Yttrium‐90 microsphere radioembolisation for unresectable hepatocellular carcinoma

Omar M Abdel‐Rahman, Zeinab Elsayed

Hepatocellular carcinoma is the most common liver neoplasm and the fifth most common cancer worldwide. Moreover, its incidence has increased dramatically since the mid-2000s. While surgical resection and liver transplantation are the main curative treatments, only around 20% of people with early hepatocellular carcinoma may benefit from these therapies. Current treatment options for unresectable hepatocellular carcinoma include various ablative and trans-arterial therapies in addition to the drug sorafenib. To determine the benefits and harms of yttrium-90 microsphere trans-arterial radioembolisation either as a monotherapy or in combination with other systemic or locoregional therapies versus placebo, no treatment, or other similar systemic or locoregional therapies for people with unresectable hepatocellular carcinoma. We reviewed data from the Cochrane Hepato-Biliary Controlled Trials Register, Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, and Science Citation Index Expanded. We also checked reference lists of primary original studies and review articles manually for further related articles (cross-references) up to December 2015. Eligible studies included all randomised clinical trials comparing yttrium-90-90 microsphere radioembolisation either as a monotherapy or in combination with other systemic or locoregional therapies versus placebo, no treatment, or other systemic or locoregional therapies for unresectable hepatocellular carcinoma. The two review authors independently extracted the relevant information on participant characteristics, interventions, study outcomes, and data on the outcomes for this review, as well as information on the design and methodology of the studies. The two review authors assessed risk of bias of the included trials using pre-defined risk of bias domains. We used Trial Sequential Analysis to control the risk of random errors. We assessed the methodological quality with GRADE. Two randomised clinical trials with 68 participants fulfilled our inclusion criteria. Both trials were at high risk of bias, and we rated the evidence as very low quality. One of the included trials compared radioembolisation versus chemoembolization for intermediate stage hepatocellular carcinoma as classified by the Barcelona Clinic Liver Cancer (BCLC) staging system, while the other included trial was an interim analysis of a randomised trial assessing radioembolisation combined with sorafenib versus sorafenib monotherapy in participants with BCLC-advanced stage hepatocellular carcinoma. The available data were insufficient to perform the planned analyses. Neither of the two trials reported data on all-cause mortality, cancer-related mortality, or time to progression of the tumour. The trial comparing radioembolisation with chemoembolization reported quality of life and serious adverse events, and there were no statistically significant differences between the trial groups with regard to these outcomes at week 12. On the basis of the two included randomised clinical trials, single-session radioembolisation appeared to be as safe as multiple sessions of chemoembolization for intermediate stage hepatocellular carcinoma and had a similar impact on quality of life, but data were too sparse to exclude even major differences. Radioembolisation followed by sorafenib appeared to be as well tolerated as sorafenib alone for advanced stage hepatocellular carcinoma, but data were too sparse to exclude even major differences. We also identified five ongoing studies evaluating the topic of our review. There was insufficient evidence to assess the beneficial and harmful effects of yttrium-90 microsphere radioembolisation for people with unresectable hepatocellular carcinoma. Further randomised clinical trials are mandatory to better assess the potential beneficial and harmful outcomes of yttrium-90 microsphere trans-arterial radioembolisation either as a monotherapy or in combination with other systemic or locoregional therapies versus placebo, no treatment, or other systemic or locoregional therapies for people with unresectable hepatocellular carcinoma.