Regular aspirin intake reduces risk for lethal prostate cancer
Men who took aspirin regularly demonstrated a reduced risk for lethal prostate cancer, according to retrospective study results presented at the Genitourinary Cancers Symposium.
Among men diagnosed with prostate cancer during the study period, those who began to use aspirin regularly after diagnosis demonstrated a lower risk for prostate cancer mortality.
“It is premature to recommend aspirin for prevention of lethal prostate cancer, but men with prostate cancer who may already benefit from aspirin’s cardiovascular effects could have one more reason to consider regular aspirin use,” Christopher Brian Allard, MD, urologic oncology fellow at Brigham and Women’s Hospital and Massachusetts General Hospital, as well as instructor in surgery at Harvard Medical School, said in a press release. “When discussing potential benefits of aspirin with their doctors, in terms of both cardiovascular health and risk of prostate cancer death, men should also consider potential risks of regular aspirin use.”
Prior studies have yielded conflicting results about aspirin’s chemopreventive effects against several malignancies, including prostate cancer.
Allard and colleagues analyzed data from 22,071 men enrolled in the Physicians’ Health study between 1982 and 2009 to assess the association between regular aspirin intake — defined as more than three tablets per week — and lethal prostate cancer, defined as metastases or prostate cancer death.
Secondary outcomes included incidence of total cancers, high-grade cancers (Gleason 8-10) and advanced cancers (T3b-T4, or N1 or M1).
During 27 years of follow-up — which included 533,261 person-years — 3,193 men were diagnosed with prostate cancer; of these, 403 had lethal disease.
Among men who did not have prostate cancer at the time of study entry, those who took aspirin regularly demonstrated a 24% lower multivariate-adjusted risk for lethal prostate cancer. However, aspirin did not affect the likelihood of being diagnosed with any, high-grade or locally advanced prostate cancer.
Among men diagnosed with prostate cancer during the study period, those who took aspirin regularly after diagnosis — regardless of whether they used aspirin prior to diagnosis — demonstrated a 39% reduced risk for dying of prostate cancer.
The reason for this benefit is unknown, Allard said.
“The hypothesis I find appealing is that the main effect of aspirin is it limits platelets, which galvanizes the immune system to identify cancer cells and prevent metastases,” Allard said during a press conference.
Use of aspirin only prior to diagnosis did not confer a measurable benefit.
The primary limitation of the study was the uncertainty about aspirin dosing, Allard said.
Sumanta K. Pal
When the study began in 1982, men were taking 325 mg aspirin about 3 times a week. However, after 5 years, that changed and dosages were not monitored in all cases. Some men continued with a 325-mg daily dose, some switched to an 81-mg daily dose and others fell somewhere in between.
“This study suggests there may be yet one more benefit of aspirin beyond those we’ve already seen in colorectal cancer and heart disease,” press conference moderator Sumanta K. Pal, MD, assistant clinical professor in the department of medical oncology and therapeutics research at City of Hope and a HemOnc Today Editorial Board member, said in a press release. “While taking aspirin does carry certain side effects that patients should discuss with their physician, it’s intriguing that this low-cost medicine may lower the risk of death from prostate cancer.” – by Anthony SanFilippo
Allard CB, et al. Abstract 306. Presented at: Genitourinary Cancers Symposium; Jan. 7-9, 2016; San Francisco.
Disclosure: The researchers and Pal report no relevant financial disclosures.