High Success Rates With Down-Staging of Liver Cancer Prior to Transplant

By Reuters Staff

August 30, 2021

NEW YORK (Reuters Health) - Down-staging of hepatocellular carcinoma (HCC) prior to liver transplant based on United Network for Organ Sharing (UNOS) criteria is successful most of the time using either chemoembolization or Y-90 radioembolization, new research indicates.

UNOS has adopted uniform criteria for down-staging (UNOS-DS) of HCC prior to liver transplantation (LT), but the success rate around the country is unclear.

To investigate, Dr. Neil Mehta of the University of California, San Francisco, and colleagues evaluated 209 consecutive patients with HCC undergoing down-staging based on UNOS-DS criteria at seven centers (four UNOS regions) between 2016 and 2019.

They observed a "very high" overall probability of successful down-staging to within Milan criteria in 83% of the patients.

The cumulative probability of successful down-staging was 68% at six months, 83% at one year and 88% at two years, after the first down-staging treatment, they report in Gastroenterology.

About two-thirds were successfully down-staged after a single local regional therapy. Over 90% of the cohort received either trans-arterial chemoembolization (TACE) or Y-90 as initial down-staging treatment.

"Although not statistically significant, we observed a higher rate of complete pathologic response and a lower probability of tumor under-staging and microvascular invasion in the explant in those initially receiving Y-90," the researchers report.

"Until a large multi-center randomized trial comparing Y-90 and TACE is undertaken, the choice between these modalities as initial down-staging treatment will depend on center expertise and remain a matter of debate," they advise.

They also observed "excellent" post-LT survival of 100% at one year and 95% at two years, although the follow-up period was too short for post-LT outcomes to be the primary objective of the study.

Tumor burden measured by the sum of the largest tumor diameters was the only factor predicting successful down-staging, the team reports. "Even those with a total tumor diameter >7 cm had an 81% probability of successful down-staging (versus 88% for those with total tumor diameter <6 cm)."

"These findings validate the feasibility of down-staging on a broad scale under the current UNOS-DS guidelines, and highlight the importance of setting upper limits in the tumor burden to ensure a high down-staging success rate. Relaxing the eligibility criteria on initial tumor burden would result in a significantly lower down-staging success rates and potentially worse post-LT outcomes," they write.

Summing up, they say this "first prospective multi-regional study based on UNOS-DS criteria" found a ">80% probability of initial down-staging with relatively low likelihood of subsequent tumor progression, and validated the feasibility of down-staging on a broad scale under the current UNOS-DS guidelines. We found similar efficacy of TACE and Y-90 as initial down-staging treatment."

SOURCE: https://bit.ly/3fzIksI Gastroenterology, online July 27, 2021.