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

Abstract

Purpose: 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.

Methods: 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.

Results: 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).

Conclusion: 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.

Keywords: Breast cancer; Cancer du sein; Chimiothérapie néoadjuvante; Neoadjuvant chemotherapy; Pathologic response; Réponse histologique; Survie; Survival.