Tamoxifen-induced nonalcoholic steatohepatitis in breast cancer patients treated with adjuvant tamoxifen.
OBJECTIVE
The benefits of 5-year tamoxifen administration for patients with estrogen receptor-positive breast cancer undoubtedly outweigh the risk of any adverse effects. Massive hepatic steatosis is an example of its side effects. Here we show risk factors for the development of massive hepatic steatosis and describe a representative clinical course of these patients treated with fibrates for the first time.


METHODS
Computed tomography (CT) numbers of the liver and spleen were measured and correlated to body mass index (BMI) and pregnanetriol/pregnanediol ratio in urine (P3/P2 ratio).


METHODS
We enrolled 56 premenopausal women treated with breast conservation treatment. They received oral tamoxifen (40 mg/day for 2 to 3 years) as adjuvant endocrine therapy with systemic chemotherapy.


RESULTS
Serum estradiol level in 48 of 56 patients treated with tamoxifen was less than 10 pg/ml. The ratio of hepatic CT number to splenic CT number<0.9 was related to increased BMI (>23.6 kg/sqm) and reduced P/P2 ratio (<1). Fibrates are potent enough to improve hepatic steatosis in tamoxifen-induced hepatic steatosis.


CONCLUSIONS
P3/P2 ratio<1 was related to sufficient blockade of estrogen receptor proven by the development of massive hepatic steatosis. Therefore, we propose that tamoxifen is not a mere antagonist of estrogen, but it may also suppress estrogen synthesis when estrogen receptor is blocked sufficiently. The undetectable level of serum estrogen in tamoxifen-treated premenopausal women may partially explain why tamoxifen was so effective in estrogen receptor-positive early breast cancer.
Nemoto
Yoshihisa
Y
Department of Internal Medicine, Kochi Medical School, Nankoku.
Saibara
Toshiji
T
Ogawa
Yasuhiro
Y
Zhang
Ting
T
Xu
Nan
N
Ono
Masafumi
M
Akisawa
Naoaki
N
Iwasaki
Shinji
S
Maeda
Takashi
T
Onishi
Saburo
S
D000328:Adult; D018931:Antineoplastic Agents, Hormonal / Q000009:adverse effects* / Q000627:therapeutic use; D001629:Bezafibrate / Q000627:therapeutic use; D001943:Breast Neoplasms / Q000188:drug therapy*; D056487:Chemical and Drug Induced Liver Injury, Chronic / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000209:etiology*; D004958:Estradiol / Q000097:blood; D005234:Fatty Liver / Q000139:chemically induced* / Q000000981:diagnostic imaging / Q000188:drug therapy; D005260:Female; D006801:Humans; D000960:Hypolipidemic Agents / Q000627:therapeutic use; D013629:Tamoxifen / Q000009:adverse effects* / Q000627:therapeutic use; D014057:Tomography, X-Ray Computed
D018931:Antineoplastic Agents, Hormonal; D000960:Hypolipidemic Agents; D013629:Tamoxifen; D004958:Estradiol; D001629:Bezafibrate