Aim: The aim was to identify a subset of breast cancer patient with positive sentinel nodes (SNs) for whom secondary axillary clearance would be unnecessary.
Methods: Between March 1999 and May 2001, 288 patients with T0-T2 breast cancer less than 3cm in diameter had SN detection either by a colorimetric method or using a combined technique. SNs were stained with haematoxylin and eosin (H&E). For all negative SNs, serial sections and immunochemistry (IHC) were performed. All patients with positive SNs underwent a complete axillary lymph node dissection. One hundred and twenty patients were SN positve.
Results: Non-sentinel node positivity (NSNP) was closely associated with the size of the tumour (14.3%, 54.1% and 51.8% for pT1a-b, pT1c and pT2 tumours respectively) and with the size of the SN metastasis: 15.9% IHC detected micrometastasis, 33.3% and 78.8% micro- and macrometastasis detected with H&E staining respectively. NSNP was found in 24.0% and 42.8% of patients with pT1c breast cancer and with micrometastasis detected by IHC and H&E staining. The node positivity rate reached 81.1% for pT1c lesions with macrometastasis in the SN. For the patients with pT2 breast cancer, these rates were 12.5% (IHC), 28.5% (H&E) 91.1% (macrometastasis).
Conclusions: We are unable to isolate precisely a subset of patients for whom total axillary lymph node dissection would be unnecessary. A subset of 14 small tumours (<1cm diameter) demonstrated micrometastases in the SN without NSNP.