REVIEWS Minimal access surgery for rectal cancer: an update Vanessa W. Hui and José G. Guillem Abstract | Minimally invasive or minimal access surgery (MAS) for colon and rectal cancer was introduced in the early 1990s. Although laparoscopic colon surgery is now practiced worldwide, technical barriers, including a steep learning curve, preclude the widespread adoption of MAS techniques for rectal cancer. In addition, although randomized controlled trials have demonstrated that MAS techniques for colon cancer are oncologically equivalent to open surgery, similar confirmatory studies for rectal cancer have yet to be reported. In this Review, current evidence in support of laparoscopic and robotic total mesorectal excision for rectal cancer resection is presented. Other MAS approaches, such as transanal endoscopic microsurgery and natural orifice transluminal endoscopic surgery, are also discussed. Hui, V. W. & Guillem, J. G. Nat. Rev. Gastroenterol. Hepatol. 11, 158–165 (2014); published online 5 November 2013; doi:10.1038/nrgastro.2013.203

Introduction

Department of Surgery, Colorectal Service, Memorial SloanKettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA (V. W. Hui, J. G. Guillem).

Current minimally invasive or minimal access surgery (MAS) approaches for colorectal cancer include multiport and single-port laparoscopy, robotic-assisted resection, transanal endoscopic microsurgery (TEM) and natural orifice transluminal endoscopic surgery (NOTES). Concerns were initially raised regarding the feasibility and oncologic safety of laparoscopic colon cancer resection. However, several multicentre random­ized controlled trials (RCTs) have now demonstrated that laparoscopic colon resection is oncologically equivalent to open resection in terms of providing a curative resection. Laparoscopy also provides additional peri­operative benefits, such as faster return of bowel function, less surgical blood loss and shorter hospital stay, than open surgery.1–5 Reservations of clinicians regarding MAS for rectal cancer are generally twofold. First, unlike l­aparoscopic colon cancer resection, the long-term safety and o­ncologic outcomes of rectal MAS have not been complet­ely substantiated. Thus far, only one RCT has reported outcomes and others are ongoing.6–11 Second, rectal cancer resection is technically more demanding than colon cancer resection, as the surgeon strives to perform a sphincter-preserving­ total mesorectal excision (TME) within the confines of a bony pelvis. The steep learning curve associated with performing a proper TME via open surgery or MAS approaches further complicates an already challenging procedure. When considering a MAS approach for rectal cancer, the surgeon must consider technical challenges, feasibility, functional outcomes and oncologic safety. Definitive data supporting MAS techniques for rectal cancer have yet to be reported. Here, we summarize available evidence that addresses the oncologic efficacy,

Correspondence to: J. G. Guillem [email protected]

Competing interests The authors declare no competing interests.

158  |  MARCH 2014  |  VOLUME 11

technical safety and potential benefits of laparoscopic, robotic and TEM approaches for rectal cancer. We also examine some of the potential barriers associated with their implementation in clinical practice.

Standard laparoscopic surgery Although laparoscopy for rectal cancer is currently widely practiced, to date only one large multicentre RCT comparing laparoscopic TME with open TME has been able to report long-term survival data.4 The evidence from this study, as well as other studies regarding laparoscopic rectal cancer resection, are discussed below.

Efficacy Several single-centre RCTs have noted that the number of harvested lymph nodes, circumferential resection margin (CRM) and distal margin positivity were compar­ able for specimens resected by open versus laparoscopic TME.12–17 These studies also noted comparable estimated 5‑year local recurrence rates, disease-free survival (DFS) and overall survival among the two groups. Although these studies support the use of laparoscopic TME, the reliability of the data is limited, given the small sample sizes, single-institution participation and probable associated biases, such as study criteria limited to either the inclusion of rectosigmoid or upper rectal cancers, with few, if any, mid-to-distal rectal cancers.12,15–17 The Medical Research Council conventional versus laparoscopic-assisted surgery in colorectal cancer (MRC CLASICC) trial, the first and only multicentre RCT with long-term outcomes, provides strong support for the oncologic equivalence of laparoscopic TME, in terms of providing a curative resection.4,18,19 The study cohort comprised 794 patients with colorectal cancer, approximately 63% of whom had at least T3 disease and 34%



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REVIEWS Key points ■■ Laparoscopy for colon cancer resection is a widely practiced minimally invasive or minimal access surgery (MAS) technique ■■ MAS techniques have been shown to be oncologically equivalent to open rectal cancer resection in terms of the number of harvested lymph nodes and margin negativity ■■ Barriers such as a steep learning curve and the lack of long-term data on recurrence and survival preclude the widespread use of MAS approaches for rectal cancer ■■ Several ongoing studies are evaluating the use of transanal endoscopic microsurgery for post-treatment rectal cancers that were initially staged at T 2 or higher ■■ Natural orifice transluminal endoscopic surgery remains an investigational approach for rectal cancer resection at this time

had at least N1 disease. Analyses were performed on the cohort of 381 (48%) patients with rectal cancer, 253 (66%) of whom were randomly assigned to undergo laparo­ scopic TME and 128 (34%) open TME. Lymph node yield was similar amongst the two groups.4 Although patients who underwent a laparoscopic anterior resection (presumably for rectal cancer) had what seems to be greater CRM positivity than those who underwent open surgery, no statistical significance was observed (P = 0.19), nor did this finding translate to a difference in long-term survival (Table 1).4,18,19 3-year local recurrence rates (9.7% versus 10.1%), DFS (66.3% versus 67.7%) and overall survival (68.4% versus 66.7%) were compar­able amongst the laparoscopic and open groups.18 The 5‑year local recurrence rate was 17.7% for laparoscopic TME compared with 8.9% for open TME, but this difference was not statistically significant. Furthermore, no

differences were observed in 5‑year DFS (53.2% versus 52.1%) and overall survival (60.3% versus 52.9%) when comparing laparoscopic TME with open TME.19 Wound or port-site tumour seeding was initially a concern with laparoscopy for colorectal cancer; the CLASICC study, however, observed only a 1.9% i­ncisional recurrence at 5 years in both arms.18,19 Early data from the ongoing COREAN (comparison of open versus laparoscopic surgery for mid and low rectal cancer after neoadjuvant chemoradiotherapy) trial also suggest that laparoscopic TME is oncologically compar­ able to open resection in terms of providing a curative resection.6 The COLOR II (colorectal cancer laparoscopic or open resection) trial, an international multicentre RCT, reported similar short-term outcomes (such as comparable numbers of harvested lymph nodes, CRM positivity and complications) between laparoscopic and open groups.20 Survival and local recurrence outcomes from these studies are forthcoming. The Japan Clinical Oncology Group (JCOG0404) and the American College of Surgeons (ACOSOG Z6051) trials are other multi­ centre RCTs awaiting completion and data maturation.9,10 Table 1 is an abbreviated summary of some perioperative end points measured in these multicentre RCTs.

Safety In expert hands, TME-based rectal cancer resection along with autonomic nerve preservation is technically feasible using a laparoscopic approach.21,22 Several nonrandomized trials and case studies demonstrate equiv­ alent outcomes for laparoscopic and open techniques, including similar rates of mortality and morbidity,

Table 1 | Perioperative results from RCTs comparing laparoscopic TME with open TME Trial

CLASICC*

COLOR II

COREAN

ACOSOG Z6051

JCOG 0404*

Sample size (n)

381

1,044

340

650‡

1,050‡

Lap:open (n)

253:128

699:345

170:170

ND

ND

Lesions

cT0–4N0–2 Rectum

T0–3N0–2 ≤15 cm from anal verge

cT3N0–2 ≤9 cm from anal verge

cT3N0 or cT1–3N1–2 ≤12 cm from anal verge

cT3N0–2 Rectosigmoid tumour

Minimal access surgery for rectal cancer: an update.

Minimally invasive or minimal access surgery (MAS) for colon and rectal cancer was introduced in the early 1990s. Although laparoscopic colon surgery ...
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