A Retrospective Study: Tumor Recurrence and Overall Survival in HCC Patients Treated with Y-90 Therapy

Abstract

Research Question: In patients with unresectable hepatocellular carcinoma (HCC), what is the tumor recurrence and overall survival in patients that were treated with Y-90 SIR-spheres® compared with Y-90 TheraSphere™ radioembolization?

Background, Significance, and Rationale for the Question: Many treatment modalities for unresectable hepatocellular carcinoma have evolved over the last 30 years and are used in elaborate, and often, overlapping treatment algorithms due to the complex nature of the disease. Primary liver cancer is the second-fastest growing cancer in the US, carrying a 5-year survival rate of only 16%. Initial treatment modalities include resection and transplantation, but the majority of patients are deemed unresectable. There is a lack of statistical research regarding the modalities aimed at treating those with unresectable HCC such as Y-90 radioembolization, TAE, TACE, MWA, and SBRT. This study aims to provide the impact of Y-90 radioembolization on tumor recurrence and overall survival. Additionally, this study is unique in the utilization of explant pathology to provide exact tumor necrosis and residual tumor linked to prior locoregional therapy.

Materials and Methods: A single center retrospective analysis was performed using patient data from The Liver Institute at Methodist Dallas Medical Center to produce an outcomes-oriented study design. Patients who had previously undergone locoregional therapy for HCC were identified and then stratified based on therapy as well as transplant status. For each patient, the last 3 years of treatment with locoregional therapy was recorded in order to obtain the following data markers: overall survival, liver disease etiology, tumor morphology, tolerability of therapy, tumor response, overall survival, transplantation, and explant pathology (if applicable). This data was compared between groups to identify significant differences in overall outcomes.

Results: Our findings support that intermediate and advanced HCC respond very well to Y-90 therapy with an overall survival of > 17.5 months. This therapy was found to be tolerable and safe for patients with underlying liver disease. We noticed differences in the radiation dosages which may be explained by two different dosimetry methodologies, as well as tumor burden, but requires further investigation with a larger scale study. According to our study on explant pathology, Y-90 radioembolization is oncologically favorable with low levels of residual tumor.

Conclusion: Overall, by measuring outcomes of each treatment with these metrics, we provided quantifiable data that can be utilized in treatment plans for this complex malignancy. We hope this data will help educate other centers that have limited or no knowledge of how to apply this technology to their patient care and thereby improve the overall survival of this challenging diagnosis.