Value of internerve tissue dissection during axillary lymphadenectomy for early breast cancer

Breast cancer is one of the most commonly occurring malignancies in females in the Eastern Mediterranean Region. Axillary clearance is an integral part of the surgical treatment of breast cancer. Precise analysis of lymph node involvement for proper staging and adjuvant therapy is therefore necessary. During axillary dissection, lymph nodes at levels I, II and III 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 internerve tissue).

This study evaluates the necessity of dissecting the internerve tissue during axillary dissection in breast cancer surgery by reviewing the lymph node yield and metastasis rate in this tissue. This is a prospective non-randomized study, conducted on 50 female patients, who underwent axillary lymphadenectomy for breast cancer. The internerve tissue was excised separately after a routine axillary dissection.

Twenty eight ( 56% ) of the 50 internerve specimens contained lymph nodes; the internerve nodes were positive for carcinoma in 5 patients ( 10%). In those 5 patients, metastasis was also found in some other axillary lymph nodes. There was no incidence of isolated metastasis in the internerve tissue nodes in absence of metastatic disease to other lymph nodes in the axilla.

There is a significant incidence of lymph nodes ( 56% ) and axillary node metastases ( 10% ) in the tissue lying between the long thoracic and thoracodorsal nerves. Therefore, meticulous dissection and excision of this internerve tissue is strongly recommended in order to optimize decision making regarding adjuvant treatment and outcome in women with operable breast cancer. Key Words:Breast cancer - Axillary lymphadenectomy - Internerve tissue.