The risk of breast, cervical, endometrial and ovarian cancer in oral contraceptive users

Abstract

Oral contraceptives, mainly combined monophasic pills, are widely used by young women who expect their physicians to prescribe them safe drugs which will not harm their health and which will simplify their life. Numerous epidemiologic studies have been performed to determine the relation between oral contraceptive use and the development of neoplasms. An increased incidence of breast cancer has occurred simultaneously with the growing use of oral contraceptives. The possibility of a link between the oral contraceptive use and breast cancer has led to intensive research, but studies have provided inconsistent results causing confusion among clinicians. It was noticed that the risk of breast cancer was slightly elevated in current and recent young oral contraceptives users. That finding could be influenced by a detection bias or could be due to the biologic effect of the pills. The absolute number of additional breast cancer cases will be very small because of low baseline incidence of the disease in young women. Oral contraceptives probably promote growth of the already existing cancer, they are probably promoters not initiators of breast cancer. The available data do not provide a conclusive answer that is needed. Numerous factors may influence the development of cervical cancer. The evidence suggests that current and recent oral contraceptive users have an increased risk of cervical cancer which decline after discontinuation of the application of medication. Oral contraceptives might increase the biological vulnerability of the cervix. Cervical cancer develops slowly over a long time period and can be effectivelv prevented by periodic cervical screening. Fortunately, oral contraceptives do not mask abnormal cervical citology. Conclusions regarding invasive cervical cancer and oral contraceptive use are not definitive but if there is any increased risk, it is low. In oral contraceptive users the endometrium is almost under the influence of progestin component which suppresses endometrial mitotic activity and its proliferation. Most epidemiologic studies show that oral contraceptives reduce the risk of endometrial cancer and that this protective effect exists many years after the discontinuation of medication. It has been long known that the oral contraceptive use causes protective anovulation and reduces the risk of ovarian cancer. This powerful reduction is the best demonstrated major benefit of oral contraception. This protection is especially observed in nulliparous and seems to persist for many years after the discontinuation of medication.