Oncological outcomes of multimodality treatment for patients undergoing surgery for locally recurrent rectal cancer: A systematic review

Background: There are several strategies in the management of locally recurrent rectal cancer (LRRC) with the optimum treatment yet to be established. This systematic review aims to compare oncological outcomes in patients undergoing surgery for LRRC who underwent neoadjuvant radiotherapy or chemoradiotherapy (CRT), adjuvant CRT, surgery only or surgery and intraoperative radiotherapy (IORT). Methods: A literature search of MEDLINE, EMBASE and CINAHL was performed for studies that reported data on oncological outcomes for the different treatment modalities in patients with LRRC from January 1990 to January 2022. Weighted means were calculated for the following outcomes: postoperative resection status, local control, and overall survival at 3 and 5 years. Results: Fifteen studies of 974 patients were included and they received the following treatment: 346 neoadjuvant radiotherapy, 279 neoadjuvant CRT, 136 adjuvant CRT, 189 surgery only, and 24 surgery and IORT. The highest proportion of R0 resection was found in the neoadjuvant CRT group followed by neoadjuvant radiotherapy and adjuvant CRT groups (64.07% vs 52.46% vs 47.0% respectively). The neoadjuvant CRT group had the highest mean 5-year local control rate (49.50%) followed by neoadjuvant radiotherapy (22.0%). Regarding the 5-year overall survival rate, the neoadjuvant CRT group had the highest mean of 34.92%, followed by surgery only (29.74%), neoadjuvant radiotherapy (28.94%) and adjuvant CRT (20.67%). Conclusions: The findings of this systematic review suggest that neoadjuvant CRT followed by surgery can lead to improved resection status, long-term disease control and survival in the management of LRRC. However, treatment strategies in LRRC are complex and further comparisons, particularly taking into account previous treatments for the primary rectal cancer, are required.