Objective: To study the predictive factors that are associated with intraoperative identification of the sentinel lymph node (SLN).
Methods: Lymphatic mapping using blue dye was performed in 108 patients with stage I and II operable primary breast cancer. Subsequently the patients received operations of breast cancer including axillary dissection. Clinical and histological factors were assessed to determine those that were associated with intraoperative identification of the SLN.
Results: The sentinel node was identified at the time of surgery in 84 patients (77.78%). Of the clinical factors assessed, age(y) < 50 (chi(2) = 7.447, P < 0.01), tumour in the upper quadrant (chi(2) = 6.330, P < 0.05), diagnosis by preoperative biopsy (chi(2) = 5.509, P < 0.05), successful mapping of the lymphatic duct (chi(2) = 13.125, P < 0.01) were significant in identifying the sentinel node at operation. No histological factor was associated with intraoperative identification of the sentinel node.
Conclusion: There are the possibility of failure of SLN identification at sentinel lymph node biopsy. Our results suggest that the best predictor of intraoperative sentinel node identification is the visualization of the lymphatic duct on mapping by blue dye. Other factors such as age, tumour site as well as diagnostic method are also important in determining the success of the procedure.