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Role of three axillary lymph node sampling for predicting non-sentinel node metastases in patients with breast cancer and positive sentinel node.

694 Background: Half of breast cancer patients with positive sentinel node (SN)s do not have further metastatic non-SNs and do not need to undergo axillary lymph node dissection (ALND). This study evaluated the usefulness of three axillary lymph node (ALN) sampling for predicting non-SN metastases in breast cancer patients with SN metastases.


METHODS
SN biopsy was performed in patients with clinically node-negative breast cancer using dye and radioisotope. When SNs were diagnosed as metastasis-positive by intraoperative imprint cytology, three ALN sampling was performed, followed by ALND. The metastatic status of sampled nodes was compared with that of non-SNs. Imprint cytological evaluation was also performed for the sampled nodes and was compared with the final histological results of the sampled nodes.


RESULTS
Between 2001 and 2003, 252 patients underwent SN biopsy. Of 39 (16%) patients with positive imprint cytology, 36 (14%) were diagnosed as tumor positive on final histological examination and analyzed. The mean patient age was 51 (30-75) years old and the mean tumor size was 18 (8-28) mm. The mean number of SNs was 2.4 (1-7) and the mean number of non-SNs other than sampled nodes was 10.7 (2-27). The sensitivity, specificity and accuracy of sampled nodes for predicting non-SN metastases were 82%, 100% and 94%, respectively (sampled node+/ non-SN+, 9; +/-, 0; -/+, 2; -/-, 25). The negative predictive value and positive predictive value of sampled nodes for predicting the metastatic status of remaining ALNs other than sampled nodes were 93% and 56%, respectively. The sensitivity, specificity and accuracy of imprint cytology for sampled nodes were 86%, 97% and 95%, respectively on a node basis (cytology+/ histology+, 12; +/-, 3; -/+, 2; -/-, 91), and 90%, 96% and 94%, respectively on a patient basis (cytology+/ histology+, 9; +/-, 1; -/+, 1; -/-, 25).


CONCLUSIONS
Three ALN sampling is useful for predicting non-SN metastases and avoiding ALND in breast cancer patients with SN only metastases. Furthermore, intraoperative imprint cytological examination is useful for detecting metastases in sampled nodes. No significant financial relationships to disclose.