The Role of Primary Tumor Resection in De Novo Bone-Only Metastatic Breast Cancer: A Propensity Score-Matched Analysis

Bin Wang; Shasha Liu; Zhidong Huang; Jinhui Wang; Xirui Zhou; Shuo Li; Jianan Chen; Hong Liu

doi:10.1002/jso.70277

The Role of Primary Tumor Resection in De Novo Bone-Only Metastatic Breast Cancer: A Propensity Score-Matched Analysis

J Surg Oncol. 2026 Apr 29. doi: 10.1002/jso.70277. Online ahead of print.

Authors

Bin Wang¹, Shasha Liu¹, Zhidong Huang¹, Jinhui Wang¹, Xirui Zhou¹, Shuo Li¹, Jianan Chen², Hong Liu¹

Affiliations

¹ The Second Surgical Department of Breast Cancer, Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Breast Cancer Prevention and Therapy, Tianjin's Clinical Research Center for Cancer, Tianjin Medical University, Tianjin, China.
² Department of Clinical Sciences, H. Lee Moffitt Cancer Center & Research Institute, Tampa, Florida, USA.

PMID: 42057318
DOI: 10.1002/jso.70277

Abstract

Objective: To evaluate the impact of primary tumor resection (PTR) on overall survival (OS) and cancer-specific survival (CSS) in women with de novo bone-only metastatic breast cancer (MBC).

Methods: Women diagnosed with de novo bone-only metastatic breast cancer between 2010 and 2017 were identified from the Surveillance, Epidemiology, and End Results (SEER) database. Patients were included if they had bone metastasis at diagnosis but no lung, liver, or brain involvement. Primary tumor resection was defined as any cancer-directed breast surgery. Propensity scores were calculated using multivariable logistic regression incorporating demographics, tumor features, and treatment factors, followed by 1:1 nearest-neighbor matching (caliper = 0.2 SD). Kaplan-Meier, Cox proportional hazards, and restricted mean survival time (RMST) analyses assessed overall survival (OS) and cancer-specific survival (CSS). Time-dependent ROC curves (timeROC) evaluated model discrimination. Determinants of PTR were examined using multivariable logistic regression.

Results: A total of 3296 women with de novo bone-only metastatic breast cancer were included (1252 with PTR; 2044 without). After 1:1 matching, 2002 well-balanced patients remained (1001 per group). Median OS and CSS were significantly longer among patients undergoing surgery (OS: 69 vs. 39 months; CSS: 76 vs. 41 months; both p < 0.0001). PTR remained an independent predictor of improved OS (HR = 0.54, 95% CI 0.48-0.60, p < 0.001), with consistent benefit across subgroups. RMST differences (surgery - no surgery) increased with time, reaching 9.05 months for OS and 8.79 months for CSS at 60 months. Model discrimination was acceptable (AUCs for OS: 0.753, 0.734, 0.717 at 1-, 3-, and 5-years). Radiation therapy was positively associated with PTR (OR = 1.37, 95% CI 1.12-1.68, p = 0.002), whereas well/moderate grade predicted lower odds (OR = 0.80, 95% CI 0.66-0.99, p = 0.036).

Conclusions: In this large SEER-based propensity-matched analysis, primary tumor resection was associated with significantly improved overall and cancer-specific survival among women with de novo bone-only metastatic breast cancer. These findings suggest that selected patients with isolated bone metastasis may benefit from locoregional surgery, warranting further prospective validation.

Keywords: SEER program; metastatic breast cancer; primary tumor resection; propensity score matching; survival analysis.