colorectal cancer was 1.29 cases per 1000 person-years. The study was a population-based study testing over 96,000 patients with inflammatory bowel disease (IBD).
Excess risks for colorectal cancer, however, have declined substantially over time. This drop in numbers could be the result of more widespread use of medicine in treating Crohn’s and colitis. This has, perhaps, led to fewer people with inflammation and eventual development of colorectal cancer.
Are there other risk factors?
Several additional factors may increase risk:
- Family history of colorectal cancer. The risk is highest if you have a parent or sibling under the age of 50 who has suffered from colorectal cancer.
- Primary Sclerosing Cholangitis (PSC). Primary sclerosing cholangitis, a disease of the bile ducts, is a rare disorder that affects males twice as often as females. Bile ducts are thin, long, tube-like structures that transport bile from the liver to the small intestine. PSC is known to affect around 1 in 25 people with ulcerative colitis, and up to 1 in 50 people with Crohn’s disease. The mechanism by which concomitant PSC increases the risk of colorectal cancer in patients with IBD is unknown. Chronic inflammatory activity may be the driver.
- Gender and Age. Men with Crohn’s disease or colitis have been found to have a slightly higher chance of developing colorectal cancer than women. The risk of bowel cancer is higher in people over the age of 50.
What can I do to reduce the risk of colorectal cancer?
- Routine follow-up care with your doctor. Schedule regular doctor visits and discuss with your doctor changes in symptoms at any time. Know your body. If something doesn’t feel right or you are concerned, speak with your doctor.
- Adhere to your medications. Long-term inflammation is linked to the development of colorectal cancer. Regular medications will give your bowel a chance to heal and reduce risk.
- Schedule regular colonoscopies. Early detection is key. Screen for colorectal cancer regularly with a colonoscopy. A colonoscopy is a type of examination that allows a specialist to look directly at the lining of the colon and rectum using a colonoscope, a long flexible tube. Sometimes abnormal cells can be removed at the time of the colonoscopy, avoiding the need for a surgical procedure. Screening is generally done every 1-2 years in people who have had symptoms of IBD for 8 years or longer. The frequency of testing may be even lesser than every 1-2 years, depending on the results of the previous colonoscopy.
- Reduce intake of red and processed meat. Red meat includes beef, lamb, pork, veal and goat. Sausage, bacon, ham, deli meat and canned meat are examples of processed meats.
- High fiber diet. If you have Crohn’s disease or colitis and have problems with a high-fiber diet, talk to your doctor or dietitian.
- Avoid or limit your consumption of alcohol
- Stop smoking
- Physical activity
- Take vitamin D supplements. In both people with IBD and the general population, a low level of vitamin D is linked to increased risk of colorectal cancer. More research is needed to better understand the link between vitamin D and colorectal cancer. Speak with your doctor about taking vitamin D supplements. Other health benefits of vitamin D include strengthening bones, which may be weakened from inflammation, and the side effects of medications, such as steroids.
What if I am diagnosed with colorectal cancer?
- If you are diagnosed early, bowel cancer is treatable and curable. Because you’ll be regularly assessed due to IBD, it’s likely any cancer that might occur will be detected early.
- Your healthcare team will discuss the benefits and risks of the different treatment options available.
It is important to build a collaborative relationship with all your doctors, especially your gastroenterologist, to achieve the best long-term results. Establish good communications with your doctor and discuss your symptoms openly. Colorectal cancer is a highly treatable condition when detected early. Scheduling regular colonoscopies, especially if you have IBD for more than 8-10 years, and maintaining a healthy lifestyle will reduce your risk of developing colorectal cancer. The best way to control IBD and any complications are by taking medications as prescribed by your doctor.