Retrospective evidence has suggested that removing the primary breast tumor in patients diagnosed with de novo metastatic breast cancer (MBC) might improve outcomes, yet randomized controlled trials (RCTs) have produced inconsistent findings. This analysis aimed to determine whether surgery of the primary tumor extends survival in this setting. We conducted a systematic literature search to identify RCTs comparing surgical excision of the primary breast tumor with no surgery in patients presenting with de novo MBC. Searches were performed in the Cochrane Library, Embase, Medline (OVID), and Web of Science, most recently updated in July 2023, and supplemented by manual review of conference abstracts. Extracted data included patient demographics, tumor features, and clinical outcomes. A random-effects meta-analysis was applied to account for heterogeneity across studies. Out of 3255 identified records, 5 RCTs met the inclusion criteria, encompassing 1381 patients. In the pooled intention-to-treat population, surgical removal of the primary tumor did not improve overall survival (HR = 0.93; 95% CI, 0.76–1.14). No subgroups defined by receptor status or metastatic pattern showed survival benefit, except for younger or premenopausal patients (HR = 0.74; 95% CI, 0.58–0.94). Surgery was associated with better local progression-free survival (HR = 0.37; 95% CI, 0.19–0.74). Overall, excision of the primary tumor does not confer a survival advantage in de novo MBC, though younger or premenopausal patients may benefit. The role of surgery should be explored within the context of rigorously designed clinical trials.
