Total mesorectal excision in colorectal cancer

Stephanie Breukink
MD PhD
Surgeon
The Queen Elizabeth Hospital
Adelaide, Australia

Colorectal cancer is one of the most common cancers in the Western world. Considerable progress has been made over the last two decades in the management of patients with rectal cancer. The total mesorectal excision (TME) technique creates the best chance for cure in these patients.(1) This technique uses an avascular plane between the presacral fascia and the fascia propria to include the entire mesorectum. In this fashion, local tumour extension, tumour deposits and micrometastases in the mesorectum are radically removed en bloc with the tumour. Adjuvant therapy by short-term preoperative radiotherapy leads to an additional reduction of local recurrence rate.(2) The laparoscope may facilitate mobilisation of the rectum and may limit autonomic nerve disruption due to optimal
visualisation and magnification of the pelvic cavity.

Discussion
Although the technical feasibility of laparoscopic total mesorectal excision (LTME) surgery has previously been reported by several authors, most of these data are from uncontrolled observational studies.(3) In a prospective nonrandomised study we assessed the feasibility and short-term outcome of LTME after short-term preoperative radiotherapy and compared the results with a matched-control group of open TME (OTME).(4) A series of 41 patients with primary rectal cancer underwent LTME for rectal cancer and were matched with a historical control group of 41 patients who underwent OTME. There was no mortality in the LTME group and 2% mortality in the OTME group. The overall postoperative morbidity was 37% in the LTME group and 51% in the OTME group, including an anastomotic leakage of 9% and 14% in the LTME and OTME groups, respectively. In addition to less blood loss, a quicker return to normal diet and a shorter hospital stay (12 vs 19 days) were found for the laparoscopic group (4 vs 7 days). This study indicates that LTME surgery is feasible, has clinically relevant short-term advantages and may result in a lower morbidity than open resection.

This is in accordance with a systematic review and a recent published meta-analysis both describing LTME under traditional perioperative treatment for rectal cancer.(5)

Concomitant with the laparoscopic developments, evidence is accumulating that accelerated multimodal rehabilitation programmes result in significantly improved postoperative recovery in open colonic surgery. Compared with colonic surgery, rectal surgery is considered to result in a longer postoperative stay and more morbidity. There is a lack of evidence regarding the positive effect of accelerated multimodal rehabilitation programmes for OTME. In a recently published randomised clinical trial, an enhanced recovery programme has been applied comparing laparoscopic and open surgery for colo­rectal cancer. In this study of 60 patients, 15 patients with rectal cancer underwent a laparoscopic resection (12 low anterior resection; three abdomoniperineal resection) and five patients underwent open resection (four low anterior resection; one abdominoperineal resection). Despite the small study size, better short-term outcomes were seen after laparoscopic surgery.(6) These data suggest that laparoscopic resection of rectal cancer within an enhanced recovery programme may provide the best short-term clinical outcomes for patients with curative rectal cancer.

Because definitive long-term results are not yet available, the oncological adequacy of laparoscopic surgery for treatment of rectal cancer remains unproven. In the absence of survival data of LTME, the judgement of the TME resection specimen can be used as a proxy parameter and provides useful information about the prognosis of the patient. Patients with an incompletely removed mesorectum have a worse prognosis, more local recurrence distant metatases and worse survival rates.(7)

By using a three-grade scoring system, the quality of the mesorectum completeness was judged in 25 LTME patients and compared with a historical group of 25 OTME patients.(8) The two groups were matched for gender and type of resection (low anterior or abdominoperineal resection). No differences were observed between the LTME and OTME groups. These data support the hypothesis that the oncological resection of LTME is feasible and adequate. LTME can be performed as efficaciously as OTME. Although the results of this study show at least similar surgical completeness after LTME compared with OTME for T2 and limited T3 rectal tumours, further multicentre, randomised clinical trials, such as the CLASSIC and COLOR2, will determine whether LTME for curative rectal cancer will be implemented as a standard treatment.(9)

With the higher survival rate and reduction of local recurrence rate following radiotherapy and TME, quality of life (QoL) data become more important. We investigated how the QoL of patients with rectal cancer changes over time after LTME. One year after LTME we found improvement in some important QoL outcomes, including global QoL. However, sexual functioning significantly decreased from three months until one year postoperatively and was worse in patients undergoing APR than in those with LAR.

Prospective studies are necessary to test the hypothesis whether QoL after LTME is superior to QoL after OTME. Meanwhile, extensive pretreatment information and counselling is necessary regarding good QoL prospects but with probably worse sexual functioning after both LTME and OTME. This information supply may contribute to the improvement of QoL after treatment of rectal cancer, as
adverse effects may be better tolerated if they can be anticipated.

Regarding sexual and bladder dysfunction in rectal patients, it is still uncertain which specific psychophysiological mechanisms play a role in male and female urogenital response. In our study we found, for both male and female patients, worse objectively assessed physical sexual dysfunction. In male patients this did not lead to impaired overall sexual satisfaction, and in female patients it did not affect the sexual relationship negatively. This suggests that psychological factors probably play a more determining role than physical variables in sexual functioning in patients after LTME.

Conclusion
Based on evidence (mainly from nonrandomised studies), LTME appears to have clinically measurable short-term advantages in patients with primary respectable rectal cancer. Randomised controlled trials comparing short-term outcome of LTME with accelerated multimodal rehabilitation programmes are needed. The long-term impact on oncological endpoints awaits the findings from large ongoing randomised trials. To evaluate long-term outcome of LTME versus OTME, follow-up should be at least five years. In addition to local recurrence rates, outcome should include quality of life.

References

1. Heald RJ, Ryall RD. Recurrence and survival after total mesorectal excision for rectal cancer. Lancet 1986;1:1479-82. 
2. Kapiteijn E, Marijnen CA, Nagtegaal ID, et al. Preoperative radiotherapy combined with total mesorectal excision for resectable rectal cancer. N Engl J Med 2001;345:638-46.
3. Breukink SO, Pierie JP, Hoff C, et al. Technique for laparoscopic autonomic nerve preserving total mesorectal excision. Int J Colorectal Dis 2006;21:308-13.
4. Breukink SO, Pierie JP, Grond AJ, et al. Laparoscopic versus open total mesorectal excision: a case-control study. Int J Colorectal Dis 2005;20:428-33. 
5. Breukink S, Pierie J, Wiggers T. Laparoscopic versus open total mesorectal excision for rectal cancer. Cochrane Database Syst Rev [4], CD005200. 2006.
6. King PM, Blazeby JM, Ewings P, et al. Randomized clinical trial comparing laparoscopic and open surgery for colorectal cancer within an enhanced recovery programme. Br J Surg 2006;93:300-8. 
7. Nagtegaal ID, van de Velde CJ, van der WE, et al. Macroscopic evaluation of rectal cancer resection specimen: clinical significance of the pathologist in quality control. J Clin Oncol 2002;20:1729-34. 
8. Breukink SO, Grond AJ, Pierie JP, et al. Laparoscopic versus open total mesorectal excision for rectal cancer: an evaluation of the mesorectum’s macroscopic quality. Surg Endosc 2005;19:307-10.
9. Guillou PJ, Quirke P, Thorpe H, et al. Short-term endpoints of conventional versus laparoscopic-assisted surgery in patients with colorectal cancer (MRC CLASICC trial): multicentre, randomised controlled trial. Lancet 2005;365:1718-26.