ASCO Annual Meeting

ASCO Annual Meeting

Perspective from Heinz-Josef Lenz, MD, FACP
June 13, 2019
3 min read

Laparoscopy as safe, effective as open surgery for colorectal liver metastases

Perspective from Heinz-Josef Lenz, MD, FACP
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Åsmund Avdem Fretland, MD
Åsmund Avdem Fretland

CHICAGO — Laparoscopic surgery for colorectal liver metastases nearly equaled or surpassed open surgery for almost all outcomes, according to results of the randomized, phase 3 OSLO-COMET trial presented at ASCO Annual Meeting.

Also known as keyhole surgery, laparoscopy for colorectal liver metastases resulted in lower complication rates, shorter hospital stays and better postsurgical quality of life, with negligible difference in cost, compared with open surgery.

“Open surgery has been the standard operation for liver metastases, and laparoscopic surgery is considered a minimally invasive alternative,” Åsmund Avdem Fretland, MD, of the department of HPB surgery at Oslo University Hospital and one of the study’s co-authors, said during a press conference. “Our trial is the first to compare laparoscopic with open surgery for colorectal metastases, a trial in which we sought to determine if laparoscopic liver surgery is better for patients than open surgery.”

OSLO-COMET included 280 patients with colorectal cancer and radically resectable liver metastases at Oslo University Hospital between February 2012 and January 2016. The surgical team at Oslo University Hospital had performed more than 400 laparoscopic liver operations before the study started enrolling patients.

Fretland and colleagues randomly assigned these patients to undergo laparoscopic (n = 133) or open parenchyma-sparing liver resection (n = 147).

Postoperative morbidity within 30 days served as the study’s primary outcome, with OS as a secondary endpoint.

Patients in the laparoscopy group were more often men (65% vs. 54%) and had a slightly older mean age (67 years vs. 66 years) than patients in the open surgery group. Other baseline characteristics, including number of mean metastases (laparoscopy, 1.5 vs. open, 1.6) appeared similar between the two groups; however, patients in the laparoscopy group were twice as likely (18% vs 9%) to have undergone previous liver resection.

Results showed significantly lower 30-day morbidity rates in the laparoscopy group than the open surgery group (19% vs 31%; P = .021). The rate of free resection margins was nearly identical (laparoscopy, 94% vs. open, 93%) and the cost of surgery was slightly higher for laparoscopy ($15,793 vs. $15,307).

Researchers determined long-term OS based on a minimum of 36 months of follow-up, with a median follow-up of 45 months.

Results showed identical OS between the groups at 3 years (71%), with a slight OS advantage for laparoscopy at 1 year (94% vs. 93%) and a similar advantage for open surgery at 5 years (57% vs. 56%). Median OS was 81 months (95% CI, 42-120) with open surgery vs. 80 months (95% CI, 52-108) with laparoscopy.


Open surgery showed slightly better RFS rates at all three time intervals examined (1 year, 54% vs. 53%; 3 years, 39% vs. 34%; 5 years, 31% vs. 29%). Median RFS was 16 months (95% CI, 10-22) with open surgery vs. 19 months (95% CI, 8-24) with laparoscopy.

The median postoperative hospital stay was significantly shorter for the laparoscopy group than with open surgery (53 hours, 95% CI, 45-61, vs. 96 hours, 95% CI, 89-103; P < .001). Patients in the laparoscopy group also reported significantly higher postoperative Short Form-36 health-related quality-of-life scores 4 months after surgery (0.024 vs. 0.022; P = .001).

“Laparoscopic surgery did not change the chance of survival compared with open liver surgery and is available to patients at no additional overall costs to society,” Fretland said. “We hope these results will encourage more hospitals to establish laparoscopic liver surgery programs that must include structured training of surgeons.” – by Drew Amorosi


Fretland ÅA, et al. Abstract LBA3516. Presented at: ASCO Annual Meeting; May 31-June 4, 2019; Chicago.

Disclosures: Fretland reports honoraria from Olympus Medical Systems. Please see the abstract for all other authors’ relevant financial disclosures.