The impact of non-structured PSA testing on prostate cancer-specific mortality on New Zealand Māori men

To assess the impact of differences in Prostate-Specific Antigen (PSA) testing rates on prostate cancer (PCa) diagnosis and PCa-specific mortality among Māori men in a New Zealand (NZ) population.

Māori men aged 40 years or older, without a history of PCa, with a PSA test between 2006 and 2018 were included. The cohort was divided into two groups; the "screened group" (ScG) consisting of men who had at least one PSA test every four years or less, and the "non-screened group" (non-SG). We measured the rate of cancer diagnoses and used competing risk analysis to assess survival.

The study cohort included 63,939 Māori men, with 37,048 (58%) in the ScG. PCa was more frequently diagnosed in the ScG (3.7% vs. 3.0%, P < 0.001). A higher proportion of high-grade cancers were found in the non-SG (32.7% vs. 25.6%, P = 0.001). The 10-year cancer-specific survival was significantly higher in the ScG (99.4% vs. 98.5%, P < 0.001). In a multivariable risk model, PSA testing frequency was an independent predictor of PCa mortality. (HR 2.43, [95% CI 1.97-3.01], P < 0.001).

In a cohort of only Māori men, lower PSA testing rates were associated with a higher risk of PCa-related death. Therefore, regular PSA testing for Māori could improve cancer-specific survival among Māori men. Regular PSA testing should be considered a priority area for improving PCa survival in this population.