Surgical implications of sentinel node with micrometastatic disease in invasive breast cancer

Aim To assess the rate of positive axillary clearance (AC) when the sentinel node biopsy (SNB) contains micrometastatic disease in invasive breast cancer and to evaluate the factors that could predict positivity. Patients and methods This is a prospective study carried out on 542 successive women undergoing SNB for unifocal T0–T1 N0 invasive breast cancer without previous treatment. Results Five hundred and twenty-five sentinel nodes (SN) were found, 142 contained metastases. Fifty-five of the positive SN contained micrometastatic disease only. Of them, 40 patients underwent completion of AC. Six out of 40 patients who had micrometastatic SN had a positive AC, five for micrometastasis between 0.2 and 2 mm (5/34), one for isolated cells in the SN (1/6). None of the studied factors (age, histological tumour size, histological grade, estradiol receptor (ER), histological tumour type, size and method of micrometastasis detection) could significantly predict the status of the AC. Conclusion As long as the results of ongoing prospective randomised studies are unknown, it remains necessary to perform AC when the SNB contains micrometastatic disease, whatever the size or the detection mode of the metastasis.