Purpose of This Summary
This PDQ cancer information summary for health professionals provides comprehensive, peer-reviewed, evidence-based information about endometrial cancer prevention. It is intended as a resource to inform and assist clinicians who care for cancer patients. It does not provide formal guidelines or recommendations for making health care decisions.
Reviewers and Updates
This summary is reviewed regularly and updated as necessary by the PDQ Screening and Prevention...
Endometrial cancer is the most common invasive gynecologic cancer in U.S. women, with an estimated 49,560 new cases expected to occur in 2013. This disease primarily affects postmenopausal women at an average age of 60 years at diagnosis. In the United States, it is estimated that approximately 8,190 women will die of endometrial cancer in 2013. Incidence rates of endometrial cancer have been increasing by an average of 1.1% per year from 2004 to 2008. Death rates from cancer of the uterine corpus have been increasing by an average of 0.3% per year from 1998 to 2007.
In the mid-1970s, the diagnosis of approximately 15,000 cases of postmenopausal endometrial cancers in excess of those expected on the basis of the underlying secular trend, has been related to the use of postmenopausal estrogen therapy. Additional risk factors may be related to estrogenic effects, including obesity, a high-fat diet, polycystic ovarian syndrome, tamoxifen use and reproductive factors such as nulliparity, early menarche, and late menopause.
Women with hereditary nonpolyposis colorectal cancer (HNPCC) syndrome have a markedly increased risk of endometrial cancer compared with women in the general population. Among women who are HNPCC mutation carriers, the estimated cumulative incidence of endometrial cancer ranges from 20% to 60%.[5,6]
Compared with white Americans, endometrial cancer incidence is lower in Japanese Americans (relative risk [RR] = 0.6; 95% confidence interval [CI], 0.46–0.83) and in Latinas (RR = 0.63; 95% CI, 0.46–0.87), but not in African Americans (RR = 0.76; 95% CI, 0.53–1.08) or in native Hawaiians (RR = 0.92; 95% CI, 0.58–1.46). Higher mortality from endometrial cancer in African Americans is at least partly attributable to lower socioeconomic issues that impair access to care.
Factors that have been associated with a decreased incidence of endometrial cancer include parity, lactation, use of combined oral contraceptives, a diet low in fat and high in plant foods, and physical activity.
Interventions Associated With Decreased Risk
Use of combination oral contraceptives (COC) for at least 1 year reduces endometrial cancer risk by approximately 40%, as demonstrated by case-control studies and prospective cohort studies.[9,10,11] This decrease in risk persists for at least 15 years after discontinuation of COCs. A meta-analysis of ten case-control studies and one prospective study found an association between risk reduction and duration of use. Overall, 4 years of COC use was associated with a risk reduction of approximately 56%; 8 years, 67%; and 12 years, 72%. The single-prospective study did not show a duration response, but the risk was reduced by 80% after 9 years of follow-up.