A recent article in the Archives of Internal Medicine reports that oral hormone therapy is associated with the risk of ovarian cancer in women who have not undergone a hysterectomy.
Ovarian cancer is a malignancy that arises from various different cells within the ovaries. Approximately 25,000 new cases of ovarian cancer are diagnosed in the United States each year. Unfortunately, ovarian cancer often goes undetected until the disease has progressed into the abdomen or spread to other organs. The average lifetime risk for developing ovarian cancer is about 2%. Risk factors that may increase this average include a positive family history of ovarian cancer; age (since most ovarian cancer is diagnosed after menopause); obesity; a history of breast cancer; and hormone replacement therapy.
In this recent study, researchers conducted a nationwide, population-based study in Denmark. Women ages 35-79 with ovarian cancer that had been diagnosed between January 1, 1995 and May 30, 1999 were matched with a control group of women of the same age. Analysis included 376 cases of women who had not undergone hysterectomy as well as 1,111 controls.
Results of the study indicate that the risk of ovarian cancer in relation to hormone therapy was increased with the cumulative intake of estrogen replacement, but not with the progesterone component. A simple trend was found that for each additional gram of estrogen, there was the same relative risk increase. After researchers adjusted for other risk factors that the women may have had, a significant increase in the risk of ovarian cancer remained, which corresponded with the use of hormone replacement therapy.
Researchers concluded that oral hormone replacement therapy is associated with an increased risk of ovarian cancer in women who have not undergone hysterectomy. Further analysis concluded that this risk is associated with the cumulative oral estrogen intake and not the duration of the hormone therapy. This indicates that minimizing the daily dose of the estrogen component of the hormone therapy may decrease the risk of developing ovarian cancer risk. Patients may wish to discuss their risk factors for ovarian cancer and the use of hormone therapy with their physician.
Reference: Glud E, Kjaer S, Thomsen B, et al. Hormone Therapy and the Impact of Estrogen Intake on the Risk of Ovarian Cancer. Archives of Internal Medicine. 2004; 164: number 20.