Feasibility of Blue Dye Method to Identify Sentinel Lymph Node Metastasis in Patients with Oral Cancer

Objective: To examine the feasibility of a combination of the blue dye injection method and reverse transcriptase-nested polymerase chain reaction for squamous cell carcinoma antigen mRNA to detect sentinel lymph node metastasis in patients with oral cancer.Patients and Methods: Ten individuals with previously untreated oral cancer participated in the study. Sentinel lymph nodes were identified by the blue dye injection method during neck dissection. We investigated the comparative effectiveness of frozen haematoxylin and eosin section analysis and molecular analysis of squamous cell carcinoma antigen for sentinel lymph node diagnosis.Results: In 8 out of the 10 cases, sentinel lymph nodes were identified. One histologically positive sentinel lymph node also showed positive for squamous cell carcinoma antigen. The remaining 7 histologically negative sentinel lymph nodes were also negative for squamous cell carcinoma antigen. However, in 3 cases, squamous cell carcinoma antigen-positive-non-sentinel lymph nodes were detected despite sentinel lymph nodes being negative for squamous cell carcinoma antigen.Conclusion: Our preliminary results suggest that the combination of the single blue dye injection method and reverse transcriptase-nested polymerase chain reaction for the squamous cell carcinoma antigen mRNA was not very accurate for detection of sentinel lymph node metastasis in patients with oral cancer.