Oral Contraceptives and Cancer Risk: Questions and Answers

 Some cancers depend on naturally occurring sex hormones for their development and growth. Researchers are interested in learning whether the hormones in oral contraceptives affect cancer risk in women (see Question 1).  Some studies have shown an increased risk of breast cancer in women taking oral contraceptives, while other studies have shown no change in risk (see Question 2).  Oral contraceptive use has been shown in multiple studies to decrease the risk of ovarian and endometrial cancer (see Question 3).  Oral contraceptives have been shown to increase the risk of cervical cancer; however, human papillomavirus is the major risk factor for this disease (see Question 4).  The risk of liver cancer is increased in women who take oral contraceptives and are otherwise considered low risk for the disease (see Question 5).