Trends in uterine cancer incidence and mortality are influenced by factors that alter circulating estrogen and progesterone levels, including hormone replacement therapy and oral contraceptives. Risk of uterine cancer will increase if endometrial tissue is exposed to estrogen that is unopposed by progestogen.15,39,40 Thus, estrogen-replacement therapy (ERT), in which estrogen is given to postmenopausal women without any progestogen, increases uterine cancer risk. In the United States, a doubling of estrogen prescriptions (ERT) to treat menopausal symptoms beginning in 1966 resulted in the epidemic of endometrial cancer that ended in the late 1970s,41 when progestogens were increasingly added to ERT to reduce or possibly eliminate this risk. Rates peaked in 1975 among white women of all ages and African-American women under the age of 50 years; rates peaked among African-American women over 50 years old 2 years later in 1977. As a result of the epidemic, ERT for menopausal symptoms among women who had not had a hysterectomy was largely discontinued. Following these changes, incidence rates of uterine cancer decreased 26% from 1976 to 1987, when they began to stabilize. Incidence was slightly higher in 1998 than 1991 for both African-American and white women (2.0%, African Americans; 2.4%, whites); however, rates of uterine cancer in the 1990s were generally stable (Fig. 1.4).
In contrast to ERT, oral contraceptives decrease the risk of endometrial cancer. Oral contraceptives, which deliver an estrogen and a high-dose progestogen for 21 days of a 28-day cycle, diminish risk by decreasing the duration of exposure of the endometrium to estrogen unopposed by progestogen from the 2 weeks of a normal menstrual cycle to the 1 week when the oral contraceptive is not taken.42-44 Endogenous estrogen levels are low during the 7 days when the oral contraceptive is not used.
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Are Menopause Symptoms Playing Havoc With Your Health and Relationships? Are you tired of the mood swings, dryness, hair loss and wrinkles that come with the change of life? Do you want to do something about it but are wary of taking the estrogen or antidepressants usually prescribed for menopause symptoms?