Child and adolescent/young adult cancer incidence and survival for Māori in Aotearoa New Zealand

Abstract

Cancer does not occur equally within populations, and this is also true within children and young adults. In this study we draw-together comprehensive national health record data to describe cancer incidence and survival for Māori children and adolescents/young adults (AYA), and compare this with the experience of Europeans. All incident cases of cancer diagnosed between 2007 and 2019 among those aged less than 25 years old at the time of diagnosis were extracted from the New Zealand Cancer Registry. Cancer incidence numbers and rates were compared between Māori and European children/AYA. We also used Kaplan-Meier (1, 3 and 5-year cancer-specific survival) and Cox proportional hazards models (hazard ratios) to compare survival outcomes between these groups. We found differences between Māori and Europeans in terms of propensity toward certain types of child/AYA cancers: Māori are more likely to be diagnosed with poorer-prognosis cancers (like CNS/brain) and less likely to be diagnosed with good-prognosis cancers (like Hodgkin's lymphoma and melanoma). Māori are less likely to survive their cancer once diagnosed even after adjusting for differences in cancer type, with the extent of survival disparities differing depending on the cancer under investigation, noting that these cancer-specific observations were prone to precision problems due to low absolute numbers of deaths. Further quantitative and qualitative research on the drivers of survival disparities, particularly in the context of access to early diagnosis and treatment, could usefully inform actions aimed at improving survival for Māori and addressing disparities.

Keywords: AYA cancer; Child cancer; Indigenous cancer; Māori cancer; Paediatric cancer.