Toremifene-induced fatty liver and NASH in breast cancer patients with breast-conservation treatment

We have described fatty liver, diagnosed by computed tomography scanning (C T) in more than 30% of patients with breast cancel who received tamoxifen. Therefore, it is urgent to elucidate the frequency and the degree of fatty liver induced by toremifene, an analogue of tamoxifen, which is also used i n br east cancer. We enrolled 52 breast cancer patients who were treated wi th breast-conservation treatment and administered oral toremifene for 3-5 y ears as adjuvant endocrine therapy. We evaluated the degree of fatty liver by abdominal CT performed annually. CT demonstrated toremifene-induced fatt y liver in four (7.7%) of 52 breast cancer patients. Toremifene-induced fat ty liver did not correlate with abnormal levels of AST, ALT, GGT or total c holesterol. One patient who demonstrated moderate fatty liver by CT was his tologically diagnosed as non-alcoholic steatohepatitis (NASH) by liver biop sy. The incidence of toremifene-induced fatty liver was significantly lower than that induced by tamoxifen. Accordingly, in terms of fatty liver and N ASH, toremifene is considered to be more appropriate agent than tamoxifen. Though toremifene is less likely to induce fatty liver, the possibility rem ains that toremifene-induced steatohepatitis occurs. Because the diagnosis of fatty liver or NASH can be easily missed if only a blood test is perform ed, it is necessary to screen fatty liver by annual CT examination for pati ents who receive an antiestrogen agent.