Background: This study aimed to assess the prognostic significance of endoluminal ultrasound-defined total length of disease and endoluminal ultrasound defined tumor volume (EDTV) in esophageal cancer. The hypothesis was that endoscopic ultrasound (EUS)-defined total length of disease and EDTV are both significant prognostic indicators and better predictors of outcome than endoscopic tumor length.
Methods: In this study, 174 consecutive patients (median age, 64 years and 128 months) underwent specialist EUS, and the maximum potential EDTV was calculated (pir(2) L, where r is the tumor thickness and L is the total length of disease) including proximal and distal lymph node metastases. Of the 174 patients, 104 underwent surgery (70 had neoadjuvant chemotherapy), 60 underwent definitive chemoradiotherapy, and 10 had palliative therapy.
Results: Survival was related to EUS T stage (p = 0.013), EUS N stage (p = 0.001), EUS M1a stage (p = 0.004), EUS disease length (<8 cm; p = 0.001), and EDTV (all patients <25 cm(3), p = 0.001; surgical patients <40 cm(3), p = 0.036). Forward conditional multivariate analysis showed three factors to be associated with survival: EUS N stage (hazard ratio [HR], 1.646; 95% confidence interval [CI], 1.041-2.602; p = 0.033), EUS M1a stage (HR, 2.702; 95% CI, 1.069-6.830; p = 0.036), and EDTV (HR, 2.702; 95% CI, 1.069-6.830; p = 0.025). Median and 2-year survival for EDTV <25 cm(3) versus >25 cm(3) was 43.4 months and 56%, respectively, compared with 23.5 months and 35%.
Conclusions: In this study, EDTV based on total EUS-defined length of disease emerged as a new and important prognostic indicator for patients with esophageal cancer.