Does surgery improve survival in metastatic breast cancer?

TOPLINE:

Surgery of the primary tumor in patients with de novo metastatic breast cancer does not prolong overall survival, except potentially in younger, premenopausal patients.

METHODOLOGY:

• Given conflicting results from prospective trials and improved outcomes reported in retrospective studies, removing the primary tumor in patients with metastatic breast cancer remains common practice but also “controversial,” the authors explained.
• To clarify whether to remove the primary tumor in metastatic breast cancer, investigators performed a meta-analysis of the five randomized clinical trials evaluating the issue.
• The five trials, published from 2015 to 2023, included 1,381 women with de novo metastatic breast cancer; half had their primary tumor removed, half did not.

TAKEAWAY:

• The analysis revealed no overall survival benefit for patients who underwent surgical excision of their primary breast tumor (hazard ratio [HR], 0.93; 95% confidence interval [CI], 0.76-1.14).
• Surgery was not associated with an overall survival benefit in subgroup analyses by receptor status, pattern of metastasis (bone vs. viscera or oligometastatic vs nonoligometastatic disease), number of metastatic sites, or location of metastatic lesions.
• The one possible exception: Surgery did appear to improve overall survival in younger, premenopausal women (HR, 0.74; 95% CI 0.58-0.94), but “the lack of uniform definitions and inconsistent trial results suggest that this subgroup analysis should be viewed as exploratory and requiring further validation,” the authors said.
• Breast surgery was associated with improved local progression-free survival (HR, 0.37) but not distant progression-free survival or patient-reported quality of life.

IN PRACTICE:

“We conclude that surgical excision of the primary tumor in case of de novo metastatic breast cancer is not associated with improved patient survival,” with a “potential exception” among younger patients, the authors said. “As such, besides the need to palliate local symptoms, surgery should not be routinely offered to patients with metastatic disease.”

SOURCE:

The work, led by Guillermo Villacampa of the SOLTI Breast Cancer Research Group in Barcelona, was published Sept. 12 in The Oncologist.

LIMITATIONS:

The five trials had various weaknesses, including imbalances in patient characteristics, protocol violations regarding planned and administered treatment, and missing information on associations between surgical margins and outcomes.

DISCLOSURES:

There was no funding for the work. Investigators reported speaker fees, consultant fees, and/or research funding from various companies, including Merck, AstraZeneca, Pfizer, and Novartis.

A version of this article first appeared on Medscape.com.