High rate of complete histopathological response in hepatocellular carcinoma patients after combined transarterial chemoembolization and stereotactic body radiation therapy

Stereotactic body radiation therapy (SBRT) in patients with hepatocellular cancer-a narrative review and expert opinion

Background and Objective

Stereotactic body radiation therapy (SBRT) is a highly conformal technique of external beam radiotherapy precisely delivering high total (ablative) doses in a small number of fractions to clearly defined target volumes. Its development enabled efficient and safe radiation treatments in patients with localized hepatocellular cancer (HCC) unsuitable for other local treatment options. Moreover, it can be easily combined with several other therapy approaches. Thus, the aim of this narrative review is to outline the current role of SBRT in the multifocal treatment of HCC patients.

Methods

We searched PubMed for articles dealing with SBRT alone, in combination with other local or systemic treatments or in comparison to other local treatments in patients with HCC. This included original articles, reviews and conceptional articles dealing with the technique of SBRT. All articles were analysed for suitability by two independent reviewers.

Key Content and Findings

This review summarizes the currently available evidence for SBRT as a definitive treatment for HCC as well as its role within combination approaches including bridging to transplantation. SBRT is an effective and safe definitive treatment option in patients with localized HCC unsuitable for surgery and/or other local therapies based on retrospective and prospective series. Its combination with other local treatments yields superior results compared to single modality treatment based on non-randomized data. A growing number of prospective trials confirmed at least similar if not superior rates of local control with low toxicities compared to well established other local treatments even in non-selected patients.

Conclusions

SBRT is a promising tool in the treatment of HCC. It can be used either as definitive treatment, within combination approaches or as a bridging tool. Several phase III trials comparing SBRT with other local options are ongoing, which will further clarify its encouraging role.

Bridge Therapy before Liver Transplant for Advanced Hepatocellular Carcinoma

Hepatocellular carcinoma is the most common primary liver tumor. Orthotopic liver transplant is one of the best treatment options, but its waiting list has to be considered. Bridge therapies have been introduced in order to limit this issue. The aim of this study is to evaluate if bridge therapies in advanced hepatocellular carcinoma can improve overall survival and reduce de-listing. We selected 185 articles. The search was limited to English articles involving only adult patients. These were deduplicated and articles with incomplete text or irrelevant conclusions were excluded. Sorafenib is the standard of care for advanced hepatocellular carcinoma and increases overall survival without any significant drug toxicity. However, its survival benefit is limited. The combination of transarterial chemoembolization + sorafenib, instead, delays tumor progression, although its survival benefit is still uncertain. A few studies have shown that patients undergoing transarterial chemoembolization + radiation therapy have similar or even better outcomes than those undergoing transarterial chemoembolization or sorafenib alone for rates of histopathologic complete response (89% had no residual in the explant). Also, the combined therapy of transarterial chemoembolization + radiotherapy + sorafenib was compared to the association of transarterial chemoembolization + radiotherapy and was associated with a better survival rate (24 vs. 17 months). Moreover, immunotherapy revealed new encouraging perspectives. Combination therapies showed the most encouraging results and could become the gold standard as a bridge to transplant for patients with advanced hepatocellular carcinoma.

Role of Stereotactic Body Radiation Therapy in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC)is a common type of liver cancer with a poor prognosis, especially in patients with advanced stages or underlying liver disease. While surgical resection, liver transplantation, and ablation therapies have traditionally been the mainstay of treatment for HCC, radiation therapy has become increasingly recognized as an effective alternative, particularly for those who are not surgical candidates. Stereotactic Body Radiation Therapy (SBRT) is a highly precise form of radiation therapy that delivers very high doses of radiation to the tumor while sparing surrounding healthy tissue. Several studies have reported favorable outcomes with SBRT in HCC treatment. Moreover, SBRT can be used to treat recurrent HCC after prior treatment, offering a potentially curative approach in select cases. While SBRT has demonstrated its efficacy and safety in treating HCC, future studies are needed to further investigate the potential role of SBRT in combination with other treatments for HCC.

Stereotactic Body Radiation Therapy With or Without Transarterial Chemoembolization Versus Transarterial Chemoembolization Alone in Early-Stage Hepatocellular Carcinoma: A Systematic Review and Meta-Analysis

PURPOSE

This study aims to review the current evidence on the utility of stereotactic body radiation therapy (SBRT), with or without transarterial chemoembolization (TACE), for early-stage hepatocellular carcinoma (ESHCC) patients not amenable to standard curative treatment options.

METHODS

Literature search was conducted using PubMed, ScienceDirect, and Google Scholar. Comparative studies reporting oncologic outcomes were included in the review.

RESULTS

Five studies (one phase II randomized controlled trial, one prospective cohort, three retrospective studies) compared SBRT versus TACE. Pooled analysis showed an overall survival (OS) benefit after 3 years (OR 1.65, 95% CI 1.17-2.34, p = 0.005) which persisted in the 5-year data (OR 1.53, 95% CI 1.06-2.22, p = 0.02) in favor of SBRT. RFS benefit with SBRT was also seen at 3 years (OR 2.06, 95% CI 1.03-4.11, p = 0.04) which continued after 5 years (OR 2.35, 95% CI 1.47-3.75, p = 0.0004). Pooled 2-year local control (LC) favored SBRT over TACE (OR 2.96, 95% CI 1.89-4.63, p < 0.00001). Two retrospective studies compared TACE + SBRT versus TACE alone. Pooled analysis showed significantly improved 3-year OS (OR 5.47; 95% CI 2.47-12.11, p < 0.0001) and LC (OR: 21.05; 95% CI 5.01-88.39, p ≤ 0.0001) in favor of the TACE + SBRT group. A phase III study showed significantly improved LC and PFS with SBRT after failed TACE/TAE versus further TACE/TAE.

CONCLUSIONS

Taking into account the limitations of the included studies, our review suggests significantly improved clinical outcomes in all groups having SBRT as a component of treatment versus TACE alone or further TACE. Larger prospective studies are warranted to further define the role of SBRT and TACE for ESHCC.

Concomitant Irradiation to Checkpoint Inhibitor Therapy of Hepatocellular Carcinoma Patients: A Systematic Retrospective, Single-Center Analysis

INTRODUCTION

Immunotherapy has been established as the standard treatment option for patients with advanced hepatocellular carcinoma (aHCC). Despite the increased efficacy, disease progression occurs in a relevant proportion of patients even after an objective response. Combination concepts with locoregional therapy are currently under investigation for hepatic disease but are also in discussion for the control of distant metastasis. Radiotherapy is a highly effective treatment modality for local tumor control. It is also thought to increase the efficacy of checkpoint inhibition and sensitize distant lesions to the effects of immunotherapy, but may potentially increase adverse effects. In our center, few patients with aHCC treated with immune checkpoint inhibitors (ICIs) received concomitant radiotherapy for symptom or disease control. The aim of this study was to retrospectively analyze adverse effects and efficacy of concomitant radiotherapy in patients with aHCC treated with checkpoint inhibition.

METHODS

To this aim, patients who received a combination of ICI and radiotherapy in our institution were retrospectively considered for analysis. The predefined inclusion criterion was radiotherapy after initiated checkpoint inhibition and continuation of ICI therapy for at least 8 weeks. Adverse effects and efficacy measurements were performed according to local standards.

RESULTS

The database search of 2016-2021 revealed six consecutive patients fulfilling the predefined criteria for concomitant ICI and radiotherapy. Three patients received high-dose-rate brachytherapy (15 Gy) to treat progredient hepatic lesions. Two patients received stereotactic body radiotherapy (SBRT) (25-30 Gy) for symptom control, and 1 patient received brachytherapy and SBRT to treat metastases. No severe adverse events were reported in the period (<6 months) after concomitant radiotherapy. In 5 out of 6 cases, long-term tumor control could be achieved by this therapeutic combination.

CONCLUSION

A good efficacy of concomitant radiotherapy and checkpoint inhibition has been achieved with no safety concerns. Further investigations should evaluate the safety, appropriate clinical context, and efficacy of this promising approach.

Comparison of the Treatment Response of Drug-Eluting Bead Transarterial Chemoembolization and Conventional Transarterial Chemoembolization in Patients With Hepatocellular Carcinoma

Introduction Hepatocellular carcinoma (HCC) is a common primary hepatic cancer. Its early diagnosis can aid in its treatment by curative means such as surgery or ablation. Advanced-stage diagnosis limits these treatment options, and such cases can be treated with transarterial chemoembolization (TACE). Conventional transarterial chemoembolization (cTACE) and drug-eluting bead transarterial chemoembolization (DEB-TACE) are usually used, and follow-up response is evaluated using modified Response Evaluation Criteria in Solid Tumors (mRECIST) criteria. This study was done to compare the treatment response of cTACE and DEB-TACE in patients with HCC. Materials and methods A retrospective review of electronic medical records of all patients diagnosed with HCC from January 2021 to August 2022 who underwent cTACE or DEB-TACE was undertaken at the Department of Interventional Radiology, Indus Hospital and Health Network. Both male and female patients aged 18 years or above with Child-Pugh class A and B were included. DEB-TACE or cTACE was performed by a fellowship-trained interventional radiologist, and the response was evaluated at six weeks follow-up using mRECIST criteria. Results A total of 129 patients were included in this study, with a mean age of 54.1 ± 10.8 years. The mean size of HCC was 3.1 ± 1.7 cm. Seventy-eight (60.5%) patients underwent cTACE, and 51 (39.5%) underwent DEB-TACE. Out of the 78 patients who underwent cTACE, complete response (CR) was found in 28 (35.9%), partial response (PR) was found in 33 (42.3%), stable disease (SD) was found in 12 (15.4%), and progressive disease (PD) was found in five (6.4%) patients. Of the 51 patients who underwent DEB-TACE, CR was found in 13 (25.5%), PR was found in 20 (39.2%), SD was found in 11 (21.6%), and PD was found in seven (13.7%) patients. Conclusion The response rate of TACE in the form of complete or partial response was higher with a lower frequency of stable or progressive disease. cTACE has a high response rate as compared to DEB-TACE.

Locoregional Treatments for Bridging and Downstaging HCC to Liver Transplantation

Liver transplantation (LT) is the first-line treatment for patients diagnosed with unresectable early-stage hepatocellular carcinoma (HCC) in the setting of cirrhosis. It is well known that HCC patients within the Milan criteria (solitary tumour ≤ 5 cm or ≤3 tumours, each <3 cm) could undergo LT with excellent results. However, there is a growing tendency to enlarge inclusion criteria since the Milan criteria are nowadays considered too restrictive and may exclude patients who would benefit from LT. On the other hand, there is a persistent shortage of donor organs. In this scenario, there is consensus about the role of loco-regional therapy (LRT) during the waiting list to select patients who would benefit more from LT, reducing the risk of drop off from the waiting list as well as decreasing tumour dimension to meet acceptable criteria for LT. In this review, current evidence on the safety, efficacy and utility of LRTs as neoadjuvant therapies before LT are summarized.