Clinical implications of the extent of invasion of T3 esophageal cancer by endoscopic ultrasound

Background: Endoscopic ultrasound (EUS) is an accurate imaging modality for local staging of esophageal cancer. We aimed to determine if depth of tumor invasion beyond muscularis propria (MP), as determined by preoperative EUS, is predictive of tumor recurrence or survival (a positive change in mortality) in patients with T3 esophageal cancer. Methods: Records and images of all patients with T3 N1 M0 esophageal cancer staged with EUS at our institution between January 1999 and October 2003 were reviewed. EUS images were independently reviewed by five blinded endosonographers and tumors were classified as minimally invasive (invasion <3 mm beyond MP) or advanced (invasion ≥3 mm beyond MP) T3 disease. Results: One hundred and sixty-five patients with esophageal cancer underwent EUS for staging and 39 patients with T3 N1 esophageal cancer were identified; 17 patients had minimally invasive T3 disease and 22 had advanced disease. All patients underwent neoadjuvant chemoradiation therapy followed by esophagectomy. Median follow up was 13 months. Adjusting for age and sex, minimally invasive disease was not associated with a statistically significant improvement in recurrence-free survival (hazard ratio, 1.45; 95% CI, 0.88-2.41, P = 0.14) or mortality (hazard ratio, 0.96; 95% CI: 0.49-1.78, P = 0.91). Conclusions: The extent of invasion of T3 esophageal cancer beyond MP, as determined by EUS, is not a significant predictor of tumor recurrence or mortality.