Risk of fatty liver and hepatic fibrosis associated with long-term use of tamoxifen or anastrozole may be overestimated in patients with breast cancer

Abstract Background Nonalcoholic fatty liver disease (NAFLD) is prevalent among women with breast cancer. The impact of endocrine therapy on the severity and progression of NAFLD in the long term remains unclear. Aims To assess the prevalence and severity of NAFLD related to hormone therapy for breast cancer, and to investigate risk factors associated with its occurrence and progression. Methods Cross-sectional study recruited women with breast cancer. Abdominal ultrasound was used to detect liver steatosis, and transient elastography to evaluate fibrosis. Results 171 patients were enrolled – mean age 58 ± 10 years and follow-up period 1-315 months (median 53, interquartile range 25–102). Comorbidities: diabetes (26.9%), hypertension (53.2%), dyslipidemia (31.0%) and obesity (70.2%). Four groups were formed: 55 (32.2%) patients unexposed to hormone therapy, 72 (42.1%) exposed only to tamoxifen, 16 (9.4%) only to anastrozole, and 28 (16.4%) to both drugs. Liver steatosis was detected in 57.9%, with no significant differences between groups (p = 0.092). Liver stiffness was similar between groups: median 5.4 kPa (p = 0.200), 12.3% with liver stiffness ≥ 8 Kpa (p = 0.568) and 5.8% ≥12 Kpa (p = 0.177). Diabetes was independently associated with steatosis, and metabolic syndrome with advanced fibrosis, even after adjustment for hormone therapy duration. Conclusion More than half of patients had NAFLD, and approximately 10% had advanced fibrosis. Metabolic risk factors were independently associated with occurrence and progression of NAFLD, regardless of hormone therapy exposure. The risk of NAFLD induced by tamoxifen and anastrozole seems to have been previously overestimated.