Appropriate Timing of Surgery after Neoadjuvant ChemoRadiation Therapy for Locally Advanced Rectal Cancer

Background: Surgery is the corner stone for the management of rectal cancer. The purpose of this study was to demonstrate the optimal time of surgical resection after the completion of neoadjuvant chemo-radiotherapy (CRT) in treatment of locally advanced rectal cancer. Materials and Methods: This study compared 2 groups of patients with locally advanced rectal cancer, treated with neoadjuvant CRT followed by surgical resection either 6-8 weeks or 9-14 weeks after the completion of chemo-radiotherapy. The impact of delaying surgery was tested in comparison to early surgical resection after completion of chemo-radiotherapy. Results: The total significant response rate that could result in functional preservation was estimated to be 3.85% in group I and 15.4% in group II. Some 9.62% of our patients had residual malignant cells at one cm surgical margin. All those patients with positive margins at one cm were in group I (19.23%). There was less operative time in group II, but the difference between both groups was statistically insignificant (P0.845). The difference between both groups regarding operative blood loss and intra operative blood transfusion was significantly less in group II (P0.044). There was no statistically significant difference between both groups regarding the intra operative complications (P0.609). The current study showed significantly less post-operative hospital stay period, and less post-operative wound infection in group II (P0.012 and 0.017). The current study showed more tumor regression and necrosis in group II with a highly significant main effect of time F61.7 (P<0.001). Pathological TN stage indicated better pathological tumor response in group II (P0.04). The current study showed recurrence free survival for all cases at 18 months of 84.2%. In group I, survival rate at the same duration was 73.8%, however none of group II cases had local recurrence (censored) (P0.031). Disease free survival (DFS) during the same duration (18 months) was 69.4 % for patients in group I and 82.3% for group II (P0.429). Conclusions: Surgical resection delay up to 9-14 weeks after chemo-radiation was associated with better outcome and better recurrence free survival.