Boston—Taking a low-dose aspirin daily appears to reduce ovarian cancer risk by 23%, according to a new study.

The report in JAMA Oncology also suggests that women who were heavy long-term users of nonaspirin nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen or naproxen, increased their risk.

The study, involving researchers from Harvard T.H. Chan School of Public Health in Boston and the H. Lee Moffitt Cancer Center & Research Institute in Tampa, Florida, analyzed data from more than 200,000 women who took part in the Nurses’ Health Studies.

Of the participants, 1,054 developed ovarian cancer. Researchers looked at the participants’ use of aspirin (325 milligrams), low-dose aspirin (100 milligrams or less), nonaspirin NSAIDs, and acetaminophen.

For each analgesic type, timing, duration, frequency, and number of tablets used were evaluated and exposure information was updated every 2 to 4 years.

Results indicate that significant associations between aspirin and ovarian-cancer risk were not observed when current versus nonuse of any aspirin was evaluated, despite dosage.

When low-dose (≤100-mg) and standard-dose (325-mg) aspirin were evaluated separately, however, an inverse association for low-dose aspirin (HR, 0.77; 95% CI, 0.61-0.96) but no association for standard-dose aspirin (HR, 1.17; 95% CI, 0.92-1.49), was observed.

At the same time, current use of nonaspirin NSAIDs was positively associated with risk of ovarian cancer compared with nonuse (HR, 1.19; 95% CI, 1.00-1.41). Researchers also report significant positive trends for duration of use (P = .02 for trend) and cumulative average tablets per week (P = .03 for trend), although no clear associations were identified with use of acetaminophen.

“These results appear to be consistent with case-control studies that show a reduced risk of ovarian cancer among regular users of low-dose aspirin,” study authors conclude. “An increased risk of ovarian cancer with long-term high-quantity use of other analgesics, particularly non-aspirin NSAIDs, was observed, although this finding requires confirmation.”

“We’re not quite at the stage where we could make the recommendation that daily aspirin use lowers ovarian cancer risk. We need to do more research. But it is definitely something women should discuss with their physician,” added coauthor Shelley Tworoger, PhD, associate center director for Population Science at Moffitt.

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