What about Enbrel? My mom was on it for rheumatoid arthritis and got lymphoma. According to the prescribing information,
"Patients have been observed in clinical trials with ENBREL® for over five years. Among 4462 rheumatoid arthritis patients treated with ENBREL® in clinical trials for a mean of 27 months (approximately 10000 patient-years of therapy), 9 lymphomas were observed for a rate of 0.09 cases per 100 patient-years. This is 3-fold higher than the rate of lymphomas expected in the general population based on the Surveillance, Epidemiology, and End Results Database.10 An increased rate of lymphoma up to several fold has been reported in the rheumatoid arthritis patient population, and may be further increased in patients with more severe disease activity11, 12 (emphasis mine).
I guess the question is how much increased risk is tolerable in a drug? To me, a 3-fold higher risk of cancer is not acceptable in the least, no matter what the benefit of the drug is (in my mom's case, the drug worked wonderfully for her arthritis).