Smoking is one of the major risk factors for the development of bladder cancer and is also associated with cardiac disease, hyperlipidemia, and atherosclerosis.
Consequently, it is not uncommon for patients with bladder cancer to have concomitant cardiac disease and hyperlipidemia. The 3-Hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors (statins) are widely used in the treatment of hyperlipidemia and, in fact are available as over the counter drugs in some countries due to a perceived significant impact on overall mortality from cardiac disease.
In the January issue of the New England Journal of Medicine, Hoffmann and colleagues reported on a series of patients with bladder cancer who were treated with BCG. Of the 84 patients, 19 were also receiving statin therapy. After a median follow-up of 46 months, it appeared that patients receiving statin therapy had a higher incidence of disease progression (10 of 19 (53%) versus 12 of 65 (18%), p = 0.004). The number of recurrences did not differ significantly between the groups. While a larger number of patients on statin therapy underwent radical cystectomy, among the patients who underwent radical cystectomy, the number in whom metastases developed and the time to their development were similar in the two groups. The authors concluded that 'Our observations suggest that the discontinuation of statin therapy during BCG immunotherapy might improve the clinical outcome'.
In the March issue of NEJM, Kamat and Wu reported on the outcomes of a cohort of 156 patients who received BCG treatment; 39 took statins during BCG, and 117 did not. After a median follow-up: 56 months, there was no difference in recurrences (59% in both groups, p = 0.801), tumor progression (30% vs. 28%, p = 0.57) or deaths. Furthermore, there was no difference in outcomes, even when accounting for whether patients received only induction BCG therapy or induction BCG plus maintenance therapy.
At the current time, treating urologists and patients should view the available data as inconclusive, at best. This is especially important since patients with bladder cancer commonly use statins, and some reports have documented antiproliferative effects of statins urothelial cancer cell lines. Further more, since it has been shown that discontinuation of statin therapy can have adverse cadiac outcomes, it seems prudent to continue statin therapy in bladder cancer patients who are on BCG, until more robust data to suggest otherwise are presented.