Prognostic factors in patients with stage yp0-I rectal cancer after preoperative concurrent chemoradiotherapy

Abstract

Objective To determine the prognostic factors in patients with stage yp0-I rectal cancer following preoperative concurrent chemoradiotherapy. Methods Eighty-seven patients who received preoperative concurrent chemoradiotherapy and total mesorectal excision (TME) for stage yp0-I rectal cancer from January 2008 to December 2013 were enrolled into the present study. TME was performed 4-8 weeks after the concurrent chemoradiotherapy (CRT). Whole pelvic radiotherapy was given at a dose of 45.0-50.4 Gy, along with concurrent chemotherapy using capecitabine or capecitabine combined with oxaliplatin. Local recurrence-free survival (LRFS), distant metastasis-free survival (DMFS), disease-free survival (DFS), and overall survival (OS) were calculated using the Kaplan-Meier method, and compared by the Logrank test. Univariate and multivariate prognostic analyses were performed using the Logrank test and the Cox model, respectively. Results The median interval between preoperative CRT and TME surgery was 51 days. Approximately 45% of the patients received adjuvant chemotherapy following TME. The 3-year LRFS, DMFS, DFS, and OS were 98%, 93%, 93%, and 96%, respectively. The multivariate prognostic analysis showed that the downstaging depth score (DDS), which is based on the pre-treatment clinical stage and postoperative pathological stage, was correlated with DMFS and DFS (P=0.020 and 0.005, respectively). The area under the receiver operating characteristic curve of DDS for predicting 3-year DFS was 0.803 at a cut-off value of 5 points. Conclusions Satisfactory long-term survival is achieved in patients with yp0-I stage rectal cancer after preoperative CRT, and DDS can be used as a prognostic factor for long-term survival. Key words: Rectal neoplasms/chemoradiotherapy; Neoplasm stage; Prognosis