The report comes from recent research that pooled data from two large studies totaling 77,525 women and 49,403 men, for up to twenty years, wherein 333 people developed kidney cancer. Subjects that took a non-aspirin non-steroidal anti-inflammatory drug (non-aspirin NSAIDs, such as ibuprofen) twice or more per week were 51% more likely to develop kidney cancer than non-regular users. According to the news reports, this “is the second time this month that NSAIDs have been associated with health risks.”

However, the occurrence of renal cancer was very low in the groups studied: less than 0.3% in the 20-year follow-up period. Also, the study only looked at associations, which means we cannot determine any sort of cause beyond a reasonable doubt as to what actually brought on the kidney cancer. These details, although left out of the original news reports, give the study a strong sense of uncertainty.

What’s more, the cancer cases were further divided into how frequently they used NSAIDs; the reported tripling of cancer risk only applied to those who regularly used NSAIDs for more than ten years, a group which consisted of only 19 cancer cases. The link was only significant if the drugs were used regularly for a long period of time. To put this study in perspective, the absolute risk of kidney cancer is low. 

This study hails from the halls of Harvard Medical School and Brigham Women’s Hospital. Funding was graciously provided by the US National Institutes of Health, the Kidney Cancer Association and the Dana-Farber/Harvard Cancer Center Kidney Cancer Specialized Programs of Research Excellence. It was published in the journal Archives of Internal Medicine.

Despite the accurate coverage of this research, leading newspapers could have provided even better coverage by highlighting the fact the the absolute risk for cancer remained low, even after taking into account the effect of the drugs.

According to the researchers, painkillers are the most commonly used drugs in the country. (One could also say that other drugs, such as caffeine, alcohol, or tobacco, are more commonly used because they are more assimilated into out daily lives.) Still, some studies have demonstrated the potential health benefits of painkillers such as aspirin, ibuprofen, or other NSAIDs, included protection from cardiovascular disease and bowel cancer. This information must be considered in light of the new research on kidney cancer.

With both sides of the research brought to light, it seems reasonable to continue to use painkillers, if you need it. Anti-inflammatory drugs are beneficial because they remove inflammation, a large factor in disease. On the other hand, inflammation can be the body’s natural response to a threat. To play it safe, maintaining a a stress- and inflammation-free lifestyle by getting plenty of sleep, good food, and plenty of water will keep inflammation away.