Analysis Of Axillary Lymph Node Status In Patients With Breast Pathological Complete Response After Neoadjuvant Chemotherapy

Objective:To explore the axillary lymph node status in patients with breast pathological complete response after neoadjuvant chemotherapy,and the relationship between them and molecular typing of breast cancer.To provide a theoretical basis for the omission or reduction of axillary surgery after neoadjuvant chemotherapy.Methods:This study is a retrospective review of 749 patients with cT1-3N0-1 breast cancer who received neoadjuvant chemotherapy and underwent surgery in the first hospital of Jilin University from January 2011 to December 2018.According to the pathological results,the patients were divided into bpCR group and non-bpCR group.All statistical analyses were performed using SPSS 25.0 statistical software.The positive rate of pathological lymph nodes in bpCR group and non-bpCR group were calculated.?2 test test was used for comparison between the two groups,P<0.05 was considered to be statistically significant.The positive rate of pathological lymph nodes in different molecular types and initial axillary lymph node staging were calculated and compared using relative risk ratios with 95%CIs.Results:The analysis included 749 patients with cT1-3N0-1 breast cancer underwent surgery after neoadjuvant chemotherapy.The overall rate of breast pCR was 21.2%.The breast pCR rate was 8.7%?23.4%?45.3%?35.9% in HR-positive/HER2-negetive?HR-positive/HER2-positive?triple negative?HR-negetive/HER2-positive breast cancer.In 218 clinically node negative patients(cN0),4.9%(2/41)with breast pCR being ypN positive compared with 31.6%(56/177)without breast pCR(RR=7.1,95%CI(1.8-28.3);P<0.001).In the bpCR group,there was 1 pathologic lymph node positive case in triple negative and the HR-negative/HER2-positive breast cancer,and the number of positive nodes was less than 3.Neither HR-positive/HER2-positive nor HR positive/HER2-positive group had lymph positive nodes.In 531 cN1 patients,26.3%(31/118)with breast pCR being ypN positive compared with 81.5%(340/413)without breast pCR(RR=6.5,95%CI(4.5-9.4);P<0.001).The node positive rate of triple negative and HR-negative/HER2-positive breast cancer in cN1 patients with bpCR was 12.5%(4/32)and 16.7%(5/30),respectively.Patients without a breast pCR had a relative risk for positive nodal metastases of 5.1 compared with those with a breast pCR.Conclusion:(1)bpCR after NAC is correlated with the rate of axillary lymph node metastasis.(2)Patients with cN0 achieved bpCR can safely perform SLNB.(3)SLNB can be performed in patients with cN1 triple negative or HER2-positive with bpCR,but need to be cautious.