EDITORIALS Does Size Matter? Association Between Number of Patients Treated and Patient Outcome in Metastatic Testicular

There is increasing evidence that, in the treatment of ad-vanced testicular cancer, centers that do not treat a certain “criti-cal mass ” of patients may not achieve optimal treatment out-come. In this issue of the Journal, Collette et al. (1) further substantiate and extend past observation by finding that, in a large (n 4 380) four-arm European Organization for Research and Treatment of Cancer/Medical Research Council (EORTC/ MRC) trial for “poor-prognosis ” metastatic nonseminomatous germ cell tumors (GCTs) (2), patients treated at institutions ac-cruing fewer than five patients to the trial had an inferior failure-free and overall survival compared with that among patients treated at institutions accruing five or more patients. These re-sults are disconcerting, given the high cure rate of GCTs and the widespread knowledge of treatment success. The first highly successful clinical trial for the treatment of advanced testicular cancer was initiated in 1974 (3). Within 4 years after this trial was started, survival rates for patients with advanced testicular cancer in the National Cancer Institute’s Surveillance, Epidemiology, and End Results (SEER)1 popula-tion-based cancer registry program had improved dramaticall