The preventable burden of endometrial and ovarian cancers in Australia: A pooled cohort study

Gynecol Oncol. 2019 Jun;153(3):580-588. doi: 10.1016/j.ygyno.2019.03.102. Epub 2019 Mar 29.

Abstract

Objective: Evidence on the endometrial and ovarian cancer burden preventable through modifications to current causal behavioural and hormonal exposures is limited. Whether the burden differs by population subgroup is unknown.

Methods: We linked pooled data from six Australian cohort studies to national cancer and death registries, and quantified exposure-cancer associations using adjusted proportional hazards models. We estimated exposure prevalence from representative health surveys. We then calculated Population Attributable Fractions (PAFs) with 95% confidence intervals (CIs), accounting for competing risk of death, and compared PAFs for population subgroups.

Results: During a median 4.9 years follow-up, 510 incident endometrial and 303 ovarian cancers were diagnosed. Overweight and obesity explained 41.9% (95% CI 32.3-50.1) of the endometrial cancer burden and obesity alone 34.5% (95% CI 27.5-40.9). This translates to 12,800 and 10,500 endometrial cancers in Australia in the next 10 years, respectively. The body fatness-related endometrial cancer burden was highest (49-87%) among women with diabetes, living remotely, of older age, lower socio-economic status or educational attainment and born in Australia. Never use of oral contraceptives (OCs) explained 8.1% (95% CI 1.8-14.1) or 2500 endometrial cancers. A higher BMI and current long-term MHT use increased, and long-term OC use decreased, the risk of ovarian cancer, but the burden attributable to overweight, obesity or exogenous hormonal factors was not statistically significant.

Conclusions: Excess body fatness, a trait that is of high and increasing prevalence globally, is responsible for a large proportion of the endometrial cancer burden, indicating the need for effective strategies to reduce adiposity.

Keywords: Cohort; Endometrial cancer; Ovarian cancer; Population attributable fraction; Preventable; Risk factors.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adiposity
  • Adolescent
  • Adult
  • Age Factors
  • Aged
  • Aged, 80 and over
  • Australia / epidemiology
  • Body Mass Index
  • Cohort Studies
  • Contraceptives, Oral / therapeutic use
  • Diabetes Mellitus / epidemiology*
  • Endometrial Neoplasms / epidemiology*
  • Endometrial Neoplasms / prevention & control
  • Female
  • Health Surveys
  • Hormone Replacement Therapy
  • Humans
  • Incidence
  • Menopause
  • Middle Aged
  • Obesity / epidemiology*
  • Ovarian Neoplasms / epidemiology*
  • Ovarian Neoplasms / prevention & control
  • Protective Factors
  • Registries
  • Residence Characteristics
  • Risk Factors
  • Rural Population
  • Socioeconomic Factors
  • Young Adult

Substances

  • Contraceptives, Oral