If you regularly take painkillers, you may be putting yourself at an increased risk of developing kidney cancer.

Results of a study published in the Archives of Internal Medicine, September 2011 issue, suggest that men and women who take nonsteroidal anti-inflammatory drugs (NSAIDs), which include the over-the counter painkillers ibuprofen and naproxen, and the prescription Celebrex, are equally at risk, and the longer you use such drugs, the higher your cancer risk. Though aspirin is also an NSAID, no association was found between kidney cancer and aspirin use.

Kidney cancer is the seventh leading type of cancer among men and the ninth among women in the United States. Renal cell cancer (RCC) is the most common type of kidney cancer, accounting for 85 percent of all cases. The incidence of RCC has been rising in the U.S. and worldwide. The types of painkillers included in the study are among the most commonly used groups of drugs in the U.S..

It's important to note that the study did not prove that painkiller use causes cancer, and the difference between regular users and non-users in the study was small. Experts say that the overall risk is still quite low and they do not recommend that you should stop taking NSAIDs in the short term or that doctors should stop recommending them to patients who would benefit from them. However, participants who took NSAIDs other than aspirin, including ibuprofen and naproxen, were about 50 percent more likely than non-medication users to be diagnosed with the cancer.

Researchers including Eunyoung Cho, ScD, assistant professor of medicine at Harvard Medical School, examined the records of more than 77,000 women and nearly 50,000 men, all of whom were participants in one of these research studies: the Nurses' Health Study or the Health Professionals Follow-Up Study. The team looked at the relationship between painkiller use and kidney cancer risk. The studies tracked the use of these medications for 16 years and 20 years, respectively.

The risk of kidney cancer was highest in people who took NSAIDs regularly for ten or more years. The American Cancer Society estimates that about 64,770 new cases of kidney cancer (40,250 in men and 24,520 in women) will occur in 2012, and about 13,570 people (8,650 men and 4,920 women) will die from this disease. Renal cell cancer, the type that was studied, accounts for about 85 percent of all kidney cancers, which are often treatable if caught early.

Sources:

Prospective Evaluation of Analgesic Use and Risk of Renal Cell Cancer. Archives of Internal Medicine, Sep 12, 2011, Vol 171, No. 16
http://archinte.jamanetwork.com/article.aspx?articleid=1106087

American Cancer Society
http://www.cancer.org/Cancer/KidneyCancer/DetailedGuide/kidney-cancer-adult-key-statistics