Objectives: To assess the reliability of determining sentinel node status in staging regional lymph nodes in breast cancer.
Design and setting: Prospective validation study in a major public teaching hospital, comparing histological sentinel node status with that of remaining axillary nodes.
Patients: 117 women who underwent sentinel node biopsy and axillary dissection for primary breast cancer between 1995 and 1998.
Main outcome measures: Intraoperative success rate in sentinel node identification; false negative rate; predictive value of negative sentinel node status; overall accuracy of sentinel node status.
Results: The sentinel node was identified at operation in 95 patients (81.2%). Tumour involvement of the sentinel node was demonstrated in 29 of 31 women (93.5%; 95% CI, 79%-99%). Sixty-four of the 66 women in whom the sentinel node was negative for tumour showed no further involvement of remaining axillary nodes (standard haematoxylin-eosin histological assessment), giving a predictive value of negative sentinel node status of 97% (95% CI, 89%-100%). The overall accuracy in 95 women in whom sentinel node status was compared with axillary node status was 97.9%.
Conclusions: Histopathological examination of the sentinel node is an accurate method of assessing axillary lymph node status in primary breast cancer and is likely to be incorporated into future surgical management of women with primary breast cancer.