Survival Outcomes for Breast Cancer Patients with Liver Metastases: A Population-Based Study of 3,549 Patients

Abstract

There are limited published data on the risk factors, incidence, and survival in breast cancer patients with liver metastases. In this study, we aim to utilize the Surveillance, Epidemiology, and End Results (SEER) database to further explore the impact of liver metastases in patients with Stage IV breast cancer. Using the SEER 18 registries, we included 14,932 patients diagnosed with Stage IV breast cancer from 2010-2014 with metastatic disease to the lung, bone, liver, and brain. Kaplan-Meier analyses and multivariate Cox proportional hazard models were utilized to assess the impact of liver metastases on overall survival (OS). The median OS for the entire cohort was 29 months with 43.3% of patients alive at 3 years. 3,549 (23.8%) patients had metastases to liver and 1,045 (7%) patients had liver metastases without involvement of the bone, lung or brain. Patients recorded as having liver metastases in the absence of brain, lung, or bone metastases (HR = 1.36, CI 1.24-1.49, P <0.001), as well as patients recorded as having liver metastases plus additional sites had worse OS than all comers with M1 disease not recorded as in the liver. The median OS for patients with liver metastases at time of diagnosis was 20 months versus 32 months for patients without liver metastases. For patients with liver metastases without involvement of the lung, bone, or brain, median OS was 27 months with only 16% patients alive at 3 years. For patients with liver and lung metastases, median OS was 15 months with only 7.5% patients alive at 3 years. This population-based hypothesis-generating analysis suggests that Stage IV breast cancer patients with liver metastases have worse OS and may benefit from aggressive upfront therapies. These findings may inform future therapeutic investigations to improve the prognosis of breast cancer patients harboring hepatic metastases at presentation.