Treatment for rectal cancer is very standardized. However, for total mesorectal excision (TME) with positive margins at microscopic pathological examination (classified R1 ), there is no consensus regarding management. The objective of this update was, through a review of the literature, to identify the most suitable management to improve overall survival and/or recurrence-free survival after R1 TME for rectal cancer.

Published national quality guidelines and original studies were searched on Pubmed. Only studies and recommendations concerning the specific management of patients who had undergone R1 TME resection were selected.

Five original non-randomized studies and seven published national quality guidelines were selected for review. For patients who have undergone R1 TME resection, the French and European published guidelines issued a Grade A recommendation in favor of post-operative radio-chemotherapy (RCT) for those in whom it had not already been performed pre-operatively. The French and European guidelines recommendation for adjuvant chemotherapy was based only on expert agreement. The original studies emphasized the survival benefit of adjuvant chemotherapy, as opposed to post-operative RCT, which did not seem to improve survival. Salvage surgery was not recommended in any of the studies.

After R1 TME resection for rectal cancer, adjuvant chemotherapy seems to be indicated when feasible, whereas post-operative RCT and salvage surgery do not appear to improve patient survival.