A population-based cohort study on sun habits and endometrial cancer

Br J Cancer. 2009 Aug 4;101(3):537-40. doi: 10.1038/sj.bjc.6605149. Epub 2009 Jun 23.


Background: No large cohort study has examined the risk of endometrial cancer in relation to sun exposure.

Methods: A population-based cohort study of 29,508 women who answered a questionnaire in 1990-92, of whom 24,098 responded to a follow-up enquiry in 2000-02. They were followed for an average of 15.5 years.

Results: Among the 17,822 postmenopausal women included, 166 cases of endometrial cancer were diagnosed. We used a multivariate Cox regression analysis adjusting for age and other selected demographic variables to determine the risk of endometrial cancer. Women using sun beds >3 times per year reduced their hazard risk (HR) by 40% (0.6, 95% confidence interval (CI) 0.4-0.9) or by 50% when adjusting for body mass index or physical activity (HR 0.5, 95% CI 0.3-0.9), and those women who were sunbathing during summer reduced their risk by 20% (HR 0.8 95% CI 0.5-1.5) compared with women who did not expose themselves to the sun or to artificial sun (i.e., sun beds).

Conclusion: Exposure to artificial sun by the use of sun beds >3 times per year was associated with a 40% reduction in the risk of endometrial cancer, probably by improving the vitamin D levels during winter.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Cohort Studies
  • Endometrial Neoplasms / prevention & control*
  • Female
  • Humans
  • Middle Aged
  • Multivariate Analysis
  • Risk Factors
  • Sunlight*
  • Vitamin D / administration & dosage


  • Vitamin D