Breast Tumor Response & Axillary Clearance After Neoadjuvant Chemotherapy

Abstract

Background and Objective: Neoadjuvant chemotherapy (NAC) is widely used in the management of breast cancer (BC) and provides an opportunity to evaluate treatment response in both the primary tumor and axillary lymph nodes (LNs). Understanding the relationship between breast tumor response and axillary clearance may inform surgical decision-making and prognostication. Methods: In this retrospective study, patients with histologically confirmed BC who received NAC followed by definitive breast and axillary surgery at a tertiary referral center between 1987 and 1990 were included. Exclusion criteria were male sex and incomplete pathological data regarding breast tumor response, axillary LN status, or immunohistochemical profile. Chi-square test (χ2) and odds ratio (OR) with 95% confidence intervals (CI) were used for statistical analysis. Results: A total of 375 patients with BC treated with NAC were evaluated for breast tumor response and axillary LN response at definitive surgery. A strong association was observed between breast tumor response and axillary LN response, with patients demonstrating a favorable breast tumor response showing significantly higher odds of axillary clearance (OR 5.18, 95% CI 3.07 - 8.75; P < 0.001). In addition, breast tumor response was significantly associated with non-luminal immunohistochemical status (OR 1.76, CI95% 1.02 - 3.03; P = 0.03), as was axillary LN response (OR 2.43, 95% CI 1.48 - 3.99; P < 0.001). Conclusions: Breast tumor response following NAC is strongly correlated with axillary LN response and is associated with tumor biology. These findings support the potential role of response-based stratification in guiding individualized management strategies for patients with BC.