Background: The aim of this study was to investigate whether endosonography on demand with miniprobes and conventional endoscopic ultrasound improves the accuracy of endosonographic staging of upper gastrointestinal tract cancer.
Methods: Altogether, 173 patients underwent endoscopic ultrasonography for preoperative staging of esophageal (n = 63) or gastric cancer (n = 110). Depending on the endoscopic appearance (i.e., size and growth pattern), tumors were examined with a linear-array echoendoscope (7.5 MHz) or with high-resolution miniprobes (12.5 MHz). The results of preoperative staging were correlated with histopathology of the resection specimen.
Results: The overall accuracy of miniprobe ultrasonography and endoscopic ultrasound in assessing the infiltration depth of upper gastrointestinal cancer was 87% and 81%, respectively. Miniprobe ultrasonography was superior to conventional endoscopic ultrasound in the staging of early cancers, particularly T1 tumors (accuracy, 81% vs 56%). The combined accuracy of both techniques for all tumor stages was 82%. Correct diagnosis of lymph node involvement was obtained with miniprobe ultrasonography or endoscopic ultrasound in 76% and 71% of the cases, respectively. The combined accuracy in assessing the lymph node status was 73% (sensitivity, 68%; specificity, 81%).
Conclusions: Endosonography on demand using either miniprobes or conventional endoscopic ultrasound may result in more effective and less invasive staging of esophageal and gastric cancer. Selective use of high-resolution miniprobes and conventional endoscopic ultrasound offers accurate staging of all tumor stages.