Two long-term studies of health professionals have uncovered a disconcerting link between the use of certain popular pain relievers and the risk of kidney cancer. Over 77,000 nurses have been tracked for roughly 16 years and almost 50,000 men have been followed up for 20 years. The volunteers answered questions about diet, exercise and medication use every two years. The heaviest users of NSAID pain relievers other than aspirin were at greatest risk for kidney cancer. Overall, those who took drugs such as ibuprofen or naproxen on a regular basis were about 50 percent more likely to be diagnosed with renal cell carcinoma. The longer people used such pain relievers, the higher their risk. Those who had been taking an NSAID for 10 years or more nearly tripled their chance of developing a tumor.
Only 333 cases of renal cell carcinoma were reported among all these people during this time, so the absolute risk is very low. The investigators estimate that an additional case of kidney cancer would occur for approximately 10,000 people taking NSAIDs for a year. Neither aspirin nor acetaminophen was associated with any increased risk of kidney cancer.
