266P - Pathologic response and survival efficacy in patients with initial nodal involvement after neoadjuvant chemotherapy in early breast cancer

Abstract

BackgroundNodal involvement is a common prognostic factor in early breast cancer (EBC) but their response and assessment after neoadjuvant chemotherapy (NAC) is controversial, hence its impact in survival is not clear. MethodsWe analyze a cohort of 308 EBC patients with initial nodal involvement and their response to neoadjuvant chemotherapy and their impact in disease free survival (DFS). ResultsMedian age was 52 (range 29-87), median tumor size was 38mm (10-100) and 178 patients (57,8%) had initial palpable node involvement. According to the immunohistochemical expression of hormonal receptors, Ki 67 and HER2; 110 patients (35,7%) was HER2 positive, 119 (38,6%) luminal and 79 (25,6%) triple negative breast cancer. After NAC we found a total of pathological complete response in breast (pCRb) of 30% and pathological complete response in axilla (pCRa) of 45%. Response by different subtypes was: in HER2 a pCRb 41,8% and pCRa 56,3%; luminal a pCRb 13% pCRa 30,3% and triple negative a pCRb 41,8% pCRa 50,6%. Luminal patients achieved the worst axillary response (p:0,004) and without other variables with significant association like tumor initial size or palpable axillary nodes. The global coincidence between pCRb and pCRa was 83% and very similar in the different subtypes. Axillary pCR was associated with a better DFS in the global series (HR: 0,377 p:0,000) but not in the luminal patients (HR:0,455 p:0,072) and the median survival in patients with pCRa was 157 months in contrast to 121 in patients that not achieve a pCRa (153 vs 99 in HER2, 160 vs 141 in luminal and 167 vs 93 in triple negative). ConclusionsThe complete pathological response in axila after neoadjuvant chemotherapy is 45% in our serie but lower in luminal patients with only a 30%. There was a high level of concordance between pCR in breast and axilla in all subtypes with an 83%. Achieving pCR in axilla is associated with better disease free survival but this benefit is lower in luminal phenotype. Legal entity responsible for the studyThe authors. FundingHas not received any funding. DisclosureAll authors have declared no conflicts of interest.