'Clinical equipoise' seen for surgical approaches to early rectal cancer

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Randomized trial is the next step

Local excision is an ideal management strategy for early-stage rectal cancer patients, T1 and/or T2 with no nodal involvement and no metastases. It would be great if we could pursue local excision as a primary management strategy. At this point, however, the data in the literature suggest that radical resection is associated with superior oncological outcomes.

Robust data from a randomized controlled trial are needed to decide management. Dr. Chadi was said that such a trial would have to include patients who are candidates for either procedure and are diagnosed using a standard procedure such as magnetic resonance imaging or endorectal ultrasound. Comorbidities and receipt of adjuvant therapy would be among the main confounders to consider in trial design. Study subgroups would include patients with lesions in either the lower one-third or the upper two-thirds of the rectum, and the sample size would need to be powered to account for the selection bias for lower third lesions to have local resection.

Since the initiation of local resection, newer techniques have become available that allow for better visualization and more precise dissections. This has given rise to the hope that oncologic outcomes—historically superior with radical resection—might now be similar with local resection.

Dr. Allyson H. Stone, of the Dartmouth-Hitchcock Medical Center in Lebanon, N.H., was the invited discussant of the study. She had no relevant financial disclosures.



PHOENIX – Two differing surgical approaches for early rectal cancer – radical resection and local resection—appear to be essentially equivalent treatment options, finds a systematic review and meta-analysis.

The conclusion is based on an analysis of morbidity and mortality data from 13 studies with a total of 2,855 patients with stage T1N0M0 rectal adenocarcinoma. All of the studies were published after 1979, when total mesorectal excision and modern local resection techniques were being used.

There are "improved results with the newer techniques of TEMS [transanal endoscopic microsurgery] and TAMIS [transanal minimally invasive surgery], as well as comparable outcomes when we adjust for the fact that there is a bit of a selection bias in the literature for lower-third lesions to be performed by local resection," lead investigator Dr. Sami A. Chadi reported at the annual meeting of the American Society of Colon and Rectal Surgeons.

"We know that quality of life data is better with local resection," he commented. Relative to radical resection, local resection was associated with an 87% lower risk of postoperative complications, a 69% lower risk of perioperative mortality, and an 83% lower risk of permanent ostomy.

On the other hand, local resection also was associated with a 46% higher likelihood of death at 5 years. Survival no longer differed significantly, however, when analyses took into account the greater use of local resection for cancers located in the lower third of the rectum.

"The implication is that we have established clinical equipoise between groups with T1N0M0 adenocarcinoma of the rectum, thus prompting the need for a prospective randomized, controlled trial on these two procedures," he maintained. "We do need further data to assess whether or not there is a role for neoadjuvant or adjuvant therapy in these groups." Ongoing studies are assessing the role of therapy, as well as the potential for local resection to be performed for T2 lesions.

Dr. Chadi, a surgeon with the University of Western Ontario in London, and his colleagues analyzed data from 12 observational studies and one randomized, controlled trial among patients with T1N0M0 cancer.

The 5-year rate of overall survival was poorer with local resection (relative risk, 1.46), with the difference between groups corresponding to 72 more deaths per 1,000 patients in the local resection group, according to Dr. Chadi, who disclosed no conflicts of interest related to the research.

However, this difference was largely driven by transanal excision (TAE) local procedures. There was no significant difference in this outcome for TEMS local procedures as compared with radical resection.

The researchers also repeated the survival analysis with an adjustment for cancers in the lower third of the rectum. In these patients, the surgical choice is more often local resection, potentially leading to selection bias.

When the ratio of lower-third cancers was equal in both the radical and local resection groups, there was no longer a significant difference in 5-year overall survival.

Compared with radical resection, local resection yielded a lower risk of postoperative complications (rate ratio, 0.13), with the difference corresponding to 129 fewer complications per 1,000 patients in the local resection group. The difference was significant for both TAE and TEMS individually as compared with radical resection.

Local resection also was associated with a lower risk of perioperative mortality (rate ratio, 0.31), with the difference corresponding to 11 fewer deaths per 1,000 patients in the local resection group, and a lower risk of permanent ostomy (risk ratio, 0.17), with the difference corresponding to 225 fewer permanent ostomies per 1,000 patients in the local resection group.

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