Popular pill's protective properties proficient on cancer, too

Aspirin racks up gains in three new studies on reducing the chance of contracting Hodgkin's lymphoma, esophageal and prostate cancer

By Robin Searle

Aspirin relieves pain, reduces blood clotting and reduces the risk of heart attack. Now, a trio of studies adds Hodgkin's lymphoma, esophageal cancer and prostate cancer to the list of maladies that may yield to aspirin's chemistry.

Two studies in the February 18 issue of the Journal of the National Cancer Institute report that aspirin influences Hodgkin's lymphoma and esophageal adenocarcinoma.

In the first study, researchers from the Harvard School of Public Health in Boston analyzed the influence of regular use -- at least two tablets per week -- and non-regular use -- less than two tablets weekly -- of aspirin, non-aspirin nonsteroidal anti-inflammatory drugs (NSAIDS), and acetaminophen over five years. Dr Ellen Chang and colleagues studied 565 patients with Hodgkin's disease and 679 control subjects.

Those who took aspirin regularly were 40% less likely to develop Hodgkin's lymphoma than non-regular users. This effect was specific, as other NSAIDs had no influence on the risk of lymphoma.

The specificity of aspirin's effect, combined with what is known of the targets of the drug, led the researchers to propose that aspirin acts to inhibit the activation of a molecule called transcription factor nuclear factor kappa-B. When activated, kappa-B may trigger some cancerous growth.

In the second study, Dr Chin Hur and colleagues from Massachusetts General Hospital, Boston, modelled the cost-effectiveness of aspirin in preventing the development of adenocarcinoma in Barrett's esophagus (the abnormal growth of stomach cells into the esophagus in gastroesophageal reflux disease). The model assumed that a daily 325mg dose of aspirin was effective in preventing adenocarcinoma. The researchers' constructed the model to compare four strategies for the management of Barrett's esophagus: use of aspirin alone, use of biopsies alone, use of aspirin and regular biopsies, and no intervention.

The model predicts that aspirin use alone or in combination with regular monitoring of the esophagus is better than doing nothing. In considering the benefits of aspirin weighed against potential complications, "aspirin use for primary prevention may be an obvious recommendation," concluded the authors.

Finally, a meta-analysis of previously published studies reports on the influence of NSAIDs on the course of prostate cancer, "second only to lung cancer in terms of number of deaths it causes," according to Dr Salaheddin Mahmud from McGill University, Montreal. Dr Mahmud is the lead author of a report in the February issue of the British Journal of Cancer. The McGill researchers found that the use of aspirin for at least four years was associated with a 30% reduction in the risk of advanced prostate cancer and a 10% drop in total risk from the cancer. Results of other NSAIDs were not compelling. While it may be too early to recommend regular use of aspirin for prostate cancer prevention, "the time is right for prospective trials" to investigate these latest findings, noted Dr Mahmud.