Assessment of the Effect of Treatment with Neoadjuvant Chemotherapy on Breast Cancer Axillary Lymph Node

Neoadjuvant chemotherapy is the standard of care for patients with locally advanced breast cancer (LABS). The aim of this study was to determine the effects of neoadjuvant chemotherapy on metastatic and nonmetastatic breast cancer axillary lymph nodes (ALNs). Seventy-seven patients with LABS and cytologically documented ALN metastases were treated in two prospective trials. Patients had breast surgery with level I and level II axillary dissection followed by additional chemotherapy or radiation treatment. Clinical nodal status was determined by physical examination and compared with histological and immunohistochemical findings. The regressive changes in primary tumor and ALNs were achieved using scoring systems. Objective clinical response in primary tumor was seen in 48.05% of patients. Histologic evidence of regression was noted in 46 cases (59.75%), with complete histologic regression achieved in 5 cases (6.49%). The number of cases according to the ALNs regression scoring system was as follows: 0 grade - viable metastases without effect - 21 patients (30%); 1 grade - cytotoxic effect in metastases - 20 patients (28.58%), 2 grade - micrometastasis - only3 patients (4.28%); 3 grade - no residual metastatic disease - 1 patient (1.43%); 4 grade - negative ALNs before and after treatment - 25 patients (35.71%). Nodular fibrotic area and iron-loaded macrophages suggested previous presence of tumor metastasis. There was significant relationship between histologic regression in the primary tumor and the presence of effect of cytotoxic agents on ALNs metastases (r=0.9123; p<0.00001). As chemotherapy is widely used in the treatment of breast carcinoma, pathologists should be aware of chemotherapy-induced changes in metastatic and in non­metastatic ALNs.