Comment on: Oncological outcomes after transanal total mesorectal excision for rectal cancer

We read with interest the descriptive study by Francis et al.1 on the clinical outcomes of transanal (ta) total mesorectal excision (TME). The authors abstracted data from centres that already contribute to the International taTME registry. It is unclear whether the data had already been published elsewhere. We feel that we would be contributing to the external validity of the core message with following comments. We have concerns about the indications for taTME in the study. The main advantage touted for taTME seems to be the surgeon’s ability to control the distal margin visually. Nonetheless, three patients had an involved distal resection margin. The median tumour distance from the anal verge was 7 cm, the median BMI was 28 kg/m2, and no data on gynaecoid and/or android pelvis was provided. Most of said patients could have been offered transabdominal TME as they were neither obese, nor did they present with distal rectal cancer. The authors did not specify what proportion of the cohort received total neoadjuvant therapy or adjuvant chemotherapy. Such data are critical in evaluating the disease-free and overall survival rates. The authors reported a local recurrence rate of 7.3 per cent (but not whether it was unifocal or multifocal), despite the fact that 50.8 per cent of the patients had T0, T1, or T2 disease. Seminal RCTs on patients with locally advanced disease (T3, T4 or N+ status) who have undergone transabdominal TME reported rates ranging from 4.0 to 6.9 per cent. Finally, patients with comparable characteristics who underwent transabdominal TME should have been included as a control group. In fact, a previous study with a similar crude rate of local recurrence discovered that taTME conferred a significantly increased local recurrence rate compared with transabdominal TME only when a Cox regression analysis stratified by several variables and TN stage was performed.