Prognostic value of the post-operative red blood cell distribution width in patients with rectal cancer with neoadjuvant chemoradiation followed by surgery

Purposes: Several studies have reported that elevated red cell distribution width (RDW) is related to poor prognosis in several cancers; however, the prognostic significance of perioperative RDW in patients with rectal cancer that received neoadjuvant chemoradiation therapy (NACRT) is unclear. Methods: A total of 120 patients with rectal cancer who received NACRT followed surgery were retrospectively reviewed from Affiliated Cancer Hospital of Zhengzhou University between 2013 and 2015. Data for peripheral blood tests prior to the initiation of NACRT, before surgery and first chemotherapy after surgery were collected, respectively. The optimal cutoff values of RDW were determined by ROC analysis, respectively. The relationship between RDW and the prognosis of patients was evaluated by the Kaplan Meier method, respectively. Results: The post-operative RDW(High) patients had significantly worse 5-year overall survival (OS, P=0.001) and disease-free survival (DFS, P<0.001) than the post-operative RDW(Low) patients, respectively. Whereas high pre-operative RDW was the only marker correlated with worse DFS (P=0.005) than the pre-operative RDW(Low) patients, no relationship was found between pre-RDW and prognosis (OS, P=0.069; DFS, P=0.133). Multivariate analysis showed post-operative RDW had better predictive value than pre-RDW and pre-operative RDW. Conclusion: Post-operative RDW might be a useful prognostic indicator in patients with rectal cancer received neoadjuvant chemoradiation.