Sorafenib modulates the radio sensitivity of hepatocellular carcinoma cells in vitro in a schedule-dependent manner

Measurable imaging-based changes in enhancement of intrahepatic cholangiocarcinoma after radiotherapy reflect physical mechanisms of response

Background

Although escalated doses of radiation therapy (RT) for intrahepatic cholangiocarcinoma (iCCA) are associated with durable local control (LC) and prolonged survival, uncertainties persist regarding personalized RT based on biological factors. Compounding this knowledge gap, the assessment of RT response using traditional size-based criteria via computed tomography (CT) imaging correlates poorly with outcomes. We hypothesized that quantitative measures of enhancement would more accurately predict clinical outcomes than size-based assessment alone and developed a model to optimize RT.

Methods

Pre-RT and post-RT CT scans of 154 patients with iCCA were analyzed retrospectively for measurements of tumor dimensions (for RECIST) and viable tumor volume using quantitative European Association for Study of Liver (qEASL) measurements. Binary classification and survival analyses were performed to evaluate the ability of qEASL to predict treatment outcomes, and mathematical modeling was performed to identify the mechanistic determinants of treatment outcomes and to predict optimal RT protocols.

Results

Multivariable analysis accounting for traditional prognostic covariates revealed that percentage change in viable volume following RT was significantly associated with OS, outperforming stratification by RECIST. Binary classification identified ≥33% decrease in viable volume to optimally correspond to response to RT. The model-derived, patient-specific tumor enhancement growth rate emerged as the dominant mechanistic determinant of treatment outcome and yielded high accuracy of patient stratification (80.5%), strongly correlating with the qEASL-based classifier.

Conclusion

Following RT for iCCA, changes in viable volume outperformed radiographic size-based assessment using RECIST for OS prediction. CT-derived tumor-specific mathematical parameters may help optimize RT for resistant tumors.

Lenvatinib with or without stereotactic body radiotherapy for hepatocellular carcinoma with portal vein tumor thrombosis: a retrospective study

BACKGROUND AND OBJECTIVES

Patients with hepatocellular carcinoma (HCC) involving portal vein tumor thrombosis (PVTT) are presently lacking effective treatment options. We aimed to compare the efficacy and safety of lenvatinib with or without SBRT for HCC with PVTT.

MATERIALS AND METHODS

This retrospective analysis included 37 patients treated with lenvatinib in combination with SBRT and 77 patients treated with lenvatinib alone from August 2018 to August 2021. Overall survival (OS), progression-free survival (PFS), intrahepatic PFS (IHPFS) and objective remission rate (ORR) were compared between the two groups, while adverse events (AEs) was analyzed between the two groups to assess safety profiles.

RESULTS

Median OS, PFS and IHPFS were significantly prolonged in the combination treatment group compared with the single treatment group (median OS, 19.3 vs. 11.2 months, p < 0.001; median PFS: 10.3 vs. 5.3 months, p < 0.001; median IHPFS, 10.7 vs. 5.3 months, p < 0.001). Moreover, a higher ORR (56.8% vs. 20.8%, P < 0.001) were observed in the lenvatinib combined with SBRT group. In subgroup analyses of Vp1-2 and Vp3-4 group, median OS, PFS and IHPFS were also significantly longer in the lenvatinib combined with SBRT group than those in the lenvatinib alone group. AEs in the combined therapy group were mostly manageable and the incidence was not statistically significant compared to the monotherapy group.

CONCLUSION

Lenvatinib plus SBRT had a significantly better survival benefit than lenvatinib monotherapy in the treatment of HCC patients with PVTT and was well tolerated.

Liver SBRT dose accumulation to assess the impact of anatomic variations on normal tissue doses and toxicity in patients treated with concurrent sorafenib

BACKGROUND AND PURPOSE

Unexpected liver volume reductions occurred during trials of liver SBRT and concurrent sorafenib. The aims were to accumulate liver SBRT doses to assess the impact of these anatomic variations on normal tissue dose parameters and toxicity.

MATERIALS AND METHODS

Thirty-two patients with hepatocellular carcinoma (HCC) or metastases treated on trials of liver SBRT (30-57 Gy, 6 fractions) and concurrent sorafenib were analyzed. SBRT doses were accumulated using biomechanical deformable registration of daily cone-beam CT. Dose deviations (accumulated-planned) for normal tissues were compared for patients with liver volume reductions > 100 cc versus stable volumes, and accumulated doses were reported for three patients with grade 3-5 luminal gastrointestinal toxicities.

RESULTS

Patients with reduced (N = 12) liver volumes had larger mean deviations of 0.4-1.3 Gy in normal tissues, versus -0.2-0.4 Gy for stable cases (N = 20), P > 0.05. Deviations > 5% of the prescribed dose occurred in both groups. Two HCC patients with toxicities to small and large bowel had liver volume reductions and deviations to the maximum dose of 4% (accumulated 36.9 Gy) and 3% (accumulated 33.4 Gy) to these organs respectively. Another HCC patient with a toxicity of unknown location plus tumor rupture, had stable liver volumes and deviations to luminal organs of -6% to 4.5% (accumulated < 30.5 Gy).

CONCLUSION

Liver volume reductions during SBRT and concurrent sorafenib were associated with larger increases in accumulated dose to normal tissues versus stable liver volumes. These dosimetric changes may have further contributed to toxicities in HCC patients who have higher baseline risks.

Concurrent Sorafenib and Radiotherapy versus Radiotherapy Alone for Locally Advanced Hepatocellular Carcinoma: A Propensity-Matched Analysis

Purpose

Evidence is lacking concerning the benefit of the combination of sorafenib and radiotherapy to treat advanced hepatocellular carcinoma (HCC). To date, no publication has reported the outcomes of radiotherapy alone versus concurrent therapy. We aimed to compare the effectiveness of radiotherapy alone versus concurrent radiotherapy and sorafenib for locally advanced hepatocellular carcinoma.

Materials and Methods

We conducted a propensity score matching (PSM) cohort study comparing the effectiveness of the concurrent use of sorafenib and external beam radiotherapy versus radiotherapy alone in Barcelona Clinic Liver Cancer (BCLC) stage B or C, nonsurgically managed, nonmetastatic patients with HCC. Two subpopulations were matched based on baseline characteristics. Stratified analysis was also performed to assess the heterogeneous effects of the two arms. Overall survival (OS) was compared. Radiation-induced liver disease (RILD) and overt gastrointestinal (GI) bleeding events were also recorded.

Results

Seven hundred thirty-one BCLC stage B or C nonmetastatic HCC patients were identified from 2007 to 2017. Of these, 347 patients met the inclusion criteria (Radiotherapy alone: 269 patients; concurrent therapy: 78 patients). Propensity score matching yielded 73 patients each in the radiotherapy and concurrent groups. The median OS was 9.6 months in the radiotherapy-alone group and 9.9 months in the concurrent group (hazard ratio (HR): 1.12; 95% CI=0.78–1.62; p=0.544). Posttreatment toxicities, including radiation-induced liver disease and overt gastrointestinal bleeding, showed no significant differences between the groups.

Conclusion

In our study, the concurrent use of sorafenib and conventional external beam radiotherapy shows no survival benefit over radiotherapy alone for locally advanced hepatocellular carcinoma.

PI3K/mTOR Dual Inhibitor PF-04691502 Is a Schedule-Dependent Radiosensitizer for Gastroenteropancreatic Neuroendocrine Tumors

Patients with advanced-stage gastroenteropancreatic neuroendocrine tumors (GEP-NETs) have a poor overall prognosis despite chemotherapy and radiotherapy (e.g., peptide receptor radionuclide therapy (PRRT)). Better treatment options are needed to improve disease regression and patient survival. The purpose of this study was to examine a new treatment strategy by combining PI3K/mTOR dual inhibition and radiotherapy. First, we assessed the efficacy of two PI3K/mTOR dual inhibitors, PF-04691502 and PKI-402, to inhibit pAkt and increase apoptosis in NET cell lines (BON and QGP-1) and patient-derived tumor spheroids as single agents or combined with radiotherapy (XRT). Treatment with PF-04691502 decreased pAkt (Ser473) expression for up to 72 h compared with the control; in contrast, decreased pAkt expression was noted for less than 24 h with PKI-402. Simultaneous treatment with PF-04691502 and XRT did not induce apoptosis in NET cells; however, the addition of PF-04691502 48 h after XRT significantly increased apoptosis compared to PF-04691502 or XRT treatment alone. Our results demonstrate that schedule-dependent administration of a PI3K/mTOR inhibitor, combined with XRT, can enhance cytotoxicity by promoting the radiosensitivity of NET cells. Moreover, our findings suggest that radiotherapy, in combination with timed PI3K/mTOR inhibition, may be a promising therapeutic regimen for patients with GEP-NET.

Stereotactic Radiotherapy for Hepatocellular Carcinoma, Radiosensitization Strategies and Radiation-Immunotherapy Combination

Simple Summary

Radiotherapy is rapidly turning into a crucial component of multidisciplinary treatment for liver cancer because many patients are not surgical treatment candidates. Thanks to technical developments, radiotherapy have achieved high precision treatments, making it possible to eliminate tumor cells without severe damage to the liver and other organs. Stereotactic Body Radiation Therapy is an advanced radiotherapy technique able to eradicate malignant tumors wherever they are located in properly selected patients. The best use of radiotherapy, the most fruitful radiotherapy strategy, and the best way to combine it with other treatments for liver cancer are largely unknown. Radiosensitizers, agents that can potentiate radiotherapy, could broaden the radiotherapeutic landscape. Radiotherapy potentiation can be achieved with diverse treatments, not only drugs but also nanoparticles. In order to clear up the performance of radiotherapy in liver cancer management in the future and the best ways to potentiate its effects, considerable medical research is needed.

Abstract

Stereotactic body radiotherapy (SBRT) is an emerging ablative modality for hepatocellular carcinoma (HCC). Most patients with HCC have advanced disease at the time of diagnosis, and therefore, are not candidates for definitive-intent therapies such as resection or transplantation. For this reason, various alternative local and regional therapies have been used to prevent disease progression, palliate symptoms, and delay liver failure. Stereotactic body radiation therapy is a non-invasive technique of delivering ablative doses of radiation to tumors while sparing normal or non-tumor hepatic tissue. Incorporation of SBRT in multidisciplinary HCC management is gradual, initially applied when other liver-directed therapies have failed or are contraindicated, and tried in combination with other locoregional or systemic therapies for more unfavorable conditions by more experienced teams. In order to improve SBRT therapeutic ratio, there has been much interest in augmenting the effect of radiation on tumors by combining it with chemotherapy, molecularly targeted therapeutics, nanoparticles, and immunotherapy. This review aims to synthesize available evidence to evaluate the clinical feasibility and efficacy of SBRT for HCC, and to explore novel radio-potentiation concepts by combining SBRT with novel therapeutics. It is expected that those approaches would result in improved therapeutic outcomes, even though many questions remain with regard to the optimal way to assemble treatments. Further trials are needed to evaluate and consolidate these promising therapies for HCC.

Radiobiology of stereotactic ablative radiotherapy (SABR): perspectives of clinical oncologists

Stereotactic ablative radiotherapy (SABR) is a novel radiation treatment method that delivers an intense dose of radiation to the treatment targets with high accuracy. The excellent local control and tolerance profile of SABR have made it become an important modality in cancer treatment. The radiobiology of SABR is a key factor in understanding and further optimizing the benefits of SABR. In this review, we have addressed several issues in the radiobiology of SABR from the perspective of clinical oncologists. The appropriateness of the linear-quadratic (LQ) model for SABR is controversial based on preclinical data, but it is a reliable tool from the perspective of clinical application because the biological effective dose (BED) calculated with it can represent the tumor control probability (TCP). Hypoxia is a common phenomenon in SABR in spite of the relatively small tumor size and has a negative effect on the efficacy of SABR. Preliminary studies indicate that a hypoxic radiosensitizer combined with SABR may be a feasible strategy, but so far there is not adequate evidence to support its application in routine practice. The vascular change of endothelial apoptosis and blood perfusion reduction in SABR may enhance the response of tumor cells to radiation. Combination of SABR with anti-angiogenesis therapy has shown promising efficacy and good tolerance in advanced cancers. SABR is more powerful in enhancing antitumor immunity and works better with immune checkpoint inhibitors (ICIs) than conventional fractionation radiotherapy. Combination of SABR with ICIs has become a practical option for cancer patients with metastases.

Multidisciplinary Treatment of Advanced Hepatocellular Carcinoma

Current strategy for treatment of hepatocellular carcinoma (HCC) based on Barcelona-Clinic Liver Cancer (BCLC) criteria dictates that patients with advanced-stage HCC are to only receive treatment with tyrosine kinase inhibitors. However, they prolong overall survival just by slightly more than 6 months. In this article, we present a patient with HCC diagnosed at an advanced stage who received multidisciplinary treatment consisting of transarterial chemoembolization, hepatic resection, pulmonary resection, radiofrequency ablation, tyrosine kinase inhibitors, and radiotherapy, and has survived for more than 2 years since diagnosis and counting.

Comparison of stereotactic body radiation therapy with and without sorafenib as treatment for hepatocellular carcinoma with portal vein tumor thrombosis

Stereotactic body radiation therapy (SBRT) has emerged as a treatment option for unresectable hepatocellular carcinoma (HCC) patients. However, the treatment outcomes for patients with portal vein tumor thrombosis (PVTT) remain poor. In this study, we evaluate the efficacy of SBRT with and or without sorafenib for advanced HCC with PVTT.Fifty four HCC patients with PVTT treated with SBRT using the Cyberknife system was retrospectively analyzed between January 2009 and June 2016. Of these, sorafenib combined with SBRT was administered to 18 patients and SBRT alone was administered to 36 patients. SBRT was designed to target the liver tumor and tumor thrombosis, with a radiation dose of 36 to 45 Gy (median 40 Gy) given in 3 to 5 fractions.The mean follow-up period for SBRT with sorafenib and SBRT alone was 13.22 ± 10.07 months and 15.33 ± 22.01 months, respectively. The response rate was comparable in both groups. Complete response and partial response rates were 77.77% for SBRT with sorafenib and 75.00% without sorafenib (P = .43). The median progression-free survival rate was 6 months (2-11 months) versus 3 months (2-5.6 months) (P = .24) and the 1- and 2-year progression-free survival rates were 25.7% and 15.2% versus 11.1% and 8.3% (P = .1225). The median, 1- and 2-year overall survival rates (OSR) were 12.5 months, 55.6% and 17.7% versus 7 months (5-13.5 months), 33.3% and 11.1% (P = .28), for SBRT with sorafenib versus SBRT alone groups, respectively.The result of our study shows that SBRT with sorafenib administered group resulted in a higher median, progression-free, and OSR for HCC patients with PVTT. However, the trends did not attain statistical significance. A large-scale randomized study is needed to assess the benefits of SBRT with sorafenib administration for patient with PVTT.

Enhanced cytotoxicity of human hepatocellular carcinoma cells following pretreatment with sorafenib combined with trichostatin A

Trichostatin A (TSA), a hydroxamate histone deacetylase inhibitor, is a compound that has been identified to induce anticancer activity. The aim of the present study was to investigate whether sorafenib, in combination with TSA, was able to augment the anticancer effects of TSA, identifying an optimum treatment time plan and the potential underlying molecular mechanisms involved in human hepatocellular carcinoma (HCC) in vitro. Huh7/nuclear factor-κB (NF-κB)-luc2 cells were treated with TSA or sorafenib alone, or sorafenib, prior to, in combination with or following TSA treatment. Huh7/NF-κB-luc2 cell viability following TSA treatment was determined using an MTT assay, and NF-κB activity was analyzed. In addition, the expression levels of NF-κB-regulated downstream effector proteins were assayed by western blotting. Inhibitors of mitogen-activated protein kinases (MAPKs), protein kinase B (AKT) and mutant inhibitor of NF-κBα (IκBαM) vectors were used to confirm the function of the NF-κB signal transduction pathways in response to the effects of sorafenib combined with TSA against HCC. The results of the present study indicated that pre-treatment with sorafenib followed by TSA inhibited the cell viability compared with other treatment modalities, and prevented TSA-induced extracellular-signal-regulated kinase (ERK)/NF-κB activity and expression of downstream effector proteins. It was further demonstrated that IκBαM vector sensitized Huh7/NF-κB-luc2 cells to TSA, thus it was possible to reverse TSA-induced NF-κB activity using PD98059, a MAPK/ERK kinase inhibitor. In conclusion, sorafenib pre-treatment may increase the efficacy of subsequent TSA treatment in HCC. Furthermore, sorafenib pre-treatment is hypothesized to sensitize HCC to TSA via the inhibition of the MEK/ERK/NF-κB signal transduction pathway.

Sorafenib pretreatment enhances radiotherapy through targeting MEK/ERK/NF-κB pathway in human hepatocellular carcinoma-bearing mouse model

Patients with unresectable hepatocellular carcinoma (HCC) usually have poor prognosis because current monotherapy including surgery, chemotherapy and radiotherapy (RT) are not effective. Combination therapy may be effective to overcome this clinical problem. Here, we proposed the combination of sorafenib and RT, which have been applied in HCC treatment, could improve the treatment outcome of HCC. Our previous study showed that sorafenib could suppress the expression of NF-κB which is related to the chemo- and radio-resistance. Nevertheless, the expression of NF-κB is oscillatory and is affected by the treatments. Thus, understanding the oscillation of NF-κB expression would be beneficial for determining the optimal treatment schedule in combination therapy. Here established Huh7/NF-κB-tk-luc2/rfp cell line, in which NF-κB indicates a NF-κB promoter, was utilized to noninvasively monitor the expression of NF-κB overtime in vitro and in vivo. The results show that pretreatment of sorafenib with RT suppresses the expressions of NF-κB and its downstream proteins induced by radiation through downregulation of phosphorylated extracellular signal-regulated kinase (pERK) most significantly compared with other treatment schedules. The results were further verified with Western blotting, EMSA, and NF-κB molecular imaging. These findings suggest that pretreatment of sorafenib with RT may be the ideal treatment schedule for the treatment of HCC.

Acquired resistance to tyrosine kinase inhibitors may be linked with the decreased sensitivity to X-ray irradiation

Acquired resistance to chemotherapy and radiation therapy is one of the major obstacles decreasing efficiency of treatment of the oncologic diseases. In this study, on the two cell lines (ovarian carcinoma SKOV-3 and neuroblastoma NGP-127), we modeled acquired resistance to five target anticancer drugs. The cells were grown on gradually increasing concentrations of the clinically relevant tyrosine kinase inhibitors (TKIs) Sorafenib, Pazopanib and Sunitinib, and rapalogs Everolimus and Temsirolimus, for 20 weeks. After 20 weeks of culturing, the half-inhibitory concentrations (IC₅₀) increased by 25 – 186% for the particular combinations of the drugs and cell types. We next subjected cells to 10 Gy irradiation, a dose frequently used in clinical radiation therapy. For the SKOV-3, but not NGP-127 cells, for the TKIs Sorafenib, Pazopanib and Sunitinib, we noticed statistically significant increase in capacity to repair radiation-induced DNA double strand breaks compared to naïve control cells not previously treated with TKIs. These peculiarities were linked with the increased activation of ATM DNA repair pathway in the TKI-treated SKOV-3, but not NGP-127 cells. Our results provide a new cell culture model for studying anti-cancer therapy efficiency and evidence that there may be a tissue-specific radioresistance emerging as a side effect of treatment with TKIs.

Intensity-modulated radiotherapy for hepatocellular carcinoma: dosimetric and clinical results

Since the introduction of 3-dimensional conformal radiotherapy (3DCRT), new radiotherapy techniques have expanded the indication of radiotherapy for the treatment of hepatocellular carcinoma (HCC), from the hitherto palliative to a now curative-intent purpose. Intensity-modulated radiotherapy (IMRT), currently the most advanced radiotherapy technique, is considered an attractive option for the treatment of HCC, and is more widely applied because it can deliver a higher dose to the tumor than 3DCRT while sparing surrounding normal organs. However, the advantages and potential disadvantages of IMRT for treating HCC have not been fully established. This article deals with three different IMRT techniques, including static IMRT and volumetric modulated arc therapy using conventional multileaf collimator (MLC) mounted linear accelerators, and helical IMRT using binary MLC mounted helical tomotherapy machine. We review dosimetric and clinical studies for these IMRT techniques for the treatment of HCC.

Egr-1 regulates irradiation-induced autophagy through Atg4B to promote radioresistance in hepatocellular carcinoma cells

Although hepatocellular carcinoma (HCC) is usually response to radiation therapy, radioresistance is still the major obstacle that limits the efficacy of radiotherapy for HCC patients. Therefore, further investigation of underlying mechanisms in radioresistant HCC cells is warranted. In this study, we determined the effect of early growth response factor (Egr-1) on irradiation-induced autophagy and radioresistance in HCC cell lines SMMC-7721 and HepG2. We showed that autophagy-related gene 4B (Atg4B) is induced by Egr-1 upon ionizing radiation (IR) in HCC cells. Luciferase reporter assays and chromatin immunoprecipitation (ChIP) revealed that Egr-1 binds to the Atg4B promoter to upregulate its expression in HCC cells. Suppression of Egr-1 function by dominant-negative Egr-1 dampens IR-induced autophagy, cell migration, and increases cell sensitivity to radiotherapy. Together, these results suggest that Egr-1 contributes to HCC radioresistance through directly upregulating target gene Atg4B, which may serve as a protective mechanism by preferential activation of the autophagy.

Epigastric Distress Caused by Esophageal Candidiasis in 2 Patients Who Received Sorafenib Plus Radiotherapy for Hepatocellular Carcinoma: Case Report

Sorafenib followed by fractionated radiotherapy (RT) has been shown to decrease the phagocytic and candidacidal activities of antifungal agents due to radiosensitization. Moreover, sorafenib has been shown to suppress the immune system, thereby increasing the risk for candida colonization and infection. In this study, we present the 2 hepatocellular carcinoma (HCC) patients suffered from epigastric distress caused by esophageal candidiasis who received sorafenib plus RT. Two patients who had received sorafenib and RT for HCC with bone metastasis presented with hiccups, gastric ulcer, epigastric distress, anorexia, heart burn, and fatigue. Empiric antiemetic agents, antacids, and pain killers were ineffective at relieving symptoms. Panendoscopy revealed diffuse white lesions in the esophagus. Candida esophagitis was suspected. Results of periodic acid-Schiff staining were diagnostic of candidiasis. Oral fluconazole (150 mg) twice daily and proton-pump inhibitors were prescribed. At 2-weak follow-up, esophagitis had resolved and both patients were free of gastrointestinal symptoms. Physicians should be aware that sorafenib combined with RT may induce an immunosuppressive state in patients with HCC, thereby increasing their risk of developing esophagitis due to candida species.

Yttrium-90 resin microspheres as an adjunct to sorafenib in patients with unresectable hepatocellular carcinoma

Purpose

The safety and efficacy of the combined use of sorafenib and yttrium-90 resin microspheres (Y90 RMS) to treat advanced hepatocellular carcinoma (HCC) is not well established. We determined the incidence of adverse events with this combination therapy in patients with advanced HCC at our institution and analyzed the treatment and survival outcomes.

Materials and methods

We reviewed the records of 19 patients with Barcelona Clinic Liver Cancer class B or C HCC who underwent treatment with Y90 RMS (for 21 sessions) while receiving full or reduced doses of sorafenib between January 2008 and May 2010. Therapy response was evaluated using Response Evaluation Criteria in Solid Tumors. We evaluated median overall survival (OS) and progression-free survival (PFS) as well as hepatic and extrahepatic disease PFS and incidence of adverse events.

Results

The median patient age was 67 years, and portal or hepatic venous invasion was present in eight patients (42%). Ten patients received reduced doses of sorafenib. The median Y90 radiation activity delivered was 41.2 mCi. The partial response of Response Evaluation Criteria in Solid Tumors was observed in four patients (19%). The median hepatic disease PFS was 7.82 months, extrahepatic disease PFS was 8.94 months, OS was 19.52 months, and PFS was 6.63 months. Ninety days after treatment with Y90 RMS, five patients (26%) had grade II adverse events and four patients (21%) had grade III adverse events.

Conclusion

OS and PFS outcomes were superior to those observed in prior studies evaluating sorafenib alone in patients with a similar disease status, warranting further study of this treatment combination.

Phase 1 Trial of Sorafenib and Stereotactic Body Radiation Therapy for Hepatocellular Carcinoma

PURPOSE

To determine the maximally tolerated dose of sorafenib delivered before, during, and after stereotactic body radiation therapy (SBRT) in hepatocellular carinoma (HCC).

METHODS AND MATERIALS

Eligible patients had locally advanced Child-Pugh class A HCC, showed Eastern Cooperative Oncology Group performance status 0-1, and were ineligible for standard local-regional therapies. Sorafenib was dose escalated in 2 strata: (1) low effective irradiated liver volume (veff) < 30% and (2) high veff 30%to 60%. Sorafenib (400 mg daily = dose level 1) was administered for 12 weeks, with 6 fractions SBRT delivered weeks 2 and 3, and escalation to full dose (400 mg twice daily) after 12 weeks as tolerated. Standard 3 + 3 cohorts with dose escalation of sorafenib were planned.

RESULTS

Sixteen patients (4 low veff, median dose 51 Gy; 12 high veff, median dose 33 Gy) were treated at 2 sorafenib dose levels. Of those patients 75% were had Barcelona Clinic Liver Cancer stage C, and 63% had main branch portal vein invasion. In the low veff stratum, no dose-limiting toxicities (DLTs) were observed in 4 patients treated with SBRT and sorafenib 400 mg. Inb the high veff stratum: 2 of 3 evaluable patients treated with sorafenib 400 mg experienced DLT (grade 3 large bowel bleed and grade 4 bowel obstruction 51 and 27 days, respectively, after SBRT). One of 6 evaluable patients at dose level -1 (200 mg once daily) experienced a grade 3 tumor rupture at week 5. Median overall survival and in-field local progression have not been reached. Worsening of Child-Pugh liver function class was seen in 6 of 12 patients in the high veff stratum.

CONCLUSIONS

Significant toxicity was observed in the high veff stratum, and concurrent SBRT with sorafenib is not recommended outside a clinical trial.

Phase 2 study of combined sorafenib and radiation therapy in patients with advanced hepatocellular carcinoma

PURPOSE

This phase 2 study evaluated the efficacy of radiation therapy (RT) with concurrent and sequential sorafenib therapy in patients with unresectable hepatocellular carcinoma (HCC).

METHODS AND MATERIALS

Forty patients with unresectable HCC unfit for transarterial chemoembolization were treated with RT with concurrent and sequential sorafenib. Sorafenib was administered from the commencement of RT at a dose of 400 mg twice daily and continued to clinical or radiologic progression, unacceptable adverse events, or death. All patients had underlying Child-Pugh A cirrhosis. The maximal tumor diameter ranged from 3.0 cm to 15.5 cm. Coexisting portal vein thrombosis was found in 24 patients and was irradiated simultaneously. The cumulative RT dose ranged from 40 Gy to 60 Gy (median, 50 Gy). Image studies were done 1 month after RT and then every 3 months thereafter.

RESULTS

Thirty-three (83%) completed the allocated RT. During RT, the incidence of hand-foot skin reactions ≥ grade 2 and diarrhea were 37.5% and 25%, respectively, and 35% of patients had hepatic toxicities grade ≥2. Twenty-two (55.0%) patients achieved complete or partial remission at the initial assessment, and 18 (45%) had stable or progressive disease. The 2-year overall survival and infield progression-free survival (IFPS) were 32% and 39%, respectively. A Cancer of the Liver Italian Program (CLIP) score ≥2 was associated with an inferior outcome in overall survival. Six patients (15%) developed treatment-related hepatic toxicity grade ≥3 during the sequential phase, and 3 of them were fatal.

CONCLUSIONS

When RT and sorafenib therapy were combined in patients with unresectable HCC, the initial complete or partial response rate was 55% with a 2-year IFPS of 39%. A CLIP score ≥2 was associated with an inferior outcome in overall survival. Hepatic toxicities are a major determinant of the safety; the combination should be used with caution and needs further investigation.

A sorafenib derivative and novel SHP-1 agonist, SC-59, acts synergistically with radiotherapy in hepatocellular carcinoma cells through inhibition of STAT3

Radiotherapy shows limited benefit as treatment for hepatocellular carcinoma (HCC). In this study, we aimed to overcome the radioresistance of HCC by using a novel sorafenib derivative, SC-59 that targets SHP-1-related signaling. HCC cell lines (SK-Hep1, Hep3B, and Huh7) were treated with sorafenib, SC-59, radiation, sorafenib plus radiation, or SC-59 plus radiation, and then apoptosis, colony formation, signal transduction and the phosphatase activity were analyzed. The synergistic effect of radiotherapy and SC-59 was analyzed using a combination index (CI) approach. In vivo efficacy was determined in a Huh7-bearing subcutaneous model. Mice were treated with radiation (5 Gy, one fraction per day) for 4 days, SC-59 (10mg/kg/day) for 24 days, or a combination. Tumor samples were further analyzed for p-STAT3 and SHP-1 activity. SC-59 displayed a better synergistic effect when used in combination with radiotherapy than sorafenib in HCC cell lines. SC-59 downregulated p-STAT3 and its downstream targets and increased SHP-1 phosphatase activity. Both ectopic STAT3 and inhibition of SHP-1 abolished SC-59-induced radiosensitization. Moreover, SC-59 significantly synergized radiotherapy in a Huh7 xenograft model by targeting SHP-1/STAT3 signaling. The novel sorafenib derivative, SC-59, acting as a SHP-1 agonist, displays a better synergistic effect when used in combination with radiotherapy than sorafenib for the treatment of HCC. Further clinical investigation is warranted.

Concurrent versus sequential sorafenib therapy in combination with radiation for hepatocellular carcinoma

Sorafenib (SOR) is the only systemic agent known to improve survival for hepatocellular carcinoma (HCC). However, SOR prolongs survival by less than 3 months and does not alter symptomatic progression. To improve outcomes, several phase I-II trials are currently examining SOR with radiation (RT) for HCC utilizing heterogeneous concurrent and sequential treatment regimens. Our study provides preclinical data characterizing the effects of concurrent versus sequential RT-SOR on HCC cells both in vitro and in vivo. Concurrent and sequential RT-SOR regimens were tested for efficacy among 4 HCC cell lines in vitro by assessment of clonogenic survival, apoptosis, cell cycle distribution, and γ-H2AX foci formation. Results were confirmed in vivo by evaluating tumor growth delay and performing immunofluorescence staining in a hind-flank xenograft model. In vitro, concurrent RT-SOR produced radioprotection in 3 of 4 cell lines, whereas sequential RT-SOR produced decreased colony formation among all 4. Sequential RT-SOR increased apoptosis compared to RT alone, while concurrent RT-SOR did not. Sorafenib induced reassortment into less radiosensitive phases of the cell cycle through G₁-S delay and cell cycle slowing. More double-strand breaks (DSBs) persisted 24 h post-irradiation for RT alone versus concurrent RT-SOR. In vivo, sequential RT-SOR produced the greatest tumor growth delay, while concurrent RT-SOR was similar to RT alone. More persistent DSBs were observed in xenografts treated with sequential RT-SOR or RT alone versus concurrent RT-SOR. Sequential RT-SOR additionally produced a greater reduction in xenograft tumor vascularity and mitotic index than either concurrent RT-SOR or RT alone. In conclusion, sequential RT-SOR demonstrates greater efficacy against HCC than concurrent RT-SOR both in vitro and in vivo. These results may have implications for clinical decision-making and prospective trial design.