Value of Sentinel Lymph Node Biopsy in Breast Cancer Surgery with Simple Pathology Facilities -An Iranian Local Experience with a Review of Potential Causes of False Negative Results

Introduction: Sentinel lymph node biopsy (SLNB) is a precise procedurefor lymphatic staging in early breast cancer. In a valid SLNB procedure,axillary lymph node dissection (ALND) can be omitted in node- negativecases without compromising patient safety. In this study, detection rate,accuracy and false negative rate of SLNB for breast cancer was evaluated in asetting with simple modified conventional pathology facilities without anyserial sectioning or immunohistochemistry.Material and Method: Patients with confirmed breast cancer wereenrolled in the study. SLNB and ALND were performed in all cases. Lymphnode metastasis was evaluated in SLN and in nodes removed by ALND todetermine the false negative rate. Pathologic assessment was carried out onlyby modified conventional technique with only 3 sections. Detection rate wasdetermined either by lymphoscintigraphy or during surgery.Results: 78 patients with 79 breast units were evaluated. SLN was detectedin 75 of 79 cases (95%) in lymphoscintigraphy and 76 of 79 cases (96%)during surgery. SLN metastases was detected in 30 of 75 (40%) cases either inSLNB and ALND groups. Accuracy of SLNB method for detecting LNmetastases was 92%. False negative rate was 3 of 30 of positive cases: 10%. In7 of 10 cases with axillary lymphadenopathy, LN metastastates was detected.Conclusion: SLNB is recommended for patients with various tumor sizeswithout palpable lymph nodes. In modified conventional pathologicexamination of SLNs, at least macrometastases and some micrometastasescould be detected similar to ALND. Consequently, ALND could be omitted innode-negative cases with removal of all palpable LNs. We conclude thatSLNB, as one of the most important developments in breast cancer surgery,could be expanded even in areas without sophisticated pathology facilities.