Findings from a Norwegian review of 61 patients who had liver transplants for unresectable colorectal liver metastases found half of patients were still alive at 5 years, and about one in five appeared to be cured at 10 years.
“It seems likely that there is a small group of patients with unresectable colorectal liver metastases who should be considered for transplant, and long-term survival and possibly cure are achievable in these patients with appropriate selection,” Ryan Ellis, MD, and Michael D’Angelica, MD, wrote in a commentary published alongside the study in JAMA Surgery.
The core question, however, is how to identify patients who will benefit the most from a liver transplant, said Dr. Ellis and Dr. D’Angelica, both surgical oncologists in the Hepatopancreatobiliary Service at Memorial Sloan Kettering Cancer Center, New York. Looking closely at who did well in this analysis can offer clues to appropriate patient selection, the editorialists said.
Three decades ago, the oncology community had largely abandoned liver transplant in this population after studies showed overall 5-year survival of less than 20%. Some patients, however, did better, which prompted the Norwegian investigators to attempt to refine patient selection.
In the current prospective nonrandomized study, 61 patients had liver transplants for unresectable metastases at Oslo University Hospital from 2006 to 2020.
The researchers reported a median overall survival of 60.3 months, with about half of patients (50.4%) alive at 5 years.
Most patients (78.3%) experienced a relapse after liver transplant, with a median time to relapse of 9 months and with most occurring within 2 years of transplant. Median overall survival from time of relapse was 37.1 months, with 5-year survival at nearly 35% in this group and with one patient still alive 156 months after relapse.
The remaining 21.7% of patients (n = 13) did not experience a relapse post-transplant at their last follow-up.
Given the variety of responses to liver transplant, how can experts differentiate patients who will benefit most from those who won’t?
The researchers looked at several factors, including Oslo score and Fong Clinical Risk Score. The Oslo score assesses overall survival among liver transplant patients, while the Fong score predicts recurrence risk for patients with CRC liver metastasis following resection. These scores assign one point for each adverse prognostic factor.
Among the 10 patients who had an Oslo Score of 0, median overall survival was 151.6 months, and the 5-year and 10-year survival rates reached nearly 89%. Among the 27 patients with an Oslo Score of 1, median overall survival was 60.3 months, and 5-year overall survival was 54.7%. No patients with an Oslo score of 4 lived for 5 years.
As for FCRS, median overall survival was 164.9 months among those with a score of 1, 90.5 months among those with a score of 2, 59.9 months for those with a score of 3, 32.8 months for those with a score of 4, and 25.3 months for those with the highest score of 5 (P < .001). Overall, these patients had 5-year overall survival of 100%, 63.9%, 49.4%, 33.3%, and 0%, respectively.
In addition to Oslo and Fong scores, metabolic tumor volume on PET scan (PET-MTV) was also a good prognostic factor for survival. Among the 40 patients with MTV values less than 70 cm3, median 5-year overall survival was nearly 67%, while those with values above 70 cm3 had a median 5-year overall survival of 23.3%.
Additional harbingers of low 5-year survival, in addition to higher Oslo and Fong scores and PET-MTV above 70 cm3, included a tumor size greater than 5.5 cm, progressive disease while receiving chemotherapy, primary tumors in the ascending colon, tumor burden scores of 9 or higher, and nine or more liver lesions.
Overall, the current analysis can help oncologists identify patients who may benefit from a liver transplant.
The findings indicate that “patients with liver-only metastases and favorable pretransplant prognostic scoring [have] long-term survival comparable with conventional indications for liver transplant, thus providing a potential curative treatment option in patients otherwise offered only palliative care,” said investigators led by Svein Dueland, MD, PhD, a member of the Transplant Oncology Research Group at Oslo University Hospital.
Perhaps “the most compelling argument in favor of liver transplant lies in the likely curative potential evidenced by the 13 disease-free patients,” Dr. Ellis and Dr. D’Angelica wrote.
But even some patients who had early recurrences did well following transplant. The investigators noted that early recurrences in this population aren’t as dire as in other settings because they generally manifest as slow growing lung metastases that can be caught early and resected with curative intent.
A major hurdle to broader use of liver transplants in this population is the scarcity of donor grafts. To manage demand, the investigators suggested “extended-criteria donor grafts” – grafts that don’t meet ideal criteria – and the use of the RAPID technique for liver transplant, which opens the door to using one graft for two patients and using living donors with low risk to the donor.
Another challenge will be identifying patients with unresectable colorectal liver metastases who may experience long-term survival following transplant and possibly a cure. “We all will need to keep a sharp eye out for these patients – they might be hard to find!” Dr. Ellis and Dr. D’Angelica wrote.
The study was supported by Oslo University Hospital, the Norwegian Cancer Society, and South-Eastern Norway Regional Health Authority. The investigators and editorialists report no relevant financial relationships.
A version of this article first appeared on Medscape.com.