Axillary pathologic response after neoadjuvant chemotherapy and surgery according to breast cancers subtypes and survival impact

Abstract

To retrospectively assess the rate of pathologic complete response in the axilla according to breast cancer biologic subtypes, and to study the impact of nodal response on survival. Inclusion criteria were all T-stage breast cancers with initial lymph node involvement, non-metastatic, treated with neoadjuvant chemotherapy followed by surgery with axillary lymph node dissection, managed at the George-François Leclerc Cancer Center in Dijon, France, between 2000 and 2018. Among 437 patients included, the rate of complete nodal response rate varied according to tumor subtypes: 69.4% in Hormone Receptors (HR)-/HER2-positive, 47.4% in HR-/HER2-negative, 46.7% in HR+/HER2-positive, 8.5% in HR+/HER2-negative. By multivariate analysis, the factors significantly associated with complete nodal response were HER2-positive profile (OR 4.48 [2.14-9.65], P<0.001 if HR+; OR 8.02 [3.54-18.74], P<0.001 if HR-), triple negative tumors (OR 3.01 [1.40-6.58], P=0.005), SBRIII grade (OR 6.85 [2.28-29.58], P=0.002) and breast complete response (OR 18.69 [9.67-38.53], P<0.001). Five-year recurrence rates were 15.7% in ypN0, 23% in ypN1, 41.2% in ypN2, 50% in ypN3 patients (P<0.001). Five-year overall survival rates were 92.2% in ypN0, 85.7% in ypN1, 72.2% in ypN2, 65.4% in ypN3 patients (P<0.001). The impact of nodal response on survival was significant. Pathologic complete response in the axilla appears to be a good surrogate marker of long-term outcome in patients treated for these cancers.