Drastically reduced neoplastic seeding related to radiofrequency ablation for hepatocellular carcinoma

Lenvatinib radiofrequency ablation sequential therapy offers survival benefits for patients with unresectable hepatocellular carcinoma at intermediate stage and the liver reserve of Child-Pugh A category: A multicenter study

AIM

This study aims to evaluate the efficacy and safety of lenvatinib radiofrequency ablation (RFA) sequential therapy for certain hepatocellular carcinoma (HCC) patients.

METHODS

One hundred and nineteen patients with unresectable HCC in the intermediate stage with Child-Pugh A were retrospectively recruited in a multicenter setting. Those in the lenvatinib RFA sequential therapy group received lenvatinib initially, followed by RFA and the retreatment with lenvatinib. The study compared overall survival (OS), progression-free survival (PFS), tumor response, and adverse events (AEs) between patients undergoing sequential therapy and lenvatinib monotherapy.

RESULTS

After propensity score matching, 25 patients on sequential therapy and 50 on monotherapy were evaluated. Independent factors influencing OS were identified as sequential therapy, modified albumin-bilirubin (mALBI) grade, and relative dose intensity (%) with hazard ratios (HRs) of 0.381 (95% confidence interval [CI], 0.186-0.782), 2.220 (95% CI, 1.410-3.493), and 0.982 (95% CI, 0.966-0.999), respectively. Stratified analysis based on mALBI grades confirmed the independent influence of treatment strategy across all mALBI grades for OS (HR, 0.376; 95% CI, 0.176-0.804). Furthermore, sequential therapy was identified as an independent factor of PFS (HR, 0.382; 95% CI, 0.215-0.678). Sequential therapy significantly outperformed monotherapy on survival benefits (OS: 38.27 vs. 18.96 months for sequential therapy and monotherapy, respectively, p = 0.004; PFS: 13.80 vs. 5.32 months for sequential therapy and monotherapy, respectively, p < 0.001). Sequential therapy was significantly associated with complete response by modified Response Evaluation Criteria in Solid Tumors (odds ratio, 63.089). Ten of 119 patients experienced grade 3 AEs, with no AE beyond grade 3 observed.

CONCLUSION

Lenvatinib RFA sequential therapy might offer favorable tolerability and potential prognostic improvement compared to lenvatinib monotherapy.

Clinical utility of postablation liver tumor biopsy and possibility of gene mutation analysis

AIM

Radiofrequency ablation (RFA) is regarded as a first-line treatment for hepatocellular carcinoma (HCC) at an early stage. When treated with RFA, tumor biopsy may not be performed due to the risk of neoplastic seeding. We previously revealed that the risk of neoplastic seeding is significantly reduced by performing biopsies after RFA. In this study, we investigated the possibility of pathological evaluation and gene mutation analysis of post-RFA tumor specimens.

METHODS

Radiofrequency ablation was undertaken on diethylnitrosamine-induced mouse liver tumor, and tumor samples with or without RFA were subjected to whole exome sequencing. Post-RFA human liver tumor specimens were used for detection of TERT promoter mutations and pathological assessment.

RESULTS

The average somatic mutation rate, sites of mutation, and small indels and base transition patterns were comparable between the nontreated and post-RFA tumors. We identified 684 sites of nonsynonymous somatic substitutions in the nontreated tumor and 704 sites of nonsynonymous somatic substitutions in the post-RFA tumor, with approximately 85% in common. In the human post-RFA samples, the TERT promoter mutations were successfully detected in 40% of the cases. Pathological evaluation was possible with post-RFA specimens, and in one case, the diagnosis of adenocarcinoma was made.

CONCLUSION

Our findings suggest that post-RFA liver tumor biopsy is a useful and safe method for obtaining tumor samples that can be used for gene mutation analysis and for pathological assessment.

Challenges Facing Percutaneous Ablation in the Treatment of Hepatocellular Carcinoma: Extension of Ablation Criteria

As an emerging minimally invasive treatment method, percutaneous ablation is more and more widely used in the treatment of liver tumors. It has been recommended by guidelines for diagnosis and treatment of hepatocellular carcinoma (HCC) as a curative treatment alongside surgical resection and liver transplantation. In recent years, with the continuous advancement and innovation of percutaneous ablation technologies, their clinical efficacy and safety have been significantly improved, which has led to the expanded application of percutaneous ablation in the treatment of HCC—more and more patients who were previously considered unsuitable for ablation therapies are now being treated with percutaneous ablation. Obviously, percutaneous ablation can reduce the risk of treatment changes from curative strategies to palliative strategies. Based on clinical practice experience, this review enumerates the advantages and disadvantages of different ablative modalities and summarizes the existing combinations of ablation techniques, thus will help clinicians choose the most appropriate ablative modality for each patient and will provide scientific guidance for improving prognosis and making evidence-based treatment decisions. In addition, we point out the challenges and future prospects of the ablation therapies, thereby providing direction for future research.

Locoregional therapies in the era of molecular and immune treatments for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the fourth leading cause of cancer-related mortality and has an increasing incidence worldwide. Locoregional therapies, defined as imaging-guided liver tumour-directed procedures, play a leading part in the management of 50-60% of HCCs. Radiofrequency is the mainstay for local ablation at early stages and transarterial chemoembolization (TACE) remains the standard treatment for intermediate-stage HCC. Other local ablative techniques (microwave ablation, cryoablation and irreversible electroporation) or locoregional therapies (for example, radioembolization and sterotactic body radiation therapy) have been explored, but have not yet modified the standard therapies established decades ago. This understanding is currently changing, and several drugs have been approved for the management of advanced HCC. Molecular therapies dominate the adjuvant trials after curative therapies and combination strategies with TACE for intermediate stages. The rationale for these combinations is sound. Local therapies induce antigen and proinflammatory cytokine release, whereas VEGF inhibitors and tyrosine kinase inhibitors boost immunity and prime tumours for checkpoint inhibition. In this Review, we analyse data from randomized and uncontrolled studies reported with ablative and locoregional techniques and examine the expected effects of combinations with systemic treatments. We also discuss trial design and benchmarks to be used as a reference for future investigations in the dawn of a promising new era for HCC treatment.

Assessment of hepatocellular carcinoma treatment response with LI-RADS: a pictorial review

Computed tomography (CT) and magnetic resonance imaging (MRI) play critical roles for assessing treatment response of hepatocellular carcinoma (HCC) after locoregional therapy. Interpretation is challenging because posttreatment imaging findings depend on the type of treatment, magnitude of treatment response, time interval after treatment, and other factors. To help radiologists interpret and report treatment response in a clear, simple, and standardized manner, the Liver Imaging Reporting and Data System (LI-RADS) has developed a Treatment Response (LR-TR) algorithm. Introduced in 2017, the system provides criteria to categorize response of HCC to locoregional treatment (e.g., chemical ablation, energy-based ablation, transcatheter therapy, and radiation therapy). LR-TR categories include Nonevaluable, Nonviable, Equivocal, and Viable. LR-TR does not apply to patients on systemic therapies. This article reviews the LR-TR algorithm; discusses locoregional therapies for HCC, treatment concepts, and expected posttreatment findings; and illustrates LI-RADS treatment response assessment with CT and MRI.

Percutaneous treatment of hepatocellular carcinoma: State of the art and innovations

Percutaneous treatment of hepatocellular carcinoma (HCC) encompasses a vast range of techniques, including monopolar radiofrequency ablation (RFA), multibipolar RFA, microwave ablation, cryoablation and irreversible electroporation. RFA is considered one of the main curative treatments for HCC of less than 5 cm developing on cirrhotic liver, together with surgical resection and liver transplantation. However, controversies exist concerning the respective roles of ablation and liver resection for HCC of less than 3 to 5 cm on cirrhotic liver. In line with the therapeutic algorithm of early HCC, percutaneous ablation could also be used as a bridge to liver transplantation or in a sequence of upfront percutaneous treatment, followed by transplantation if the patient relapses. Moreover, several innovations in ablation methods may help to efficiently treat early HCC, initially considered as "non-ablatable", and might, in some cases, extend ablation criteria beyond early HCC, enabling treatment of more patients with a curative approach.

Rate of seeding with biopsies and ablations of hepatocellular carcinoma: A retrospective cohort study

Biopsies of liver masses that prove to be hepatocellular carcinomas (HCCs) are associated with a risk of seeding the abdominal or chest wall with tumor cells. The reported frequency of seeding varies greatly in the literature. We performed a retrospective cohort study in a large integrated health care system to examine rates of seeding in patients with HCC who had targeted liver biopsies, ablations, or both performed by community radiologists. We reviewed pathology and radiology records to determine the occurrence of wall seeding, defined as a chest or abdominal wall lesion along a definite or probable needle tract. A total of 1,015 patients had targeted liver biopsies (795), ablations (72), or both (148). Multiple procedures were done in 284 patients (28%). Six cases of seeding were identified. The rate of wall seeding was 2/795 patients (0.13%; 95% confidence interval [CI], 0.00%-0.60%) if only biopsies were done versus 4/220 (1.82%; 95% CI, 0.05%-3.58%) if ablations were performed (P = 0.01). The rate was 0/72 (0.00%; 95% CI, 0.00%-0.04%) with ablations alone and 4/148 (2.70%; 95% CI, 0.74%-6.78%) if both procedures were done (P = 0.31). Of those with 1 year follow-up (n = 441), the rate of seeding was 2/269 (0.74%; 95% CI, 0.00%-1.77%) if biopsies alone were done and 4/172 (2.33%; 95% CI, 0.07%-4.58%) if ablations were done. In none of the cases was the seeding a proximate cause of death. Conclusion: Biopsies of liver masses are associated with a low rate of wall seeding when performed in a community setting and when they are the sole procedures. Ablations may have a higher rate of seeding, particularly if done with biopsies, but are still rare. (Hepatology Communications 2017;1:841-851).