Chemoembolization Combined with Radiofrequency Ablation for Medium-Sized Hepatocellular Carcinoma: A Propensity-Score Analysis

Clinical question
Compare the effectiveness of combined chemoembolization and RF ablation, chemoembolization alone, and RF ablation alone in the treatment of patients with medium-sized HCC’s (3-5cm in size).

Take away point Large-bore aspiration mechanical thrombectomy is safe with a high technical (100%) and clinical success (88%) rates.

Reference
Chu, Hee Ho et al. Chemoembolization Combined with Radiofrequency ablation for Medium-Sized Hepatocellular Carcinoma: A Propensity-Score Analysis. Journal of Vascular and Interventional Radiology, Volume 30, Issue 10, 1533-43

Click here for abstract

Study design
Single-center, retrospective, cohort study of 538 patients treated between March 2000 – December 2016, with follow up until March 2018

Funding Source
None

Setting
Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.

Figure 2
Flow chart to determine treatment of a single medium-sized (3.1-5.0 cm) HCC. Patients included in this study were unsuitable for surgery or liver transplantation and had one the three treatments.

Summary

Definitive treatment of single medium-sized HCC, according to Barcelona Clinic Liver Cancer (BCLC), is surgical resection. However, this is not always feasible secondary to patient comorbidities and/or tumor location. Radiofrequency (RF) ablation is considered as curative in patients with small (<3cm) HCC’s. However, no such definitive literature exits for single lesions that fall in the medium-size range, between 3-5 cm. Multiple treatment modalities have been used to treat these medium sized lesions including a combination of TACE and RF ablation, TACE alone, and RF alone. The authors performed a retrospective analysis of these treatment types in patients with single medium sized HCC. Additionally they took their data and performed a propensity-score analysis with inverse probability weighting to reduce bias in treatment selection and other confounding variables.

All patients in this study has single medium sized HCC’s and were treated with one of the three therapies. The treatment pathways were chosen as the digression of the interventionist. TACE was performed with a combination of Lipiodol and Cisplatin (1:1 ratio) with a cisplatin dose of 2mg/kg body weight. Gel-foam slurry was infused after administration until arterial stasis was achieved. RF ablation was performed under ultrasound guidance within 2 weeks of chemoembolization (if performed). Of note there were statistically significant differences in the patient population with regards to Child-Pugh class, serum albumin level and tumor size. No major complications were reported as defined by SIR criteria.

The primary endpoint was overall survival (OS) from initial procedure to death. The secondary endpoint was recurrence free survival (RFS), which was determined from initial treatment to recurrence or death. Recurrence included local or distant recurrence and local was defined by a margin of 1 cm.

The mean follow up time for all patients was 59.6 months (SD – 46.9 mo; range: 2-208). Overall survival in combined, chemoembolization-only, and RF-only were 85 mo (95% CI: 51.2-118.8 mo), 56.5 mo (95% CI: 51.7-61.3 mo), and 52.1 mo (95% CI: 40.7-63.5 mo), respectively. Treatment was found to be a significant independent factor associated with OS (P=0.023). During follow up recurrent disease was found in 68.8% of combined group, 78% of the chemoembolization-only group, and 74.8% of the RF-only group. RFS in the combined, chemoembolization-only, and RF-only were 26.5 mo (95% CI: 22-31 mo), 14.1 mo (95% CI: 10.9-17.3 mo), and 14.1 mo (95% CI 9.7-18.5 mo), respectively.

Inverse probability weighting was performed to balance baseline characteristics. The differences in OS remained statistically significant with a P value of 0.022 (Fig 4a). Additionally the differences in RFS values were statistically significant with a P value of 0.002 (Fig 4b).

Commentary

The authors performed a similar study to multiple previous authors, with a much larger patient sample. The findings of this study fit and reinforce all of the current data in treating “unresectable” medium-sized HCC’s. However, the retrospective nature of the study and single center analysis limits its broad applications. Taking this into consideration we now have a larger pool of retrospective data to help reinforce the current trend in treating medium-sized HCC’s. This study provides evidence for future prospective studies to look at this question and help solidify an evolving treatment paradigm.

Post author
Hasnain Hasham, MD
Interventional Radiology Fellow
Dotter Interventional Institute
Oregon Health and Science University, Portland, OR
@irhasham