Clinical features and prognosis of patients with first-episode liver metastasis of different molecular subtypes of breast cancer

Abstract

To investigate the clinical features and prognosis of patients with first-episode liver metastasis of different molecular subtypes of breast cancer and risk factors for liver metastasis of breast cancer. A retrospective analysis was performed for 122 breast cancer patients with first-episode liver metastasis from January 2009 to January 2014. According to the cell surface receptors of breast cancer, these patients were divided into the four molecular subtypes of Luminal A, Luminal B, human epidermal growth factor receptor 2 (HER2) overexpression, and triple-negative breast cancer (TNBC). The association of patients' age at initial diagnosis, body mass index (BMI), menstruation status, clinical TNM (cTNM) stage, levels of lactate dehydrogenase (LDH) and alkaline phosphatase (ALP) at recurrence, liver metastasis, and treatment condition with the patients' prognosis were analyzed. The chi-square test and Fisher's exact test were used for categorical data, the Kaplan-Meier method was used for survival analysis, the log-rank test was used for univariate analysis of influencing factors, and the Cox regression model was used for multivariate analysis. Among the 122 patients, 12 had Luminal A subtype, 61 had Luminal B subtype, 30 had HER2 overexpression subtype, and 19 had TNBC subtype. In the patients with Luminal A, Luminal B, HER2 overexpression, and TNBC subtypes, the median disease-free survival (DFS) was 32, 23, 16, and 10 months, respectively (P = 0.001), the median overall survival (OS) was 54, 35, 26, and 13 months, respectively (P = 0.003), and the median OS after liver metastasis was 30, 16, 10, and 9 months, respectively (P = 0.019). In HER2-positive patients, the application of trastuzumab in the past significantly prolonged the patients' DFS by 11 months and OS by 18 months (P < 0.05). The results of the multivariate analysis showed that cTNM stage, molecular subtype, and targeted therapy were independent influencing factors for DFS of breast cancer patients with liver metastasis (P < 0.05), and that BMI, increased LDH at recurrence, cTNM stage, molecular subtype, salvage chemotherapy, radiotherapy, and targeted therapy were independent influencing factors for OS of breast cancer patients with liver metastasis (P < 0.05). The patients with TNBC, HER2 overexpression, and Luminal B subtypes exhibited worse prognosis and had a risk of recurrence 15.97, 8.81, and 4.76 times higher than those with Luminal A subtype. The risk of death in the patients with TNBC, HER2 overexpression, and Luminal B subtypes was 8.42, 6.02, and 3.86 times that in those with Luminal A subtype. The prognosis of breast cancer patients with first-episode liver metastasis is associated with the increase in LDH when liver metastasis occurs, BMI, cTNM stage, and molecular subtype. Compared with the patients with Luminal subtypes, those with HER2 overexpression and TNBC subtypes tend to develop liver metastasis in early stage and have a shorter OS. Salvage chemotherapy, targeted therapy, and radiotherapy can significantly improve the prognosis of patients with liver metastasis.