Finasteride e carcinoma mammario nell'uomo. Prima segnalazione di sospetta ADR in Italia

Finasteride is indicated for the treatment and control of Benign Prostatic Hyperplasia (BPH). It works by selectively inhibiting 5-alpha-reductase, an enzyme that metabolizes intracellular transforming testosterone into dihydrotestosterone (DHT), a molecole with greater androgenic activity. Breast cancer in male is a very rare condition with an estimated incidence in the general population of 1 case out of 100,000 person-years. In the literature some cases of finasteride-associated gynecomastia and breast cancer are available. We describe the clinical case, reported by a general practitioner in the province of Ferrara, of a patient with BPH who has been diagnosed with breast cancer following treatment with finasteride (Finastid®). In the National Network of Pharmacovigilance, which collects reports of suspected adverse drug reactions, this is the first report of male breast cancer patients treated with finasteride: the Naranjo algorithm for the causality assessment, suggests a drug-reaction relationship. Breast cancer in male patients induced by administration of finasteride is probably a very rare complication but it should be considered in case of any changes in breast tissue, such as lumps, pain or discharge and promptly reported.