Long‐term oncological outcomes of the sphincter preserving total mesorectal excision with varying distal resection margins

Abstract

Introduction: A subcentimeter distal resection margin (DRM) appears to be acceptable for most patients, however, long-term follow up and specific subsets where DRM would influence recurrences have not been adequately investigated. Methods: A retrospective analysis of all sphincter-preserving resections for mid and low rectal cancers between July 2011 and May 2015 was performed. Extended total mesorectal excisions (TME) and patients with positive pathologic circumferential margins (CRM) were excluded. Results: Two hundred and thirty-six patients fit the inclusion criteria. DRM > 20 mm was obtained in 117 patients (49.6%), between 10 and 20 mm in 78 (33%) and <10 mm in 41 (17.4%) patients. Pathological DRM was positive in 4 patients (1.7%).Sixty-five recurrences occurred at a median follow up of 78.5 months. DRM did not influence any of the oncological outcomes. In a subset analysis of patients with poor pathological response to neoadjuvant radiation, that is, tumor regression grade > 3, DRM influenced disease-free survival (DFS) but not overall survival with a hazard ratio of 4.4 (p = 0.02). This was confirmed on multivariate regression analysis in this subgroup as well where pathological nodal status and DRM < 10 mm were independent predictors of DFS.Conclusions: A subcentimeter DRM may be acceptable in most patients except those who have an inadequate response to neoadjuvant radiation.With growing enthusiasm for sphincter preservation, many studies have demonstrated that a reduction in the distal resection margin (DRM) allows acceptable oncological outcomes after total mesorectal excision (TME) for rectal cancers. Much has been studied about the length of adequate DRM and we have evolved from historical 5 cm margins to 2 cm 1 and a DRM of less than 1 cm is also currently acceptable after neoadjuvant chemoradiation (CRT). 2 The length of the distal margin depends on the distal intramural spread of

Impact of the distal resection margin on local recurrence after neoadjuvant chemoradiation and rectal excision for locally advanced rectal cancer

“…Other reports have recently analyzed the role of the DRM in patients with rectal cancer 18 . They demonstrated that the DRM did not influence oncologic outcomes, except in patients who had a poor response to neoadjuvant radiation.…”

Comparative study of functional outcomes between ultra‐low anterior resection and inter‐sphincteric resection: a propensity matched analysis

“…Advancements in surgical technique, precise instrumentation and the use of surgical staplers have increased the rate of sphincter preservation without detriment in the long-term oncological outcomes. 1,2 Continence is attributed to several factors: the anal sphincter complex (anatomical) and the rectum with its reservoir and neurological functions (physiological). Surgical treatment changes the structure and the physiology of the anorectum, leading to functional problems.…”

“…Continence is perhaps the most critical issue in treated rectal cancers from a patient's perspective and functional outcomes. Advancements in surgical technique, precise instrumentation and the use of surgical staplers have increased the rate of sphincter preservation without detriment in the long‐term oncological outcomes 1,2 . Continence is attributed to several factors: the anal sphincter complex (anatomical) and the rectum with its reservoir and neurological functions (physiological).…”

Coloanal Anastomosis

“…While there was once considered a 5-cm rule for the distal margin in rectal cancer, the safe distal resection margin has been reduced to 1 cm or less in low rectal tumors with the emergence of neoadjuvant multimodal therapy and tumor downstaging. 1 2 The reduction in distal resection margin has increased the boundaries for sphincter preservation in patients with tumors that were once determined to require an abdominoperineal resection (APR). With an increase in patients who could have sphincter preservation, there is a need to describe technique and options for restoration of intestinal continuity with a colon to anal anastomosis.…”