Assessment of the efficacy and safety of methylene blue dye for sentinel lymph node mapping in early breast cancer with clinically negative axilla

Background : The benefits of sentinel lymph node (SLN) biopsy in breast cancer patients with clinically negative axillary nodes are now well established. SLN biopsy has been performed using different techniques including injection of isosulfan blue dye (IBD), radioactive colloid, and methylene blue. The aim of this study was to assess the safety and efficacy of methylene blue dye (MBD) as a mapping agent for SLN biopsy in axillary node negative breast carcinoma. Materials and Methods: Between February 2010-2012, a total of 27 female patients of 18 years and above, with established diagnosis of breast carcinoma with clinically negative ipsilateral axillary lymph nodes were studied. After induction of anesthesia, 5 ml of 1% methylene blue was infiltrated into the subareolar tissue on the affected side. The lymph nodes receiving the blue dye were excised as the SLN. Modified radical mastectomy (MRM) was completed and the excised breast with the axillary tissue was sent for histopathological examination to correlate with the findings of the SLN biopsy. Results: The incidence of breast cancer was highest at 41-50 years. Of 27 cases, SLN was identified in 24 cases using MBD. The identification rate was 88.9%. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were 81.8, 100, 100, and 86.7%, respectively. Conclusion: This study confirms the safety and efficacy of methylene blue as a mapping agent for SLN biopsy in axillary node negative breast cancer.