Prognostic Value of Tumor Regression Grade Based on Ryan Score in Squamous Cell Carcinoma and Adenocarcinoma of Esophagus.

Abstract

Tumor regression grade (TRG) of the primary tumor after neoadjuvant therapy is one of the most sensitive prognostic factors among patients with locally advanced esophageal cancer, although no TRG system is fully accepted. The Ryan score was proposed in 2005 to evaluate TRG in rectal cancer and could be adaptable for pathological evaluation of esophageal cancer. The objective of this study is to evaluate the prognostic value of the Ryan score for esophageal cancer in the setting of trimodal therapy. We performed a retrospective cohort study in which patients with locally advanced esophageal cancer, submitted to neoadjuvant therapy followed by surgical resection, were selected. One hundred thirty-four patients were selected. All tissue specimens were assessed as per the TRG system proposed by Ryan et al. Survival curves were assessed by the Kaplan-Meier method and log-rank test. Chi-square test or likelihood-ratio test was used for absolute and relative variables. Kruskal-Wallis and analysis of variance tests were used to assess significant differences on a continuous dependent variable by a categorical independent variable. Of the 134 included patients, 94 (70.1%) had squamous cell carcinoma, and 40 (29.9%) adenocarcinoma. Ryan score was correlated with histological type (p < 0.001), and clinical (p = 0.044) and pathological (p < 0.001) staging. Mean follow-up was 31.1 months. Multivariate analysis showed that Ryan score can safely predict survival, and systemic and lymphatic recurrence (p < 0.05). Ryan score is an effective system to evaluate TRG and can predict risk for lymph node or distant metastasis, overall survival, and disease-free survival.