The randomized OSLO-COMET trial found that laparoscopic surgery did not change chances of survival, when compared to open surgery, to remove metastases that had spread to the liver in patients with colorectal cancer.

“Laparoscopic liver surgery not only had a lower rate of post-operative complications, an improved quality of life, and was cost-effective, compared to open liver surgery, it also had life expectancies that are similar to open surgery,” said lead study author Åsmund Avdem Fretland, MD, Surgeon in the Intervention Centre and the Department of HPB Surgery at Oslo University Hospital, Norway. “After many years of improvements in laparoscopic surgery, we now have results showing that survival is as good with this procedure as with open surgery, and morbidity is lower, so we expect that this will cause a shift to even more operations on the liver being done laparoscopically,” noted Bjørn Edwin, MD, PhD, Intervention Centre and the Department of HPB Surgery at Oslo University Hospital, Norway, who is leading the research effort.

Laparoscopic surgery, sometimes known as keyhole surgery, is considered to be minimally invasive. In more conventional open surgery, a single incision, inches long or more, is made to access the abdomen. Laparoscopic surgery, however, uses several incisions of one-quarter inch or less. In one incision, a laparoscope is used to send images of the abdominal cavity to a monitor so that the surgeon can use tools inserted through the other incisions to perform the operation.

The first report of laparoscopic liver surgery was in 1991, with several other reports worldwide occurring shortly thereafter. The use of laparoscopic surgery has become more common, but until this study, no one had looked at long-term outcomes in cancer that has metastasized to the liver in a randomized trial, according to the researchers.

The surgeons in this study had extensive training in laparoscopic liver surgery. Open surgery is considered a good option if a surgeon does not have sufficient training in laparoscopy.

About the Study
From February 2012 to January 2016 the investigators randomly assigned 280 colorectal cancer patients with liver metastases to either laparoscopic surgery or open surgery. The operations were performed with a liver sparing technique, which means that the surgeons removed only the tumors and a minimal amount of surrounding liver tissue. One-hundred and thirty-three people received laparoscopic surgery, while 147 people had open surgery. About half of the patients received chemotherapy before or after their surgery, following standard Norwegian guidelines, which included the use of chemotherapy medicines 5-fluorouracil plus leucovorin (folinic acid) and oxaliplatin (Eloxatin).

When looking solely at the surgical process, there was no difference between the groups in terms of the rate of complete tumor removal, or the amount of tissue removed beyond the observable tumor.

Patients reported improved health-related quality of life after laparoscopy, which also had less post-operative complications (19% with laparoscopy vs. 31% with open surgery). The researchers found that the monetary costs for either type of surgery were comparable, however, differences in costs may vary in other countries.

Next Steps
Dr. Fretland and colleagues are now using artificial intelligence, genetic, and digital-image analyses to parse results from the study so that they can improve the diagnosis and treatment of future patients. They plan to explore new aspects of minimally invasive liver surgery, including enrolling patients in multicenter randomized trials to examine other types of liver operations. The researchers are also exploring ablation of liver tumors using heat to kill cancer cells.

This study received funding from South-East Norway Regional Health Authority.

This article is a news release from 2019 ASCO Annual Meeting. Read the original here.