Ethnic and socio-economic disparities in prostate cancer screening: lessons from New Zealand

Objectives To investigate the presence of ethnic and socio-economic disparities in prostate cancer (PCa) screening and identify its impact on cancer outcomes. Materials and Methods From January 2008 to December 2017, all men in the Northern region of New Zealand who had a prostate-specific antigen (PSA) test performed in the community were identified from the electronic laboratory reports database. Asymptomatic men, with no known diagnosis of PCa, were included. Variables collected were age, ethnicity, social deprivation, medical therapy, PSA test information and cancer data. Disparities were investigated by comparing the frequency of PSA testing, proportions of men screened, and rates of cancer detection, between Maori (indigenous) and non-Maori ethnic groups. Results The study cohort included 248 491 men, who each received approximately 3.45 PSA tests over the 10-year study period. Maori men were less likely to be tested compared to non-Maori men (25.4% vs 46.1% of the total aged-matched region population;P< 0.001). Moreover, they received less frequent PSA testing irrespective of their deprivation status (mean difference of 0.97 PSA tests per person;P< 0.001). The higher testing frequency in non-Maori men was associated with increased PCa diagnosis rates. Nevertheless, cancers detected in Maori men were 73% more likely to be of high grade (Gleason 8 or above), compared to those in non-Maori men. Conclusion There were significant ethnic disparities in PCa screening rates in the Northern region of New Zealand. Maori men, regardless of other demographic factors, were disproportionately affected. The difference in the rates of screening by ethnicity had influenced the incidence and clinical significance of the diagnosed cancers.