SBRT Equivalent to TACE as Bridge to Transplant for Patients With HCC

Use of stereotactic body radiation therapy (SBRT) was equally effective as transarterial chemoembolization (TACE) as a method of bridge to transplant among patients with hepatocellular carcinoma, according to preliminary results of a phase II study (abstract 223) presented recently at the 2017 American Society of Clinical Oncology (ASCO) Gastrointestinal Cancers Symposium, held January 19–21 in San Francisco.

“SBRT appears equivalent to TACE at controlling the treated lesion when utilized as a bridge to transplant in patients with Childs-Pugh class A/B disease,” said study presenter Francis W. Nugent, MD, of Lahey Hospital and Medical Center, Burlington, Mass.

According to Nugent, the current standard of care for patients with HCC is a bridging procedure prior to transplant. The most common bridging procedure in the United States is TACE; however, there are some disadvantages to TACE including that it requires hospitalization and has a major morbidity of 0.5% to 3%.  Other bridging strategies exist, but there is no one standard approach, he said.

Use of SBRT as a bridge to transplant has some potential advantages for patients. SBRT is performed as an outpatient procedure, has no direct tumor disruption, and reduces major morbidity. Therefore, in this single-center study, Nugent and colleagues compared SBRT to TACE in patient with hepatocellular carcinoma undergoing liver transplant.

The expected accrual of the trial is 60 patients and the primary endpoint is time to residual or recurrent disease. Nugent presented preliminary data for 30 patients with Milan Criteria Childs-Pugh Class A/B cirrhosis. Patients were randomly assigned to either TACE or SBRT.

TACE was given as two treatments one month apart using DEBDOX beads, and patients were hospitalized after each treatment. SBRT was given at a median total dose of 45 Gy delivered over five fractions using fiducials. Patient response was assessed at 2 months and every 3 months until liver transplant or death.

At the time of follow-up, no patients assigned to SBRT had residual disease compared with 24% of patients assigned TACE. The median time to residual disease for patients assigned TACE was 83 days from the last treatment date.

Nugent also presented explant data showing that of the five patients assigned SBRT who have undergone transplant two had residual disease and for the six patients assigned TACE who have been transplanted, three have residual disease. However, Nugent noted that this is a “bad endpoint.”

“The reality is if you intervene and somebody takes a year to get a new liver or you intervene and someone takes 3 months, what you see pathologically can be quite different and that may have little to do with how effective the treatment was,” Nugent said.

The researchers also evaluated quality of life using a questionnaire given at baseline, during, and 2 weeks after treatment, and then every 3 months until study completion. Quality of life measures favored the SBRT arm for both physical and mental function. The noted differences were statically unlikely to have happened as a result of chance, Nugent said, but he noted that whether they are clinically meaningful is uncertain.

Overall, toxicity of the two treatments favored the SBRT arm and SBRT was very well tolerated. Data suggested that anorexia, fatigue, nausea, and pain were greater in the TACE arm. One patient in the TACE arm had a major event, a portal vein thrombus and liver infarction; however, the patient was still able to undergo liver transplantation.