Common over-the-counter pain relievers may interfere with the detection of prostate cancer, according to a study published in the Oct. 15 issue of the journal Cancer.

The study found that regular use of nonsteroidal anti-inflammatory drugs, such as aspirin and ibuprofen, may reduce levels of the prostate biomarker PSA (prostate specific antigen).

After surveying 1,319 men over the age of 40, researchers found that regular users of pain killers had PSA levels about 10 percent lower than those who do not regularly use them. This could muddle test results because increased levels of PSA are considered a possible indication of prostate cancer, according to the study.

Although NSAIDS lower PSA levels, researchers said it is unclear whether they offer protection against prostate cancer.

"Given the widespread consumption of NSAIDs and the regular use of PSA for the assessment of prostate cancer risk, the potential implications of our findings may be substantial and warrant further investigation," the authors wrote in their study.

Click here to read more on this study published early in the online edition of Cancer.