Advanced age and prostate cancer specific mortality among geriatric patients with metastatic prostate cancer.

Abstract

319 Background: Data from clinical trials has shown that octogenarians are at increased risk for prostate cancer specific mortality (PCSM). Patients with significant comorbidities were excluded from the trials; consequently, the findings from clinical trials may not be applicable to the general population. Data on patients age 80+ with metastatic prostate cancer in the general population are limited. This population-based study assesses PCSM for metastatic prostate cancer patients diagnosed at age 70+. Methods: Using the Surveillance, Epidemiology, and End Results (SEER) database, identified 418,982 patients diagnosed with prostate cancer at age 70+ between 01/01/2004-12/31/13, of which 12,749 had metastatic prostate cancer. The SEER database covers about 28% of the US population from all racial/ethnic groups. We used Cox proportional hazards (PH) model to calculate cause specific hazard ratio adjusted by age, race, marital status, urban-rural classification, income level, insurance type, primary cancer therapy, stage, and diagnosis period. Results: Of the 12,749 patients, 49.4% of the patients were in their 70's and 8.3% in their 90's+, with 79.1% of patients white and 57.1% married. About 17% of these patients received radiotherapy as their primary cancer treatment. The distribution of M1 subtype is: M1a (4.2%), M1b (68.5%), M1c (22.7%), M1 Not Otherwise Specified (or NOS,4.6%). The median survival for patients with M1 prostate cancer aged 70-79, 80-89 and 90+ were 25, 15, and 7 months, respectively. Compared to patients diagnosed in their 70's, there was 38% and 109% increase in PCSM among those diagnosed at ages 80-89 and 90+ respectively (Table). Conclusions: PCSM increases among geriatric patients with metastatic prostate cancer after accounting for potential confounding factors. Further investigation is needed to shed light on the underlying biological mechanisms. [Table: see text]