Accuracy of Preoperative Diagnosis of Lymph Node Metastasis for Thoracic Esophageal Cancer Patients from JCOG9907 Trial

Background: Accurate clinical evaluation of lymph nodes is crucial for selection of the optimum treatment strategy for individual esophageal cancer patients. This study investigated the accuracy of preoperative clinical diagnosis of lymph node metastasis for patients with clinical stage II/III esophageal squamous cell carcinoma.

Methods: Patients assigned to receive surgery and postoperative chemotherapy in JCOG9907 trial were studied to evaluate the concordance between clinical and pathological nodes. Preoperative diagnosis was based on computed tomography or magnetic resonance imaging.

Results: Among 166 patients in the postoperative group, 160 with sufficient pathological data were studied. The patient background characteristics were: male/female, 147/13; median age, 61 years (range 39-75 years); primary tumor site (upper/middle/lower), 15/76/69; cN0/cN1, 53/107. The sensitivity and specificity of clinical nodes for diagnosis of pathological nodes were 72.7 and 51.3 %, respectively; the positive and negative predictive values were 82.2 and 37.7 %, respectively. The lymph nodes overestimated in the preoperative diagnosis included thoracic paratracheal lymph nodes (#106) (n = 8), middle thoracic paraesophageal lymph nodes (#108) (n = 4), lymph nodes along the lesser curvature (#3) (n = 4), right cardiac lymph nodes (#1) (n = 3), and left cardiac lymph nodes (#2) (n = 2).

Conclusion: Diagnosis of clinical nodes has low specificity and low negative predictive value for prediction of pathological node category in the preoperative diagnosis of lymph node metastasis for patients with locally advanced resectable esophageal cancer. Clinical staging techniques must therefore be improved for accurate preoperative diagnosis.