Aim: The increasing number of sentinel lymph node biopsy in patients with early stage breast cancer increased the diagnosis of micrometastasis. The clinical importance of micrometastasis is still discussed. The aim of this study is to evaluate the incidence and the risk factors for metastasis in the axillary non-sentinel lymph nodes in patients with early stage breast cancer and micrometastatic sentinel lymph node.
Method: Data about the axillary sentinel and non-sentinel lymph nodes collected from January 2000 to December 2008 were reviewed retrospectively. In the patients with micrometastatic sentinel lymph nodes, the incidence of non-sentinel metastasis was correlated with some features of the primary tumour, such as the T status, the grading, the proliferation index and the peritumoral lymphvascular invasion. Statistical univariate analysis was performed.
Results: The sentinel lymph node biopsy was performed in 370 patients with early stage breast cancer, and 87 metastatic lymph nodes were found. Macrometastasis were 63, micrometastasis were 23 and only 1 case of isolated tumour cells was found. In the patients with micrometastatic sentinel lymph node, 7 patients (30,4%) had involvement of non-sentinel lymph nodes. The grading, the proliferation index and the peritumoral lymphvascular invasion were statistically significant.
Conclusions: The presence of micrometastasis in the sentinel lymph node is associated to a high risk of metastasis in the non-sentinel lymph nodes, specially in tumours with aggressive features, such as high grade, high mitotic pattern, peritumoral lymphvascular invasion. These results suggest that even in micrometastatic sentinel lymph nodes we must perform axillary lymph node dissection.
