Is sentinel lymph node biopsy necessary for all clinically node negative breast cancer patients?

Abstract

Objective. While sentinel lymph node biopsy (SLNB) is now widely accepted as the standard for staging clinically node-negative breast cancer patients, the majority who undergo this procedure will be found to be free of lymph node metastases. The purpose of our study was to determine if a lymph node staging procedure could be omitted altogether for some breast cancer patients based upon a combined analysis of biologic markers, tumor features, and demographic parameters. Methods. We prospectively studied 200 breast cancer patients undergoing SLNB. In addition to complete histologic review of the primary breast tumors, we examined tumor-associated biologic markers and demographic parameters. Statistical analysis was performed using an SAS statistical software package. Results. Tumors ranged from 0.1 to 9.0 cm (median, 1.5 cm). Overall, 34% of the patients had lymph node metastases. While patients with lymph node metastases had larger tumors than those without (mean tumor size, 2.28 ± 0.15 versus 1.44 ± 0.1 cm, P < 0.001), 18% of patients with T1a and T1b tumors and 32% of patients with T1c tumors had lymph node metastases. Lymph node metastases were seen in 72% of patients whose tumors exhibited angio or lymphatic invasion versus 18% of those whose tumors did not ( P < 0.0001). Nodal metastases were present in 72% of patients with an elevated preoperative serum CA 27.29 and mean levels were higher among node positive patients (26 ± 1.6 versus 19 ± 1.1, P = 0.0007). There was no significant association between any of the demographic, histologic, or molecular features of the breast cancers that we investigated and lymph node metastases, including mitotic rate, tumor grade, ER/PR status, S-phase fraction, ploidy, Ki-67 expression, p53 expression, HER-2/neu expression, and serum CEA levels. Conclusions. We did not identify histologic, demographic, or molecular tumor features that can reliably include or exclude associated lymphatic metastases. Therefore, we recommend that SLNB be performed in breast cancer patients with clinically negative axillary lymph nodes. Additionally, due to the small, but potentially clinically important, false-negative rate for SLNB, consideration should be given to routine completion axillary lymph node dissection for patients with elevated CA 27.29 and for those whose tumors exhibit angio or lymphatic invasion.