Innovative therapy for hepatocellular carcinoma: three-dimensional high-dose photon radiotherapy

Non-Surgical Locoregional Therapies Alone or in Combination with Systemic Therapy in Patients with Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the most common primary liver cancer, representing the third-leading cause of cancer-related deaths worldwide. Curative intent treatment options for patients with HCC include liver transplantation, resection and ablation of small lesions. Other potentially curative therapies include cryoablation, microwave ablation and percutaneous alcohol injection. For locally advanced disease, different arterially directed therapies including transarterial chemoembolization and selective internal radiation therapy, plus external beam radiation including three-dimensional conformal radiation therapy, intensity-modulated radiation therapy, stereotactic body radiation therapy and proton beam therapy, are available or studied. Systemic therapies based on checkpoint inhibitors and tyrosine kinase inhibitors are available for the management of metastatic HCC and sometimes for locally advanced disease. Combinations of locoregional therapies with systemic drugs are currently the subject of several clinical trials.

Hepatic tumours and radiotherapy

We present the update of the recommendations of the French society of oncological radiotherapy on hepatic tumours. Recent technological progress led to develop the concept of focused liver radiation therapy. We must distinguish primary and secondary tumours, as the indications are restricted and must be discussed as an alternative to surgical or medical treatments. The tumour volume, its liver location close to the organs at risk determine the irradiation technique (repositioning method, total dose delivered, dose fractionation regimens). Tumour (and liver) breathing related motions should be taken into account. Strict dosimetric criteria must be observed with particular attention to the dose-volume histograms of non-tumoral liver as well as of the hollow organs, particularly in case of hypofractionated high dose radiotherapy "under stereotaxic conditions". Stereotactic body radiotherapy is being evaluated and is often preferred to radiofrequency for primary or secondary tumours (usually less than 5cm). An adaptation can be proposed, with a conformal fractionated irradiation protocol with or without intensity modulation, for hepatocellular carcinomas larger than 5cm.

Hepatocellular carcinoma: French Intergroup Clinical Practice Guidelines for diagnosis, treatment and follow-up (SNFGE, FFCD, GERCOR, UNICANCER, SFCD, SFED, SFRO, AFEF, SIAD, SFR/FRI)

INTRODUCTION

This document is a summary of the French Intergroup guidelines regarding the management of hepatocellular carcinoma (HCC) published in March 2019.

METHOD

It is a collaborative work under the auspices of most of the French medical societies involved in the management of HCC. It is based on the previous guidelines published in 2017. Recommendations are graded in 3 categories according to the level of evidence of data found in the literature.

RESULTS

The diagnosis and staging of HCC is essentially based on clinical, biological and imaging features. A pathological analysis obtained by a biopsy of tumoral and non-tumoral liver is recommended. HCCs can be divided into 2 groups, taking into account not only the tumor stage, but also liver function. HCCs accessible to curative treatments are tumors that are in Milan criteria or with an AFP score ≤ 2, mainly treated by surgical resection, local ablation or liver transplantation. Intermediate and advanced HCCs with no liver insufficiency, accessible only to palliative treatments, benefit from TACE, SIRT or systemic therapy according to the presence or absence of macrovascular invasion or extrahepatic spread.

CONCLUSION

Such recommendations are in permanent optimization and each individual case must be discussed in a multidisciplinary expert board.

Transarterial chemoembolization plus iodine-125 implantation for hepatocellular carcinoma: a systematic review and meta-analysis

BACKGROUND

Hepatocellular carcinoma (HCC) is the most common malignancy in liver. Transarterial chemoembolization (TACE) is recommended as an effective treatment in advanced HCC patients. Recent studies showed iodine-125 seed (a low-energy radionuclide) can provide long-term local control and increase survival for HCC patients. The aim of the study was to evaluate the outcome of TACE plus iodine-125 seed in comparison with TACE alone for HCC.

METHODS

A comprehensive search of studies among PubMed, Embase, Cochrane Central Register of Controlled Trials, and Cochrane Database of Systematic Reviews was conducted with published date from the earliest to January 10th, 2018. No language restrictions were applied, while only prospective randomized controlled trials (RCTs) or non-randomized controlled trials (non-RCTs) were eligible for a full-text review. The primary outcome was overall survival (OS), response rate (the rate of partial atrophy or complete clearance of the tumor lesion) and adverse events (AEs). The odds ratios (ORs) were combined using either fixed-effects model or random-effects model. All statistical analyses were performed using the Stata 12.0 software.

RESULTS

9 studies were included, involving 894 patients. Among them, 473 patients received combined therapy of TACE plus iodine-125 implantation, compared with 421 patients with TACE alone. Patients receiving combined therapy of TACE plus iodine-125 showed significantly improvement in 1-year OS (OR = 4.47, 95% confidence intervals (CI): 2.97-6.73; P < 0.001), 2-year OS (OR = 4.72, 95% CI: 2.63-8.47; P < 0.001). No significant publication bias was observed in any of the measured outcomes.

CONCLUSIONS

Based on these findings, TACE plus iodine-125 implantation achieves better clinical efficacy compared with TACE alone in the treatment of HCC.

External beam radiotherapy for unresectable hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma is the most common liver neoplasm, the sixth most common cancer worldwide, and the third most common cause of cancer mortality. Moreover, its incidence has increased dramatically in the past decade. 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 transarterial therapies in addition to the drug sorafenib.

OBJECTIVES

To assess the benefits and harms of external beam radiotherapy in the management of localised unresectable hepatocellular carcinoma.

SEARCH METHODS

We searched the Cochrane Hepato-Biliary Group Controlled Trials Register, Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library, MEDLINE (OvidSP), Embase (OvidSP), Science Citation Index Expanded (Web of Science), and clinicaltrials.gov registry. We also checked reference lists of primary original studies and review articles manually for further related articles (cross-references) up to October 6, 2016.

SELECTION CRITERIA

Eligible studies included all randomised clinical trials comparing external beam radiotherapy 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.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. We used a random-effects model as well as a fixed-effect model meta-analysis but in case of discrepancy between the two models (e.g. one giving a significant intervention effect, the other no significant intervention effect), we reported both results; otherwise, we reported only the results from the fixed-effect model meta-analysis. We assessed risk of bias of the included trials using predefined risk of bias domains; assessed risks of random errors with Trial Sequential Analysis; and presented the review results incorporating the methodological quality of the trials using GRADE.

MAIN RESULTS

Nine randomised clinical trials with 879 participants fulfilled our inclusion criteria. All trials were at high risk of bias, and we rated the evidence as low to very low quality. All of the included trials compared combined external beam radiotherapy plus chemoembolisation versus chemoembolisation alone in people with unresectable hepatocellular carcinoma; moreover, three of the trials compared external beam radiotherapy alone versus chemoembolisation alone. All trials were conducted in China. The median age in most of the included trials was around 52 years, and most trial participants were male. The median follow-up duration ranged from one to three years. None of the trials reported data on cancer-related mortality, quality of life, serious adverse events, or time to progression of the tumour. For the comparison of radiotherapy plus chemoembolisation versus chemoembolisation alone, the risk ratio for one-year all-cause mortality was 0.51 (95% confidence interval (CI) 0.41 to 0.62; P < 0.001; 9 trials; low-quality evidence); for complete response rate was 2.14 (95% CI 1.47 to 3.13; P < 0.001; 7 trials; low-quality evidence); and for overall response rate defined as complete response plus partial response was 1.58 (95% CI 1.40 to 1.78; P < 0.001; 7 trials; low-quality evidence), all in favour of combined treatment with external beam radiotherapy plus transarterial chemoembolisation and seemingly supported by our Trial Sequential Analysis. Additionally, the combined treatment was associated with a higher risk of elevated total bilirubin and elevated alanine aminotransferase. The risk ratio for the risk of elevated alanine aminotransferase was 1.41 (95% CI 1.08 to 1.84; P = 0.01; very low-quality evidence), while for elevated total bilirubin it was 2.69 (95% CI 1.34 to 5.40; P = 0.005; very low-quality evidence). For the comparison of radiotherapy versus chemoembolisation, the risk ratio for one-year all-cause mortality was 1.21 (95% CI 0.97 to 1.50; 3 trials; I² = 0%; very low-quality evidence) which was not supported by our Trial Sequential Analysis.In addition, we found seven ongoing randomised clinical trials evaluating different external beam radiotherapy techniques for people with unresectable hepatocellular carcinoma.

AUTHORS' CONCLUSIONS

We found very low- and low-quality evidence suggesting that combined external beam radiotherapy and chemoembolisation may be associated with lower mortality and increased complete and overall response rates, despite an increased toxicity as expressed by a higher rise of bilirubin and alanine aminotransferase. A high risk of systematic errors (bias) as well as imprecision and inconsistency suggest that these findings should be considered cautiously and that high-quality trials are needed to assess further the role of external beam radiotherapy for unresectable hepatocellular carcinoma.

[Hepatic tumors and radiotherapy]

Recent technological developments led to develop the concept of focused liver radiation therapy. We must distinguish primary and secondary tumors as the indications are restricted and must be discussed as an alternative to surgical or medical treatments. For hepatocellular carcinoma 5 to 10cm (or more), a conformational radiation with or without intensity modulation is performed. Stereotactic body radiotherapy (SBRT) is being evaluated and is increasingly proposed as an alternative to radiofrequency ablative treatment for primary or secondary tumors (typically less than 5cm). Tumor (and liver) movements induced by respiratory motions must be taken into account. Strict dosimetric criteria must be met with particular attention to the dose-volume histograms to liver and the hollow organs, including cases of SBRT.

Improvement of Survival Rate for Patients with Hepatocellular Carcinoma Using Transarterial Chemoembolization in Combination with Three-Dimensional Conformal Radiation Therapy: A Meta-Analysis

BACKGROUND Transarterial chemoembolization (TACE) has been used alone or in combination with three-dimensional conformal radiation therapy (3DCRT) for treating hepatocellular carcinoma (HCC). The overall survival rate of HCC patients undergoing both treatments, however, has not been systematically studied. The aim of this meta-analysis-based study was to evaluate the overall efficacy of the combined therapy or monotherapy, thereby providing information for clinical treatment. MATERIAL AND METHODS We searched Google Scholar, PubMed, and Chinese National Knowledge Infrastructure (CNKI) for eligible studies, and a total of 17 case-control studies (including HCC patients treated by TACE plus 3DCRT or TACE alone) were included to perform the meta-analysis. Based on the available data, we assessed the improvements of 1-year, 2-year, and 3-year survival rate for the combination therapy of TACE and 3DCRT or TACE alone. Furthermore, the analysis was also stratified by the tumor response: complete response (CR), partial response (PR), no response (NR) and progressive disease (PD). Statistical analysis was performed using STATA 12 (Stata Statistical Software: Release 12). RESULTS The results show that HCC patients receiving combination therapy have significantly increased overall survival rate when compared to those receiving TACE alone (1-year survival rate: OR=1.95, 95% CI 1.54-2.47, p=7.3×10^-8; 2-year survival rate: OR=1.87, 95% CI 1.49-2.34, p=1.6×10^-7; 3-year survival rate: OR=2.00, 95% CI 1.52-2.64, p=1.8×10^-6). CONCLUSIONS Assessment of tumor response demonstrates that the combination therapy can efficiently increase the tumor response rate (CR+PR: OR=2.29, 95% CI 1.70-3.08, p=1.1×10^-7), with a lower rate of subsequent tumor development (PD: OR=0.25, 95% CI 0.15-0.40, p=5.5×10^-8).

PARP inhibition and the radiosensitizing effects of the PARP inhibitor ABT-888 in in vitro hepatocellular carcinoma models

Background

Hepatocellular carcinoma is the third cause of cancer related death for which new treatment strategies are needed. Targeting DNA repair pathways to sensitize tumor cells to chemo- or radiotherapy is under investigation for the treatment of several cancers with poly(ADP-ribose) polymerase (PARP) inhibitors showing great potential. The aim of this preclinical study was to evaluate the expression of PARP and PARG genes in a panel of liver cancer cell lines and primary human hepatocytes, their DNA repair capacity and assess the impact on cell survival of PARP inhibitors alone and in combination with radiotherapy.

Methods

Quantitative PCR was used to measure PARP-1, -2, -3 and PARG mRNA levels and western blotting for PARP-1 protein expression and ADP-ribose polymer formation after exposure of cells to doxorubicin, a topoisomerase II poison. DNA repair capacity was assessed using an in vitro DNA lesion excision/synthesis assay and the effects on cell killing of the PARP inhibitor ABT-888 alone and in combination with ionizing radiation using clonogenic survival.

Results

Although a wide range in expression of the PARPs and PARG was found correlations between PARP-1 and PARP-2 mRNA levels and PARP-1 mRNA and protein levels were noted. However these expression profiles were not predictive of PARP activity in the different cell lines that also showed variability in excision/synthesis repair capacity. 4 of the 7 lines were sensitive to ABT-888 alone and the two lines tested showed enhanced radiosensitivity in the presence of ABT-888.

Conclusions

PARP inhibitors combined with radiotherapy show potential as a therapeutic option for hepatocellular carcinoma.

Update on hepatocellular carcinoma breakthroughs: poly(ADP-ribose) polymerase inhibitors as a promising therapeutic strategy

Hepatocellular carcinoma is the most common form of primary liver cancer which is the fifth most common cancer in men and the seventh in women and the third most common cause of cancer-related death worldwide. Only 10-20% of patients are eligible for curative treatments that result in a 5-year survival rate of 40% to 70%. Therefore, the development of novel treatment options is necessary for the majority of patients and remains a considerable challenge. Conformal radiotherapy is used in certain circumstances and preliminary data obtained from phase 1/2 trials are showing promising curative effects. There is thus an interest in identifying drugs that can be exploited to enhance radiation sensitivity that could be used in therapy and might improve clinical outcome. Small molecules inhibitors of poly(ADP-ribose) polymerases (PARP) are an example of a radio- and chemo-sensitizing drug, as well as being an efficient single agent treatment in certain genetic backgrounds. In this review, we discuss the role of PARP-1 in hepatocellular carcinoma and present the results of preclinical studies that have assessed the potential of PARP inhibition as a single treatment or combined with chemotherapy or radiotherapy for the treatment of hepatocellular carcinoma.

New progress of non-surgical treatments for hepatocellular carcinoma

Many non-surgical treatments of hepatocellular carcinoma (HCC) have significantly improved in the last few decades and have shown survival benefits for selected patients with HCC. Today ablation can improve survival in individuals diagnosed in early HCC and even offer a curative treatment in selected candidates. Patients with intermediate-stage HCC benefit from transarterial chemoembolization (TACE). Drug-eluting bead transarterial chemoembolization (DEB-TACE) has shown a better combined ischemic and cytotoxic effect locally and less system toxicity when compared with conventional TACE. Those diagnosed at advanced stage benefit from sorafenib. In addition to TACE and sorafenib which could improve survival for selected patients, three-dimensional conformal radiotherapy treatment (3-DCRT), selection internal radiation therapy and systemic chemotherapy have also shown anti-tumor activity in the treatment of advanced HCC, but their survival benefit have not been proven. The limited effects of single therapy suggested that the combination would enhance the overall treatment effect. Other potential non-surgical therapies like gene therapy and immunotherapy are still in testing phases, except for some small-scale clinical trials which have been reported to show some beneficial effect. Here, we review the current non-surgical treatments in HCC and the new advances in this field.

Dosimetric differences among volumetric modulated arc radiotherapy (RapidArc) plans based on different target volumes in radiotherapy of hepatocellular carcinoma

We investigated the dosimetric differences among volumetric-modulated arc radiotherapy (RapidArc, RA) plans designed for various target volumes in hepatocellular carcinoma (HCC). Ten HCC patients underwent 3D-CT scanning at free breathing (FB), 3D-CT at end inspiration hold (EIH) assisted by an Active Breathing Coordinator (ABC), and 4D-CT scanning. Gross tumor volumes (GTVs) were manually contoured on CT images. The individualized internal gross target volume (IGTV(1)) was obtained from 10 GTVs from 4D-CT images. Tumor individual margins were measured from GTV(FB) to IGTV(1). The IGTV(2) was obtained from GTV(FB) by applying individual margins. Four planning target volumes (PTV(1-4)) were obtained from IGTV(1), IGTV(2), GTV(FB), and GTV(EIH), respectively. An RA plan was designed for each of the PTVs (RA(1-4)). One 358° arc was used for PTVs(1-3), while three 135° arcs were used for PTV(4). It was found that PTV(2) and PTV(3) were larger than PTV(1) and PTV(4). The mean values of PTV(3)/PTV(1) and PTV(3)/PTV(4) were 2.5 and 1.9, respectively. The individual margins in the X, Y and Z axial directions varied greatly among these patients. There were no significant differences in the conformal index or homogeneity index among the four RA plans. RA(1) and RA(4) significantly reduced the radiation dose of normal liver tissue compared with RA(2) and RA(3) (P < 0.01). There were no significant differences between the radiation doses of the stomach and duodenum. RapidArc combined with 4D-CT or ABC technology is a promising method in radiotherapy of HCC, and accurately targeted the tumor volume while sparing more normal liver tissue.

RapidArc combined with the active breathing coordinator provides an effective and accurate approach for the radiotherapy of hepatocellular carcinoma

PURPOSE

The goal of this research was to investigate the feasibility of volumetric modulated arc therapy, RapidArc (RA), in association with the active breathing coordinator (ABC) for the treatment of hepatocellular carcinoma (HCC) with radiotherapy.

PATIENTS AND MATERIALS

A total of 12 patients with HCC, after receiving transcatheter arterial chemoembolization (TACE) treatment, underwent three-dimensional computer tomography (3D-CT) scanning associated with ABC using end inspiration hold (EIH), end expiration hold (EEH), and free breathing (FB) techniques. The three-dimensional conformal radiotherapy (3D-CRT), intensity-modulated radiotherapy (IMRT), and RA plans (three 135° arcs) were designed on different CT images, respectively. The liver volume, gross tumor volume (GTV), and planning target volume (PTV) of the three breath status and the dosimetric differences of the different plans were compared.

RESULTS

There were no significant differences in the volumes of live and GTV between the three breathing techniques (p > 0.05); the PTV in FB was greater than in the EEH and EIH (p < 0.05). The overall conformality index (CI) and homogeneity index (HI) for RA (CI 0.92, HI 0.90) were better than IMRT (CI 0.90, HI 0.89) and 3D-CRT (CI 0.70, HI 0.84) for the three breathing techniques (p< 0.05). The RA and IMRT significantly reduced the mean dose, V(20), V(30), and V(40) of normal liver compared to 3D-CRT, while the V(5) and V(10) in RA were higher than in IMRT. The mean values in mean dose, V(10), V(20), V(30), and V(40) of the normal liver were reduced from 13.12 Gy, 46%, 24%, 13%, and 8% in RA(FB) to 10.23 Gy, 35%, 16%, 8%, and 5% in RA(EEH) and 9.23 Gy, 32%, 16%, 8%, and 5% in RA(EIH ), respectively. In addition, the treatment time of RA was equal to 3D-CRT, which was significantly shorter than IMRT.

CONCLUSION

RA in conjunction with ABC for the treatment of HCC with radiotherapy can achieve better dose delivery and ensure the accuracy of the target volume, which spares more organs at risk, uses fewer monitor units, and shortens treatment time.

[Transarterial chemoembolization and conformal radiotherapy for hepatocellular carcinoma]

Hepatocellular carcinoma is a poor prognosis tumour. The potential curative therapeutic options are orthotopic liver transplantation, surgical resection and radiofrequency ablation. Unfortunately, only a minority of patients (around 20%) are eligible for these techniques. Thus, patients can benefit from palliative options, such as transarterial chemoembolization (TACE) or sorafenib that bring only modest benefit on survival. Conformal radiotherapy allows delivering high dose radiation within a precise tumour volume while sparing the surrounding liver parenchyma. As employed in monotherapy, conformal radiotherapy is highly efficient for small size hepatocellular carcinoma (<5 cm). Above 5 cm, its efficacy is more limited but its association with TACE gives spectacular rates of complete responses. Controlled phase 2 or 3 trials are urgently warranted to define its indications in the therapeutic algorithm of hepatocellular carcinoma.

[Nonsurgical management of hepatocellular carcinoma]

Most of patients with hepatocellular carcinoma (HCC) cannot benefit from surgical therapies. Among nonsurgical options, only radiofrequency can challenge surgery for small size tumours. Conformal radiotherapy is likely highly efficient on solitary tumours, but controlled studies are warranted to conclude. Other options are purely palliative. Transarterial hepatic chemoembolization is the goal-standard for multifocal hepatocellular carcinoma and sorafenib for hepatocellular carcinoma with portal vein invasion, leading to modest but significant benefit on survival rates. Yttrium-90 radioembolization is under evaluation through controlled studies, and could be of major interest for multifocal hepatocellular carcinoma with or without portal venous invasion.