Primary tumor resection in de novo metastatic breast cancer from an oligometastatic perspective: A systematic review and meta-analysis

Whether patients with de novo metastatic breast cancer (de novo MBC) benefit from primary tumor resection (PTR) is controversial, and the efficacy of treatment of primary tumor in patients with oligometastases is uncertain. A comprehensive search was conducted for studies published from January 1, 2008 to January 1, 2024 that compared PTR with no PTR for de novo MBC that quantified the extent of metastasis. Ten studies and 83,559 patients with de novo MBC were included. A meta-analysis showed a significant improvement in overall survival after PTR compared with no PTR (hazard ratio [HR], 0.60; 95% confidence interval [CI], 0.53-0.67; p < 0.00001). Similar results were seen in patients with 1 metastatic organ, ≤2 metastatic organs, and ≤3 metastatic organs. Oligometastatic patients are expected to be a beneficial subgroup for PTR in patients with MBC, especially when metastasis occurs in only one organ.