Background: Sentinel node (SN) mapping in esophageal cancer has been reported to be technically feasible with an acceptable detection rate and accuracy. However, the clinical significance and survival analysis findings associated with the metastatic status of SNs in patients with early-stage esophageal cancer have not been clarified. In this study, we investigated the clinical significance and survival impact of SN mapping in early-stage esophageal cancer.
Methods: Among patients who were diagnosed preoperatively with clinical T1N0M0 or T2N0M0 esophageal cancer and who underwent SN mapping, 70 consecutive patients who were diagnosed with pathological T1 primary thoracic esophageal cancer were enrolled in this study. Sixty-four (91 %) patients were diagnosed with squamous cell carcinoma while 5 (7 %) patients were with adenocarcinoma. Endoscopic injection of technetium-99m tin colloid was performed before surgery, and radioactive SNs were identified by preoperative lymphoscintigraphy and intraoperative gamma probing. Standard esophagectomy with lymphadenectomy was performed in all patients, and all resected nodes were evaluated by routine pathological examination.
Results: SNs were successfully detected in 65 (92.9 %) of 70 patients with pT1 esophageal cancer. The sensitivity to predict lymph node metastasis was 91.7 %, and the diagnostic accuracy based on SN status was 96.9 %. Although there was a wide distribution of SNs from cervical to abdominal areas, 84.5 % of the patients had no lymph node metastasis or had lymph node metastasis only in SN. The disease-specific survival of the patients with metastatic non-SNs was significantly worse relative to that of the patients with no lymph node metastasis or lymph node metastasis only in SN.
Conclusions: This study demonstrated that radio-guided SN mapping is useful not only as an accurate diagnostic tool for detecting lymph node metastasis but also as a tool for prognostic stratification in patients with cN0 early esophageal cancer.