Liver transplant might be the next big thing for extensive hepatic metastases in colorectal cancer, according to an editorial published in JAMA Surgery .
“Many centers around the world, including our own, [have] started offering liver transplant to patients with colorectal liver metastases,” write Ralph Quillin III, MD, and Shimul Shah, MD, liver transplant surgeons at the University of Cincinnati.
However, they admit that the concept is controversial. “One need only to go to a tumor board to hear critics of the concept of liver transplant for isolated colorectal liver metastases,” the pair write, adding that opponents might argue that transplant patients could have done as well with chemotherapy.
There’s also the problem of deceased donor organ scarcity, Dr. Quillin and Dr. Shah acknowledge.
Nevertheless, the editorial is effusive about a new comparative effectiveness study that it accompanies in JAMA Surgery from a team at the Oslo University Hospital, led by Svein Dueland, MD, PhD.
The new study shows that for select patients with liver metastases, the 5-year survival rate with transplant is higher than for patients who receive standard of care – portal vein embolization (PVE) and surgical resection.
“[Dr.] Dueland et al. have laid the groundwork for the world to follow and took a concept from being experimental to possibly standard of care: liver transplant for colorectal liver metastases with heavy tumor burden,” the editorialists declare.
Using data from their hospital, the Oslo team compared 50 patients who had colorectal cancer liver metastases from previous liver transplant studies (2006-2019) with a retrospective cohort of 53 patients (2006-2015) from studies with similar selection criteria who underwent PVE with the intent to perform liver resection.
Patients with a high liver-only metastatic load had nine or more tumors, or the largest of their tumors had a diameter of at least 5.5 cm. Among 29 such patients treated with liver transplant, the 5-year overall survival (OS) rate was 33.4%, and the median OS was 40.5 months. Among eight such patients treated with PVE and liver resection, the 5-year OS rate was 12.5%, and the median OS was 29.8 months.
The OS among patients with a high metastatic load who received a transplant may be unprecedented, according to the investigators.
The Oslo team “should be commended for a very aggressive surgical approach” for patients whom “many would deem unresectable and palliative from the start,” comment Dr. Quillin and Dr. Shah.
Refining patient selection
In the past, finding the ideal candidate with extensive colorectal liver metastases for liver transplant was like “discovering the proverbial needle in the haystack,” Dr. Quillin and Dr. Shah say. Critics have said the impressive outcomes reported in past studies reflect extreme patient selection.
The new study results make selection easier and may expand the transplant patient population.
The patients in the study had no extrahepatic metastases, and their primary colorectal tumors had been resected. Such patients may represent an expanded transplant population. They were younger than 72 years, and their performance status score was 0-1. They had undergone standard-of-care chemotherapy before their liver procedures.
The high-burden transplant patients were all judged to have nonresectable tumors by the university’s tumor board; 14 of 29 had 16 or more liver lesions.
The maximum number of tumors in the PVE group was 15, so these patients were expected to live longer, owing to the fact that survival is longer for colorectal cancer patients who have fewer liver metastases. However, as noted above, that’s not how it worked out.