When used to prevent breast cancer recurrence, tamoxifen doubles the risk of non-alcoholic steatohepatitis in overweight women, according to the results of a recent randomized, double-blind trial; but three's no evidence to suggest progression to cirrhosis after following patients for about 9 years.

To reach that conclusion, Italian researchers randomly assigned about 5,400 healthy women who had had hysterectomies to receive either 20 mg tamoxifen or placebo daily for five years. During follow-up, 64 women saw their alanine aminotransferase levels climb at least twice in 6 months. Of these, 12 tested positive for hepatitis C virus and 52 (34 tamoxifen, 18 placebo) were confirmed by ultrasonography to have non-alcoholic fatty liver disease (hazard ratio 2.0).

Those women who were overweight, obese, had hypercholesterolemia, or arterial hypertension were 2.4, 3.6, 3.4, and 2.0 times as likely, respectively, to develop non-alcoholic fatty liver disease as those with none of these conditions.

Bruno S, Maisonneuve P, Castellana P, et al. Incidence and risk factors for non-alcoholic steatohepatitis: prospective study of 5408 women enrolled in Italian tamoxifen chemoprevention trial. BMJ. 2005;330:932-935.