A class of drugs that prevents bone loss may also help reduce women’s risk of developing endometrial cancer, according to a new study published online December 22 in Cancer.
Women who had a history of taking bisphosphonates were about half as likely as women who had not taken the drugs to develop endometrial cancer.
The study looked only at bisphosphonates that contain nitrogen, which have the strongest anticancer effects among the class of drugs, according to prior studies.
Sharon Hensley Alford, PhD, from the Department of Public Health Sciences, Henry Ford Hospital, Detroit, Michigan, and colleagues looked at data from 29,254 women aged 60 years and older in the National Cancer Institute’s Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial. The survey included a questionnaire on bone health and use of medications, including bisphosphonates.
Among the women who had used bisphosphonates, the researchers saw 8.7 cases of endometrial cancer per 10,000 person-years, compared with 17.7 cases per 10,000 person-years among women who had never used the drugs (rate ratio, 0.49; 95% confidence interval, 0.30 – 0.80).
After adjusting for a variety of variables, including age, race, smoking history, hormone therapy history, and body mass index, the hazard ratio for women taking the drugs compared with those not taking them was 0.56 (95% confidence interval, 0.34 – 0.93).
Endometrial cancer is the fourth most common cancer in women and the eighth most common cause of cancer death. Nearly half of all gynecologic cancers are endometrial. Endometrial cancer is most often diagnosed in women in their 60s and 70s, when they are postmenopausal and their bone density has decreased.
Previous research showed that bisphosphonates can slow tumor growth and the spread of cancer cells in patients with certain types of cancer, but no study had specifically looked at endometrial cancer.
The study’s main findings focused on the more common type 1 endometrial cancer, which is related to high estrogen levels. Researchers called for further studies with a larger sample to better assess the drug’s relationship to the more aggressive type 2 endometrial cancer, which is not hormonally related.