The Impact of Tumour Distance From the Anal Verge on Clinical Management and Outcomes in Patients Having a Curative Resection for Rectal Cancer

Abstract

Aim: The clinico-oncological significance of the distance of rectal cancer from the anal verge is unclear and not well reported. The aim of this study is to assess the influence of the rectal cancer distance from the anal verge on clinical management and long-term outcomes after curative resection in a specialised colorectal cancer unit.

Methods: Prospectively collected data on patients who underwent primary rectal cancer treatment at our unit between January 2005 and December 2010 were analysed. Low rectal cancer (LRC) was defined as tumour < 5 cm from the anal verge on MRI scan. Recurrent cancer, palliative resections, perforated tumours and those requiring total pelvic exenteration were excluded.

Results: Three hundred fifty-nine patients underwent surgery for rectal cancer (226 male/133 female). Of these, 149 (41.5%) patients had low rectal cancer (LRC). Compared to patients with mid/upper rectal cancer (M/URC), patients with low rectal cancers were significantly more likely to receive neo-adjuvant therapy (75.2 vs 38%; p < 0.001), to be associated with lower rate of restorative surgery (15.4 vs 79%; p < 0.001) and to have higher rates of pathological positive circumferential resection margin involvement (14.1 vs 7.1%; p = 0.047). There were however no significant difference in the rates of recurrent disease or survival among the two groups.

Conclusion: Distance of rectal cancer from the anal verge does influence the use of neo-adjuvant treatment and ultimate R0 resection rate. It does not influence loco-regional or systemic recurrence rates.

Keywords: Abdominoperineal excision of the rectum (APER); Anterior resection; Circumferential resection margin; Laparoscopic surgery; Rectal cancer; Rectal tumour distance from anal verge; Restorative surgery.