Clinical

Narrower margin OK for resection of colorectal liver metastases

Last Updated: 2013-06-12 17:00:23 -0400 (Reuters Health)

NEW YORK (Reuters Health) - When resecting colorectal liver metastases, a 1-mm margin should be the standard of care, instead of a 1-cm margin, according to researchers at two major liver resection centers in the UK.

This study, the investigators say in their report, "rejects the null hypothesis that a 1-mm margin is not sufficient for cure of patients with resectable colorectal liver metastases. It supports previous studies that the width of cancer-free resection margin is not important in modern liver resection practice."

Their conclusion is drawn from data on 2,715 consecutive patients who had primary liver resection for colorectal metastases, under similar assessment and resection protocols.

"There is consensus that a histological positive resection margin is a predictor of disease recurrence after resection of colorectal liver metastases," Dr. Zaed Hamady of St. James's University Hospital, Leeds and colleagues say. Yet, there is ongoing debate over the appropriate width of a cancer-free resection margin.

In a paper online now in Annals of Surgery, they say a "handful" of observational studies in the last decade have argued for or against a 1-cm margin as the minimum for curative resection.

Some studies have suggested that a 1-mm microscopic cancer-free resection margin is sufficient for a curative resection and for achieving long-term survival matching that of a 1-cm cancer-free resection margin. But others have argued that patients with less than a 1-cm margin have poorer outcomes.

That's not what Dr. Hamady and colleagues found.

In their series, a 1-mm cancer-free resection margin was sufficient to achieve 33% five-year overall disease-free survival, and extra margin width did not further boost disease-free survival.

Also, in a propensity score case-matched analysis, there was no statistical difference in disease-free survival between patients with negative narrow and wider margin clearance. The hazard ratio was 1.0 at a cutoff of 5-mm and 1.1 at a cutoff of 10-mm.

"Our study represents the strongest evidence up to date in support of the concept that a narrow (and clear) margin of tumor clearance is sufficient," the researchers say.

But, the paper says, patients with extrahepatic disease and positive lymph node primary tumor had an "extremely short survival time after what was assumed to be curative resection, even if the resection margin was clear and more than 1-mm. This may indicate that tumor biology is a more important factor in disease-free survival than surgical margin clearance."

The authors did not respond to a request for comment.

SOURCE: http://bit.ly/11WpOu0

Ann Surg 2013.