Analgesics use associated with increased risk for renal cell carcinoma

Eunyoung Cho, Sc.D., assistant professor of medicine at Harvard Medical School and associate epidemiologist at Brigham and Women's Hospital in Boston, and colleagues conducted a preliminary meta-analysis of 18 studies from six countries to examine analgesics use and its relation to the risk for renal cell carcinoma (RCC).

"Our meta-analysis was the largest analysis of analgesics and risk for RCC," Cho said. "Our study is the first few of those studies raising [the] possibility that these commonly used painkillers may elevate the risk for certain types of cancer."

Cho and colleagues conducted a Medline database search for case-control or cohort studies on acetaminophen, aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs), published between 1966 and July 1, 2011. They found 12 studies examining risk for acetaminophen, 12 for aspirin and five for NSAIDs.

Results demonstrated that any use of acetaminophen was associated with a 33 percent increased risk for RCC, and use of other NSAIDs was linked with a 26 percent increased risk. No significantly increased risk for RCC was found with the use of aspirin.

The meta-analysis revealed similar trends with high-dose analgesics intake. Researchers found no significant difference in associations based on study design, type of controls in case-control studies, study outcome or gender.

"The positive association with nonaspirin NSAIDs was somewhat expected since we recently published on the association from two prospective studies [in Archives of Internal Medicine], which were included in this meta-analysis," Cho said. "However, the association with use of acetaminophen was not found in the publication and was thus unexpected. Several relatively small studies of use of acetaminophen and RCC did suggest positive associations. When we conducted a meta-analysis of these studies to improve statistical power, the summary results came out statistically significant."