The increasing burden of uterine cancer and the role of overweight and obesity: an Australian study — The Association Specialists
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  3. The increasing burden of uterine cancer and the role of overweight and obesity: an Australian study

The increasing burden of uterine cancer and the role of overweight and obesity: an Australian study (23838)

Rebecca G Harris 1 , Chuyao Jin 1 , Rohan Lourie 2 , Louise Wilson 3 , Renhua Na 1 4 , Penelope M Webb 1 4 , Susan J Jordan 1 4
  1. School of Public Health, The University of Queensland, Brisbane, QLD, Australia
  2. Mater Pathology, Mater Health Services, South Brisbane, QLD, Australia
  3. Australian Women and Girls Health Research Centre, School of Public Health, The University of Queensland, Brisbane, QLD, Australia
  4. Population Health Program, QIMR Berghofer, Brisbane, QLD, Australia

Background
Uterine cancer incidence is increasing globally, potentially due to rising obesity prevalence. However, incidence and mortality trends by age and histological subtype and the proportion attributable to overweight and obesity have not been well studied.

Methods
We sourced counts of uterine cancer cases by subtype and deaths from the Australian Institute of Health and Welfare. Incidence and mortality rates (2001-2020) were calculated for women aged 25 and older, corrected for hysterectomy prevalence. Trends were analysed using joinpoint regression to estimate average annual percentage changes (AAPCs) across the study period. We calculated population attributable fractions (PAFs) for overweight and obesity and incidence overall and separately for each subtype for the years 2001, 2010 and 2020.

Findings
Incidence of uterine cancer increased from 28.64 to 34.27 per 100,000 women between 2001-2020 (APC:0.83, 95% CI: 0.60, 1.06). Endometrioid cancer similarly increased (AAPC:0.70, 95% CI: 0.35, 1.04) but a larger increase was observed for serous cancers (AAPC:4.26, 95% CI: 2.22, 5.98). Uterine cancer mortality also increased over time (AAPC:0.99, 95% CI: 0.51, 1.50). In 2020, PAFs for overweight/obesity were 49% for endometrioid and 25% for serous cancers, increasing from 31% and 12% respectively in 2001. Increased overweight and obesity prevalence likely completely explained the increasing incidence of endometrioid cancer, but only partly explained changes in incidence of serous cancers and cancers in women aged <55 years.

Interpretation
While increases in adiposity likely explain much of the rise in uterine cancer incidence in Australia, increases in mortality are likely driven by increases in aggressive serous carcinomas, which may not be fully attributable to overweight and obesity. Further research is needed to identify factors contributing to the upward trend in incidence of aggressive serous carcinomas and early onset cancers.