Impact of Primary Tumor Surgery on Survival in Breast Cancer Patients With Bone Metastases: A SEER-Based Analysis

Breast cancer with bone metastases represents an advanced disease state with limited long-term survival. The role of primary tumor surgery in patients who already present with metastatic disease remains controversial. This study evaluated the impact of surgical resection of the primary breast tumor on overall survival among women with breast cancer and bone metastases using a large population-based cohort.

Data were extracted from the Surveillance, Epidemiology, and End Results (SEER) database (1992–2022). Female patients diagnosed with primary breast cancer and synchronous bone metastases at presentation were included. Demographic, tumor-related, and treatment characteristics were analyzed. Overall survival (OS) was compared between patients who underwent surgical resection of the primary tumor versus those who did not using Kaplan–Meier curves with log-rank testing. Multivariable Cox proportional hazards models were used to identify independent predictors of OS.

A total of 6,046 eligible patients with breast cancer and bone metastases were identified; approximately 25% underwent primary tumor surgery. Kaplan–Meier analysis demonstrated significantly improved OS in the surgery group compared with those who did not undergo surgery (p < 0.0001). At 1, 3, and 5 years, the surgical cohort showed consistently higher survival rates. In multivariable analysis, surgery remained an independent predictor of improved OS (adjusted HR < 1), after controlling for age, race, marital status, tumor grade, chemotherapy, and radiation therapy. Additional favorable prognostic factors included younger age, hormone receptor–positive histology, lower tumor grade, and receipt of systemic therapy.

Primary breast tumor surgery is associated with substantial improvement in overall survival among women presenting with breast cancer and synchronous bone metastases. These findings support a potential role for locoregional surgical management in carefully selected metastatic patients as part of a multimodal treatment approach. Prospective studies are needed to clarify optimal patient selection and therapeutic sequencing.