Alternative antiandrogen therapy in patients with castration‐resistant prostate cancer: A single‐center experience

Outcomes of alternative (second‐line) antiandrogen therapy in 112 patients with relapsing prostate cancer after first‐line hormonal therapy were analyzed. A good response (prostate‐specific antigen [PSA] decrease ≥50%) and a partial response (PSA decrease of 0–50%) by switching from bicalutamide (BCL) to flutamide (FLT) and from FLT to BCL were achieved in 35.4% (28/79) and 30.4% (24/79), and in 45.0% (9/20) and 20.0% (4/20) of cases, respectively. A good response and a partial response with the change from chlormadinone acetate (CMA) to a non‐steroidal antiandrogen (FLT or BCL) and from a non‐steroidal antiandrogen to CMA were obtained in 25.0% (2/8) and 37.5% (3/8), and in 20.0% (1/5) and 0% (0/5) of cases, respectively. In multivariate analyses, a second‐line good response was significantly predictive of cause‐specific survival from first therapy relapse to cancer death in all patients. Patients (52/112, 46.4%) with ≥30% decrease in PSA levels were associated with significantly better cause‐specific survival as measured from the start of first‐line treatment and first‐line relapse.