The implications of a pathological complete response of the primary tumour after neoadjuvant chemotherapy for breast cancer on axillary surgery

Abstract

Abstract Background Management of the node-positive axilla after neoadjuvant chemotherapy is controversial. The aim of this study is to predict the group of patients who may require a less invasive approach for axillary management. One possible group are patients with pathological complete response of the primary after chemotherapy. Results A unicentral retrospective cohort study including all breast cancer patients with axillary node metastases at presentation who received neoadjuvant chemotherapy resulting in pathological complete response. Pathological complete response in the axillary lymph nodes was recorded. A correlation between the response in the primary tumour and the lymph nodes was assessed. A subgroup analysis was conducted for different biological groups. Complete response was seen in the axillary nodes in 80.5% of patients. Patients with lobular cancer were less likely to show a similar response in the axilla as the primary tumour (p = 0.077). A higher incidence of axillary response was observed in HER2-positive tumours (p = 0.082). All patients with grade 3 tumours achieved complete response in the axilla (p = 0.094). Patients with negative or weak positive hormone receptor status had a significantly higher rate of complete response in the axilla compared to strongly positive hormone receptor status (OR, 7.8; 95% CI, 1.7–34.5; p = 0.007). Conclusion A less invasive axillary surgery may be safely recommended in selected group of node-positive patients after neoadjuvant chemotherapy when the primary tumour shows complete response. This group may include HER2-positive, ER-negative and grade 3 tumours. Less response is expected in ER-positive and lobular carcinoma even with complete response in the primary.

Keywords

• Neoadjuvant chemotherapy
• Complete pathological response
• Management of axilla