Risks and benefits of the contraceptive pill. A review of the results of an Italian study

The association between oral contraceptives (o.c.) and disease risk was reviewed on the basis of data from a network of a case-control studies conducted in northern Italy since the early 1980's on about 150 cases below age 55 with acute myocardial infarction, 150 with gallstone disease, 350 with uterine fibromyoma, 170 with endometrial cancer, 700 with benign or malignant ovarian tumours, 2000 with breast cancer, 360 with intraepithelial and 370 with invasive cervical cancer, 20 with liver cancer plus over 2000 control women admitted to hospital for acute, non hormone-related non neoplastic diseases. The relative risk (RR) of myocardial infarction was 2.1 (95% confidence interval from 0.7 to 7.1) among current o.c. users, but only 4% of women were current users. There was no association between gallstone disease, uterine fibromyoma and o.c. use. Significant protections were observed with reference to endometrial cancer and benign, borderline and malignant ovarian tumours, while the RR was above unity (RR = 1.9) for invasive cervical cancer, but not for intraepithelial cervical neoplasia. A significantly increased risk was observed for primary liver cancer, which is however extremely rare in young women. With reference to breast cancer, there was no consistent duration-risk relationship, and the RR was 0.8 for use for 5 or more years. Thus, these data provide reassuring information on the relationship between o.c. use and the risk of several important diseases in a Southern European population.