Location of Metastases in Contemporary Prostate Cancer Patients Affects Cancer-Specific Mortality

We reported the effect of location of metastases on cancer-specific mortality and other-cause mortality in contemporary metastatic prostate cancer patients relying on competing-risks methods. Analyses were additionally performed after stratifying for age group. We showed that concomitant visceral, bone, and lymph node metastases have the worst prognosis. Purpose: To quantify the prognostic effect of the location of prostate cancer (PCa) metastases on cancer-specific mortality (CSM) and the rate of other-cause mortality (OCM) in contemporary newly diagnosed metastatic PCa (mPCa) patients. Patients and Methods: Within the Surveillance Epidemiology and End Results database (2004-2014), we focused on newly diagnosed mPCa patients. Data were stratified according to the site of metastases and age group. Cumulative incidence smoothed plots were generated for CSM and OCM at 5 years after diagnosis, according to the competing-risks methods. Multivariable competing-risks analyses tested the effect of the location of PCa metastases on CSM. Results: Among 18,404 patients with mPCa, the majority had exclusively bone metastases (63.6%). At 5 years, CSM rate was 59.7% and OCM rate was 14%. According to the location of metastases, CSM rates were 44.5%, 57.9%, 67.1%, 62.7%, 66%, and 76.3% for exclusively lymph node (LN), exclusively bone, bone plus LN, exclusively visceral, visceral plus LN, and visceral plus LN and bone disease, respectively. In multivariable competing-risks models, PCa-specific mortality rate was 1.58-, 1.79-, 1.91-, 2.10-, and 2.47-fold higher in patients with exclusively bone, bone plus LN, exclusively visceral, visceral plus LN, and visceral plus bone and LN involvement compared to those with exclusively LN metastases (all P <.001). Conclusion: Patients with concomitant visceral, bone, and LN metastases have the worst prognosis. Similarly, when either bone or visceral metastases coexist with concomitant LN metastases, CSM rates are higher than when no concomitant LN metastases are present.