Pre-transplant TACE Therapy Response May Help Select Liver Transplant Recipients

Currently, patients with hepatocellular carcinoma (HCC) are selected for liver transplantation based on a variety of factors, including the size and number of liver tumors. How well patients respond to a type of pre-transplant therapy to reduce tumor size may offer a better way to select suitable transplant recipients, according to a study published in the August 2006 issue of Liver Transplantation.

German researchers conducted a study to assess the role of transarterial chemoembolization (TACE) in selecting patients with tumors suitable for liver transplantation. TACE is a treatment that involves injecting chemotherapy drugs into the hepatic artery that supplies blood to the liver, along with chemicals that embolize, or block, small hepatic blood vessels.

The trial included 96 consecutive patients with HCC who received TACE therapy every six weeks. Of the total, 34 initially met the Milan criteria -- a cut-off for tumor number and size traditionally used to indicate which patients are eligible for liver transplantation -- and were immediately put on the transplant waiting list. Other patients were listed after successful TACE led to down-staging of their tumors.

Results

50 patients eventually received liver transplants (34 who initially met the Milan criteria and 16 who were listed after TACE).

Among the original 96 patients, the overall 5-year survival rate was 51.9%.

The survival rate was 80.9% for patients who underwent transplantation, compared with 0% for those who did not receive transplants (P < 0.0001).

Tumor recurrence was primarily influenced by whether HCC was control with continued TACE during the waiting period.

94.5% of patients (n = 39) who did not progress with TACE during the waiting period were still free of tumor recurrence after 5 years.

The tumor recurrence rate was significantly higher -- 35.4% -- among patients (n = 11) who experienced HCC progression after starting TACE but before transplantation (P = 0.0017).

In a multivariate analysis, lack of HCC progression with TACE during the waiting period (P = 0.006; risk ratio 8.95) and a limited number of tumor nodules in surgical specimens (P = 0.025; risk ratio 0.116) were significant predictors of freedom from tumor recurrence.

Whether or not patients initially met the Milan criteria did not influence tumor recurrence rates.

Conclusion

"Our study suggests that oncological control reached by the scheduled TACE pretreatment during the waiting time is obviously of greater importance for the long-term prognosis than downstaging itself," the authors wrote. "[F]avorable tumors seem to be selected with a much higher degree of reliability if the process of tumor control persists during the total waiting time." They suggested that even large or numerous tumors can allow for successfully liver transplantation if they respond well and remain stable during pre-transplant TACE therapy.

In conclusion, they wrote, "Our data suggest that sustained response to TACE is a better selection criterion for [liver transplantation] than the initial assessment of tumor size or number."

In an accompanying editorial, Francis Yao, MD, from the University of California at San Francisco noted that this study, which demonstrated to no upper limit to the tumor size or number that allowed for successful outcomes, could suggest that all patients might potentially be suitable for transplantation as long they respond well to TACE. However, he noted that other research contradicts these findings, and suggested instead that response to TACE should be considering in addition to -- rather than instead of -- tumor size and number.

8/04/06

References

G Otto, S Herber, M Heise, and others. Response to Transarterial Chemoembolization as a Biological Selection Criterion for Liver Transplantation in Hepatocellular Carcinoma. Liver Transplantation 12(8): 1260-1267. August 2006.

F Y Yao. SelectionCriteria for Liver Transplantation in Patients with Hepatocellular Carcinoma: Beyond Tumor Size and Number? [Editorial]. Liver Transplantation 12(8): 1189-1191. August 2006.