Accuracy of linear-array EUS for preoperative staging of gastric cardia cancer

Background: The feasibility of a less invasive operation for early stage cancer of the gastric cardia with a low frequency of lymph node involvement has been previously demonstrated by us. Precise discrimination among mucosal, submucosal, and advanced cancers, as well as accurate evaluation of the proximal tumor margin are prerequisites for such stage-specific treatment. EUS is considered the most reliable staging modality. However, there is no EUS study specifically of cardia cancer. Methods: Forty-five patients with gastric cardia cancer who underwent gastrectomy with at least first-tier lymphadenectomy were retrospectively analyzed. The results of preoperative linear-array echoendoscopy (7.5 MHz) with respect to cancer depth, lymph node involvement, and esophageal invasion were compared with postoperative histopathologic findings. Results: Overall diagnostic accuracy for depth of invasion was 71%. Sensitivity for T1, T2, and T3 lesions was 100%, 31% and 75%, respectively. Overstaging of T2 cancers was the main diagnostic error. Mucosal (pT1-m) and submucosal (pT1-sm) cancers were correctly discriminated in 81% of patients. Diagnostic accuracy for lymph node involvement was 80%. EUS had positive and negative predictive values of 90% and 80%, respectively, for esophageal invasion. Conclusions: For gastric cardia cancer, the linear-array echoendoscope yielded satisfactory results with respect to depth of invasion, lymph node involvement, and esophageal invasion evaluation. The information obtained is useful to the performance of stage-specific treatment.