Transanal total mesorectal excision for abdominoperineal resection is associated with poor oncological outcomes in rectal cancer patients: A word of caution from a multicentric Canadian cohort study

Abstract

Aim:The main objective of this study was to compare the oncological outcomes of patients undergoing abdominoperineal resection (APR) versus low anterior resection (LAR) through a transanal total mesorectal excision (taTME) approach.Method: A total of 360 adult patients with a diagnosis of rectal cancer were enrolled at participating centres from the Canadian taTME Expert Collaboration. Forty-three patients received taTME-APR and received 317 taTME-LAR. Demographic, operative, pathological and follow-up data were collected and merged into a single database. Results are presented as hazard ratio (HR) and 95% confidence interval. All analyses were performed in the R environment (v.3.6). Results:The proportion of patients with a positive circumferential radial margin status was higher in the taTME-APR group than the taTME-LAR group (21% vs. 9%, p = 0.001).Complete TME was achieved in 91% of those undergoing APR compared with 96% of those undergoing LAR (p = 0.25). APR was associated with a greater rate of local recurrence relative to LAR, although it was not significant [crude HR = 3.53 (95% CI 0.92-13.53)]. Circumferential margin positivity was significantly associated with a higher rate of systemic recurrence [crude HR = 3.59 (95% CI 1.38-9.3)]. Conclusion:Our results demonstrate inferior outcomes in those undergoing taTME-APR compared with taTME-LAR. The use of this technique for this particular indication needs to be carefully considered.

Response to Raj et al Abdominoperineal resection by trans‐anal TME approach: are we refuting the technology a bit too early?

“…Dear Editor, We congratulate Williams et al [1] for their article describing a well-organised set-up for implementing neoadjuvant chemotherapy (NAC) for locally advanced colon cancer (T3-4 with extramural extension ≥5 mm) following the results of the FOxTROT trial [2]. The results of FOxTROT trial were withheld for 3 years if one ignores the contradictory results presented as abstracts.…”

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We thank Raj et al for their interest in our recent publication 'Transanal total mesorectal excision for abdominoperineal resection (taTME-APR) is associated with poor oncological outcomes in rectal cancer patients.A word of caution from a multicentric Canadian cohort study' [1]. We are appreciative of the opportunity to further explain the objectives, methodology and findings of our study.

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“…A word of caution from a multicentric Canadian cohort study' [1]. We are appreciative of the opportunity to further explain the objectives, methodology and findings of our study.…”

“…Nagtegaal et al [3] called for a change of approach in APR as they recognized these findings to be associated with the quality of surgery. Since the evidence points to the problem being technical in nature, we hypothesize that its mechanical effect is based on not having a 'protective' physical envelope that maintains tissue planes together, allowing for exposure of the 'waist', which also occurs during traction of the surgical specimen during taTME; therefore it could potentially require a technique in which no to minimal traction is applied [1].…”

Transanal total mesorectal excision for abdominoperineal resection is associated with poor oncological outcomes in rectal cancer patients: A word of caution from a multicentric Canadian cohort study

“…We read with interest the study by Caycedo-Marulanda et al [1] on the oncological outcomes of transanal total mesorectal excision (taTME), comparing abdominoperineal resection (APR) versus low anterior resection (LAR) at participating centres from the Canadian taTME Expert Collaboration (CaTaCO). Patients receiving an APR have historically experienced worse oncological outcomes than those undergoing a LAR [2].…”