Neoadjuvant chemoradiation for patients with advanced esophageal cancer- Which response grading system best impacts prognostic discrimination?

AIM: Neoadjuvant chemoradiation reduces tumor volume and improves R0 resection rate, followed by extended survival for patients with advanced esophageal cancer. The degree of tumor regression has high prognostic relevance. To date, there is still no generally accepted tumor regression grading system. The aim of this study was to compare the prognostic discrimination power of different histological regression grading systems: a. the fibrosis/tumor ratio within the primary tumor (Mandard), b. the percentage of residual vital tumor cells (VTC) compared to the original primary tumor (Cologne Regression), and c. the ypT Category, in patients with cT3 carcinoma of the esophagus after neoadjuvant chemoradiation.

METHODS AND RESULTS: This study included 216 patients with esophageal cancer clinically staged as cT3NxM0 and treated from 2009 to 2012 with standardized chemoradiation followed by esophagectomy (median age 62 years, 176 (81%) male and 138 (64%) adenocarcinoma patients). The subgroup frequencies of the three classification systems were ypT-category: ypT0=18%, ypT1=14%, ypT2=23%, ypT3=44%, ypT4=1%; Mandard Classification: TRG1=18%, TRG2=26%, TRG3=24%, TRG4=30%, TRG5=2%; and Cologne Regression Scale: no tumor=18%, 1-10% VTC=27%, 10-50% VTC=26% and >50% VTC=29%. The Mandard and Cologne Regression classifications showed better prognostic differentiation for the subgroups than ypT-category. The four-tiered Cologne Regression system had a good prognostic relevance. Comparing results of the reevaluated Cologne Regression classification with the classification by routine pathological report showed very good inter-rater agreement, with kappa value 0.891.

CONCLUSION: Tumor regression grading system using the percentage of residual vital tumor compared to the original primary tumor has prognostic relevance. This article is protected by copyright. All rights reserved.