Kozak MM, et al. - The role of pathologic nodal response as a predictor of outcomes in women aged ≤ 40 years with breast cancer treated with neoadjuvant chemotherapy (NAC) was investigated. They observed excellent outcomes among women aged ≤ 40 years who achieved pathologic complete response (pCR); however, similar outcomes were reported in those who achieved a pathologic response in the lymph nodes (LNs) but had residual disease in the breast as compared with those who remained LN-positive.

Methods

• Researchers performed a retrospective review of 220 patients treated with NAC between 1991 and 2015.
• No evidence of residual invasive tumor in the breast and lymph nodes (LNs) (ypT0/Tis ypN0) was the definition of pathologic complete response (pCR); partial response was defined by no tumor in the LNs but residual tumor in the breast (ypT+ ypN0) or residual tumor in the LNs (ypT0/Tis ypN+); and limited response was defined as residual tumor in both the breast and the LNs (ypT+ ypN+).
• They determined factors predictive for overall survival (OS) via Kaplan-Meier and Cox proportional hazards analyses.

Results

• Among a total of 155 patients, 39 patients (25.2%) achieved pCR, 57 (36.8%) achieved partial response (either ypT+ ypN0 or ypT0/Tis ypN+), and 59 (38.1%) had limited response after NAC.
• Local failure, regional failure, and distant failure was experienced by 22 patients (14.2%), 20 patients (12.9%), and 59 (38.1%), respectively.
• Findings revealed median OS for patients who achieved pCR was not reached, and was significantly worse for patients who had residual disease in the breast and/or LNs (P<.001).
• Among patients who had residual disease in the breast alone vs those who remained LN-positive, OS did not differ (97 vs 83 months, respectively; P=.25).
• In subset analysis, no differences were seen in OS based on year of treatment or cN1 disease at the time of initial diagnosis.