Advances in locoregional surgical treatment of de-novo stage IV breast cancer: a review.

PURPOSE: Breast cancer is the most common malignancy among women worldwide. A notable subset of patients presents with de-novo stage IV breast cancer at initial diagnosis, meaning metastatic lesions are already present. These patients typically receive primary systemic therapy aimed at palliative care, with locoregional treatment remaining controversial. Although numerous retrospective studies have suggested that resection of the primary tumor may improve survival, prospective randomized trials have not demonstrated a clear benefit, and routine surgical intervention is not generally advocated. This paper aims to review and discuss the research progress regarding locoregional surgical treatment for de-novo stage IV breast cancer. METHODOLOGY: Recent retrospective and prospective studies on locoregional surgery for de-novo stage IV breast cancer were searched, with a focus on prospective randomized controlled trials (RCTs). The collected evidence was reviewed to evaluate the role of local surgery in this patient population. RESULTS: Most retrospective studies and meta-analyses report that primary breast surgery is associated with improved prognosis when stage IV disease is first diagnosed. However, significant selection bias exists in these data. Women who undergo surgery tend to be younger, have smaller primary tumors, fewer comorbidities, and lower metastatic burden-particularly fewer visceral metastases. They are also more likely to receive higher-quality overall care. These factors suggest that surgeons preferentially select patients with a better expected prognosis for surgery. In contrast, prospective randomized trials have consistently failed to demonstrate that locoregional surgery provides additional survival benefits beyond systemic therapy alone. Consequently, routine locoregional surgical treatment is not recommended for most patients with de-novo stage IV breast cancer. Nevertheless, a notable exception exists for patients with bone-only metastases. CONCLUSION: Although retrospective analyses support a survival advantage from locoregional surgery in de-novo stage IV breast cancer, prospective RCTs have not confirmed a benefit for the general patient population. However, locoregional surgery does appear to offer survival benefits for patients with bone-only metastases. Further prospective clinical trial data are certainly needed to better define the value of locoregional surgery in de-novo stage IV breast cancer.