The regular use of aspirin reduces the incidence of and risk for death from lethal prostate cancer, according to the results of a large observational study reported at the 2016 ASCO Genitourinary Cancers Symposium. For the purposes of this study, lethal prostate cancer was defined as metastatic disease or prostate cancer–specific death.
Aspirin is cheap and widely available, and this evidence suggests a reason to take aspirin in addition to cardiovascular protection. But this does not mean that men with a diagnosis of prostate cancer should add aspirin to their list of medications. First, they should discuss the risks (mainly gastrointestinal bleeding) and benefits of taking aspirin with their oncologist.
“It is premature to recommend aspirin to prevent lethal prostate cancer, but men with prostate cancer who already may benefit from aspirin’s cardiovascular effects could have one more reason to consider regular aspirin use,” said lead investigator Christopher B. Allard, MD, Harvard Program in Urology, Massachusetts General Hospital and Brigham and Women’s Hospital, Boston. “Physicians can discuss these findings with patients,” he added.
The Physicians’ Health Study enrolled 22,071 male physicians. After 27 years of follow-up, 3183 men were diagnosed with prostate cancer, and 402 of them had lethal prostate cancer.
Regular aspirin use (≥3 tablets weekly) reduced the risk for lethal prostate cancer by 24% in the overall trial compared with nonusers, according to a multivariate analysis adjusted for age, race, body mass index, and smoking status. Among men with a diagnosis of prostate cancer, regular aspirin use after diagnosis reduced the risk for prostate cancer–specific death by 39% compared with nonusers.
Dr Allard emphasized that regular aspirin had no effect on the risks for prostate cancer, high-grade prostate cancer, or locally advanced disease.
At a premeeting presscast, he said that he and his coinvestigators plan to study mechanisms related to aspirin’s effect on lethal prostate cancer and to determine which subsets of men might benefit. Also, the study did not control for the dose of aspirin, so an optimal dose remains to be determined.
“This is a provocative paper, but it is an observational study and we need formal clinical trials to determine the right dose and the right patients who will benefit. Remember, aspirin causes bleeding,” said presscast moderator Sumanta K. Pal, MD, who is an ASCO spokesperson, and Assistant Clinical Professor, Department of Medical Oncology and Therapeutics Research, City of Hope, Duarte, CA, but was not involved in this study.
Randomized controlled trials are needed to study the protective effects of regular use of aspirin in men with prostate cancer.