Analysis Of Influencing Factors And Prognostic Significance Of Tumor Regression Grade In Patients With Rectal Carcinoma Treated With Neoadjuvant Therapy

Objective:To explore the impact of clinicopathologic factors and prognostic value of tumor regression grade after neoadjuvant therapy in locally advanced rectal cancer.Methods:This study consisted of 292 consecutive patients with locally advanced rectal cancer treated with neoadjuvant chemoradiotherapy followed by radical surgery form January 2010 to December 2014 at the Colorectal Surgery Department in Fujian Union Hospital.Biopsy specimens were reevaluated to identify tumor regression grading(TRG)by using the seventh edition of the American Joint Committee On Cancer(AJCC)scoring standard.Univariate and multivariate analysis were used to analyze the clinicopathologic factors associated with TRG by X2 test or Fisher exacttest and logistic regression analysis.The survival was estimated by the Kaplan-Meier method,and the differences between groupswere compared with the Log-rank test.Multivariate analysis was performed by Cox's model.Results: TRG0,TRG1,TRG2 and TRG3 were found in 12.0%?33.6%?45.9%and 8.5%of the resected specimens respectively.Univariate analysis showed that the circumferential extent of tumor(P=0.024),the interval between preoperative chemoradiotherapy(CRT)and surgery(P=0.014),Preoperative chemotherapy regimen(P=0.024)were correlated with AJCC.Multivariate analysis revealed that the circumferential extent of tumor(<1/2 cycle),the interval between CRT and surgery(? 6 weeks)were independent factors for tumor regression(P<0.05).The 5-year overall survival(OS)of all patients was 85.8%.Five-year disease-free survival(DFS)after neoadjuvant therapy and radical surgery was 85.7%for TRG0,77.6%for TRG1,72.4% for TRG2 and 44.0%for TRG3.Multivariate analysis showed that the yp N stage was the most important independent prognostic factor for DFS.Conclusions:Patients undergoing preoperative radiochemotherapy with less circumferential extent of tumor and longer interval between CRT and surgery were more likely to achieve better tumor regression.Good TRG response improved DFS after preoperative CRT.yp N stage was the strongest prognostic factor for all three end points.