Ethnic and regional differences in the temporal trends of prostate cancer incidence and mortality in New Zealand

Background: Prostate cancer (Pca) is the most frequently diagnosed cancer in New Zealand (NZ) men and the third leading cause of cancer deaths. Temporal changes in Pca incidence and mortality have not been reported despite changes in the Pca landscape. This study aims to analyse the temporal trends in Pca with focus on ethnic and regional variations. Methods: The study cohort was identified from the NZ Cancer Registry and the mortality collection databases. Men who were diagnosed with Pca between 2000 and 2018 were included in the incidence analysis. Men who died from Pca between 2000 and 2015 were included in the mortality analysis. Other data collected were ethnicity and geographical information. Pca incidence and mortality were calculated as age-standardized rates using the 2001 World Health Organization population. Results: A total of 58 966 men were diagnosed (incidence: 105.2 per 100 000) and 14 749 men died (mortality: 49.3 per 100 000) from Pca. When compared to European men, Maori and Asian men had significantly lower Pca incidence. Mortality rates demonstrated a steady decline, which was more prominent until 2010. Maori and Pacific men had higher mortality rates when compared to European men. In most recent years, the difference in mortality is decreasing for Maori but increasing for Pacific men. There were no regional differences in mortality. Conclusion: Pca incidence in NZ has fluctuated over the last 20 years, while mortality rates have shown to steadily decline. Pca mortality was shown to disproportionately affect Maori and Pacific men.