Differences in survival between Maori and New Zealand Europeans with prostate cancer

This study aims to examine the survival disparity between Maori men and New Zealand (NZ) Europeans diagnosed with prostate cancer. We identified men aged 40+ years in the Midland Cancer Network region registered with prostate cancer in 2007-2010 in the Cancer Registry. Data were extracted from patient notes of all Maori men and a sample of NZ Europeans. The survival disparity between Maori men and Europeans was estimated by the Kaplan-Meier method and Cox proportional-hazards regression models after adjusting for other factors. This study included 535 men with prostate cancer (135 Maori men and 400 Europeans). The 5-year cancer-specific survival was 98.6% for men diagnosed with localised cancer, 88.8% for locally advanced disease and 19.1% for metastatic cancer. The all-cause survival and the cancer-specific survival were both significantly poorer for Maori men than for NZ Europeans (log rank test: P=0.004, 0.006 respectively). The hazard ratio of cancer-specific survival for Maori men was 2.01 (95% CI: 1.21-3.36) compared with NZ Europeans. Maori men with prostate cancer had poorer all-cause survival and cancer-specific survival than NZ Europeans. Maori men were at risk of having more advanced disease at diagnosis, which explains most of the survival inequity between Maori men and NZ Europeans.