Locoregional Recurrence After Mastectomy: Risk Factors and Implications for Postmastectomy Radiation

Area of Science:

• Oncology
• Surgical Oncology
• Breast Cancer Research

Background:

• Locoregional recurrence (LRR) is a significant concern following mastectomy for breast cancer.
• Contemporary recurrence patterns are not well-defined given modern therapies and increased use of postmastectomy radiation therapy (PMRT).

Purpose of the Study:

• To define contemporary recurrence patterns after mastectomy.
• To identify predictors of LRR and overall recurrence in the era of modern breast cancer treatment.

Main Methods:

• Retrospective review of 595 women undergoing mastectomy (2014-2020).
• Analysis of patient demographics, clinicopathologic features, treatments, and outcomes.
• Use of Cox proportional hazards regression to identify LRR predictors.

Main Results:

• The 5-year LRR rate was 3.9% (median follow-up 4.8 years).
• Lymphovascular invasion (HR 6.28) and close margins (HR 3.02) were independent predictors of LRR.
• Nodal status and young age did not predict LRR; higher stage, close/positive margins, and lymphovascular invasion predicted overall recurrence.

Conclusions:

• LRR rates remain low in contemporary breast cancer patients post-mastectomy.
• Lymphovascular invasion and close surgical margins are significant independent predictors of LRR.
• Findings support focusing on margin status and lymphovascular invasion for personalized PMRT recommendations.