Sublethal irradiation induces vascular endothelial growth factor and promotes growth of hepatoma cells: implications for radiotherapy of hepatocellular carcinoma

Stereotactic Body Radiotherapy Combined With Lenvatinib With or Without PD-1 Inhibitors as Initial Treatment for Unresectable Hepatocellular Carcinoma

PURPOSE

The aim of this study was to compare the clinical benefit and safety of the triple combination of stereotactic body radiotherapy (SBRT), lenvatinib, and programmed cell death protein 1 (PD-1) inhibitors with the dual combination of SBRT and lenvatinib in patients with unresectable hepatocellular carcinoma (uHCC).

METHODS AND MATERIALS

Patients with uHCC who received SBRT in combination with lenvatinib and PD-1 inhibitors or SBRT in combination with lenvatinib alone as first-line treatment from October 2018 to July 2022 were reviewed in this study. The primary endpoints were overall survival (OS) and progression-free survival (PFS). The secondary endpoints were intrahepatic PFS, extrahepatic PFS, and objective remission rate. In addition, safety profiles were assessed by analyzing treatment-related adverse events between the two groups to assess safety profiles.

RESULTS

In total, 214 patients with uHCC who received combination therapy were included in this retrospective study. Among them, 146 patients received triple combination therapy of SBRT, lenvatinib, and PD-1 inhibitors (SBRT-L-P group), and 68 patients received dual therapy of SBRT and lenvatinib (SBRT-L group). The median OS times of the 2 groups were 31.2 months and 17.4 months, respectively (P < .001). The median PFS time was significantly longer in the SBRT-L-P group than in the SBRT-L group (15.6 months vs 8.8 months, P < .001). Additionally, the median intrahepatic PFS (17.5 vs 9.9 months, P < .001) and extrahepatic PFS (20.9 vs 11.6 months, P < .001) were significantly longer in the SBRT-L-P group than in the SBRT-L group. The objective remission rate in the SBRT-L-P group was higher than in the SBRT-L group (63.0 vs 39.7%, P = .002). The incidence and severity of treatment-related adverse events in the SBRT-L-P group were comparable to those in the SBRT-L group.

CONCLUSION

The use of both lenvatinib and PD-1 inhibitors with SBRT in patients with uHCC was associated with improved overall survival compared with lenvatinib and SBRT alone with a manageable safety profile.

C-C chemokine receptor 4 (CCR4)-positive regulatory T cells interact with tumor-associated macrophages to facilitate metastatic potential after radiation

PURPOSE

Our previous study revealed that elevated C-C motif chemokine ligand 2 (CCL2) secretion by irradiated cancer cells recruited C-C motif chemokine receptor 2 (CCR2)-positive myeloid cells and polarized M2-type tumor-associated macrophages (TAMs), promoting lung metastasis in an established mouse model. This study investigated the impact of CCL2 and TAMs on adaptive immunity.

METHODS

We assessed the influence of CCL2 and TAMs on adaptive immunity through two ectopic allograft mouse models constructed with MB49 bladder cancer cells and Lewis lung carcinoma cells. Both models exhibited delayed primary tumor growth following radiation therapy (RT), but RT promoted the development of pulmonary metastases in C57BL/6 mice. Additionally, we employed a direct coculture system to investigate the interaction between macrophages and target cells in the context of adaptive immunity.

RESULTS

C-C motif chemokine receptor 4 (CCR4)-positive regulatory T cells (Tregs) were recruited to the postirradiated tumor microenvironment (TME). Utilizing a CCR4 antagonist to inhibit CCL2-CCR4 activation reversed the infiltration of CCR4 + Tregs and reduced the incidence of pulmonary metastases. In addition, a positive feedback loop between M2-type TAMs and Tregs was observed. The combined blockade of the CCL2-CCR4 and CCL2-CCR2 signaling pathways further decreased the risk of RT-promoted lung metastasis.

CONCLUSION

The recruitment of CCR4 + Tregs to the postirradiated TME increases the metastatic potential of tumor cells through increased interactions with M2-type TAMs. A significant reduction in post-RT lung metastases in ectopic mouse models was achieved by disrupting the recruitment of both CCR4 + Tregs and CCR2 + myeloid cells, which are TAM precursors.

Advances in radiotherapy and immunity in hepatocellular carcinoma

Primary liver cancer is one of the most common malignant tumours worldwide; it caused approximately 830,000 deaths in 2020. Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer, accounting for over 80% of all cases. Various methods, including surgery, chemotherapy, radiotherapy, and radiofrequency ablation, have been widely used in the treatment of HCC. With the advancement of technology, radiotherapy has become increasingly important in the comprehensive treatment of HCC. However, due to the insufficient sensitivity of tumour cells to radiation, there are still multiple limitation in clinical application of radiotherapy. In recent years, the role of immunotherapy in cancer has been increasingly revealed, and more researchers have turned their attention to the combined application of immunotherapy and radiotherapy in the hope of achieving better treatment outcomes. This article reviews the progress on radiation therapy in HCC and the current status of its combined application with immunotherapy, and discusses the prospects and value of radioimmunotherapy in HCC.

SIB-IMRT combined with apatinib for unresectable hepatocellular carcinoma in patients with poor response to transarterial chemoembolization

BACKGROUND

Radiotherapy combined with apatinib exhibits synergistic anti-tumor effect, while the application of simultaneous integrated boost intensity modulated radiotherapy (SIB-IMRT) combined with apatinib in HCC patients is scarce. Hence, this study aimed to explore the treatment response, survival, and safety profile of the SIB-IMRT combined with apatinib in unresectable HCC (uHCC) patients.

METHODS

A total of 19 uHCC patients with deficient response to transarterial chemoembolization (TACE), who scheduled for SIB-IMRT combined with apatinib treatment were enrolled. The SIB-IMRT was applied at the following dose: 95% planning target volume (PTV) at 30-50 Gy/2-2.5 Gy/15-20f and 90% Boost of 45-72 Gy/3-4.5 Gy/15-20f at 5 times per week with cone beam computerized tomography validation. During and after radiotherapy, the apatinib was administrated orally with the initial dose of 500 mg per day.

RESULTS

The complete response, partial response, stable disease, and progressive disease rates were 31.6%, 36.8%, 21.1% and 10.5%, respectively. Consequently, the objective response rate and disease control rate were 68.4% and 89.5%, respectively. During a median follow-up duration of 9.0 months, the median progression-free survival (PFS) was 6.0 (95% confidential interval (CI): 4.9-7.1) months with 1-year PFS rate of 42.1%; the median overall survival (OS) was not reached with 1-year OS rate of 54.6%. The safety profile was acceptable with the most common adverse events including myelosuppression (42.1%), skin reaction (36.8%), and albuminuria (26.3%).

CONCLUSION

SIB-IMRT combined with apatinib exhibits a good efficacy and tolerable safety profile, which could be considered as a potential treatment choice for uHCC patients who have deficient response to TACE.

Ocular complications with the use of radium-223: a case series

Background

Radium-223 is used for the treatment of osseous metastases in castrate-resistant prostate cancer, and has been shown to increase time to the first skeletal-related event, reduce the rate of hospitalization, and improve quality of life. It is well tolerated, with hematologic toxicity as the main adverse event. Thus far, no ocular complication has been reported in the literature after initial administration of radium-223 with a single case reported of ocular complications after a patient’s second course of radium-223.

Case presentations

We present three cases of ocular complications after the use of radium-223 in patients with metastatic prostatic adenocarcinoma. Ocular complications presented as blurry vision, and formal diagnosis included uveitis and hyphema.

Conclusions

Documentation of adverse events is exceedingly important due to the high incidence of metastatic prostate cancer and increasing interest for the use of radium-223 in other osteoblastic disease. The authors postulate that these ocular complications may be a result of radiation’s potential effect on neovascularization, polypharmacy, or the biomolecular effects of radium-223 on integral signaling proteins, potentially coupled with poor underlying ocular health.

Radiation Therapy Promotes Hepatocellular Carcinoma Immune Cloaking via PD-L1 Upregulation Induced by cGAS-STING Activation

PURPOSE

Radiation therapy (RT) is one of the main treatments for patients with unresectable hepatocellular carcinoma (HCC). Emerging evidence indicates that the cyclic guanosine monophosphate-adenosine monophosphate synthase (cGAS) stimulator of interferon gene (STING) pathway is crucial in RT-induced antitumor immune responses. Here, we discovered that activation of the cancer cell-intrinsic cGAS-STING pathway mediated immune cloaking after RT-induced DNA damage.

METHODS AND MATERIALS

Key regulatory proteins in the cGAS-STING signaling pathway in human and murine HCC cell lines were knocked out or down using CRISPR and CRISPR-associated protein 9 or small interfering RNA. The underlying mechanism of immune cloaking and clinical significance of cGAS-STING-induced programmed cell death ligand 1 (PD-L1) expression were studied with both ex vivo analyses and in vitro experiments.

RESULTS

RT upregulated PD-L1 in patients with HCC, which correlated with poor survival. RT activated cGAS-STING, increasing immune-checkpoint PD-L1 expression in human and mouse liver cancer cells. Ionizing radiation activated the STING-TANK-binding kinase 1 (TBK1)-interferon regulatory factor 3 (IRF3) innate immune pathway, leading to PD-L1 upregulation in HCC cells and inhibiting cytotoxic T-lymphocyte activity and protecting tumor cells from immune-mediated eradication. Knockdown of cGAS, STING, TBK1, and IRF3 reversed the antitumor effect of cytotoxic T-lymphocyte-mediated cytotoxicity after ionizing radiation in vitro or in vivo. RT potentiated the antitumor effect of programmed cell death protein 1 and PD-L1 axis blockade and augmented cytotoxic T-cell (CTL) infiltration in HCC tumors in immunocompetent mice. CD8 depletion compromised the synergetic antitumor effect of combined RT and anti-PD-L1 blockade, demonstrating that CD8⁺ CTLs are required for antitumor immunity induced by combination therapy.

CONCLUSIONS

Our results identified an immune-cloaking mechanism for RT-activated, innate immune cGAS-STING and suggested that RT enhances HCC immunotherapy.

Reconciling two opposing effects of radiation therapy: stimulation of cancer cell invasion and activation of anti-cancer immunity

PURPOSE

The damage caused by radiation therapy to cancerous and normal cells inevitably leads to changes in the secretome profile of pro and anti-inflammatory mediators. The inflammatory response depends on the dose of radiation and its fractionation, while the inherent radiosensitivity of each patient dictates the intensity and types of adverse reactions. This review will present an overview of two apparently opposite reactions that may occur after radiation treatment: induction of an antitumor immune response and a protumoral response. Emphasis is placed on the molecular and cellular mechanisms involved.

CONCLUSIONS

By understanding how radiation changes the balance between anti- and protumoral effects, these forces can be manipulated to optimize radiation oncology treatments.

Inhibition of c-MET reverses radiation-induced malignant potential in pancreatic cancer

As a treatment option for PDAC, radiation therapy induces good local control. However, radiation also reportedly enhances the malignant potential (e.g., invasion and migration ability) in various cancers, thus increasing the risk of distant metastasis. It remains unclear how radiation induces malignant potential, and how such enhanced malignant potential can be suppressed. In the current study, we evaluated the sequential change of c-Met expression in pancreatic cancer cells following irradiation. We found that irradiation transiently induced c-Met expression in vitro. In an in vivo subcutaneous tumor mouse model, irradiation also enhanced downstream phosphorylated Met (p-Met). Furthermore, this enhancement of p-Met protein expression was suppressed by oral administration of the c-Met inhibitor INC280. Irradiated pancreatic cancer cells with enhanced c-Met expression exhibited higher malignant potential, including invasion and migration ability, compared with cells showing low c-Met expression. Pancreatic cancer cells that overexpressed c-met also showed enhanced malignant potential, which was reversed by c-Met inhibition. Additionally, c-Met inhibitor suppressed the metastatic potential in a liver metastasis mouse model using c-met-overexpressing cells. Overall, our present results revealed that irradiation could induce c-met expression in pancreatic cancer cells, leading to enhanced malignant potential (e.g., invasion and migration ability) and thus promoting distant metastasis. Moreover, a c-Met inhibitor could reverse this enhanced malignant potential.

Blocking the CCL5-CCR5 Axis Using Maraviroc Promotes M1 Polarization of Macrophages Cocultured with Irradiated Hepatoma Cells

Purpose

The C-C chemokine ligand 5 (CCL5)–C-C chemokine receptor (CCR5) axis facilitates tumor progression via multiple mechanisms. Herein, we elucidated the effect of a CCR5 antagonist (maraviroc [MVC]; blocking the CCL5–CCR5 axis) on the phenotype of macrophages cocultured with irradiated hepatoma cells. In addition, we investigated whether modulation of macrophage polarization can alter tumor cell sensitivity to radiation.

Materials and Methods

Quantitative reverse-transcription polymerase chain reaction, Western blotting, and enzyme-linked immunosorbent assays were applied to examine the levels of macrophage-associated markers. The mechanisms of macrophage polarization were explored by Western blotting in an in vitro model of coculture of human hepatoma cells with macrophages. The radiation sensitivity was examined in a clonogenic radiosensitivity assay. Tumor cell apoptosis was detected by Western blotting and flow cytometry. A mouse model of a subcutaneous tumor was also established.

Results

CCL5 skewed THP-1 M0 macrophages toward an M2-like phenotype. In coculture with hepatoma cells, macrophages manifested high levels of interleukin (IL) 10, IL-12, tumor necrosis factor α (TNF-α), transforming growth factor β1 (TGF-β1), arginase 1 (ARG1), and IL-1β. Tumor cell irradiation further upregulated these markers in macrophages. After incubation of macrophages with MVC for 24 h, levels of M1 cytokines significantly increased, whereas those of M2 phenotype factors ARG1, TGF-β1, and IL-10 decreased, accompanied by the activation of signal transducer and activator of transcription 3 (STAT3) and downregulation of suppressor of cytokine signaling 3 (SOCS3). The macrophage phenotype reverted to M2 states after treatment with a STAT3 inhibitor. The shift of macrophages toward the M1 phenotype enhanced the radiosensitivity and apoptosis of hepatoma cells. Mice receiving a combination of X-ray irradiation and MVC experienced a better antitumor effect than those receiving either MVC or irradiation alone did.

Conclusion

M2 polarization of macrophages induced by CCL5–CCR5 signaling can be inhibited using MVC via the STAT3–SOCS3 pathway. The shift of macrophages toward the M1 phenotype promotes the sensitivity of human hepatoma cells to X-ray irradiation.

Adverse effects of chemoradiotherapy on invasion and metastasis of tumor cells

The phenomenon of enhanced invasion and metastasis of residual tumor cells has been observed in an increasing number of patients receiving chemoradiotherapy recently, and tumor metastasis will undoubtedly limit patient prognosis. However, the key mechanism by which chemoradiotherapy affects the invasion and metastasis of tumor cells remains unclear. Studies have shown that chemoradiotherapy may directly act on tumor cells and alter the tumor microenvironment, or induce cell apoptosis and autophagy to promote tumor cell survival and metastasis. In this review, we summarize the potential mechanisms by which chemoradiotherapy may affect the biological behavior of tumor cells and open up new avenues for reducing tumor recurrence and metastasis after treatment. These insights will improve the efficacy of chemoradiotherapy.

CSC Radioresistance: A Therapeutic Challenge to Improve Radiotherapy Effectiveness in Cancer

Radiotherapy (RT) is a modality of oncologic treatment that can be used to treat approximately 50% of all cancer patients either alone or in combination with other treatment modalities such as surgery, chemotherapy, immunotherapy, and therapeutic targeting. Despite the technological advances in RT, which allow a more precise delivery of radiation while progressively minimizing the impact on normal tissues, issues like radioresistance and tumor recurrence remain important challenges. Tumor heterogeneity is responsible for the variation in the radiation response of the different tumor subpopulations. A main factor related to radioresistance is the presence of cancer stem cells (CSC) inside tumors, which are responsible for metastases, relapses, RT failure, and a poor prognosis in cancer patients. The plasticity of CSCs, a process highly dependent on the epithelial–mesenchymal transition (EMT) and associated to cell dedifferentiation, complicates the identification and eradication of CSCs and it might be involved in disease relapse and progression after irradiation. The tumor microenvironment and the interactions of CSCs with their niches also play an important role in the response to RT. This review provides a deep insight into the characteristics and radioresistance mechanisms of CSCs and into the role of CSCs and tumor microenvironment in both the primary tumor and metastasis in response to radiation, and the radiobiological principles related to the CSC response to RT. Finally, we summarize the major advances and clinical trials on the development of CSC-based therapies combined with RT to overcome radioresistance. A better understanding of the potential therapeutic targets for CSC radiosensitization will provide safer and more efficient combination strategies, which in turn will improve the live expectancy and curability of cancer patients.

Suitability of boric acid as a boron drug for boron neutron capture therapy for hepatoma

Hepatoma is the second leading cause of cancer death worldwide. Due to the poor outcomes of patients with late diagnosis, newer treatments for hepatoma are still needed. As an emerging therapy, boron neutron capture therapy (BNCT) may be an effective solution in hepatoma management. In this study, boric acid (BA) was used as the boron drug for in vivo analysis of action mechanism. The N1S1 single liver tumor-bearing rat and the VX2 multifocal liver tumor-bearing rabbit models were used to investigate the retention status of BA in the tumor regions during BNCT. The autoradiographic examination showed BA can localize specifically not only in the hepatoma cells but also in tumor blood vessels. Our findings indicate that superior hepatoma targeting could be achieved in BA-mediated BNCT, which supports BA to be a suitable boron drug for BNCT for hepatoma.

Dark Side of Cytotoxic Therapy: Chemoradiation-Induced Cell Death and Tumor Repopulation

Accelerated tumor repopulation following chemoradiation is often observed in the clinic, but the underlying mechanisms remain unclear. In recent years, dying cells caused by chemoradiation have attracted much attention, and they may manifest diverse forms of cell death and release complex factors and thus orchestrate tumor repopulation cascades. Dying cells potentiate the survival of residual living tumor cells, remodel the tumor microenvironment, boost cell proliferation, and accelerate cancer cell metastasis. Moreover, dying cells also mediate the side effects of chemoradiation. These findings suggest more caution when weighing the benefits of cytotoxic therapy and the need to accordingly develop new strategies for cancer treatment.

Combined Hyperthermia and Radiation Therapy for Treatment of Hepatocellular Carcinoma

Background:

There is no doubt that hyperthermia is one of the powerful radiosensitizers. Finding a proper mechanism working in hyperthermia/radiation combination is still pronounced challenge.

Objectives:

This study is focusing on the anti-cancer activities (anti-proliferative, anti-angiogenic and antiapoptotic) of thermoradiotherapy.

Materials and Methods:

Liver cancer cell line (HepG2) was treated by 37^oC, 40^oC and 43^oC hyperthermia degrees combined with three radiation doses (2 Gy, 4 Gy and 8 Gy) for 24, 48 and 72 hrs. Cell viability, apoptotic/necrotic cell screening, apoptotic (BAX and FasL) and antiapoptotic (BCL-2 and GRP78) genes, and pro-angiogenic mediators [vascular endothelial- (VEGF) and Platelet derived-growth factors (PDGF) ware investigated.

Results:

Our data showed that 40^oC temperature combined with 4 Gy radiation gives a significant decrease (p<0.05) in cell viability. Maximum cytotoxicity was reported 48 hr post-treatment followed by slight restoration of cell viability after 72 hr. Compared with untreated cells, only 5% of viable cells with a high percentage of apoptotic (31%) and necrotic (63%) cells were demonstrated in 40^oC/4 Gy/48 hr group. Expression of pro-apoptotic genes (BAX and FasL) were increased after hyperthermia with apparent elevation in 40^oC/4 Gy/48 hr group coincides with moderate expression of antiapoptotic BCL-2 and GRP78 genes. A significant reduction (p<0.001; p<0.05) in VEGF and PDGF levels; respectively was shown at 40^oC/4 Gy/48 hr group.

Conclusions:

This pilot study proposed 40^oC mild temperature hyperthermia as a favorable hyperthermal condition with 4 Gy radiotherapy in HCC treatment. A further research has to be performed considering an application of more than one session of radiothermal therapy at 40^oC/4 Gy for total abrogation of cancer cells.

Endothelial Microparticles and Vascular Endothelial Growth Factor in Patients With Head and Neck Cancer Undergoing Radiotherapy or Radiochemotherapy

BACKGROUND

Endothelial microparticles (EMPs) released from activated or apoptotic endothelial cells may play a role in coagulation and thrombus formation. However, there is insufficient evidence regarding the impact of EMPs on angiogenesis in patients with cancer.

MATERIALS AND METHODS

Sixteen patients with head and neck cancer (HNC) undergoing radiotherapy/radiochemotherapy (RT/RCT) and 10 healthy controls were studied. Serum EMPs were counted by flow cytometry, and vascular endothelial growth factor (VEGF) was measured by enzyme-linked immunosorbent assay (ELISA).

RESULTS

The mean EMP level was significantly higher in patients with HNC before RT/RCT (1,601±1,479 EMP/μl) compared to the control group (782±698 EMP/μl). The number of EMPs was not notably increased after RT/RCT (1,629±769 EMP/μl). There was no significant correlation between the plasma EMP number and concentration of VEGF before (r=0.131; p=0.625), 1 day after (r=-0.042, p=0.874), nor 3 months after RT/RCT (r=0.454, p=0.076).

CONCLUSION

Released EMPs may not influence promotion of neovascularization in patients with HNC.

Transcatheter arterial chemoembolisation followed by three-dimensional conformal radiotherapy versus transcatheter arterial chemoembolisation alone for primary hepatocellular carcinoma in adults

BACKGROUND

Hepatocellular carcinoma, also called malignant hepatoma, is a primary malignancy of the liver. Despite regular surveillance conducted in high-risk populations, most people with hepatocellular carcinoma are diagnosed at an advanced stage. Consequently, only a minority of people with the disease are suitable for surgical resection when diagnosed.

OBJECTIVES

To compare the beneficial and harmful effects of transcatheter arterial chemoembolisation (TACE) followed by three-dimensional conformal radiotherapy (3-DCRT) versus TACE alone in adults with primary hepatocellular carcinoma, considered unsuitable for surgical resection.

SEARCH METHODS

We searched The Cochrane Hepato-Biliary Group Controlled Trials Register, CENTRAL, MEDLINE, Embase, LILACS, Science Citation Index Expanded, and Conference Proceedings Citation Index - Science up to 31 May 2018. We checked reference lists for all included studies and related reviews for further relevant articles.

SELECTION CRITERIA

We included all randomised clinical trials comparing TACE followed by 3-DCRT versus TACE alone in people with primary hepatocellular carcinoma.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures as suggested by Cochrane. We presented the results of the fixed-effect model in the absence of statistical heterogeneity. Otherwise, we reported the results from the random-effects model meta-analysis. We assessed risk of bias of the included trials using bias risk domains and presented the review results incorporating the methodological quality of the trials using GRADE. Our main conclusions were based on the analysis up to three years' follow-up.

MAIN RESULTS

We identified eight randomised clinical trials (632 participants) that fulfilled our inclusion criteria. All eight trials were at high risk of bias, and we rated the evidence as low to very low certainty. The mean age ranged from 16 years to 78 years. The proportion of men ranged from 60% to 75% and the proportion of people with stage III primary hepatocellular carcinoma ranged from 22% to 85%. The median follow-up duration was 12 months (2 months to 38 months).TACE followed by 3-DCRT compared with TACE alone may have reduced all-cause mortality at three years' follow-up (risk ratio (RR) 0.80, 95% confidence interval (CI) 0.73 to 0.88; 552 participants; 7 trials; low-certainty evidence). TACE followed by 3-DCRT compared with TACE alone may reduce the proportion of participants without tumour response (complete response plus partial response) (RR 0.49, 95% CI 0.39 to 0.61; 632 participants; 8 trials; low-certainty evidence). Data, from one trial on health-related quality of life, favoured the TACE followed by 3-DCRT group, but the provided data were ill-defined (very low-certainty evidence). None of the trials reported serious adverse events. The results on non-serious adverse events were as follows: TACE followed by 3-DCRT compared with TACE alone showed no difference in the results for proportion of participants with leukopenia (RR 1.12, 95% CI 0.92 to 1.34; 438 participants; 5 trials; very low-certainty evidence) and serum transaminases elevation (RR 1.67, 95% CI 0.66 to 4.27; 280 participants; 4 trials; very low-certainty evidence). However, the proportion of participants with total bilirubin elevation was larger in the TACE followed by 3-DCRT group than in the TACE alone group (RR 2.69, 95% CI 1.34 to 5.40; 172 participants; 2 trials; very low-certainty evidence). The rate of participants with serum alpha-fetoprotein (AFP) without decline or normalisation was significantly lower in the TACE followed by 3-DCRT group than in the TACE group, but these data were from one trial only (Chi² = 7.24, P = 0.007; very low-certainty evidence).

AUTHORS' CONCLUSIONS

TACE followed by 3-DCRT may be associated with lower all-cause mortality and increased tumour response, despite the increased toxicity expressed by a higher rise of total bilirubin. Our review findings should be considered with caution because of the methodological weaknesses in the included trials, resulting in low- to very low-certainty evidence. Data on serious adverse events and health-related quality of life are lacking. We are also very much uncertain in the results of the reported non-serious adverse events. High-quality trials are needed to assess further the role of TACE followed by 3-DCRT for unresectable hepatocellular carcinoma.

Hypoxia and tumor angiogenesis in the era of hepatocellular carcinoma transarterial loco-regional treatments

This review focuses upon interactions and potential therapeutic targets in the ‘vicious cycle’ between hypoxia and neoangiogenesis following treatment of hepatocellular carcinoma with transarterial loco-regional therapies. Biomarkers correlated with angiogenesis have been studied by many authors as prognostic determinants following transarterial intrahepatic therapy. According to these results future therapies directed toward specific factors related to angiogenesis could play a significant role in preventing local tumor recurrence and remote metastasis.

Effects of radiation on the metastatic process

Radiotherapy remains one of the corner stones in the treatment of various malignancies and often leads to an improvement in overall survival. Nonetheless, pre-clinical evidence indicates that radiation can entail pro-metastatic effects via multiple pathways. Via direct actions on cancer cells and indirect actions on the tumor microenvironment, radiation has the potential to enhance epithelial-to-mesenchymal transition, invasion, migration, angiogenesis and metastasis. However, the data remains ambiguous and clinical observations that unequivocally prove these findings are lacking. In this review we discuss the pre-clinical and clinical data on the local and systemic effect of irradiation on the metastatic process with an emphasis on the molecular pathways involved.

EphA2 blockade enhances the anti-endothelial effect of radiation and inhibits irradiated tumor cell-induced migration of endothelial cells

BACKGROUND

EphA2 tyrosine kinase plays an important role in tumor angiogenesis, but whether targeting this pathway can affect response to ionizing radiation (IR) remains unknown.

METHODS

We investigated, using a soluble EphA2-Fc chimera, whether EphA2 inhibition could sensitize A549 and MCF-7 tumor cells, as well as human umbilical vein endothelial cells (HUVEC) and dermal microvascular endothelial cells (HDMEC), to IR.

RESULTS

EphA2-Fc resulted in a greater response of endothelial cells (EC) to IR than either treatment alone. EphA2-Fc significantly increased apoptosis and decreased clonogenic survival, tube formation and migration in irradiated EC after stimulation with vascular endothelial growth factor (VEGF), without an affecting their proliferation. No difference in proliferation or survival was found in A549 and MCF-7 tumor cells. In a co-culture model, EphA2-Fc inhibited an irradiated A549 cell-induced increase in EC migration. VEGF supplementation, as well as condiotioned medium from irradiated A549 cells, phosphorylated EphA2 in EC. The latter was abrogated by EphA2-Fc.

CONCLUSIONS

EC were most sensitive to a combination of EphA2 inhibition and radiotherapy. The induction of paracrine growth factors and activation of EphA2 in EC suggest a protective mechanism that tumors probably use to attenuate IR-induced antivascular effects. Our data justify further investigation to explore targeting EphA2 in tumor radiosensitivity in vivo.

Radiation therapy-induced metastasis: radiobiology and clinical implications

Radiation therapy is an effective means of achieving local control in a wide range of primary tumours, with the reduction in the size of the tumour(s) thought to mediate the observed reductions in metastatic spread in clinical trials. However, there is evidence to suggest that the complex changes induced by radiation in the tumour environment can also present metastatic risks that may counteract the long-term efficacy of the treatment. More than 25 years ago, several largely theoretical mechanisms by which radiation exposure might increase metastatic risk were postulated. These include the direct release of tumour cells into the circulation, systemic effects of tumour and normal tissue irradiation and radiation-induced changes in tumour cell phenotype. Here, we review the data that has since emerged to either support or refute these putative mechanisms focusing on how the unique radiobiology underlying modern radiotherapy modalities might alter these risks.

Does the mobilization of circulating tumour cells during cancer therapy cause metastasis?

Despite progressive improvements in the management of patients with locoregionally confined, advanced-stage solid tumours, distant metastasis remains a very common - and usually fatal - mode of failure after attempted curative treatment. Surgery and radiotherapy are the primary curative modalities for these patients, often combined with each other and/or with chemotherapy. Distant metastasis occurring after treatment can arise from previously undetected micrometastases or, alternatively, from persistent locoregional disease. Another possibility is that treatment itself might sometimes cause or promote metastasis. Surgical interventions in patients with cancer, including biopsies, are commonly associated with increased concentrations of circulating tumour cells (CTCs). High CTC numbers are associated with an unfavourable prognosis in many cancers. Radiotherapy and systemic antitumour therapies might also mobilize CTCs. We review the preclinical and clinical data concerning cancer treatments, CTC mobilization and other factors that might promote metastasis. Contemporary treatment regimens represent the best available curative options for patients who might otherwise die from locally confined, advanced-stage cancers; however, if such treatments can promote metastasis, this process must be understood and addressed therapeutically to improve patient survival.

Caspase 3 in dying tumor cells mediates post-irradiation angiogenesis

Cytotoxic radiotherapy unfavorably induces tumor cells to generate various proangiogenic substances, promoting post-irradiation angiogenesis (PIA), which is one of major causes of radiotherapy failure. Though several studies have reported some mechanisms behind PIA, they have not yet described the beginning proangiogenic motivator buried in the irradiated microenvironment. In this work, we revealed that dying tumor cells induced by irradiation prompted PIA via a caspase 3 dependent mechanism. Proteolytic inactivation of caspase 3 in dying tumor cells by transducing a dominant-negative version weakened proangiogenic effects in vitro and in vivo. In addition, inhibition of caspase 3 activity suppressed tumor angiogenesis and tumorigenesis in xenograft mouse model. Importantly, we identified vascular endothelial growth factor (VEGF)-A as a downstream proangiogenic factor regulated by caspase 3 possibly through Akt signaling. Collectively, these findings indicated that besides acting as a key executioner in apoptosis, caspase 3 in dying tumor cells may play a central role in driving proangiogenic response after irradiation. Thus, radiotherapy in combination with caspase 3 inhibitors may be a novel promising therapeutic strategy to reduce tumor recurrence due to restrained PIA.

Activation of the JNK-c-Jun pathway in response to irradiation facilitates Fas ligand secretion in hepatoma cells and increases hepatocyte injury

Background

It is well established that some irradiated liver non-parenchymal cells secrete pro-inflammatory cytokines to facilitate the development of radiation-induced liver disease. However, little is known on whether the irradiated hepatoma cells-mediated non-irradiated hepatocyte injury occurs in HCC patients. Here, we elucidated the roles of the irradiated hepatoma cells in driving non-irradiated hepatocyte injury and its underlying mechanism.

Methods

SMMC7721 cells were cultured and divided into irradiated (4-Gy X-ray, R) and non-irradiated (NR) groups. At 24th hour after irradiation, conditioned medium (CM) from these cultures was mixed with normal culture medium in specific proportions, and termed as 7721-R-CM and 7721-NR-CM. Following incubation with these CM compound, the biological characteristics of L02 cells related to liver cell injury including viability, apoptosis and liver dysfunction indices were comparatively analyzed. Simultaneously, the levels of proliferation- and apoptosis-related cytokines in irradiated and non-irradiated SMMC7721 cells were also measured. FasL as a cytokine with significantly differential expression, was selected to clarify its effects on L02 apoptosis. Subsequently, FasL expression following irradiation was examined in SMMC7721 and other HCC cells with varying malignant potentials, as well as in HCC tissues, the related mechanism of higher expression of FasL in irradiated HCC cells was further investigated.

Results

Apoptosis and liver dysfunction indices were all significantly enhanced in L02 cells treated with 7721-R-CM, whereas viability was suppressed, compared to those with 7721-NR-CM stimulation. FasL was identified as a leading differential cytokine in the irradiated SMMC7721 cells. Higher proportion of apoptosis was also found in L02 cells following FasL incubation. A recombinant Fas-Fc protein, which blocks Fas-FasL interaction, ameliorated 7721-R-CM-induced apoptosis in L02 cells. FasL was highly expressed in a dose-dependent manner, and peaked at the 24th hour post-irradiation in different HCC cells and their culture supernatant. Meanwhile, phosphorylation levels of JNK, ERK, Akt, and p38 were all upregulated significantly in irradiated HCC cells. But, only JNK inhibition was validated to block radiation-induced FasL expression in HCC cells. c-Jun, the target transcription factor of JNK, was also activated.

Conclusion

In HCC cells, the JNK-c-Jun pathway plays an important role in mediating irradiation- induced FasL expression, which may be critical in determining non-irradiated hepatocyte injury.

Electronic supplementary material

The online version of this article (doi:10.1186/s13046-016-0394-z) contains supplementary material, which is available to authorized users.

How to Improve Therapeutic Ratio in Radiotherapy of HCC

BACKGROUND

During the past two decades, external-beam radiation technology has substantially changed from traditional two-dimensional to conformal three-dimensional to intensity-modulated planning and stereotactic body radiotherapy (SBRT).

SUMMARY

Modern techniques of radiotherapy (RT) are highly focused and capable of delivering an ablative dose to targeted hepatocellular carcinoma (HCC) tumors. SBRT is an option for selected patients with limited tumor volume and non-eligibility for other invasive treatments. Moreover, RT combined with a radiation sensitizer (RS) to increase the therapeutic ratio has shown promising results in select studies, prompting further investigation of this combination. With the undetermined role of RT in treatment guidelines and variation in patterns of treatment failure after RT in patient with HCC, useful biomarkers to guide RT decision-making and selection of patients are needed and emerging.

KEY MESSAGE

The objective of this review is to summarize the current RS with SBRT schemes and biomarkers for patient selection used to maximize the effect of RT on HCC.

Consensus for Radiotherapy in Hepatocellular Carcinoma from The 5th Asia-Pacific Primary Liver Cancer Expert Meeting (APPLE 2014): Current Practice and Future Clinical Trials

A consensus meeting to develop practice guidelines and to recommend future clinical trials for radiation therapy (RT), including external beam RT (EBRT), and selective internal RT (SIRT) in hepatocellular carcinoma (HCC) was held at the 5th annual meeting of the Asia-Pacific Primary Liver Cancer Expert consortium. Although there is no randomized phase III trial evidence, the efficacy and safety of RT in HCC has been shown by prospective and retrospective studies using modern RT techniques. Based on these results, the committee came to a consensus on the utility and efficacy of RT in the management of HCC according to each disease stage as follows: in early and intermediate stage HCC, if standard treatment is not compatible, RT, including EBRT and SIRT can be considered. In locally advanced stage HCC, combined EBRT with transarterial chemoembolization or hepatic arterial infusion chemotherapy, and SIRT can be considered. In terminal stage HCC, EBRT can be considered for palliation of symptoms and reduction of morbidity caused by the primary tumor or its metastases. Despite the currently reported benefits of RT in HCC, the committee agreed that there is a compelling need for large prospective studies, including randomized phase III trial evidence evaluating the role of RT. Specifically studies evaluating the efficacy and safety of sequential combination of EBRT and SIRT are strongly recommended.

Angiogenic Response following Radioembolization: Results from a Randomized Pilot Study of Yttrium-90 with or without Sorafenib

PURPOSE

To compare the regulation of serum angiogenic factors in patients with unresectable early hepatocellular carcinoma (HCC) treated with yttrium-90 ((90)Y) radioembolization alone vs with sorafenib.

MATERIALS AND METHODS

In a single-center pilot study, 23 patients with unresectable HCC awaiting orthotopic liver transplantation were prospectively randomized to receive radioembolization alone (n = 12) or radioembolization with sorafenib (n = 11). Serum angiogenic markers (angiopoietin-2 [Ang-2], hepatocyte growth factor, interleukin [IL]-6, IL-8, c-reactive protein, platelet-derived growth factor [PDGF], and vascular endothelial growth factor [VEGF]) were assayed at baseline and at 2 and 4 weeks after radioembolization ((90)Y alone, n = 6; (90)Y plus sorafenib, n = 7).

RESULTS

In the (90)Y-alone group, all growth factors were elevated above baseline levels at 2 and 4 weeks: VEGF increased 36% vs baseline at 2 weeks and 22% at 4 weeks, and PDGF increased 24% at 2 weeks and 3% at 4 weeks. In the (90)Y/sorafenib arm, Ang-2 and PDGF decreased at 2 weeks and the remainder increased. By 4 weeks, only PDGF remained below baseline levels. VEGF increased 49% at 2 weeks and 28% at 4 weeks, and PDGF decreased 31% at 2 weeks and 39% at 4 weeks. Differences were statistically significant for hepatocyte growth factor (P = .03) and PDGF (P = .02) at 2 weeks and for IL-6 (P = .05) at 4 weeks.

CONCLUSIONS

Radioembolization is associated with a mild increase in angiogenic markers. The addition of sorafenib blunts PDGF response; other factors such as VEGF remain unaffected. The predominant effect of sorafenib may be through downregulation of PDGF and not VEGF.

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).

Therapy with Multipotent Mesenchymal Stromal Cells Protects Lungs from Radiation-Induced Injury and Reduces the Risk of Lung Metastasis

AIMS

Previous thorax irradiation promotes metastatic spread of tumor cells to the lung. We hypothesized that vascular damage facilitates lung metastasis after thorax irradiation and that therapeutically applied multipotent mesenchymal stromal cells (MSCs) with reported repair activity may prevent these adverse effects of ionizing radiation by protecting lung endothelia from radiation-induced damage.

RESULTS

Previous whole-thorax irradiation (WTI) with 15 Gy significantly enhanced seeding and metastatic growth of tumor cells in the lung. WTI was further associated with endothelial cell damage, senescence of lung epithelial cells, and upregulation of invasion- and inflammation-promoting soluble factors, for example, endothelial matrix metalloproteinase 2 (Mmp2), its activator Mmp14, the cofactor tissue inhibitor of metalloproteinases 2 (Timp2), chemokine (C-C motif) ligand 2 (Ccl2), and urokinase-type plasminogen activator (Plau/uPA), and recruitment of CD11b+CD11c- myelomonocytic cells. Inhibition of Mmp2 counteracted radiation-induced vascular dysfunction without preventing increased metastasis. In contrast, therapy with bone marrow or aorta-derived MSCs within 2 weeks postirradiation antagonized radiation-induced damage to resident cells as well as the resulting secretome changes and abrogated the metastasis-promoting effects of WTI.

INNOVATION

Therapy with MSCs protects lungs from radiation-induced injury and reduces the risk of lung metastasis. MSC-mediated inhibition of Mmp2 mediates their protective effects at the vasculature. Furthermore, local and systemic effects such as inhibition of radiation-induced senescence of bronchial epithelial cells and associated secretion of immunomodulatory factors may participate in the inhibitory effect of MSCs on lung metastasis.

CONCLUSION

MSC therapy is a promising strategy to prevent radiation-induced lung injury and the resulting increased risk of metastasis.

New Findings on Breast Cancer Stem Cells: A Review

Since the introduction of the "cancer stem cell" theory, significant developments have been made in the understanding of cancer and the heterogenic structure of tumors. In 2003, with the isolation of cancer stem cells from the first solid tumor, breast cancer, and recognition of the tumorigenicity of these cells, this theory suggested that the main reason for therapy failure might be the presence of cancer stem cells. This review article describes breast cancer stem cell origin, the related cellular and molecular characteristics, signaling pathways, and therapy resistance mechanisms. The databases PubMed, SCOPUS, and Embase were explored, and articles published on these topics between 1992 and 2015 were investigated. It appears that this small subpopulation of cells, with the capacity for self-renewal and a high proliferation rate, originate from normal stem cells, are identified by specific markers such as CD44(+)/CD24(-/low), and enhance a tumor's capacity for metastasis, invasion, and therapy resistance. Cancer stem cell characteristics depend on their interactions with their microenvironment as well as on the inducing factors and elements. Although uncertainties about breast cancer stem cells exist, many of researchers believe that cancer stem cells should be considered as possible therapeutic targets.

The challenges facing block copolymer micelles for cancer therapy: In vivo barriers and clinical translation

The application of block copolymer micelles (BCMs) in oncology has benefitted from advances in polymer chemistry, drug formulation and delivery as well as in vitro and in vivo biological models. While great strides have been made in each of these individual areas, there remains some disappointment overall, citing, in particular, the absence of more BCM formulations in clinical evaluation and practice. In this review, we aim to provide an overview of the challenges presented by in vivo systems to the effective design and development of BCMs. In particular, the barriers posed by systemic administration and tumor properties are examined. The impact of critical features, such as the size, stability and functionalization of BCMs is discussed, while key pre-clinical endpoints and models are critiqued. Given clinical considerations, we present this work as a means to stimulate a renewed focus on the unique chemical versatility bestowed by BCMs and a measured grasp of representative in vitro and in vivo models.

Paclitaxel poliglumex, temozolomide, and radiation for newly diagnosed high-grade glioma: a Brown University Oncology Group Study

OBJECTIVES

Paclitaxel poliglumex (PPX), a drug conjugate that links paclitaxel to poly-L-glutamic acid, is a potent radiation sensitizer. Prior studies in esophageal cancer have demonstrated that PPX (50 mg/m/wk) can be administered with concurrent radiation with acceptable toxicity. The primary objective of this study was to determine the safety of the combination of PPX with temozolomide and concurrent radiation for high-grade gliomas.

METHODS

Eligible patients were required to have WHO grade 3 or 4 gliomas. Patients received weekly PPX (50 mg/m/wk) combined with standard daily temozolomide (75 mg/m) for 6 weeks with concomitant radiation (2.0 Gy, 5 d/wk for a total dose of 60 Gy).

RESULTS

Twenty-five patients were enrolled, 17 with glioblastoma and 8 with grade 3 gliomas. Seven of 25 patients had grade 4 myelosuppression. Hematologic toxicity lasted up to 5 months suggesting a drug interaction between PPX and temozolomide. For patients with glioblastoma, the median progression-free survival was 11.5 months and the median overall survival was 18 months.

CONCLUSIONS

PPX could not be safely combined with temozolomide due to grade 4 hematologic toxicity. However, the favorable progression-free and overall survival suggest that PPX may enhance radiation for glioblastoma. A randomized study of single agent PPX/radiation versus temozolomide/radiation for glioblastoma without MGMT methylation is underway.

Considerations for radiation therapy in hepatocellular carcinoma: the radiation oncologists' perspective

Although the Barcelona Clinic Liver Cancer staging system does not recommend radiation therapy (RT) as a locoregional modality in hepatocellular carcinoma (HCC), many prospective and retrospective studies have reported excellent local control with favorable survival rates after RT using modern techniques. Additionally, there have been several comparative or meta-analysis results reporting the superiority of RT in unresectable HCC. Therefore, it might be more reasonable to apply RT in unresectable HCC as an alternative locoregional modality to improve local control in HCC. However, several considerations for the application of RT in HCC exist. The considerations for RT in HCC are purpose, combination treatment and technique. The purpose of RT should be based on baseline liver status as well as tumor extent and location. There are several reasonable advantages in local, intrahepatic and extrahepatic control when combined with other modalities, but it could lead to overtreatment in some cases. The technical considerations according to the purpose and combination modality are the final step. For the application of RT in HCC, the purpose of RT, combination strategy and technical considerations should be taken into account.

Perfusion parameters of dynamic contrast-enhanced magnetic resonance imaging predict outcomes of hepatocellular carcinoma receiving radiotherapy with or without thalidomide

BACKGROUND

To correlate between signal parameters using dynamic contrast-enhanced magnetic resonance imaging (DCEMRI) and outcomes of hepatocellular carcinoma (HCC) receiving radiotherapy with or without concomitant thalidomide.

METHODS

DCEMRI was performed in advanced HCC patients undergoing radiotherapy with or without concomitant thalidomide. Initial first-pass enhancement slopes (slope) and peak enhancement ratios (peak) were measured over an operator-defined region of interest over tumor and non-tumor liver parenchyma. The perfusion parameters were correlated with clinical outcomes. The study was registered with ClinicalTrials.gov. (identifier NCT00155272).

RESULTS

Forty-three patients were evaluable. There were 18 partial responses (PRs), 5 minimal responses (MRs), 17 stable diseases (SDs), and 3 progressive diseases (PDs). Baseline perfusion parameters as well as slope at 14 days of radiotherapy were higher in patients with PR or MR compared to SD or PD (0.81 ± 0.29 vs. 0.49 ± 0.34, p < 0.01; 0.39 ± 0.15 vs. 0.28 ± 0.16, p = 0.02; 0.97 ± 0.38 vs. 0.46 ± 0.26, p < 0.01; respectively). Multivariate analysis revealed perfusion parameters over liver parenchyma, but not over tumor, and independently predicted progression-free and overall survival (182 ± 33 vs. 105 ± 26 days, p = 0.01; 397 ± 111 vs. 233 ± 19 days, p = 0.001 respectively). For 22 patients receiving concomitant thalidomide, the perfusion parameters were not significantly different from those receiving radiotherapy alone.

CONCLUSIONS

Signal parameters of DCEMRI over tumor and liver parenchyma correlated with tumor response and survival, respectively, in HCC patients receiving radiotherapy.

Recall radiation dermatitis by sorafenib following stereotactic body radiation therapy

We report on a 63-year-old man with a history of hepatitis B virus–related hepatocellular carcinoma with a thrombus extending into the inferior vena cava, who received image-guided stereotactic body radiation therapy (SBRT) with helical tomotherapy, followed by sorafenib. A total tumor dose of 48 Gy was delivered by 6 fractions within 2 weeks. The tumor responded dramatically, and the patient tolerated the courses well. Ten days after SBRT, sorafenib (200 mg), at 1.5 tablets twice a day, was prescribed. One week later, grade 2 recall radiation dermatitis subsequently developed in the previous SBRT off-target area. SBRT followed by sorafenib for the treatment of a portal vein thrombosis provided effective results, but the potential risk of enhanced adverse effects between radiation and sorafenib should be considered with caution, especially under a SBRT scheme.

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.

Neo-adjuvant therapy for hepatocellular carcinoma before liver transplantation: Where do we stand?

Liver transplantation (LT) for hepatocellular carcinoma (HCC) within Milan criteria is a widely accepted optimal therapy. Neo-adjuvant therapy before transplantation has been used as a bridging therapy to prevent dropout during the waiting period and as a down-staging method for the patient with intermediate HCC to qualify for liver transplantation. Transarterial chemoembolization and radiofrequency ablation are the most commonly used method for locoregional therapy. The data associated with newer modalities including drug-eluting beads, radioembolization with Y90, stereotactic radiation therapy and sorafenib will be discussed as a tool for converting advanced HCC to LT candidates. The concept “ablate and wait” has gained the popularity where mandated observation period after neo-adjuvant therapy allows for tumor biology to become apparent, thus has been recommended after down-staging. The role of neo-adjuvant therapy with conjunction of “ablate and wait” in living donor liver transplantation for intermediate stage HCC is also discussed in the paper.

Multicenter phase II study of sequential radioembolization-sorafenib therapy for inoperable hepatocellular carcinoma

BACKGROUND

The safety and tolerability of sequential radioembolization-sorafenib therapy is unknown. An open-label, single arm, investigator-initiated Phase II study (NCT0071279) was conducted at four Asia-Pacific centers to evaluate the safety and efficacy of sequential radioembolization-sorafenib in patients with hepatocellular carcinoma (HCC) not amenable to curative therapies.

METHODS

Sorafenib (400 mg twice-daily) was initiated 14 days post-radioembolization with yttrium-90 (90Y) resin microspheres given as a single procedure. The primary endpoints were safety and tolerability and best overall response rate (ORR) using RECIST v1.0.Secondary endpoints included: disease control rate (complete [CR] plus partial responses [PR] and stable disease [SD]) and overall survival (OS).

RESULTS

Twenty-nine patients with Barcelona Clinic Liver Cancer (BCLC) stage B (38%) or C (62%) HCC received a median of 3.0 GBq (interquartile range, 1.0) 90Y-microspheres followed by sorafenib (median dose/day, 600.0 mg; median duration, 4.1 months). Twenty eight patients experienced ≥1 toxicity; 15 (52%) grade ≥3. Best ORR was 25%, including 2 (7%) CR and 5 (18%) PR, and 15 (54%) SD. Disease control was 100% and 65% in BCLC stage B and C, respectively. Two patients (7%) had sufficient response to enable radical therapy. Median survivals for BCLC stage B and C were 20.3 and 8.6 months, respectively.

CONCLUSIONS

This study shows the potential efficacy and manageable toxicity of sequential radioembolization-sorafenib.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00712790.

Yttrium-90 Radioembolization in Patients with Hepatocellular Carcinoma Who have Previously Received Sorafenib

Purpose: Yttrium-90 radioembolization (RE) is a locoregional therapy option for hepatocellular carcinoma (HCC). Sorafenib is a multikinase inhibitor used in HCC that can potentially affect the efficacy of RE by altering tumor vascularity or suppressing post-irradiation angiogenesis. The safety and efficacy of sorafenib followed by RE has not been previously reported.

Materials and Methods: Patients with HCC who received RE after sorafenib were included in this retrospective review. Overall survival, toxicity, and maximal radiographic response and necrosis criteria were examined.

Results: Ten patients (15 RE administrations) fit the inclusion criteria. All were Barcelona Clinic Liver Cancer (BCLC) stage C. Median follow-up was 16.5 weeks. Median overall survival and radiographic progression-free survival were 30 and 28 weeks, respectively. Significant differences in overall survival were seen based on Child-Pugh class (p = 0.002) and radiographic response (p = 0.009). Three patients had partial response, six had stable disease, and one had progressive disease. Grade 1 or 2 acute fatigue, anorexia, and abdominal pain were common. Three patients had Grade 3 ascites in the setting of disease progression. Two patients had Grade 3 biochemical toxicity. One patient was sufficiently downstaged following RE and sorafenib to receive a partial hepatectomy.

Conclusion: Yttrium-90 RE in patients with HCC who have received sorafenib demonstrate acceptable toxicity and rates of radiographic response. However, the overall survival is lower than that reported in the literature on RE alone or sorafenib alone. This may be due in part to more patients in this study having advanced disease compared to these other study populations. Larger prospective studies are needed to determine whether the combination of RE and sorafenib is superior to either therapy alone.

Efficacy of sorafenib monotherapy versus sorafenib-based loco-regional treatments in advanced hepatocellular carcinoma

BACKGROUND

Although sorafenib is accepted as the standard of care in advanced hepatocellular carcinoma (HCC), its therapeutic benefit is marginal. Here, we aimed to compare the efficacy and safety of sorafenib monotherapy (S-M) and sorafenib-based loco-regional treatments (S-LRTs) in advanced HCC.

METHODS

From 2007 to 2012, 290 patients with advanced HCC (Barcelona Clinic Liver Cancer stage C) with S-M (n = 226) or S-LRTs (n = 64) were reviewed retrospectively. Survival outcomes and treatment-related toxicities between two groups were analyzed.

RESULTS

Variables related to tumor burden and liver function were similar between the groups (all P > 0.05). Within the entire population, the S-LRTs group had both longer median overall survival (OS) (8.5 vs 5.5 months, P = 0.001) and progression-free survival (PFS) (5.3 vs 3.0 months, P = 0.002) than the S-M group. Furthermore, the S-LRTs group had longer Os than the S-M group in a subgroup with neither extrahepatic spread (EHS) nor regional nodal involvement (RNI) (18.0 vs 7.8 months, P = 0.019) and in a subgroup with EHS and/or RNI (8.3 vs 4.8 months, P = 0.028). In addition, the S-LRTs group had longer PFS than the S-M group in the subgroup with neither EHS nor RNI (9.6 vs 3.2 months, P = 0.027).

TREATMENT

Related toxicity was similar between two groups.

CONCLUSION

Combined use of sorafenib and LRTs may provide better treatment outcomes without significantly increasing treatment-related toxicities, even in patients with EHS and/or RNI. Therefore, addition of active LRTs might be considered, if feasible.

An isolate alpha-fetoprotein producing gastric cancer liver metastasis emerged in a patient previously affected by radiation induced liver disease

We report a case of an isolated hepatic neoplasia which originated in a site of the liver previously affected by radiation induced liver disease (RILD) in a patient resected for gastric cancer and referred to us for high serum alpha-fetoprotein (AFP) levels. This case challenged us in distiguishing, even histologically, between primary liver cancer and AFP producing gastric cancer metastasis. Only a panel of immunohistochemical markers allowed the definitive diagnosis of liver metastasis of endodermal stem cell-derived and AFP producing gastric cancer. We discuss the criteria for a differential diagnosis, as well as the possible link between RILD and emergence of liver neoplasia.

The hallmarks of cancer and the radiation oncologist: updating the 5Rs of radiobiology

A comprehensive, mechanistic understanding of radiobiological phenomena that can be integrated within the broader context of cancer biology offers the prospect of transforming clinical practice in radiation oncology. In this review, we revisit the six established biological hallmarks of cancer and examine how they have provided insights into novel therapeutic strategies. In addition, we discuss the potential of two emerging hallmarks to continue to expand our understanding beyond the narrow confines of the traditional 5Rs of radiobiology.

Biological rationale for the design of polymeric anti-cancer nanomedicines

Understanding the biological features of cancer is the basis for designing efficient anti-cancer nanomedicines. On one hand, important therapeutic targets for anti-cancer nanomedicines need to be identified based on cancer biology, to address the unmet medical needs. On the other hand, the unique pathophysiological properties of cancer affect the delivery and interactions of anti-cancer nanomedicines with their therapeutic targets. This review discusses several critical cancer biological properties that challenge the currently available anti-cancer treatments, including cancer heterogeneity and cancer stem cells, the complexcity of tumor microenvironment, and the inevitable cancer metastases. In addition, the biological bases of the enhanced permeability and retention (EPR) effect and tumor-specific active targeting, as well as the physiological barriers for passive and active targeting of anti-cancer nanomedicines are covered in this review. Correspondingly, possible nanomedicine strategies to target cancer heterogeneity, cancer stem cells and metastases, to overcome the challenges related to tumor passive targeting and tumor penetration, and to improve the interactions of therapeutic payloads with the therapeutic targets are discussed. The focus is mainly on the designs of polymeric anti-cancer nanomedicines.

Stimulation of hepatoma cell invasiveness and metastatic potential by proteins secreted from irradiated nonparenchymal cells

PURPOSE

To determine whether factors secreted by irradiated liver nonparenchymal cells (NPCs) may influence invasiveness and/or metastatic potential of hepatocellular carcinoma (HCC) cells and to elucidate a possible mechanism for such effect.

METHODS AND MATERIALS

Primary rat NPCs were cultured and divided into irradiated (10-Gy X-ray) and nonirradiated groups. Forty-eight hours after irradiation, conditioned medium from irradiated (SR) or nonirradiated (SnonR) cultures were collected and added to sublethally irradiated cultures of the hepatoma McA-RH7777 cell line. Then, hepatoma cells were continuously passaged for eight generations (RH10Gy-SR and RH10Gy-SnonR). The invasiveness and metastatic potential of McA-RH7777, RH10Gy-SnonR, and RH10Gy-SR cells were evaluated using an in vitro gelatinous protein (Matrigel) invasion and an in vivo metastasis assay. In addition, SR and SnonR were tested using rat cytokine antibody arrays and enzyme-linked immunosorbent assay (ELISA).

RESULTS

In vitro gelatinous protein invasion assay indicated that the numbers of invading cells was significantly higher in RH10Gy-SR (40 ± 4.74) than in RH10Gy-SnonR (30.6 ± 3.85) cells, and lowest in McA-RH7777 (11.4 ± 3.56) cells. The same pattern was observed in vivo in a lung metastasis assay, as evaluated by number of metastatic lung nodules seen with RH10Gy-SR (28.83 ± 5.38), RH10Gy-SnonR (22.17 ± 4.26), and McA-RH7777 (8.3 ± 3.8) cells. Rat cytokine antibody arrays and ELISA demonstrated that metastasis-promoting cytokines (tumor necrosis factor-α and interleukin-6), circulating growth factors (vascular endothelial growth factor and epidermal growth factor), and metalloproteinases (MMP-2 and MMP-9) were upregulated in SR compared with SnonR.

CONCLUSIONS

Radiation can increase invasiveness and metastatic potential of sublethally irradiated hepatoma cells, and soluble mediators released from irradiated NPCs promote this potential. Increased secretion of metastasis-related cytokines and factors from NPCs after irradiation may be a possible mechanism for the radiation-induced invasiveness and metastatic potential of HCC.

Neoadjuvant paclitaxel poliglumex, cisplatin, and radiation for esophageal cancer: a phase 2 trial

PURPOSE

To evaluate the pathologic complete response (CR) rate and safety of paclitaxel poliglumex (PPX), cisplatin, and concurrent radiation for patients with esophageal cancer.

PATIENTS AND METHODS

Patients with adenocarcinoma or squamous cell carcinoma of the esophagus or gastroesophageal junction with no evidence of distant metastasis received PPX (50 mg/m(2)/wk) and cisplatin (25 mg/m(2)/wk) for 6 weeks with 50.4 Gy concurrent radiation. Six to eight weeks after completion of chemoradiotherapy, patients underwent surgical resection.

RESULTS

Forty patients were enrolled, 37 patients with adenocarcinoma and 3 patients with squamous cell cancer. The treatment-related grade 3 nonhematologic toxicities included esophagitis (7%), nausea (7%), and fatigue (5%). Three patients with clinical endoscopic CR (2 with squamous cell cancer) refused surgery. Twelve of the remaining 37 patients (32%) had a pathologic CR. The 12 patients with pathologic CR all had adenocarcinoma.

CONCLUSION

PPX, cisplatin, and concurrent radiation are well tolerated, easily administered regimen for esophageal cancer with a low incidence of significant esophagitis and a high pathologic CR rate consistent with the preclinical data of PPX and radiation.

Radiotherapeutic strategies in the management of hepatocellular carcinoma

Although potentially curative therapies for hepatocellular carcinoma (HCC) are well established, they are offered only to a limited number of patients. For advanced HCC, sorafenib is now the treatment of choice. Radiotherapy technology has evolved remarkably during the past decade and can be precisely delivered, thereby permitting higher doses to the tumor and reduced doses to surrounding normal tissues. According to the Korean Liver Cancer Study Group (KLCSG) practice guidelines, radiation therapy is considered appropriate for unresectable, locally advanced HCC without extrahepatic metastasis, Child-Pugh class A or B, and tumors occupying less than two thirds of the liver with level II evidence. In this review, we discuss the radiotherapeutic strategies for each clinical setting in patients with HCC.

Treatment of hepatocellular carcinoma (HCC) by intra-arterial infusion of radio-emitter compounds: trans-arterial radio-embolisation of HCC

Traditional radiotherapy is only effective in treating hepatocellular cancer (HCC) in doses above 50 Gy, but this is above the recommended liver radiation exposure of about 35 Gy, which is an important limitation making this treatment unsuitable for routine clinical practice. Trans-arterial radio-embolisation (TARE), consists of delivery of compounds linked to radio-emitter particles which end up in hepatic end-arterioles or show affinity for the neoplasm itself, allowing localised delivery of doses beyond 120 Gy. These are well tolerated in patients treated with this type of internal radiation therapy. TARE for HCC is used for palliative treatment of advanced disease which cannot be treated in other ways, or for tumour down-staging before liver transplantation, or as adjuvant therapy for surgically resected HCC. Tumour response after TARE is between 25% and 60% if assessed by using RECIST criteria, and 80% by EASL criteria. In this review we outline the advantages and limitations of radio-emitter therapy including 131-I, 90-Y and 188-Re. We include several observational, and all comparative studies using these compounds. In particular we compare TARE to trans-arterial chemo-embolisation and other intra-arterial techniques.