Therapeutic equivalence in survival for hepatic arterial chemoembolization and yttrium 90 microsphere treatments in unresectable hepatocellular carcinoma: a two-cohort study

Abstract

Background: Intrahepatic arterial yttrium 90 ((90)Y) microspheres have been proposed as a less toxic, less invasive therapeutic option to transhepatic arterial chemoembolization (TACE) for patients with surgically unresectable hepatocellular carcinoma (HCC). TACE has demonstrated the ability to prolong survival. However, long-term survival remains uncertain.

Methods: In a 2-cohort experience in the treatment of North American patients who had advanced, unresectable, biopsy-proven HCC, 691 patients received repetitive, cisplatin-based chemoembolization; and a separate cohort of 99 patients who had similar treatment criteria received a planned, single dose of (90)Y. Over the study period, an additional 142 patients were followed without treatment (total, 932 patients).

Results: Overall survival was slightly better in the (90)Y group compared with the TACE group (median survival, 11.5 months vs 8.5 months). However, the selection criteria indicated a small but significant bias toward milder disease in the (90)Y group. By using stratification into a 3-tier model with patients dichotomized according to bilirubin levels <1.5 mg/dL, the absence of portal vein thrombosis (PVT), and low alpha-fetoprotein plasma levels (<25 U/dL), an analysis of survival in clinical subgroups indicated that the 2 treatments resulted in similar survival. In addition, patients who had PVT or high alpha-fetoprotein levels also had similar survival in both treatment groups.

Conclusions: Given the current evidence of therapeutic equivalence in survival, (90)Y and TACE appeared to be equivalent regional therapies for patients with unresectable, nonmetastatic HCC.

Figure 1. Overall survival dichotomized by treatment type

Patient survival curves dichotomized by treatment type. 95% CI are presented as dotted lines. Numbers of patients at risk at each time interval have been provided for TACE and Y90 treatment groups. The top line represents TACE and the bottom Y90.

Figure 2. Three tier model of survival with stratification based on liver function and PVT

Three tier model with cases dichotomized by bilirubin, PVT and treatment. (Median ± 95CI), Final column of statistical analysis is between TACE and Y90 groups)

Figure 3. Three tier model of survival with stratification based on liver function and AFP

Three tier model with cases dichotomized by bilirubin, AFP and treatment (Median ± 95CI in months, final column of statistical comparison between TACE and Y90 groups).