Aspirin may mask prostate cancer, study hints

NEW YORK (Reuters Health) - Middle-aged men who take aspirin or other "nonsteroidal anti-inflammatory drug" (NSAID) have significantly lower levels of a blood protein used to spot prostate cancer than men who don't take these widely used drugs, a study shows.

This raises concern that aspirin use may hamper the ability to detect early-stage prostate cancer, by lowering PSA levels "below the level of clinical suspicion," Dr. Jay H. Fowke from Vanderbilt University in Nashville noted in a briefing with reporters Sunday. PSA stands for prostate-specific antigen.

A PSA test is used widely as a method to screen men for the possibility of prostate cancer, with higher blood PSA levels suggesting a greater chance of having prostate cancer.

Fowke and his associates collected data from more than 1,200 men older than 40 years who were referred for a biopsy of the prostate. Roughly 46 percent of the men reported taking an NSAID, primarily aspirin.

They found that the use of aspirin was significantly associated with lower PSA levels. After accounting for other factors that might influence the results, PSA levels were 9 percent lower in men taking aspirin relative to those who were not.

Fowke presented data at the American Association for Cancer Research's Seventh Annual International Conference on Frontiers in Cancer Prevention Research.

"These results may suggest that aspirin use decreases the ability to detect prostate cancer and may contribute to prior investigations reporting a protective association between NSAID use and prostate cancer risk," Fowke and colleagues wrote.

More research is needed, they conclude, to determine if NSAID use is affecting prostate cancer risk or simply the ability to detect prostate cancer among NSAID users.