Long-term Use of Aspirin and Nonsteroidal Anti-inflammatory Drugs and Risk of Colorectal Cancer

Abstract

Recent randomized intervention trials have demonstrated that regular use of aspirin in patients with a history of colorectal adenoma or cancer reduces the risk of recurrent adenoma within 1 to 3 years.^1-3 However, whether aspirin similarly reduces risk of colorectal cancer and, if so, the necessary dose and duration of use, remain unclear. Although short-term aspirin use appears effective in reducing risk of adenoma, 2 randomized trials of aspirin that have specifically examined colorectal cancer as an outcome did not demonstrate a benefit after 5 or 10 years.^4,5 Moreover, intervention trials of adenoma or cancer have provided only limited and conflicting data on the optimal dose of aspirin.^1-5 Finally, it remains uncertain whether nonaspirin nonsteroidal anti-inflammatory drugs (NSAIDs), which share several underlying mechanisms with aspirin, exert a similar antineoplastic benefit.