Useful predictors of progression‐free survival for Japanese patients with LATITUDE‐high‐risk metastatic castration‐sensitive prostate cancer who received upfront abiraterone acetate

OBJECTIVE: Recently, hormonal therapy using abiraterone acetate, a second‐generation androgen receptor axis‐targeted agent, was reported to improve overall survival and progression‐free survival in men with LATITUDE‐high‐risk metastatic castration‐sensitive prostate cancer. This observational multicenter study aimed to assess the efficacy of upfront abiraterone acetate in Japanese patients with LATITUDE‐high‐risk metastatic castration‐sensitive prostate cancer. METHODS: The present study included 112 Japanese patients with LATITUDE‐high‐risk metastatic castration‐sensitive prostate cancer who received upfront abiraterone acetate at four institutions belonging to the Tokai Urologic Oncology Research Seminar group, between January 2018 and September 2020. Progression‐free survival and overall survival were assessed, and Cox regression analyses were carried out to evaluate the prognostic significance of upfront abiraterone acetate for progression‐free survival. RESULTS: Within a median follow‐up period of 13 months, the progression‐free survival and overall survival rates were 76.8% and 89.3%, respectively. Both univariate and multivariable Cox regression analyses showed that the presence of Gleason pattern 5, performance status and hemoglobin were independent predictors of progression‐free survival. The patients were subsequently divided into three groups as follows: group 1, 17 patients negative for these three independent progression‐free survival predictors; group 2, 49 patients with one positive independent progression‐free survival predictor; and group 3, 45 patients with two or three independent progression‐free survival predictors. Progression‐free survival was significantly different among these three groups (P < 0.001). CONCLUSION: Upfront abiraterone acetate might provide satisfactory outcomes for Japanese patients with LATITUDE‐high‐risk metastatic castration‐sensitive prostate cancer. Gleason pattern 5, performance status and hemoglobin are potential predictors of progression‐free survival in Japanese patients with LATITUDE‐high‐risk metastatic castration‐sensitive prostate cancer who received upfront abiraterone acetate.