How diet, nutrition and physical activity affect endometrial (womb) cancer risk. In total, we analysed 159 studies from around the world.
The endometrium is the lining of the uterus. It is subject to a process of cyclical change during the fertile years of a woman’s life. The majority of cancers that occur in the body of the uterus (womb) are endometrial cancers, mostly adenocarcinomas.
In addition to the findings on diet, nutrition and physical activity outlined above, other established causes of endometrial cancer include:
Not bearing children and a late natural menopause (after the age of 55) both increase the risk of endometrial cancer. The reverse also applies: bearing children and early menopause reduce the risk of endometrial cancer.
Oral contraceptives, which contain either a combination of oestrogen and progesterone, or progesterone only, protect against endometrial cancer. Oestrogen-only hormone replacement therapy is a cause of this cancer and is normally only prescribed to women who have had a hysterectomy. Tamoxifen, a hormonal therapy used for breast cancer, can also cause endometrial cancer.
Women with a family history of endometrial or colorectal cancer have a higher risk of endometrial cancer. Lifetime risk of endometrial cancer in women with Lynch syndrome mutations MLH1 or MSH2 is approximately 40 per cent, with a median age of 49. Women with MSH6 mutations have a similar risk of endometrial cancer but a later age of diagnosis.
Pathogenesis: how does endometrial cancer develop?
Type 1 endometrial tumours are oestrogen driven, account for around 80 per cent of endometrial cancers, and have a favourable prognosis. They follow a clear development pathway, starting with endometrial hyperplasia (an increase in the number of cells), and are relatively well differentiated. Type 2 tumours are less common, accounting for around 10 per cent of endometrial cancers. Most are associated with endometrial atrophy (wasting), tend to metastasise, and have a less favourable prognosis.
Many cases of endometrial cancers are reported in women who have no recognised risk factors – such as those that might disrupt endocrine (hormone) processes. Some studies have shown that polycystic ovary syndrome and insulin insensitivity (or resistance), which are both components of metabolic syndrome, may play a role in the pathogenesis of endometrial cancer, perhaps through hormonal disruption. The tumour-suppressor gene PTEN is also involved in the development of endometrial cancers.
Full references and a summary of the mechanisms underpinning all the findings can be found in the endometrial cancer report.
In 2018, World Cancer Research Fund International published Diet, Nutrition, Physical Activity and Cancer: a Global Perspective on behalf of AICR, WCRF and WKOF. This was the third in our series of major reports looking at the many ways in which our diets, and how active we are, affect our cancer risk. You can find out much more about endometrial cancer by downloading a pdf of the relevant chapter in the 2018 report. Please note, however, that this webpage may have been updated since the report was published.
Published findings in peer-reviewed journals
Selected findings from this report have been published in peer-reviewed journals. Details of the papers and links to the abstract in PubMed are below:
Anthropometric factors and endometrial cancer risk: A systematic review and dose-response meta-analysis of prospective studies. Aune D, Navarro Rosenblatt D, Chan DS, Vingeliene S, Abar L, Vieira AR, Greenwood DC, Bandera EV & Norat T. Ann Oncol. 2015; 26(8): 1635-8. Abstract