Flow cytometry in breast cancer: prognostic and surgical indications of the sparing of axillary lymph node dissection.

The lymph node status is still regarded as the most important prognostic factor in breast cancer. However, the utility of axillary lymph node dissection in clinically node-negative patients with breast cancer as a therapeutic approach rather than a pathologic staging procedure has been recently discussed. DNA index (DI) and S-phase fraction (SPF), evaluated by flow cytometric analysis, are two prognostic factors used especially in the assessment of the adjuvant therapy in stage N0 tumors. By studying a large number of cases, the authors aimed to assess the potential role of flow cytometry in predicting lymph node status. Two hundred eleven patients with breast cancer were included. Each tumor specimen was freshly analyzed by flow cytometry to assess DI and SPF. The authors also evaluated TNM status of patients, estrogen- and progesterone-receptor (ER and Pgr) status, and histologic grades. A group of patients with negative axillary lymph nodes was identified by means of association of tumor size of 2 cm or less, DI of 1, and SPF less than 7%. The ER and PgR status as well as histologic grade were significantly more favorable in this group of patients. These findings indicate that association of DI, SPF value, and tumor size may be predictive of axillary lymph node status in breast cancer.