Oral contraceptives and hepatocellular carcinoma.

A series of 26 white women aged under 50 who developed hepatocellular carcinoma in a non-cirrhotic liver were studied for the possible role of oral contraceptives. Eighteen of the women had used the "pill" for a median of eight years. Over 1300 women whose use of the pill had been determined in another study served as controls. Patients and controls were divided into five age and four calendar groups and the relative risks associated with oral contraceptives calculated by multivariate analysis. Short term use of the pill was not associated with an increased risk of tumour development; nevertheless, use for eight years or more was associated with a 4.4-fold increased risk (p less than 0.01). When patients with markers of hepatitis B virus infection were excluded the relative risk was 7.2 (p less than 0.01). In both instances the absolute risk for developing hepatoma remained low.