Background Liver metastasis is a key adverse prognostic factor in breast cancer patients. This research was aimed to assess the development, risk factors, and prognostic determinants of breast cancer liver metastasis (BCLM). Methods We retrospectively analyzed the data of breast cancer from the Surveillance, Epidemiology, and End Results (SEER) ( N = 560,908) and Jiangsu Province Hospital (JSPH) database ( N = 294). The risk factors for BCLM were identified via multivariate logistic regression, and overall survival (OS) was assessed with Kaplan–Meier (KM) survival curves and Cox regression models. Results In the SEER cohort, liver metastasis attacked 1.3% of patients, and the highest incidence was found in the HR−/HER2+ subtype (4.4%). The risk factors for BCLM include young age, high pathological grade, concurrent bone, lung or brain metastasis, and HER2‐positive or triple‐negative subtype. The median OS of BCLM patients was short (SEER: 22 months; JSPH: 33.5 months). OS was shorter in patients with concomitant metastasis to other organs or with HER2‐negative subtype. Hepatic resection remarkably prolonged survival (SEER: 90 vs. 35 months; JSPH: not reached vs. 31.3 months). In the JSPH cohort, molecular subtype changed in 27.5% of patients during metastasis. Conclusions The occurrence of BCLM is affected by age, tumor grade, other organ involvement, and molecular subtype. Survival was improved in BCLM patients with liver‐only metastasis, HER2‐positive subtype, or those who underwent hepatic resection. The number and molecular characteristics of liver metastasis are important prognostic predictors, and receptor conversion highlights the need for reassessment of therapeutic strategies during metastatic progression.
Yu et al. (Thu,) studied this question.