BACKGROUND/AIM: Precise evaluation of lymph node status is one of the most important factors in determining clinical outcome in treating gastro-intestinal (GI) cancer. Sentinel lymph node (SLN) mapping clearly has become highly feasible and accurate in staging GI cancer. This study aims to investigate the feasibility and accuracy of detection of SLN using methylene blue dye in patients with carcinoma of the esophagus and assess its potential role in determining the rational extent of lymphadenectomy in esophageal cancer surgery.

MATERIALS AND METHODS

Thirty-two patients of esophageal cancer diagnosed on endoscopic biopsy were enrolled in this prospective study. After laparotomy, patent methylene blue was injected into the subserosal layer adjacent to the tumor. SLNs were defined as blue stained nodes within a period of 5 min. Standard radical esophagogastrectomy with lymphadenectomy was performed in all the patients. All the resected nodes were examined postoperatively by routine hematoxylin and eosin stain for elucidating the presence of metastasis, and the negative SLNs were examined further with cytokeratin immunohistochemical staining.

RESULTS

SLNs were detected in 26 (81.25%) patients out of 32 patients who were studied. The number of SLNs ranged from 1 to 4 with a mean value of 1.7 per case. The SLNs of esophageal cancer were only found in N1 area in 21 (80.77%) cases, and in N2 or N3 area in only 19.33%. The overall accuracy of the procedure was 75% in predicting nodal metastasis. SLN had a sensitivity of 85.71% in mid esophageal tumors and 93.33% in lower esophageal tumors. The SLN biopsy had sensitivity of 87.5% in the case of squamous cell carcinoma and 92.86% in the cases of adenocarcinoma of the esophagus. The accuracy of the procedure for squamous cell carcinoma and adenocarcinoma was 60% and 76.47%, respectively.

CONCLUSION

SLN mapping is an accurate diagnostic procedure for detecting lymph node metastasis in patients with esophageal cancer and may indicate rational extent of lymphadenectomy in these patients. SLN mapping provides "right nodes" to the pathologists for detailed analysis and appropriate staging, thereby helping in individualizing the multi-modal treatment for esophageal cancer.