Surgical Considerations for Patients With De Novo Metastatic Breast Cancer Based on Prognostic Group.

INTRODUCTION

Advances in systemic therapy for de novo metastatic breast cancer (dnMBC) led to the development of a novel staging system (IVA-D), which stratifies patients into prognostic subgroups based on tumor characteristics and metastatic extent. Overall survival (OS) varies between subgroups; therefore, different treatment approaches may be considered. This study explores the association of surgery of the primary tumor with OS among prognostic subgroups.

METHODS

Patients with dnMBC (2010-2020) receiving systemic therapy were selected from the National Cancer Database (NCDB) and stratified by prognostic stage group (IVA-D). A landmark analysis was employed with OS defined as the time from diagnosis, plus 12 mo, to death due to any cause. Kaplan-Meier methods, log-rank tests, and adjusted Cox models evaluated OS differences and associations.

RESULTS

Among 42,824 patients, subgroups included IVA 7.3%, IVB 55.7%, IVC 27.4%, and IVD 9.5%. Surgery receipt varied by subgroups: IVA 34.5%, IVB 23.7%, IVC 21.5%, and IVD 29.8% (P < 0.001). After adjustment, surgery was associated with younger age, fewer comorbidities, and private insurance (all P < 0.05). Median OS varied: IVA 84.5 mo, IVB 49.4 mo, IVC 30.8 mo, and IVD 15.3 mo. Among those with IVA disease, surgery patients had better unadjusted 5-y OS (77.5% versus 49.7%, log rank P < 0.001). Despite lower absolute survival in advanced stages (IVB-D), surgery remained associated with significantly higher OS. Adjusted analysis confirmed surgery's association with improved OS (hazard ratio (HR) 0.60, 95% confidence interval (CI) 0.57-0.63).

CONCLUSIONS

Surgery of the primary tumor may be associated with better survival for selected patients with dnMBC, and future prospective studies may consider exploring this association using prognostic subgroups.