Patterns of care and outcomes in small cell carcinoma of the prostate: A national cancer database analysis

BACKGROUND: Small cell carcinoma (SCC) of the prostate is a rare, aggressive disease. Evidence is limited; however, the current standard of care is chemotherapy. The benefit of local treatment modalities is unknown. METHODS: We queried the National Cancer Database identifying all SCC/neuroendocrine cases of the prostate, excluding those with unknown nodal or metastatic status, unknown treatment, or those not receiving chemotherapy. Overall survival (OS) was calculated using Kaplan-Meier curves. Multivariable Cox proportional hazards model was used to identify factors associated with survival. A further subgroup analysis was performed on the utility of local therapy on survival in the nonmetastatic setting. RESULTS: Our final cohort included 657 patients with a median age of 68. Most patients had positive lymph nodes (60.1%) and metastatic disease (70.0%). Median survival was 12 months (95% confidence interval [95% CI], 11.1-13.3 months) with a median follow-up of 11.8 months. Metastatic disease, age greater than or equal to 70, omission of androgen deprivation therapy (ADT), and lower income (P < .05 for all) were all associated with reduced OS. Patients with prostate-specific antigen (PSA) greater than or equal to 33 ng/mL and those receiving ADT had better survival (P < .05). Those with nonmetastatic disease were more likely to undergo prostatectomy and/or prostatic/pelvic radiation (P < .0001). Prostatic/pelvic radiation in the nonmetastatic setting was associated with longer survival (P = .02). Though well powered, our study is limited by the selection bias inherent to all observational studies, despite the statistical methods utilized to reduce this effect. CONCLUSIONS: Although chemotherapy is the mainstay of treatment, radiation to the prostate/pelvis may be beneficial in the nonmetastatic setting. In addition to chemotherapy, ADT may benefit patients with an elevated PSA.