Can methylene blue dye be used as an alternative to patent blue dye to find the sentinel lymph node in breast cancer surgery?

Background: Sentinel lymph node biopsy (SLNB) is standard care to evaluate axillary involvement in early breast cancer. It has fewer complications than complete lymph node dissection; however, using blue dye in SLNB is controversial. We have evaluated the detection rate and local complications associated with methylene blue dye (MBD) used in SLNB in early breast cancer patients and compared these results to patent blue dye (PBD).

Materials And Methods: In a cohort prospective study, 312 patients with early breast cancer without axillary lymph node involvement were divided into two groups according to dye type. All of the patients received radiotracer and one type of blue dye. We filled out a checklist for the patients that contained demographic data, size of tumor, stage, detection of sentinel lymph node, and complications and then analyzed the data.

Results: Demographic and histopathologic characteristics were not significantly different in both groups. Mean (standard deviation [SD]) tumor size in all patients was 2.4 (0.8) cm. Detection rate in the MBD group was 77.5% with dye alone and 94.2% with dye and radioisotope; and in the PBD group it was 80.1% and 92.9% respectively (P > 0.05). We had blue discoloration of the skin in 23.7% in the PBD and 14.1% in the MBD group (P < 0.05) local inflammation was detected in one patient in the PBD and five in the MBD group (P < 0.05). Skin necrosis and systemic complications were not observed.

Conclusion: Methylene blue has an acceptable detection rate, which may be a good alternative in SLNB. Complication such as blue discoloration of the skin was also lower with MBD.