Implementation of transanal minimally invasive surgery (TAMIS) for rectal neoplasms: results from a single centre.

BACKGROUND: Local excisions are important in a tailored approach to treatment of rectal neoplasms. In cases of low risk T1 local excision facilitates rectal-preserving treatment. Transanal minimally invasive surgery (TAMIS) is the most recent alternative developed for local excision. In this study we evaluate the results after implementing TAMIS as the routine procedure for local excision of rectal neoplasms. METHODS: All patients who underwent TAMIS from January 2016 to January 2020 at St. Olav's University Hospital were included, and clinical, pathological and oncological data were prospectively registered. The primary endpoint was local recurrence, and the secondary endpoint was complications. RESULTS: There were 76 patients (42 men, mean age was 69 years [range 26-88 years]), The mean tumour level was 82 mm (range 20-140 mm) from the anal verge measured on rigid proctoscopy, and mean tumour size was 32 mm (range 8-73 mm). Three patients experienced complications needing intervention (Clavien-Dindo > 3A). Seventeen patients had rectal adenocarcinoma, 9 of whom underwent R0 completion total mesorectal excision (cTME). Fifty-five patients had an adenoma, 3 of whom developed recurrence (5.4%) within 12 months. All recurrences were treated successfully with a new TAMIS procedure. In addition, TAMIS was used in treatment of 2 patients with a neuroendocrine tumour, 1 patient with a haemangioma and 1 patient with a solitary rectal ulcer. CONCLUSIONS: TAMIS surgery is associated with a low risk of complications and a low recurrence rate in rectal neoplasms. In cases of adenocarcinoma, R0 cTME surgery is feasible in the sub-group with high risk T1 and T2 tumours.

Improved local control of rectal cancer reduces distant metastases.

AIM: The purpose of the present national study was to determine whether improved local control has been accompanied by a change in the incidence of metastases. METHOD: The data were from a national population-based rectal cancer registry and included all 6501 rectal cancer patients treated for cure. The study periods were 1993-1997, 1998-2000, 2001-2003 and 2004-2006. RESULTS: Major changes in the handling of rectal cancer from the first to the last study period included an increased use of MRI from zero to 81% and the use of preoperative radiotherapy from 5% to 20%. The proportion of patients with circumferential resection margin (CRM) ≤2mm decreased from 23% to 13%. The 4-year rate of local recurrence decreased from 13% to 8% (P<0.001), the overall survival increased from 65% to 73% (P<0.001) and the incidence of distant metastases decreased from 25% to 19% (P<0.001) from the first to the last period. The risk of metastases decreased by 29% (hazard ratio 0.71, 95% CI 0.60-0.84). CONCLUSION: Improved diagnostics and treatment of rectal cancer aiming at better local control and survival have resulted in a significant reduction in the incidence of distant metastases.

What is a safe distal resection margin in rectal cancer patients treated by low anterior resection without preoperative radiotherapy?

AIM: The aim of this study was to examine what constitutes an acceptable distal resection margin (DRM) when performing sphincter-saving surgery for rectal cancer without preoperative radiotherapy. METHOD: This national study consisted of 3571 patients for whom information on DRM was available and who were radically treated by anterior resection between 1993 and 2004. Of these, 3342 (93.5%) patients had not received preoperative radiotherapy. The DRM was measured on fixed specimens. RESULTS: The 5-year local recurrence rate was 14.5% for patients with a DRM of 0-10 mm compared to 9.6% for patients with a DRM of 11-20 mm, 8.9% for a DRM of 21-30 mm, 7.0% for a DRM of 31-40 mm, 7.7% for a DRM of 41-50 mm and 8.7% for a DRM of > 50 mm. After adjustment for other independent prognostic factors, a DRM of 0-10 mm was found to have significant impact on local recurrence. The DRM had no impact on distant metastases or overall survival. CONCLUSION: For rectal cancer patients treated without radiotherapy, a DRM of > 10 mm is recommended.

Circumferential resection margin as a prognostic factor in rectal cancer.

BACKGROUND: This study examined the prognostic impact of the circumferential resection margin (CRM) in patients with rectal cancer treated by total mesorectal excision (TME) with or without radiotherapy. METHODS: A national population-based rectal cancer registry included 3196 patients with known CRM status between 1993 and 2004. Some 90.5 per cent of the patients had surgery alone and 9.5 per cent had preoperative radiotherapy. Patients who did not have TME, those in whom the CRM was not measured, patients with intraoperative bowel or tumour perforation and those who received postoperative radiotherapy were excluded. RESULTS: Five-year local recurrence, distant metastasis and overall survival rates were 23.7, 43.9 and 44.5 per cent respectively for patients with a CRM of 0-2 mm, compared with 8.9, 21.7 and 66.7 per cent respectively for those with wider margins. A CRM of 2 mm or less had an impact on the prognosis of T2 and T3 tumours located 6-15 cm above the anal verge, but not on lower tumours. CRM also had a prognostic impact on the three endpoints in patients who received preoperative radiotherapy, but with less precision. CONCLUSION: A CRM of 2 mm or less confers a poorer prognosis and patients should be considered for neoadjuvant treatment.