Regular use of aspirin at a low dose may help protect against colorectal cancer, according to a study published in Gut.

Some studies have suggested that use of aspirin and other non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen may help protect against colorectal cancer. These studies, however, haven’t determined the lowest possible effective dose for colorectal cancer prevention or how long aspirin or other NSAIDs must be used to have a protective effect.

In this recent case-control study, researchers evaluated how different doses of NSAIDs and the duration of their use affected colorectal cancer risk and survival. The study included 2,279 individuals who had been diagnosed with colorectal cancer (cases) and 2,907 individuals who did not have colorectal cancer (controls). Participants completed questionnaires, which included information on NSAID use. Those who took NSAIDs more than four times per week for more than one month were considered users. Categories of NSAID use included: low-dose aspirin (75 mg), non-aspirin NSAIDs, and any NSAID.

• 16% (354) of cases were taking low-dose aspirin compared with 18% (526) of controls.
• Low-dose aspirin use was associated with a 22% reduction in risk of developing colorectal cancer.
• The reduced risk associated with low-dose aspirin became apparent one year after beginning use and increased with duration of use—to 30% at five years.
• Non-aspirin NSAID use and any NSAID use also appeared to decrease risk of colorectal cancer.
• NSAID use did not appear to improve overall survival or colorectal cancer-specific survival.

The researchers concluded that this is the first study to find that the lowest dose of aspirin (75 mg per day) may help protect against colorectal cancer. They add that aspirin must be taken regularly for one year before the effect is apparent and that protection increases for up to 10 years.

Reference: Din FV, Theodoratou E, Farrington SM, et al. Effect of aspirin and NSAIDs on risk and survival from colorectal cancer. Gut [early online publication]. September 15, 2010.

Tags: Colon Cancer, News Tips and Features, Rectal Cancer, Screening/Prevention Colon Cancer, Screening/Prevention Rectal Cancer