Aug. 1, 2002 -- Amid all the concerns about hormone replacement therapy, here's a bit of reassuring news. If women have taken it as long as five years, they haven't increased their risk of developing cancer of the endometrium, which lines the uterus.
In fact, the combination of estrogen plus progestin may actually protect women from endometrial cancer, writes lead researcher Michael Wells, MD, professor of gynecological pathology at the University of Sheffield in England. His study appears in the Aug. 3 British Medical Journal.
However, women should not take HRT just to avoid endometrial cancer, Roberta Ness, MD, MPH, director of the Epidemiology of Women's Health program at the University of Pittsburgh School of Public Health, tells WebMD.
"The cancer is very treatable with a hysterectomy," Ness says. "But women must see a doctor when they notice the primary symptom -- bleeding. Women should not ignore the bleeding. If the cancer gets into stage III or stage IV, beyond the uterine wall, it becomes very problematic."
Also, endometrial cancer cannot be detected on a Pap smear, Ness says. "Many women have the false impression that Pap smears detect ovarian and endometrial cancer, and that's just not true. Pap smears only detect cervical cancer."
''This study confirms that when women go on HRT for short-term relief of menopause symptoms, they're not going to increase their risk of uterine cancer, unless they're mistakenly taking estrogen only," says Debbie Saslow, PhD, director of breast and gynecological cancer at the American Cancer Society.
In many previous studies, estrogen-only HRT was shown to increase risk of endometrial cancer -- a threefold increase, says Ness.
In their study, Wells and colleagues tracked more than 500 postmenopausal women in 31 menopause clinics across the U.K.; 360 women were taking estrogen-progestin therapy; 164 took no HRT; and 10 took estrogen only.
At the end of five years, those taking estrogen-progestin HRT had no signs of precancerous cells or endometrial cancer. In fact, women who had been diagnosed earlier with precancerous endometrial cells actually experienced a reversal; those cells returned to normal.
"Women and their doctors need to be reassured that the long term use of hormone replacement therapy will not increase the risk of endometrial cancer," writes Wells.