Ulcerative colitis and colorectal cancer
Dr. Nikhil Agrawal | Last reviewed on
Ulcerative colitis is a disease leading to chronic inflammation of the rectum and colon. Inflammation causes ulcers in the lining of the large intestine. Ulcerative colitis and Crohn’s disease are together called inflammatory bowel disease (IBD).
Cause of ulcerative colitis
The exact cause of ulcerative colitis is not known. It is thought to be caused by a combination of the dysregulated immune system, imbalance of gut microbiota and environmental triggers in persons with genetic tendencies. The immune system of the affected individual identifies the lining of the large intestine as foreign. It mounts an attack on it, leading to inflammation.
Symptoms of ulcerative colitis
Symptoms of ulcerative colitis include diarrhoea, blood in the stool, abdominal pain, fatigue, weight loss, fever, feeling unwell, nausea and vomiting. Ulcerative colitis varies in intensity; it flares and then subsides. The remission can last from a few weeks to a few years.
Treatment of ulcerative colitis
The treatment of ulcerative colitis (UC) is based on the disease stage (active, remission), extent, and severity.
Treatment options include:
- Medications, such as corticosteroids, aminosalicylates, immunosuppressants and biological agents
- Surgery, such as total proctocolectomy with ileal pouch-anal anastomosis (IPAA)
Ulcerative colitis and the risk of colorectal cancer
Colorectal cancer starts in the cells of the inner lining of the colon or rectum. They can grow into surrounding tissues and spread to other parts of the body. Colorectal cancer is the third most common cancer worldwide.
Risk of cancer in ulcerative colitis
Long-standing ulcerative colitis can lead to colon cancer and rectal cancer. People with ulcerative colitis have an approximately 2-3-fold increased risk of developing colorectal cancer compared to the general population. 3.2% of overall ulcerative colitis patients will have colorectal cancer. The cumulative risk of colorectal cancer is 2%, 8%, and 18% after 10, 20, and 30 years of disease, respectively. Recent studies suggest that the risk may be as low as 1%, 3%, and 7% at 10, 20, and 30 years. This reflects the better treatment available these days.
Risk factors of cancer in ulcerative colitis
This risk is directly related to the duration and extent of the disease, so the longer a person has had ulcerative colitis and the more of their colon that is affected, the higher their risk of colorectal cancer. Patients with only mild inflammation of the rectum (proctitis) have a lower risk, while patients with more severe inflammation that involves most, or all of the colon (pancolitis) have the highest risk. Risk of colorectal cancer increases significantly after living with the condition for 8-10 years. Primary sclerosing cholangitis and a family history of colon cancer or rectal cancer also increase the risk.
Cause of cancer
The reason for ulcerative colitis causing cancer is not known. Chronic inflammation damages the DNA of the cells leading to dysplasia, which is precancerous changes in the cells. Dysplasia can progress to cancer.
Screening colonoscopy
To properly manage their risk, people with ulcerative colitis should get screened for colorectal cancer regularly. Most guidelines recommend that people with ulcerative colitis get a colonoscopy 8-10 years after symptoms start, then every 1-3 years thereafter. In the presence of coexisting primary sclerosing cholangitis, patients should undergo yearly surveillance. During a colonoscopy, cancer can be found and precancerous polyps can be detected and removed before they become cancerous.This can significantly improve the chances of successful treatment and survival.
The first colonoscopy performed for CRN detection purposes is referred to as the ‘screening colonoscopy’, while subsequent exams are referred to as ‘surveillance’ exams.
Surgery for colorectal cancer in ulcerative colitis
Colorectal cancer, nonadenoma dysplasia-associated lesion or mass and high-grade dysplasia are considered definite indications for surgery.
Total proctocolectomy with ileal pouch-anal anastomosis (IPAA)
When surgery is performed for colorectal cancer in patients with ulcerative colitis, the standard procedure is most often total proctocolectomy with ileal pouch-anal anastomosis (IPAA). The whole colon and rectum are removed because of the increased risk of having more cancers in the rest of the colon and developing cancer in the remaining colon later due to field cancerization.
Limited resection
However, in certain patients who meet the conditions, segmental colectomy or rectal resection may be a reasonable option. These include patients with limited disease, patients who have a high risk of surgery, strong patient preference and unifocal dysplasia.
While living with ulcerative colitis increases your risk of colon cancer, with proper screening and management, most patients do not develop colon cancer. However, if detected, colorectal cancers that develop in the setting of ulcerative colitis tend to have better outcomes with treatment.
Reducing the risk of colon and rectal cancer in ulcerative colitis
Besides regular screening, there are other steps that patients with ulcerative colitis can take to reduce their risk of colorectal cancer. These include:
Taking medication as prescribed
Medications to treat ulcerative colitis reduce inflammation and decrease cancer risk. Follow up with your doctor regularly.
Maintaining a healthy lifestyle
Eating a balanced diet, exercising regularly, and avoiding smoking and excessive alcohol consumption can all help to reduce the risk of colorectal cancer in ulcerative colitis.
Monitoring symptoms
If you experience any new or worsening symptoms, such as changes in bowel habits or rectal bleeding, it is important to see your doctor right away.
Considering surgery
In some cases, surgery to remove the colon may be recommended for people with ulcerative colitis who are at high risk of colorectal cancer.
Wish you or your loved one a speedy recovery!
