Aspirin use linked to lower prostate cancer risk

Aspirin use may reduce the risk of prostate cancer, according to the results of a meta-analysis published in the January 12th issue of the British Journal of Cancer.

Prostate cancer is the most commonly diagnosed noncutaneous cancer in the United States and Canada, “and is second only to lung cancer in terms of number of deaths it causes,” Dr. Salaheddin Mahmud from McGill University, Montreal, told Reuters Health. “So it is very unfortunate that at the moment we do not know of any modifiable risk factors for the development of this disease.”Because none of the individual trials published on nonsteroidal anti-inflammatory drug (NSAID) use and the risk of prostate cancer reached conclusive results, Dr. Mahmud and colleagues conducted a systematic review and meta-analysis of 12 reports to examine the strength and consistency of the link between NSAID use and prostate cancer.Most reports showed an inverse relationship between aspirin use and prostate cancer risk, the authors report, but only two reports were statistically significant. Studies of other NSAIDs were less consistent.The use of aspirin was associated with a 30% reduction in the risk of advanced prostate cancer and a 10% reduction in total prostate cancer risk, the report indicates.The study cited by the investigators as “best equipped to address this issue” reported a strong inverse association between aspirin use and prostate cancer risk, but only among participants that had taken aspirin for at least 4 years.The studies of nonaspirin-NSAIDs showed trends of reduced prostate cancer risk, the researchers note, but all 95% confidence intervals included a summary odds ratio of 1. Moreover, there was no consistent association of NSAID intake with prostate cancer after stratifying by study design.”NSAIDs (and aspirin in particular) appear to offer some protective effect against prostate cancer both in laboratory studies and in observational studies in humans,” Dr. Mahmud said. “It is too early to recommend regular use of aspirin for prostate cancer prevention, but the time is right for prospective trials.””Recently, two large randomized controlled trials were initiated to evaluate the protective effects of two selective COX inhibitors (celecoxib and rofecoxib),” Dr. Mahmud added. “I am not aware of any randomized controlled trials on the cheaper and more widely available non-selective inhibitors (e.g., aspirin and ibuprofen).”The focus on selective inhibitors is partially because they have fewer gastrointestinal side effects, such as stomach bleeding, and partially because they are more economically rewarding to pharmaceutical companies,” he added.(Source: Br J Cancer 2004;90:93-99: Reuters Health: February 12, 2004: Oncolink)