on behalf of the Dutch ColoRectal Cancer Audit Group BACKGROUND: Transanal total mesorectal excision (TaTME) is a relatively new and demanding technique for rectal cancer treatment. Results from national datasets are absent and comparative data with laparoscopic TME (lapTME) are scarce. Therefore, this study aimed to evaluate the initial TaTME experience in the Netherlands, by comparing outcomes with conventional lapTME. STUDY DESIGN: Patients with rectal cancer who underwent curative TaTME or lapTME were selected from the nationwide and mandatory Dutch ColoRectal Audit (DCRA), between January 2015 and December 2017. Primary outcome was circumferential resection margin (CRM) involvement. Secondary outcomes included operative details and short-term (<30 days) clinical course. Propensity score matching was performed for 7 factors. RESULTS: There were 3,777 patients included for analysis (TaTME, n ¼ 416, lapTME, n ¼ 3361). Transanal TME was performed in 38 hospitals and lapTME in 90 hospitals. Before matching, the patient category within the TaTME group was technically more challenging in terms of tumor height and preoperative threatened margins. After 1:1 matching, 396 patients were included in each group, with comparable baseline characteristics. Circumferential resection margin involvement was 4.3% after TaTME and 4.0% after lapTME (p ¼ 1.000). Conversion rate was significantly lower in TaTME (1.5% vs 8.6%, p < 0.001). Anastomotic leak rate was not significantly different (16.5% vs 12.2%, p ¼ 0.116). Other postoperative outcomes were also comparable between the groups. Significant independent risk factors for CRM involvement in TaTME were preoperative threatened margin on MRI (odds ratio [OR] 5.48, 95% CI 1.33 to 22.54) and conversion (OR 30.12, 95% CI 3.70 to 245.20). CONCLUSIONS: This first nationwide study shows early experience with adoption of TaTME in the Netherlands. Considering that current data represent initial TaTME experience, acceptable short-term outcomes were demonstrated when compared with the well-established lapTME.

Background: The risks of local recurrence and treatment-related morbidity need to be balanced after local excision of early rectal cancer. The aim of this meta-analysis was to determine oncological outcomes after local excision of pT1-2 rectal cancer followed by no additional treatment (NAT), completion total mesorectal excision (cTME) or adjuvant (chemo)radiotherapy (aCRT). Methods: A systematic search was conducted in PubMed, Embase and the Cochrane Library. The primary outcome was local recurrence. Statistical analysis included calculation of the weighted average of proportions. Results: Some 73 studies comprising 4674 patients were included in the analysis. Sixty-two evaluated NAT, 13 cTME and 28 aCRT. The local recurrence rate for NAT among low-risk pT1 tumours was 6⋅7 (95 per cent c.i. 4⋅8 to 9⋅3) per cent. There were no local recurrences of low-risk pT1 tumours after cTME or aCRT. The local recurrence rate for high-risk pT1 tumours was 13⋅6 (8⋅0 to 22⋅0) per cent for local excision only, 4⋅1 (1⋅7 to 9⋅4) per cent for cTME and 3⋅9 (2⋅0 to 7⋅5) per cent for aCRT. Local recurrence rates for pT2 tumours were 28⋅9 (22⋅3 to 36⋅4) per cent with NAT, 4 (1 to 13) per cent after cTME and 14⋅7 (11⋅2 to 19⋅0) per cent after aCRT. Conclusion: There is a substantial risk of local recurrence in patients who receive no additional treatment after local excision, especially those with high-risk pT1 and pT2 rectal cancer. The lowest recurrence risk is provided by cTME; aCRT has outcomes comparable to those of cTME for high-risk pT1 tumours, but shows a higher risk for pT2 tumours.

No signs of risk averse behaviour was found since the start of the audit. Especially the high-risk elderly patients seem to have benefitted from improvements made in colon cancer treatment in the past 8 years. For rectal cancer, trends towards the construction of more primary anastomoses are seen. Future quality improvement measures should focus on reducing surgical and non-surgical complications.