Identification and Validation of the Prognostic Impact of Metastatic Prostate Cancer Phenotypes

Castration-sensitive metastatic prostate cancer is heterogeneous. Our objective is to identify metastatic prostate cancer phenotypes and their prognostic impact on survival.The National Cancer Database was queried. The Surveillance, Epidemiology, and End Results database was used for validation. Patterns were split into: nonregional lymph node, bone only, and visceral (any brain/liver/lung). Hazard ratios (HR) with 95% confidence intervals (CI) were calculated for the univariate and multivariate Cox proportional hazards regression models, odds ratios were calculated, Kaplan-Meier curves were generated, and a nomogram of the multivariate regression model was created.The training set included 13,818 men; bone only was most common (n = 11,632, 84.2%), then nonregional lymph node (n = 1388, 10.0%), and any visceral (brain/liver/lung; n = 798, 5.8%). Risk of death was increased by metastases to a visceral organ versus nonregional lymph node (HR = 2.26; 95% CI [2.00, 2.56]), bone only metastases versus nonregional lymph node (HR = 1.57; 95% CI [1.43, 1.72]), T-stage 4 versus 1 (HR = 1.27; 95% CI [1.17, 1.36]), Grade Group 5 versus 1 (HR = 1.93; 95% CI [1.61, 2.31]), PSA20 ng/mL versus10 ng/mL (HR = 1.32; 95% CI [1.23, 1.42]), and age ≥ 80 versus50 (HR = 1.96; 95% CI [1.69, 2.29]). On internal validation, the model had C-indices 20.5%, 22.7%, and 14.6% higher than the current staging system for overall survival, 1-year, and 5-year survival, respectively.We developed and validated prognostic metastatic prostate cancer phenotypes that can assist risk stratification to potentially personalize therapy. Our nomogram (https://tinyurl.com/prostate-met) may be used to predict survival.