Interneural tissue clearance in axillary dissection for breast cancer: What is the importance?

Background: Breast cancer is the most common cancer in women and second most common type of cancer overall. The prime objectives of axillary surgery in the management of breast cancer are 1) accurate staging, 2) treatment to cure and 3) quantitative information of metastatic lymph nodes for prognostic purposes and allocation to adjuvant protocols. During axillary dissection, all 3 level lymphnodes are removed, while the important axillary structures (axillary vein, long thoracic and thoracodorsal nerves) are preserved. The latter two structures are particularly vulnerable to injury when dissecting the tissue between them (the interneural tissue).

Methods: This prospective non-randomized study, conducted on 125 female patients, who underwent axillary lymphadenectomy for breast cancer has evaluated the importance of dissection of the Interneural tissue during axillary dissection in breast cancer surgery by reviewing the lymph node yield and metastasis rate. The interneural tissue was excised separately after a routine axillary dissection.

Results: Lymph nodes were found in the interneural tissue of 70 out of 125 patients (56%). The average number of interneural lymph nodes recovered per specimen was 1.3. The interneural tissue lymph nodes were positive for metastasis in 10 (8%) patients. There was no incidence of isolated metastasis in the internerve tissue nodes.

Conclusions: There is a significant incidence of lymph nodes (56%) and axillary node metastases (8%) in the tissue lying between the long thoracic and thoracodorsal nerves. Therefore, meticulous dissection and excision of this interneural tissue is strongly recommended to optimize decision making regarding adjuvant treatment and outcome.