Sentinel node detection in breast carcinoma

The standard procedure for the evaluation of axillary nodal involvement in patients with breast cancer is still complete lymph node dissection. However, about 70% of patients are found to be free of metastatic disease while axillary node dissection may cause significant morbidity. Lymphatic mapping and sentinel lymph node (SLN) biopsy are changing this situation.

In a period of 18 months we studied 201 patients with breast cancer, excluding patients with palpable axillary nodes, tumors > 2.5 cm in diameter, multifocal or multicentric cancer, pregnant patients and patients over 80 years of age. Before surgery 99mTc-labeled colloid and vital blue dye were injected into the breast to identify the SLN. In lymph nodes dissected during surgery the metastatic status was examined by sections at reduced intervals. Only patients with SLNs that were histologically positive for metastases underwent axillary dissection.

We localized one or more SLNs in 194 of 201 (96.5%) patients; when both techniques were utilized the success rate was 100%. Histologically, 21% of patient showed SLN metastases (7.8% micrometastases) and 68% of these had metastases also in other axillary nodes. None of the patients with negative SLNs developed metastases during follow-up.

At present there is no definite evidence that negative SLN biopsy is invariably correlated with negative axillary status; however, our study and those of others demonstrate that SLN biopsy is an accurate method of axillary staging.