Oral contraceptives and intrauterine devices (IUD) appear to provide long-term protection against endometrial cancer, researchers report in the International Journal of Cancer.
Overall, 223 of the cancer patients (18.5 percent) and 302 of the controls (24.9 percent) reported using an oral contraceptive.
After accounting for other known risk factors or protective factors for endometrial cancer, the use of oral contraceptives was associated with a 25 percent reduced risk. After 72 months, the cancer risk was reduced by 50 percent.
IUD use was associated with a 47 percent lower risk of endometrial cancer. The protective effect of IUDs, they add, may be prompted by “inflammatory actions that eliminate abnormal and precancerous endometrial cells; decreased abnormal cell growth — a known risk factor for endometrial cancer — and reduce the concentration of estrogen receptors.”
Endometrial cancer involves cancerous growth of the endometrium (lining of the uterus). It mainly occurs after menopause, and presents with vaginal bleeding. A hysterectomy (surgical removal of the uterus) is generally performed.
It is the most common gynecologic cancer in the United States, with over 35,000 women being diagnosed each year in the U.S. Because of effective screening, it is only the third most common cause of gynecologic cancer deaths (behind ovarian and cervical cancer).
The same risk factors for endometrial cancer predisposes women to endometrial hyperplasia, which is a precursor lesion for endometrial cancer. An atypical complex hyperplasia carries a 30% risk of developing endometrial cancer while a typical simple hyperplasia only carries a 2-3% risk.
Endometrial cancer is often referred to as uterine cancer, however the uterus may harbor other malignacies, including cervical cancer, sarcoma, and trophoblastic disease.