Role of Surgery in Metastatic Breast Cancer: Insights from a Narrative Review

Metastatic breast cancer is difficult to cure and has a worse prognosis with higher rates of mortality. Recently, breast surgery is believed to improve the survival rates among these women, but due to limited evidence, definite conclusions cannot be made. Therefore, we undertook this narrative review to synthesize the evidence from existing studies to assess the effectiveness of locoregional surgery and surgery of metastatic sites in improving the outcomes among women diagnosed with metastatic cancer disease along with the summary of current treatment guidelines. We reviewed PubMed and Embase and included both observational studies and randomized controlled trials (RCTs) that were published in English between 2000 and 2021. Outcomes were either survival, quality of life, toxicity related to local treatment assessed by mortality at the end of one month, progression-free survival, and breast cancer-specific survival. The main effect size assessed was hazard ratio with their 95% CIs. After literature search, we found 8 observational studies and 3 RCTs. The findings of the observational studies revealed that breast cancer surgery improves survival from 30% to 50% among women. However, findings from RCTs were mixed for local and distant progression survival. Surgery improved the local progression-free survival but worsened the distant progression-free survival. Besides, there was no effect of breast surgery on quality of life. Regarding the surgery of metastatic site, studies are complex with mixed findings and variation in survival depending upon the type of metastatic site and response to initial systematic therapy and other factors. Based on the existing mixed evidence, it is not possible to make firm and definite conclusions about the effectiveness of breast surgery in improving the survival or quality of life among women with metastatic breast cancer. In future, more RCTs are required with a larger sample size to confirm the findings of observational studies.