Robin Detering

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.

Background: Adequate MRI-based staging of early rectal cancers is essential for decision-making in an era of organ-conserving treatment approaches. The aim of this population-based study was to determine the accuracy of routine daily MRI staging of early rectal cancer, whether or not combined with endorectal ultrasonography (ERUS). Methods: Patients with cT1–2 rectal cancer who underwent local excision or total mesorectal excision (TME) without downsizing (chemo)radiotherapy between 1 January 2011 and 31 December 2018 were selected from the Dutch ColoRectal Audit. The accuracy of imaging was expressed as sensitivity, specificity, and positive predictive value (PPV) and negative predictive value. Results: Of 7382 registered patients with cT1–2 rectal cancer, 5539 were included (5288 MRI alone, 251 MRI and ERUS; 1059 cT1 and 4480 cT2). Among patients with pT1 tumours, 54·7 per cent (792 of 1448) were overstaged by MRI alone, and 31·0 per cent (36 of 116) by MRI and ERUS. Understaging of pT2 disease occurred in 8·2 per cent (197 of 2388) and 27·9 per cent (31 of 111) respectively. MRI alone overstaged pN0 in 17·3 per cent (570 of 3303) and the PPV for assignment of cN0 category was 76·3 per cent (2733 of 3583). Of 834 patients with pT1 N0 disease, potentially suitable for local excision, tumours in 253 patients (30·3 per cent) were staged correctly as cT1 N0, whereas 484 (58·0 per cent) and 97 (11·6 per cent) were overstaged as cT2 N0 and cT1–2 N1 respectively. Conclusion: This Dutch population-based analysis of patients who underwent local excision or TME surgery for cT1–2 rectal cancer based on preoperative MRI staging revealed substantial overstaging, indicating the weaknesses of MRI and missed opportunities for organ preservation strategies.

Aim: This study aimed to determine predictive factors for the circumferential resection margin (CRM) within two northern European countries with supposed similarity in providing rectal cancer care.Method: Data for all patients undergoing rectal resection for clinical tumour node metastasis (TNM) stage I–III rectal cancer were extracted from the Swedish ColoRectal Cancer Registry and the Dutch ColoRectal Audit (2011–2015). Separate analyses were performed for cT1–3 and cT4 stage. Predictive factors for the CRM were determined using univariable and multivariable logistic regression analyses.Results: A total of 6444 Swedish and 12 089 Dutch patients were analysed. Over time the number of hospitals treating rectal cancer decreased from 52 to 42 in Sweden, and 82 to 79 in the Netherlands. In the Swedish population, proportions of cT4 stage (17% vs 8%), multivisceral resection (14% vs 7%) and abdominoperineal excision (APR) (37% vs 31%) were higher. The overall proportion of patients with a positive CRM (CRM+) was 7.8% in Sweden and 5.4% in the Netherlands. In both populations with cT1–3 stage disease, common independent risk factors for CRM+ were cT3, APR and multivisceral resection. No common risk factors for CRM+ in cT4 stage disease were found. An independent impact of hospital volume on CRM+ could be demonstrated for the cT1–3 Dutch population.Conclusion: Within two northern European countries with implemented clinical auditing, rectal cancer care might potentially be improved by further optimizing the treatment of distal and locally advanced rectal cancer.

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. 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. There were 3,777 patients included for analysis (TaTME, n = 416, lapTME, n = 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 = 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 = 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). 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.