Race-matched liver transplants improve survival for black patients with hepatocellular carcinoma
Race-matched liver transplants significantly improved OS among black patients with early hepatocellular carcinoma, according to study results published in Journal of the American College of Surgeons.
T. Clark Gamblin, MD, MS, MBA, FACS, chief of surgical oncology at Medical College of Wisconsin, and colleagues utilized the United Network for Organ Sharing (UNOS) Organ Procurement and Transplant Network database to obtain records for adults who underwent liver transplantation between 1994 and 2015.
Investigators identified 1,384 black patients, of whom 325 (23.5%) underwent race-matched transplant.
Those who received race-matched transplant achieved significantly longer median OS (135 months vs. 78 months; HR = 0.66; 95% CI, 0.49-0.88) and appeared significantly more likely to survive 5 years after transplant (64.2% vs. 56.9%; P = .019).
“In a large national data set, we found an intriguing signal that black patients who received a race-matched liver transplant appear to have significantly improved survival,” Gamblin told HemOnc Today. “This merits further investigation to understand if this is a worthwhile criterion to pursue.”
HemOnc Today spoke with Gamblin about the study findings, the potential explanation for why race-matched transplant may improve survival, and what research must be conducted before compatibility screening can be recommended.
Question: What prompted this study?
Answer: Our group has a strong interest in primary liver cancer. Liver transplant is one treatment option for patients with early-stage disease, but there is a scarcity of organs available for transplantation in the United States. We set out to optimize the donor-recipient matching process. Prior studies have linked unmatched donor-recipient race to worse OS for recipients of kidney, lung and heart transplants, but the role of donor race in liver transplantation has not been well defined.
Q: How did you conduct the study?
A: We analyzed the UNOS database, a large organ transplant database that tracks people who have had a liver transplant. We looked specifically at black patients. Race is not a criterion typically used in organ matching. As we began to look at the cohort of black patients who received a liver transplant, we noted some had received livers from black donors but others had not. When we compared the two cohorts, we found they were quite similar with regard to parameters such as comorbidities, age, demographics and clinical characteristics. We dug into outcomes to see how well each cohort did in terms of organ rejection and OS. Patients who received a race-matched liver did much better than those who received a liver from a donor of a different race.
Q: Did the findings surprise you?
A: Going into this study, we were not certain there would be any notable differences, so we were surprised by the dramatic difference in survival between the matched and unmatched cohorts.
Q: What factors may explain the potential association between donor race and survival?
A: We do not know. Studies of heart and kidney transplant recipients have shown similar outcomes, but we don’t understand why. We know that black patients do not do as well as patients of other races. This may be because of factors such as demographics or social support. When we look at the black population in general and recognize improvement resulting from a race-matched organ, it is very hard to interpret. We may be able to get more details from specific institutions, moving from a large database down to several centers that do many organ transplants predominantly in the black population.
Q: Is it premature to recommend a change in compatibility screening?
A: Yes. We struggle to find enough organs and we don’t want to create more regulations or obstacles for matching patients with livers. However, this is an intriguing finding. It is important to begin looking at more institutional-specific outcomes so we can have even more data to better understand the differentiating factors. If we looked at data from bigger centers that perform many liver transplants for black patients, we would then be able to look at tissue biopsies, tumor characteristics and liver characteristics to better understand what is occurring when these patients have negatively impacted outcomes. We need to assess these factors not only at the time of transplant, but also when patients’ bodies reject the liver or when their outcomes are affected. – by Joe Gramigna
For more information:
T. Clark Gamblin, MD, MS, MBA, FACS, can be reached at Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226; email: firstname.lastname@example.org.
Silva JP, et al. J Am Coll Surg. 2019;doi:10.1016/j.jamcollsurg.2018.11.016.
Disclosure: Gamblin reports no relevant financial disclosures.