A population-based study of the management of rectal malignant polyps and the use of trans-anal surgery

Rectal malignant polyps can be managed by use of trans-anal resections (TAR). Traditional techniques of resection have been replaced by use of platforms such as trans-anal minimally invasive surgery (TAMIS) or trans-anal endoscopic microsurgery (TEM). This study reviewed the management of rectal malignant polyps, in particular focussing on when clinicians used TAR.

A population wide cohort study of all malignant rectal polyps diagnosed in Queensland, Australia from 2011 to 2018 was undertaken. Patient and pathological factors were compared across the management strategies of polypectomy, TAR and rectal resection.

Overall 430 patients were diagnosed with a malignant rectal polyp during the study period, with 103 undergoing a TAR. There was increasing use of TAR across the study period as a management strategy (P < 0.001). Polypectomy alone was more likely to be the management strategy over TAR or rectal resection if there were clear margins (P < 0.001). The distance to the closest polypectomy margin was also significantly higher in the polypectomy group with mean clearance 2.09 mm in polypectomy group versus 0.86 mm in TAR group and 0.99 mm in resection group (P < 0.001). Rectal resection was more likely to be the management strategy over TAR if there was LVI (P < 0.001), depth of invasion was deeper (P < 0.001) and there was tumour budding (P = 0.001).

TAR is an effective management strategy for rectal polyps and is utilized particularly in rectal malignant polyps when there are close or involved margins. Future guideline development should consider incorporation of TAR given the advances in techniques afforded by TAMIS or TEM platforms.