PURPOSE: to evaluate which clinical, pathological or immunohistochemical factors may be predictive of metastatic involvement of other lymph nodes in patients with breast carcinoma undergoing sentinel lymph node biopsy (SLNB). METHODS: a retrospective study carried out with 1,000 successive patients with SLNB from 1998 to 2008. Age, tumor size, histological grade, lymphovascular invasion, hormone receptor status and HER-2, size of metastasis and number of positive SLN were evaluated. The associations between the characteristics of the tumors and the types of metastases were evaluated through χ2 corrected likelihood ratio tests for insufficient samples. RESULTS: mean age was 57.6 years and mean tumor size was 1.85 cm. A total of 72.2% SLN were negative and 27.8% were positive, but in 61.9% of the cases, the SLN was the only positive one, with 78.4% having macrometastases, 17.3% micrometastases and 4.3% isolated tumor cells (CTI). Tumor size was predictive of metastases in non-sentinel lymph nodes. After 54 months of follow-up, there were no recurrences in patients with CTI, but one local recurrence and two systemic recurrences were observed in the micrometastasis group, as well as four local and 30 distant metastases in the macrometastasis group. CONCLUSIONS: among the clinical parameters studied, only tumor size was correlated with metastatic involvement in axillary lymph nodes. The size of the metastases and the number of positive SLN also directly increased the possibility of systemic recurrence. The different rates of recurrence indicate that the biological significance of these types of metastases is different and that patients with SLN metastases may also have different risks of metastatic involvement of other axillary lymph nodes.
Breast neoplasms; Sentinel lymph node biopsy; Isolated tumor cells; Neoplasm metastasis; Neoplasm invasiveness; Recurrence
