Oral contraceptives and the risk of focal nodular hyperplasia of the liver: a case-control study.

OBJECTIVE: A role of female hormones, including oral contraceptives, has been suggested in the etiology of focal nodular hyperplasia of the liver. There is, however, no epidemiologic quantification of this relationship. STUDY DESIGN: A hospital-based case-control study was conducted in Italy of 23 women with histologically confirmed focal nodular hyperplasia of the liver and 94 controls in the hospital for acute diseases. Odds ratios (ORs) were computed by use of multiple logistic regression models. RESULTS: Focal nodular hyperplasia was not associated with menstrual and reproductive factors. Ever oral contraceptive use was reported by 83% of cases and 59% of controls. The multivariate OR was 2.8 (95% confidence interval [CI], 0.8-9.4) for ever use, and 4.5 (95% CI, 1.2-16.9) for use > or = 3 years. The trend in risk with duration was statistically significant. CONCLUSIONS: This study confirms previous clinical observations, and provides a quantitative estimate of the association between use of oral contraceptives and focal nodular hyperplasia of the liver.