Laparoscopic Rectal Cancer Surgery ‘Not Supported’

Minimally invasive rectal cancer resection is not proven to be noninferior to open surgery with regard to pathological criteria

medwireNews: The results of two phase III trials conducted in North American and Australasian patients challenge the use of laparoscopic-assisted resection in patients with rectal cancer.

Both studies found that the laparoscopic procedure did not meet prespecified noninferiority criteria for surgical pathology compared with open rectal cancer resection, explain Scott Strong and Nathaniel Soper, from the Northwestern University in Chicago, Illinois, USA, in an editorial accompanying the articles in JAMA.

“The technical quality of surgery in both trials was high as demonstrated by few laparoscopic conversions, high sphincter preservation rates, and low rates of anastomotic leakage and other complications in these study groups that included high-risk overweight patients, the majority of whom were male”, they write.

However, the commentators emphasise that “in both studies, the adequacy of surgical dissectiontended to be lower in the minimally invasive group comparedwith the open resection group despite comparable low ratesof distal margin involvement.”

The ACOSOG Z6051 randomised clinical trial involved 486 stage II or III patients in the USA and Canada undergoing surgery to remove tumour sited within 12 cm of the anal verge. It defined surgical efficacy as a circumferential radial margin of at least 1 mm, a clear distal margin and complete total mesorectal excision.

This composite primary endpoint was achieved in 81.7% of patients undergoing minimally invasive surgery versus 86.9% of those given open proctectomy, a –5.2% difference with confidence intervals that failed to exclude the 6% noninferiority threshold.

Similarly, the Australasian Laparoscopic Cancer of the Rectum (ALaCaRT) study failed to establish noninferiority of laparoscopic versus open surgery in 475 randomised patients with T1 to T3 rectal adenocarcinoma within 15 cm of the anal verge.

The primary endpoint of composite factors indicating adequate surgical resection – composed of complete mesorectal excision, clear circumferential margin and clear distal resection margin – was achieved by 82% of laparoscopic and 89% of open surgery patients, a –7% risk difference that did not exclude inferiority.

“The main criteria for considering laparoscopic surgery for rectal cancer should be based on long-term clinical outcomes of recurrence and overall survival”, write Andrew Stevenson, from the University of Queensland in Brisbane, Australia, and fellow ALaCaRT investigators.

“Further follow-up data from our trial are currently being acquired, along with data on other secondary end points, such as quality of life and cost effectiveness.”

James Fleshman, from the Baylor University Medical Center in Dallas, Texas, USA, and co-authors of the ACOSOG Z6051 trial agree: “The general conclusion from [earlier surgical research] reports is that laparoscopic resection of rectal cancer is safe and feasible, but the oncologic efficacy has not been definitively established.”

They therefore conclude: “Pending clinical oncologic outcomes, the findings do not support the use of laparoscopic resection in these patients.”

References

Fleshman J, Branda M, Sargent DJ, et al. Effect of laparoscopic-assisted resection vs open resection of stage II or III rectal cancer on pathologic outcomes. The ACOSOG Z6051 randomized clinical trial. JAMA 2015; 314: 1346–1355. doi:10.1001/jama.2015.10529

Stevenson ARL, Solomon MJ, Lumley JW, et al. Effect of laparoscopic-assisted resection vs open resection on pathological outcomes in rectal cancer. The ALaCaRT Randomized Clinical Trial. JAMA 2015; 314: 1356–1363. doi:10.1001/jama.2015.12009

Strong SA, Soper NJ. Minimally invasive approaches to rectal cancer and diverticulitis. Does less mean more? JAMA 2015; 314: 1343–1345. doi:10.1001/jama.2015.11454

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