Prognosis and Treatment of Metastatic Breast Cancer From A Real-World Scenario in China: A Retrospective Cohort Study

OBJECTIVES: Although metastatic breast cancer (MBC) is considered incurable, a specific subset of patients exhibits prolonged survival and even achieve a “cure”. We retrospectively identified predictive prognostic factors and systemic therapy models to find this group of potentially cured patients. METHODS: Consecutive patients diagnosed with MBC from 1991-2016 in West China Hospital were included. Univariate and multivariate analyses were conducted to assess the association of clinical factors and systemic therapy models with overall survival (OS), breast cancer-specific survival (BCSS) and progression-free survival (PFS). RESULTS: The median OS was 63.4 months. Age, tumor size, lymph node metastasis, histologic grade, molecular subtype, site and number of metastases and metastasis-free interval (MFI) were related to the prognosis of MBC (P < .05). Patients with T1, N0-1, luminal A, bone metastasis, OMBC (oligometastatic breast cancer) or metastasis-free interval (MFI) ≥ 3 years showed the median OS more than 10 years (P < .001). Independent prognostic factors that correlated with OS and BCSS were residence, lymph node metastasis, histologic grade, molecular subtype, and site of metastasis (P < .05). The group of sequential chemo-endocrine therapy (ST) in hormone receptor (HR)-positive MBC patients showed the highest overall response rate (ORR) (P < .05). However, patients who received endocrine therapy (ET) showed the best OS, BCSS and PFS in the first two-line treatment, followed by ST and chemotherapy (CT) (P < .05). CONCLUSIONS: Our study shows the predictive prognostic factors and systemic therapy models to facilitate patients likely to achieve long-term survival.