Sentinel node navigation surgery is acceptable for clinical T1 and N0 esophageal cancer

Background. If the sentinel node (SN) concept is established for esophageal cancer, it will be possible to reduce safely the extent of lymphadenectomy. Our objective was to perform SN mapping in esophageal cancer to assess distribution of lymph node metastases with the goal to reduce the need for extensive lymphadenectomy. Methods. A total of 134 patients who underwent esophagectomy with lymph node dissection were enrolled. The number of patients with clinical T1, T2, and T3 tumors was 60, 31, and 32, respectively. Eleven patients also received neoadjuvant chemoradiation therapy (CRT). ^99mTc-Tin colloid was injected endoscopically into the esophageal wall around the tumor 1 day before surgery. SNs were identified by using radioisotope (RI) uptake. RI uptake of all dissected lymph nodes was measured during and after surgery. Lymph node metastases, including micrometastases, were confirmed by hematoxylin eosin and immunohistochemical staining. Results. Detection rates of SNs were 93.3% in cT1, 100% in cT2, 87.5% in cT3, and 45.5% in CRT patients. In the 120 cases where SNs were identified, lymph node metastases were found in 12 patients with cT1, 18 with cT2, 24 with cT3 tumors, and 3 with CRT. Accuracy rate of SN mapping was 98.2% in cT1, 80.6% in cT2, 60.7% in cT3, and 40% in CRT patients. Although one false-negative case had cT1 tumor, the lymph node metastasis was detected preoperatively. Conclusions. SN mapping can be applied to patients with cT1 and cN0 esophageal cancer. SN concept might enable to perform less invasive surgery with reduction of lymphadenectomy.