Treatment outcome after sequential chemotherapy with cisplatin-etoposide, amrubicin and nogitecan in patients with treatment-related pure small-cell neuroendocrine prostate cancer

Sequential chemotherapy with etoposide plus cisplatin (or carboplatin), amrubicin and nogitecan can be helpful for patients with treatment-related pure small-cell neuroendocrine prostate cancer. Objective This study retrospectively reviewed the clinical characteristics and treatment outcomes of patients with histologically diagnosed treatment-related pure small-cell neuroendocrine prostate cancer. Methods We retrospectively evaluated data for 13 patients with treatment-related neuroendocrine prostate cancer who were diagnosed between May 2015 and February 2022. Standardized systemic therapies of etoposide plus cisplatin (or carboplatin), amrubicin and nogitecan were selected as sequential treatments. Cancer-specific survival and progression-free survival were evaluated as the primary endpoint. The Cox proportional hazards model was used to evaluate the relationships between treatment regimens, clinical variables, cancer-specific survival and progression-free survival. Results The median cancer-specific survival after diagnosis for all patients was 22.4 months (range 1.3-33.4 months). The median progression-free survival was 9.3 months after first-line etoposide plus cisplatin (or carboplatin) treatment (n = 13); 4.2 months after second-line amrubicin treatment (n = 4); and >15 months after third-line nogitecan treatment (n = 2). The median progression-free survival after first-line chemotherapy of the liver metastasis (-) group was 10.2 months, and that of the (+) group was 5.3 months (P = 0.015, hazard ratio = 11.6, 95% confidence interval = 1.01 - 133.7). No clinicopathological parameters were identified as significant independent predictors of cancer-specific survival in univariate analysis. Conclusion Sequential chemotherapy with etoposide plus cisplatin (or carboplatin), amrubicin and nogitecan may be helpful for patients with treatment-related pure small-cell neuroendocrine prostate cancer. Early biopsy of metastases and initiation of effective therapy is essential for patients with progressive castration-resistant prostate cancer and low prostate-specific antigen.