Rapid increase in endometrial cancer incidence and ethnic differences in New Zealand

Endometrial cancer accounts for 3.9% of all female cancers globally, and its incidence appears to be increasing in women under 40 years of age. This paper investigated ethnic-specific trends in endometrial cancer across different age groups in New Zealand.

Women who were diagnosed with endometrial cancer between 1996 and 2012 were identified from the New Zealand Cancer Registry. Annual age-standardized incidence and mortality rates were calculated for each ethnicity (Māori, Pacific, and non-Māori non-Pacific) in four age groups (< 40, 40-49, 50-74, and 75 +). The estimates were adjusted for hysterectomy. Joinpoint regression analysis was used to assess trends over time and annual percentage changes (APCs) were estimated.

Between 1996 and 2012, age-standardized incidence rates increased in all women and significantly in the < 40, 40-49, and 50-74 age groups (APC 9.22, 3.56, and 1.65 respectively). Incidence rates were highest in Pacific women and increased most rapidly in those under 50 years of age (APC 9.36). Conversely, age-standardized mortality rates decreased in all women and significantly in the 50-74 and 75 + age groups (APC - 5.25 and - 5.06 respectively), with the highest rate observed in Pacific women.

Pacific women had the highest incidence of endometrial cancer and the trend was increasing, particularly in young women. This could be attributed, at least in part, to a high and increasing rate of obesity in these women and should be explored in future research.