What Is the Ideal Tumor Regression Grading System in @entity5 XXXX After Preoperative Chemoradiotherapy?

@entity5 @entity1 @entity1349
Purpose: Tumor regression grade (TRG) is predictive of therapeutic response in @entity5 @entity1 after chemoradiotherapy (CRT) followed by curative resection. However, various TRG systems have been suggested, with subjective categorization, resulting in interobserver variability. This study compared the prognostic validity of four different TRG systems in order to identify the most ideal TRG system. Materials and Methods: This study included 933 @entity1 who underwent preoperative CRT and curative resection. @entity5 alone were graded according to the AJCC, Dworak, and Ryan TRG systems, and both @entity5 and regional lymph nodes were graded according to a modified Dworak TRG system. The ability of each TRG system to predict @entity1349 ( @entity1349 ) and @entity1349 ( @entity1349 ) was analyzed using   2 and C statistics. Results: All four TRG systems were significantly predictive of both @entity1349 and @entity1349 (P<0.001 each), however none was a better predictor of prognosis than ypStage. Among the four TRGs, the mDworak TRG system was a better predictor of @entity1349 and @entity1349 than the AJCC, Dworak, and Ryan TRG systems, and both the   2 and C statistics were higher for the former, although the differences were not statistically significant. The combination of ypStage and the modified Dworak TRG better predicted @entity1349 and @entity1349 than ypStage alone. Conclusion: s The modified Dworak TRG system for evaluation of entire @entity5 including regional lymph nodes is a better predictor of survival than current TRG systems for evaluation of the @entity5 alone.
