Factors influencing circumferential resection margin in rectal cancer

Abstract

Aim Abdominoperineal excision (APR) has been associated with higher circumferential resection margin (CRM) involvement and local recurrence rates than extralevator APR for low rectal cancer. This study aimed to evaluate the CRMs in APR and low anterior resection (LAR) specimens and to identify factors influencing CRM involvement. Method All pathological specimens from consecutive patients with rectal cancer who underwent curative resection at the Cleveland Clinic Florida, from January 2000 to July 2010, were reviewed by two pathologists. Demographics, tumour characteristics, operative data, postoperative pathology and Dworak’s tumour regression grade were compared between specimens with positive and negative CRMs. Results One‐hundred and fifty‐four patients underwent curative APR (n = 65) or LAR (n = 69). Mean tumour size was 3.6 cm, and mean distance from the dentate line was 5.4 cm. Nine (6.8%) patients had a positive CRM (n = 6 APR, n = 3 LAR), which was associated with tumour size > 5.9 cm (P = 0.002), a distance of ≤ 2.6 cm from the dentate line (P = 0.013), microvascular invasion (P = 0.009), perineural invasion (P < 0.001), number of positive lymph nodes (P = 0.046) and incomplete total mesorectal excision (TME) (P < 0.001). APR specimens were three times more likely than LAR specimens to have an incomplete mesorectum (9.8%vs 2.9%, P = 0.322). Conclusions Factors associated with a positive CRM were tumour size > 5.9 cm, a distance of ≤ 2.6 cm from the dentate line, incomplete TME, number of positive nodes and microvascular and perineural invasion. The incidence of a positive CRM was not significantly different between LAR and APR (n = 3 LAR and n = 6 APR).

ExtraLevatory AbdominoPerineal Excision (ELAPE) Does Not Result in Reduced Rate of Tumor Perforation or Rate of Positive Circumferential Resection Margin

“…In recent reports from specialized centers, the risk of CRM involvement after modern APE procedures was around 14%. 2,12 Also, in a recent single-center retrospective study with comparable study populations, no oncological advantages were found with ELAPE compared with conventional APE. 7 Positive CRM was found in 17% after ELAPE and 20% after conventional APE.…”

Perineal Transanal Approach

“…19,22,29 It is usually higher in low rectal cancer, as compared with high rectal tumors. 14,30 The reasons are the special anatomy of the lower rectum and the suboptimal surgical technique. The low rectum is characterized by a decreased mesorectal volume with less extrarectal tissue around the rectal tumor, 15 inducing a shorter CRM in term of millimeters 5 and subsequently an increased risk of positive CRM.…”

Lower Gastrointestinal Surgery: Robotic Surgery versus Laparoscopic Procedures

“…Similar to poor TME quality, a significant association of positive CRM with low tumors has been demonstrated [40,42].…”

“…Especially in circumferential resection margin(CRM)-negative patients, substantial damage to the mesorectal specimen is a main risk factor for local recurrence [41]. Poor quality of mesorectal resection has been shown to be associated with low rectal tumors [40,42].…”