Risk Factors for Endometrial Cancer, What Women Should Know
If 2010 is anything like 2009, about 42,000 new cases of endometrial cancer will be diagnosed, and nearly 8,000 women will die of the disease. As we remember those who have succumbed to the disease, including actress Dixie Carter, it is important that women understand the risk factors for endometrial cancer that may prevent them from being one of these statistics.
Most of the risk factors for endometrial cancer involve hormones, a natural relationship since hormone fluctuations throughout a woman’s life cause the endometrium to change. The endometrium is the inner layer or lining of the uterus. Estrogen causes the endometrium to thicken in preparation for pregnancy, but if no pregnancy occurs, progesterone prompts the innermost layer of the endometrium to shed during menstruation. Nearly all cancers of the uterus begin in the endometrium and are referred to as endometrial carcinomas.
One risk factor for endometrial cancer is use of estrogen-only hormone replacement therapy. However, when estrogen is combined with progesterone, the combination does not increase the risk of endometrial cancer. Other estrogen-related circumstances that increase the risk of endometrial cancer include early menstruation, late menopause, and never being pregnant, all situations that expose a woman to estrogen for a longer period of time.
Use of tamoxifen is another risk factor for endometrial cancer. Tamoxifen is a selective estrogen receptor modulator (SERM), a drug that acts like estrogen in selected locations in the body. Tamoxifen is used to treat breast cancer because it blocks the effects of estrogen in breast tissue, but it also increase the risk of endometrial cancer. This risk is greater in postmenopausal women.
Women who have polycystic ovary syndrome (PCOS) have an increased risk of endometrial cancer. Polycystic ovary syndrome, according to the American Congress of Obstetricians and Gynecologists, is a condition in which women produce an excess amount of male sex hormones. Many women with PCOS also produce too much insulin, another hormone, which tends to make them gain weight or to have a difficult time losing weight. PCOS is a lifelong condition and requires treatment to help prevent women from getting endometrial cancer, diabetes, and heart disease.
Obesity is yet another risk factor. Although the exact reason is not known, the increased risk may be related to high estrogen levels. A study published in the Journal of the National Cancer Institute reported that obese women had an average concentration of estrogen that was 50 to 219 percent higher than that seen in thin women. Obesity is also related to other risk factors, including polycystic ovary syndrome, lack of physical exercise, and a high-fat diet.
Women can also inherit a risk for endometrial cancer. A condition called hereditary nonpolyposis colon cancer syndrome is caused by changes in certain genes. Women who have this inherited syndrome have a much greater risk of developing endometrial cancer than women who do not have the syndrome.
Women can also take protective measures against endometrial cancer. For women who choose to use hormones, contraceptives and hormone replacement therapy should contain both estrogen and progesterone (progestin). Because both pregnancy and breastfeeding lower estrogen levels, they may lower the risk of endometrial cancer as well. Other protective measures are physical exercise, maintaining a healthy weight, and following a diet low in saturated fats.
American Cancer Society
American College of Obstetricians and Gynecologists
National Cancer Institute