What is chemoprevention and do I need it?
The ability of a medication to decrease the risk of a disease development is known as chemoprevention. In the setting of UC, investigators are looking for a safe drug that would decrease the risk of dysplasia and cancer.
5-aminosalicylate (5-ASA) compounds are the most promising chemopreventive agents. This class of drugs includes mesalamine, sulfasalazine, and balsalazide. They are used as first line therapy for mild-moderate UC. A recent analysis, summarizing the data of 9 case-control studies, included almost 2000 patients with 334 cancers and 140 cases of dysplasia. Those who used 5-ASA medications decreased their rate of cancer by about 50%, although the rate of dysplasia was unchanged.
These studies are retrospective so that even though they corrected for differences in certain patient characteristics, we have to be aware that there could be unmeasured or unadjusted factors which correlate with the use of 5-ASA. The gold standard is to perform a prospective randomized controlled trial, but such study is unlikely to be performed due to prohibitive cost and duration. As a result, the use of these medications for cancer preventions remains controversial.
Use of other UC medications, such as the immunosuppressant azathioprine, have failed to correlate with a decreased risk of colon cancer.
There is only one way to guarantee that colon cancer does not occur- take out the colon. Colectomy is often performed for patients who do not respond to UC medications or who have pre-cancerous or cancerous colonic lesions. It is rarely performed purely for prevention of colon cancer, especially since the lifetime risk of colon cancer in UC may be less than was once thought. (see previous postings)
In the future, I will examine surgical options and approaches.