According to an article in Obstetrics and Gynecology, women who used oral contraceptive pills containing low doses of both estrogen and progestin had a significantly reduced risk of ovarian cancer.
Ovarian cancer is the most deadly of gynecologic cancers. Early stages of ovarian cancer often do not cause recognizable symptoms. Furthermore, there are currently no standard screening measures for early detection of ovarian cancer. As a result, the majority of ovarian cancers are not detected until the disease has spread from its site of origin to distant sites in the body. Once ovarian cancer has reached these advanced stages, it is most often considered incurable with standard treatment approaches. In an effort to improve outcomes, research has focused on modifiable behaviors and other factors that may reduce the risk of developing ovarian cancer, particularly among women who may be at a high risk of developing the disease.
Results from previous clinical studies have indicated that use of oral contraceptive pills (OCPs) reduces the risk of developing ovarian cancer. Historically, OCPs contained much higher doses of the female hormones estrogen and progestin than they currently contain. Researchers from Hawaii recently conducted a clinical study to evaluate the potential association between low-dose OCPs and the development of ovarian cancer. This study included 745 women who had been diagnosed with ovarian cancer; they were compared to 943 women who did not have ovarian cancer.
- Women who had used low-dose OCPs containing both estrogen and progestin had an approximately 80% reduced risk of developing ovarian cancer compared with those who had never used OCPs.
- Women who used higher-dose OCPs containing both estrogen and progestin also experienced a reduced risk of developing ovarian cancer; however, this risk reduction was not as great as the reduction associated with lower-dose OCPs.
- Women who used OCPs containing progestin only at a dose of 10 mg or greater had an increased risk of developing ovarian cancer compared with those who had never used OCPs.
The researchers concluded that women who used low-dose OCPs containing both estrogen and progestin had a significantly reduced risk of ovarian cancer compared with women who had never used OCPs. Although higher doses of OCPs containing both estrogen and progestin also reduced the risk of ovarian cancer, this reduction was not as great as with lower-dose formulations.
Reference: Lurie G, Thompson P, McDuffie K, et al. Association of estrogen and progestin potency of oral contraceptives with ovarian carcinoma risk. Obstetrics and Gynecology. 2007; 109:597-607.