SUO 2017: Prostate Cancer Incidence, Treatment Trends, and Survival Among American Indians and Alaskan Natives in The U.S

Washington, DC ( Carissa Chu, MD discussed prostate cancer incidence and treatment trends for American Indians and Alaska Natives (AI/AN). These minority groups face significant disparities in cancer care with lower rates of screening, delayed diagnosis, decreased treatment access, and worse overall survival. Studies show that AI/AN men may have a lower incidence of prostate cancer (PCa) than white men, yet the highest mortality of any racial group1. The objective of this study was to characterize incidence, treatment, and survival of prostate cancer within this population using a population-level analysis. 
The authors utilized the Surveillance, Epidemiology, and End Results (SEER) database linked with Indian Health Service Contract Health Service Delivery Areas (CHSDA) data to study prostate cancer incidence, treatment patterns, and predictors of mortality. Variables of interest included demographics, PSA, Gleason score, clinical T-stage at diagnosis, calculated Cancer of the Prostate Risk Assessment (CAPRA-9) score, primary treatment, county characteristics, and prostate cancer-specific mortality. Survival analysis was performed using Cox proportional hazards model.
There were 302,354 men identified from 2000 to 2011 followed for a median time of 5.7 years. Compared to white men, AI/AN men were more likely to be diagnosed with higher stage disease (3.9% vs. 2.9% cT3-T4, p<0.0001), higher median PSA (6.9 ng/dL vs 6.1 ng/dL, p<0.0001) and higher Gleason score (8.0% vs 6.0% Gleason 9-10 p<0.0001). AI/AN men were also more likely to be diagnosed with metastasis at diagnosis than both African American and white men (2.4% vs. 1.6% vs. 2.0%, respectively, p<0.0001). Using an adjusted multivariate analysis, AI/AN patients were less likely than white men to undergo radical prostatectomy (36.6% vs 43.1%, p=0.0055) or any treatment (24.9% vs 17.0%, p<0.001). When stratified by CAPRA-9 stage, AI/AN men consistently had higher rates of mortality than all other groups. Adjusted 5-year prostate cancer-specific mortality was highest among AI/AN compared with white or African American men (3.1% vs 2.0% vs 2.5%, respectively).        

Carissa concluded that AI/AN men present with higher risk PCa, are less likely to undergo definitive treatment, and are more likely to die from their disease. Possible mechanisms for these disparities include access to screening care, provider diversity and geographical constraints, however, a role for tumor biology cannot be excluded. 

  1. Hoffman RM, Li J, Henderson JA, et al. Prostate cancer deaths and incident cases among American Indian/Alaska Native men, 1999-2009. Am J Public Health 2014;104(Suppl 3):S439-445.

Presented by: Carissa Chu, MD, Department of Urology, UCSF, San Francisco, CA
Co-Authors: Michael Leapman, Shoujun Zhao, Janet Cowan, Matthew Cooperberg

Written by: Zachary Klaassen, MD, Urologic Oncology Fellow, Society of Urologic Oncology Fellow, University of Toronto, Princess Margaret Cancer Centre at the 18th Annual Meeting of the Society of Urologic Oncology, November 20-December 1, 2017 – Washington, DC