Efficacy of Sentinel Lymph Node Biopsy in Detecting Axillary Metastasis in Breast Cancer Using Methylene Blue

Breast cancer is the leading malignancy and the second leading cause of cancer-related deaths. Axillary lymph node status is a very important prognostic factor in breast cancer patients; nodal evaluation is therefore a critical part of breast cancer management. Axillary lymph node dissection results in significant morbidity. Sentinel lymph node biopsy (SLNB) is being used in many centers to stage the axilla in planning axillary dissection management of patients and hence plays an important part in reducing morbidity among patients with carcinoma breast. The objectives of this paper is to study the (1) efficacy of sentinel lymph node biopsy in detecting axillary metastasis, (2) location of sentinel lymph node in the axilla, (3) rate of involvement of sentinel lymph nodes, and (4) incidence of skip metastasis. Thirty-five patients with breast cancer with clinically node-negative axilla were selected for the study. Methylene blue dye was injected intralesional and perilesional 20 min prior to surgery. All patients underwent modified radical mastectomy with sentinel lymph node biopsy and axillary dissection and after pathological examination diagnostic statics, namely sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were computed. Sentinel lymph node was identified in all of these patients. Sixty percent patients had pathologically positive lymph nodes in the axilla. 90.48% patients of these had sentinel lymph nodes positive for malignant cells. Incidence of skip metastasis is 9.52%. 88.57% patients had sentinel lymph node mapped to level I lymph nodes. Sensitivity of SLNB is 90.48%, specificity is 85.71%, PPV of is 90.48%, NPV is 85.71%, and accuracy is 88.57%. Sentinel lymph node biopsy is an effective method of staging the axilla and deciding on axillary clearance in patients of carcinoma breast. Unnecessary axillary dissection and associated complications can be prevented in most of patients due to sentinel lymph node biopsy.