Which patients with localized prostate cancer account for the greatest proportion of prostate cancer deaths?

Abstract

130 Background: We sought to determine which groups of patients, stratified by risk group and age, account for the greatest absolute number of deaths due to prostate cancer. Methods: Using the Surveillance, Epidemiology, and End Results (SEER) database, we identified 437,150 men diagnosed with prostate cancer from 2004 to 2014. Men were excluded if they had N1 or M1 disease, risk group could not be determined, or if prostate cancer was not their first malignancy. Men were categorized as having low (Gleason ≤6, prostate-specific antigen [PSA] < 10 ng/mL, and cT1-T2a), intermediate (Gleason 7, PSA 10-20 ng/mL, or cT2b-T2c), or high risk disease (Gleason 8-10, PSA > 20 ng/mL, or cT3-T4). We calculated the cumulative incidence of prostate cancer-specific mortality (PCSM). Results: Median follow-up was 4.8 years. The overall incidences of diagnosis of low, intermediate, and high risk disease were 29.7% (n = 129,925), 48.0% (n = 209,643), and 22.3% (n = 97,582), respectively. 5-year PCSM for men with low, intermediate, and high risk disease was 0.5%, 1.4%, and 9.4%, respectively, and the 10-year PCSM was 1.6%, 4.0%, and 16.8%. Within 10 years of diagnosis, 6.5% (n = 905) of patients who died of prostate cancer were low risk, 27.4% (n = 3,834) were intermediate risk, and 66.2% (n = 9,278) were high risk. In particular, patients age 70 or older accounted for 49.9% of all high risk prostate cancer diagnoses, but 65.3% of deaths due to high risk prostate cancer. Conclusions: While high risk disease accounted for only 22.3% of the diagnoses, it accounted for 66.2% of the prostate cancer deaths within 10 years of diagnosis. Therefore, high risk patients account for the vast majority of prostate cancer deaths and should remain the focus of the majority of our research efforts. In addition, older patients with high risk disease die of prostate cancer at a disproportionately high rate, which runs counter to the notion that the disease is less of a threat to survival in older men.