Review of current thermal ablation treatment for lung cancer and the potential of electrochemotherapy as a means for treatment of lung tumours

Advances in the Treatment of Pulmonary Nodules

BACKGROUND

Early detection and accurate diagnosis of pulmonary nodules are crucial for improving patient outcomes. While surgical resection of malignant nodules is still the preferred treatment option, it may not be feasible for all patients. We aimed to discuss the advances in the treatment of pulmonary nodules, especially stereotactic body radiotherapy (SBRT) and interventional pulmonology technologies, and provide a range of recommendations based on our expertise and experience.

SUMMARY

Interventional pulmonology is an increasingly important approach for the management of pulmonary nodules. While more studies are needed to fully evaluate its long-term outcomes and benefits, the available evidence suggests that this technique can provide a minimally invasive and effective alternative for treating small malignancies in selected patients. We conducted a systematic literature review in PubMed, designed a framework to include the advances in surgery, SBRT, and interventional pulmonology for the treatment of pulmonary nodules, and provided a range of recommendations based on our expertise and experience.

KEY MESSAGES

As such, alternative therapeutic options such as SBRT and ablation are becoming increasingly important and viable. With recent advancements in bronchoscopy techniques, ablation via bronchoscopy has emerged as a promising option for treating pulmonary nodules. This study reviewed the advances of interventional pulmonology in the treatment of peripheral lung cancer patients that are not surgical candidates. We also discussed the challenges and limitations associated with ablation, such as the risk of complications and the potential for incomplete nodule eradication. These advancements hold great promise for improving the efficacy and safety of interventional pulmonology in treating pulmonary nodules.

Edaravone: A Novel Possible Drug for Cancer Treatment?

Despite significant advancements in understanding the causes and progression of tumors, cancer remains one of the leading causes of death worldwide. In light of advances in cancer therapy, there has been a growing interest in drug repurposing, which involves exploring new uses for medications that are already approved for clinical use. One such medication is edaravone, which is currently used to manage patients with cerebral infarction and amyotrophic lateral sclerosis. Due to its antioxidant and anti-inflammatory properties, edaravone has also been investigated for its potential activities in treating cancer, notably as an anti-proliferative and cytoprotective drug against side effects induced by traditional cancer therapies. This comprehensive review aims to provide updates on the various applications of edaravone in cancer therapy. It explores its potential as a standalone antitumor drug, either used alone or in combination with other medications, as well as its role as an adjuvant to mitigate the side effects of conventional anticancer treatments.

Reirradiation with stereotactic body radiotherapy for primary or secondary lung malignancies: Tumor control probability and safety analyses

BACKGROUND

Reirradiation with stereotactic body radiotherapy (SBRT) for patients with primary or secondary lung malignancies represents an appealing definitive approach, but its feasibility and safety are not well defined. The purpose of this study was to investigate the tumor control probability (TCP) and toxicity for patients receiving reirradiation with SBRT.

PATIENTS AND METHODS

Eligible patients with recurrence of primary or secondary lung malignancies from our hospital were subjected to reirradiation with SBRT, and PubMed- and Embase-indexed articles were reviewed. The patient characteristics, pertinent SBRT dosimetric details, local tumor control, and toxicities were extracted. The logistic dose-response models were compared for TCP and overall survival (OS) in terms of the physical dose and three-, four-, and five-fraction equivalent doses.

RESULTS

The data of 17 patients from our hospital and 195 patients extracted from 12 articles were summarized. Reirradiation with SBRT yielded 2-year estimates of 80% TCP for doses of 50.10 Gy, 55.85 Gy, and 60.54 Gy in three, four, and five fractions, respectively. The estimated TCP with common fractionation schemes were 50%, 60%, and 70% for 42.04 Gy, 47.44 Gy, and 53.32 Gy in five fractions, respectively. Similarly, the 2-year estimated OS was 50%, 60%, and 70% for 41.62 Gy, 46.88 Gy, and 52.55 Gy in five fractions, respectively. Central tumor localization may be associated with severe toxicity.

CONCLUSIONS

Reirradiation with SBRT doses of 50-60 Gy in 3-5 fractions is feasible for appropriately selected patients with recurrence of peripheral primary or secondary lung malignancies, but should be carefully considered for centrally-located tumors due to potentially severe toxicity. Further studies are warranted for optimal dose/fractionation schedules and more accurate selection of patients suitable for reirradiation with SBRT.

Safety and Efficacy Outcomes From a Single-Center Study of Image-Guided Percutaneous Microwave Ablation for Primary and Metastatic Lung Malignancy

Introduction

Image-guided percutaneous microwave ablation (MWA) is becoming a more common treatment option for patients with primary and metastatic lung malignancies. Nevertheless, there is limited literature on the safety and efficacy of MWA compared with standard-of-care therapy, including surgical resection and radiation. This study will report the long-term outcomes after MWA for pulmonary malignancies and investigate the factors related to efficacy, including lesion size, location, and ablation power.

Methods

Retrospective single-center study analyzing 93 patients who underwent percutaneous MWA for primary or metastatic lung malignancies. Outcomes included immediate technical success, local tumor recurrence, overall survival, disease-specific survival, and complications.

Results

At a single institution, 190 lesions (81 primary and 109 metastatic) were treated in 93 patients. Immediate technical success was achieved in all cases. Freedom from local recurrence was 87.6%, 75.3%, and 69.2% and overall survival was 87.7%, 76.2%, and 74.3% at 1 year, 2 years, and 3 years, respectively. Disease-specific survival was 92.6%, 81.8%, and 81.8%. The most common complication was pneumothorax, which occurred in 54.7% (104 of 190) of procedures, with 35.2% (67 of 190) requiring a chest tube. No life-threatening complications occurred.

Conclusions

Percutaneous MWA seems safe and effective for treatment of primary and metastatic lung malignancies and should be considered for patients with limited metastatic burden and lesions less than 3 cm in size.

Pulsed electric fields with calcium ions stimulate oxidative alternations and lipid peroxidation in human non-small cell lung cancer

Pulsed electric fields (PEFs) are commonly used to facilitate the delivery of various molecules, including pharmaceuticals, into living cells. However, the applied protocols still require optimization regarding the conditions of the permeabilization process, i.e., pulse waveform, voltage, duration, and the number of pulses in a burst. This study highlights the importance of electrochemical processes involved in the electropermeabilization process, known as electroporation. This research investigated the effects of electroporation on human non-small cell lung cancer cells (A549) in potassium (SKM) and HEPES-based buffers (SHM) using sub-microsecond and microsecond range pulses. The experiments were performed using 100 ns - 100 μs (0.6-15 kV/cm) bursts with 8 pulses in a sequence. It was shown that depending on the buffer composition, the susceptibility of cells to PEF varies, while calcium enhances the cytotoxic effects of PEF, if high cell membrane permeabilization is triggered. It was also determined that electroporation with calcium ions induces oxidative stress in cells, including lipid peroxidation (LPO), generation of reactive oxygen species (ROS), and neutral lipid droplets. Here, we demonstrated that calcium ions and optimized pulse parameters could potentiate PEF efficacy and oxidative alternations in lung cancer cells. Thus, the anticancer efficacy of PEF in lung cancers in combination with standard cytostatic drugs or calcium ions should be considered, but this issue still requires in-depth detailed studies with in vivo models.

A Two-eRNA-Based Signature Can Impact the Immune Status and Predict the Prognosis and Drug Sensitivity of Lung Adenocarcinoma

Enhancer RNAs (eRNAs) are intergenic long noncoding RNAs (lncRNAs) participating in the development of malignant cancers via targeting cancer-associated genes and immune checkpoints. Immune infiltration of the tumor microenvironment was positively associated with overall survival (OS) in lung adenocarcinoma (LUAD). In this study, we aimed to explore the clinical significance of PCBP1-AS1 in LUAD and developed a novel prognostic signature based on two eRNAs. Our team discovered that the expression of PCBP1-AS1 was distinctly downregulated in LUAD specimens compared with nontumor specimens. Lower PCBP1-AS1 expression was related to advanced clinical stages and poor prognosis. KEGG analysis unveiled that the coexpression genes of PCBP1-AS1 were involved in the regulation of several tumor-related pathways. In addition, remarkable associations were observed between the expression of PCBP1-AS1 and the levels of several immune cells. Then, we used PCBP1-AS1 and TBX5-AS1 to develop a prognostic model. Survival assays unveiled that patients with higher risk scores exhibited a shorter OS in contrast to patients with lower risk scores. In addition, multivariable Cox regressive analysis indicated that the risk score was an independent prediction factor in LUAD sufferers. The anticancer drug sensitivity analysis indicated that risk score had a positive relationship with several anticancer drugs. Taken together, our findings indicated PCBP1-AS1 as a function modulator in LUAD development. In addition, we constructed a robust immune-related eRNA signature which might be a clinical prognosis factor for LUAD patients.

Magnetic Hyperthermia Nanoarchitectonics via Iron Oxide Nanoparticles Stabilised by Oleic Acid: Anti-Tumour Efficiency and Safety Evaluation in Animals with Transplanted Carcinoma

In this study, we developed iron oxide nanoparticles stabilised with oleic acid/sodium oleate that could exert therapeutic effects for curing tumours via magnetic hyperthermia. A suspension of iron oxide nanoparticles was produced and characterised. The toxicity of the synthesised composition was examined in vivo and found to be negligible. Histological examination showed a low local irritant effect and no effect on the morphology of the internal organs. The efficiency of magnetic hyperthermia for the treatment of transplanted Walker 256 carcinoma was evaluated. The tumour was infiltrated with the synthesised particles and then treated with an alternating magnetic field. The survival rate was 85% in the studied therapy group of seven animals, while in the control group (without treatment), all animals died. The physicochemical and pharmaceutical properties of the synthesised fluid and the therapeutic results, as seen in the in vivo experiments, provide insights into therapeutic hyperthermia using injected magnetite nanoparticles.

Advanced bronchoscopic techniques for the diagnosis and treatment of peripheral lung cancer

Lung cancer is the leading cause of cancer related deaths worldwide. As a result of the increasing use of chest CT scans and lung cancer screening initiatives, there is a rapidly increasing need for lung lesion analysis and - in case of confirmed cancer - treatment. A desirable future concept is the one-stop outpatient bronchoscopic approach including navigation to the tumor, malignancy confirmation and immediate treatment. Several novel bronchoscopic diagnostic and treatment concepts are currently under evaluation contributing to this concept. As the majority of suspected malignant lung lesions develop in the periphery of the lungs, improved bronchoscopic navigation to the target lesion is of key importance. Fortunately, the field of interventional pulmonology is evolving rapidly and several advanced bronchoscopic navigation techniques are clinically available, allowing an increasingly accurate tissue diagnosis of peripheral lung lesions. Additionally, multiple bronchoscopic treatment modalities are currently under investigation. This review will provide a concise overview of advanced bronchoscopic techniques to diagnose and treat peripheral lung cancer by describing their working mechanisms, strengths and weaknesses, identifying knowledge gaps and indicating future developments. The desired one-step concept of bronchoscopic 'diagnose and treat' peripheral lung cancer is on the horizon.

Alternative methods for local ablation-interventional pulmonology: a narrative review

OBJECTIVE

To discuss and summarise the background and recent advances in the approach to bronchoscopic ablative therapies for lung cancer, focusing on focal parenchymal lesions.

BACKGROUND

This series focusses on the challenges highlighted by increasing recognition of the prognostically more favourable oligometastatic disease rather than the more frequent, but prognostically poor, high tumour burden metastatic disease. While surgery, stereotactic body radiation therapy (SBRT), and trans-thoracic percutaneous ablative techniques such as microwave (MWA) and radiofrequency ablation (RFA) are well recognised options for selected cases of pulmonary oligometastasis, bronchoscopic approaches to pulmonary tumour ablation are becoming realistic alternatives. An underlying tenet driving research and implementation in this domain is that percutaneous ablative techniques are obliged to traverse the pleura leading to a high rate of pneumothorax, and risks also goes up for peri-vascular lesions. Historically low yield bronchoscopic targeting of isolated peripheral tumors have significantly improved by incorporating multi-modality high resolution imaging and processing, including navigation planning and real-time image guidances (ultrasound, electromagnetic navigation, cone-beam CT). Combining advanced image guidance with ablative technology adaptations for bronchoscopic delivery opens up the options for high dose local ablative therapies that may reduce transthoracic complications and provide palliative to curative options for limited stage primary and oligometastatic diseases.

METHODS

We conduct a narrative review of the literature summarizing the history of bronchoscopic tumor ablation approaches, technical details including biologic rational for their uses, and current evidence for each modality, as well as investigations into future applications. Because of the relative paucity of prospective studies, we have been very inclusive in our inclusion of experiences from the published clinical databases.

CONCLUSIONS

Whilst surgical resection and SBRT remain the current mainstay of curative therapies for peripheral cancers, in the foreseeable future, developments and further research will see bronchoscopic ablative therapies become viable lung sparing alternatives in those deemed suitable. The future is bright.

A Review on Curability of Cancers: More Efforts for Novel Therapeutic Options Are Needed

Cancer remains a major cause of death globally. Given its relapsing and fatal features, curing cancer seems to be something hardly possible for the majority of patients. In view of the development in cancer therapies, this article summarizes currently available cancer therapeutics and cure potential by cancer type and stage at diagnosis, based on literature and database reviews. Currently common cancer therapeutics include surgery, chemotherapy, radiotherapy, targeted therapy, and immunotherapy. However, treatment with curative intent by these methods are mainly eligible for patients with localized disease or treatment-sensitive cancers and therefore their contributions to cancer curability are relatively limited. The prognosis for cancer patients varies among different cancer types with a five-year relative survival rate (RSR) of more than 80% in thyroid cancer, melanoma, breast cancer, and Hodgkin's lymphoma. The most dismal prognosis is observed in patients with small-cell lung cancer, pancreatic cancer, hepatocellular carcinoma, oesophagal cancer, acute myeloid leukemia, non-small cell lung cancer, and gastric cancer with a five-year RSR ranging between 7% and 28%. The current review is intended to provide a general view about how much we have achieved in curing cancer as regards to different therapies and cancer types. Finally, we propose a small molecule dual-targeting broad-spectrum anticancer strategy called OncoCiDia, in combination with emerging highly sensitive liquid biopsy, with theoretical curative potential for the management of solid malignancies, especially at the micro-cancer stage.

Bronchoscopic ablation of peripheral lung tumors

Lung cancer is the leading cause of cancer-related death worldwide and lobectomy remains the standard of care for patients with early-stage non-small cell lung cancer (NSCLC). The combination of an aging population and the implementation of low-dose CT for lung cancer screening is leading to an increase in diagnosis of early stage NSCLC in medically "inoperable" patients. The recommended treatment for this latter group of patients is stereotactic body radiation therapy (SBRT). However, many patients cannot undergo SBRT because they have received prior radiation or because the tumor is located next to vital structures. Percutaneous ablative therapies have become an alternative to SBRT but, unfortunately, they all violate the pleura and are associated with high rate of pneumothorax. With a more favorable safety profile and the ability to provide also diagnosis and nodal staging, bronchoscopic ablation is hence emerging as a potential future therapeutic alternative for these patients. Herein we review the current state of the art including animal and human data that exists thus far. We also discuss technical and research challenges as well as future directions that this exciting new technology may take.

Advances in Interventional Pulmonology

Much has changed since the last review of interventional pulmonology (IP) published in this Clinics series. The rate of development of new techniques and their complexities require IP physicians to be constantly maintaining and updating their skill set. International agreed training pathways help ensure that the interventionalists of the present and future have the required knowledge of anatomy, manual dexterity, and clinical judgment to keep up with the continuing advances that are constantly expanding IP's diagnostic and therapeutic boundaries. IP remains one of the most desirable subspecialities in pulmonology, and the technologic advances make the future an exciting one.

Efficacy of radiofrequency ablation and microwave ablation in the treatment of thoracic cancer: A systematic review and meta-analysis

BACKGROUND

Radiofrequency ablation and microwave ablation are frequently prescribed for thoracic cancer. However, few writers have been able to draw on any systematic research into the differences between the two ablation methods.

METHODS

A literature search was carried out using Embase, PUBMED, Web of Science, Cochrane Library, and CNKI databases, with additional searches carried out manually using terms associated with thoracic cancer and thermal ablation. Then we used Google Scholar for a complementary search. Data were extracted from studies of patients that underwent radiofrequency ablation or microwave ablation, and the investigator carried out efficacy evaluation and follow up. The data obtained from the literature were summarized and analyzed using Cochrane Revman software Version 5.3 and SPSS 22.0.

RESULTS

There were seven comparative studies, but no randomized studies identified for data extraction; 246 patients received radiofrequency ablation therapy and 319 controls received microwave ablation. There was no significant difference in the six-month, one-year, two-year, and three-year survival rates, and adverse reactions were found in the two treatments. For patients' long-term survival rate, the two treatments can achieve a similar survival time.

CONCLUSION

In the treatment of thoracic cancer, microwave ablation can achieve the same efficacy as radiofrequency ablation.

Electrochemotherapy: A Review of Current Status, Alternative IGP Approaches, and Future Perspectives

The efficiency of electroporation (EP) has made it a widely used therapeutic procedure to transfer cell killing substances effectively to the target site. A lot of researches are being done on EP-based cancer treatment techniques. Electrochemotherapy (ECT) is the first EP-based application in the field of drug administration. ECT is a local and nonthermal treatment of cancer that combines the use of a medical device with pharmaceutical agents to obtain local tumor control in solid cancers. It involves the application of eight, 100µs, pulses at 1 or 5000 Hz frequency and specified electric field (V/cm) with a median duration of 25 minutes. The efficacy of chemotherapeutic drugs increases by applying short and intense electrical pulses. Several clinical studies proposed ECT as a safe and complementary curative or palliative treatment option (curative intent of 50% to 63% in the treatment of Basal Cell Carcinoma (BCC)) to treat a number of solid tumors and skin malignancies, which are not suitable for conventional treatments. It is used currently for treatment of cutaneous and subcutaneous lesions, without consideration of their histology. On the contrary, it is also becoming a practical method for treatment of internal, deep-seated tumors and tissues. A review of this method, needed instruments, alternative image-guided procedures (IGP) approaches, and future perspectives and recommendations are discussed in this paper.

Electrochemotherapy - Emerging applications technical advances, new indications, combined approaches, and multi-institutional collaboration

The treatment of tumors with electrochemotherapy (ECT) has surged over the past decade. Thanks to the transient cell membrane permeabilization induced by the short electric pulses used by ECT, cancer cells are exposed to otherwise poorly permeant chemotherapy agents, with consequent increased cytotoxicity. The codification of the procedure in 2006 led to a broad diffusion of the procedure, mainly in Europe, and since then, the progressive clinical experience, together with the emerging technologies, have extended the range of its application. Herein, we review the key advances in the ECT field since the European Standard Operating Procedures on ECT (ESOPE) 2006 guidelines and discuss the emerging clinical data on the new ECT indications. First, technical developments have improved ECT equipment, with custom electrode probes and dedicated tools supporting individual treatment planning in anatomically challenging tumors. Second, the feasibility and short-term efficacy of ECT has been established in deep-seated tumors, including bone metastases, liver malignancies, and pancreatic and prostate cancers (long-needle variable electrode geometry ECT), and gastrointestinal tumors (endoscopic ECT). Moreover, pioneering studies indicate lung and brain tumors as suitable future targets. A further advance relates to new combination strategies with immunotherapy, gene electro transfer (GET), calcium EP, and radiotherapy. Finally and fourth, cross-institutional collaborative groups have been established to refine procedural guidelines, promote clinical research, and explore new indications.

Electrochemotherapy in head and neck cancer: A review of an emerging cancer treatment

Patients affected by aggressive neoplasms with a high propensity to metastasize to the skin, including some types of head and neck cancer, may benefit from electrochemotherapy, a modality that combines the electroporation of cell membranes and chemotherapy to facilitate the transport of non-permeant molecules into cells; the host immune response consequently participates in achieving the abolition of tumors. Electrochemotherapy can be successfully used for skin metastases of head and neck tumors and, with some limitations, for primary and relapsing neoplasms; it can also be applied on an outpatient basis with a favorable cost-benefit ratio and it is a repeatable treatment that, if necessary, can be followed by traditional antineoplastic therapies. Although still a palliative treatment, the good level of tolerability and the high success rates of electrochemotherapy make it worth consideration among treatment options in selected patients.

Association between VEGF Gene Polymorphisms and the Susceptibility to Lung Cancer: An Updated Meta-Analysis

BACKGROUND AND OBJECTIVE

The association between vascular endothelial growth factor (VEGF) gene polymorphisms (-2578C/A, +936C/T, and -460C/T) and lung cancer risk has been extensively studied in the last decades, but currently available results remain controversial or ambiguous. Therefore, we conducted a meta-analysis to assess whether the relationship between the VEGF gene and lung cancer susceptibility exists.

METHODS

The meta-analysis was conducted by searching the databases PubMed, Embase, and Web of Science covering all eligible studies published up to October 1, 2017. The pooled odds ratios (ORs) as well as their 95% confidence intervals (CIs) were utilized to evaluate the possible associations. Publication bias of relevant studies was examined via Begg's funnel plots and Egger's regression tests.

RESULTS

This meta-analysis included 13 published case-control studies covering 4477 patients with lung cancer and 4346 healthy controls, who had been accrued from December 1992 to July 2012. For the overall eligible data collected in our meta-analysis, it indicated that VEGF +936C/T, -460C/T, and -2578C/A polymorphisms did not correlate with the elevated lung cancer risk in all genetic comparison models. Moreover, VEGF +460T/C polymorphism was found to be significantly associated with susceptibility to lung cancer in these models (allele model: pooled OR = 1.12, 95% CI: 1.00-1.26, P = 0.184; homozygote model: pooled OR = 1.51, 95% CI: 1.12-2.03, P = 0.821), but no significant results were detected in Caucasian populations.

CONCLUSIONS

VEGF +936C/T, -460C/T, and -2578C/A polymorphisms were not associated with the risk of lung cancer. The VEGF +460T/C polymorphism might be a risk factor for lung cancer only in Asian populations.

CT-guided percutaneous cryoablation for palliative therapy of gastric cancer liver metastases

OBJECTIVE

Liver metastases occur in approximately 4%-14% of gastric cancer patients and are associated with high mortality. However, no standardized treatment approach is available for these patients. We aimed to assess the clinical outcomes of patients with gastric cancer liver metastases (GCLM) who underwent percutaneous cryoablation.

METHODS

We retrospectively enrolled 19 patients with 27 metastatic hepatic tumors who underwent cryoablation for liver metastases after gastrectomy for primary gastric cancer. Complications, overall survival (OS), local tumor progression-free survival (PFS), recurrence rates, and quality of life were assessed.

RESULTS

After cryoablation therapy, the median OS for all 19 patients was 16.0 months (range, 5-50 months), and the 1-, 2-, and 3-year OS rates were 78.9%, 43.4%, and 21.7%, respectively. The median local tumor PFS was 8.0 months (range, 3-24 months), and the local tumor PFS rates at 6 and 12 months were 59.2% and 23.2%, respectively. Overall, patients' quality of life improved after cryoablation therapy (P < 0.05). Complications in this study were mild; no severe complications caused by technique were detected.

CONCLUSIONS

Cryoablation provided good local control, improved patients' quality of life and had a low complication rate. Our research showed that cryoablation may be an effective palliative treatment for GCLM.

Inhibition of DNA methyltransferase 1 by RNA interference reverses epithelial-mesenchymal transition in highly metastatic 95D lung cancer cells by inhibiting the Wnt signaling pathway

Epigenetic modifications serve important roles in non-small cell lung cancer (NSCLC) tumorigenesis; however, the role of DNA methyltransferase 1 (DNMT1) in lung cancer progression remains unclear. In the present study, the expression of DNMT1 in the human NSCLC cell lines 95D (high invasive ability) and 95C (low invasive ability) was analyzed by western blotting. The results demonstrated that the expression of DNMT1 in 95D cells was significantly higher, compared with in 95C cells and small airway epithelial cells. To further define the role of DNMT1 in tumor migration and invasion in NSCLC cells, RNA interference was used to silence DNMT1 expression. Depletion of DNMT1 significantly inhibited 95D cell invasion and migration. In addition, treatment with DNMT1 small interfering RNA resulted in compact cell morphology and significantly increased epithelial marker E-cadherin expression whilst also decreasing the expression of certain mesenchymal markers, including vimentin and fibronectin. Suppression of DNMT1 increased cytoplasmic β-catenin levels while downregulating nuclear β-catenin and Snail, an important regulator of EMT. The results from the present study suggest that the inhibition of DNMT1 reverses the epithelial-mesenchymal transition partly via the inhibition of the Wnt/β-catenin signaling pathway, and therefore inhibits cell migration and invasion. These results indicate that targeting DNMT1 may inhibit tumor metastasis and that DNMT1 is a promising target for the novel treatment of lung cancer.

Parametric optimization of electric field strength for cancer electrochemotherapy on a chip-based model

Electrochemotherapy (ECT), as one of the very few available treatments for cutaneous and subcutaneous tumors when surgery and radiotherapy are no longer available, requires applying a proper electric field to the tumor to realize electroporation-mediated cytotoxic drug delivery. It is impossible to exhaust all possible electrical parameters on patients to realize the optimal tradeoff between tumor suppression and adverse effects. To address this issue, this study provides a feasible solution by developing a four-leaf micro-electrode chip (F-MEC) in which the electric field was specially designed by linear distribution to cover all possible electric field strengths for ECT. Methods: We developed a F-MEC that provides a linearly varied electric field and a capacity for in situ observation of cell status. By culturing tumor cells on the F-MEC surface and in situ monitoring the cell responses to ECT drugs, the optimal electric field strength for any given cell type could be rapidly and accurately calculated in a few, or even only one, simple assay. Results: Using this chip, we monitored MCF-7 and A315 cell responses to ECT and determined the optimum ECT voltage. More importantly, we successfully verified that the in vitro determined voltage coincided with the optimal value for in vivo ECT in mice. Conclusion: In this proof-of-concept study, the in vivo tumor suppression assays proved that the optimal parameters acquired from in vitro F-MEC assay could be used for in vivo ECT.

Efficacy and safety of thermal ablation of lung malignancies: A Network meta-analysis

OBJECTIVE:

The objective of this study was to compare the efficacy and safety of radiofrequency ablation (RFA), cryoablation, and microwave ablation (MWA) for patients with lung malignancies.

METHODS:

We performed a network meta-analysis to identify both direct and indirect evidence from relevant trials by searching PubMed, Embase, and the Cochrane Library to December 31, 2017, for the treatment of malignant lung tumors with the use of RFA, MWA, or cryoablation. We extracted the relevant information from the published studies with a predefined data sheet and assessed the risk of bias with the Cochrane risk of bias tool. The primary outcomes were efficacy (local progression rate and overall survival rate) and safety (major complications rate). We did a random-effects network meta-analysis within a Bayesian framework as well as assessed the quality of evidence contributing to each network estimate using GRADE framework.

RESULTS:

We collected 34 studies eligible which included 1840 participants and 2520 lung malignancies (1318 primary lung cancer and 1202 pulmonary metastatic tumors). The quality of evidence was rated as very low in most comparisons. From the point of local progression rate, RFA and MWA were significantly more effective than cryoablation with odds ratio (OR) of 0.04 (95% confidence interval [CI]: 0.004, 0.38; P = 0.005) and 0.02 (95% CI: 0.002, 0.24; P = 0.001), respectively. No significant difference was found between MWA and RFA with an OR of 0.63 (95% CI: 0.04, 10.39; P = 0.745). Regarding the major complications, RFA, MWA, and cryoablation showed the comparable safety (P > 0.05).

CONCLUSION:

RFA and MWA offer an advantage over cryoablation for patients with malignant lung tumors.

Real-time Monitoring of Contrast-enhanced Ultrasound for Radio Frequency Ablation

Background

This study compared the realtime monitoring effects of conventional ultrasound and contrast-enhanced ultrasound (CEUS) on evaluating radio frequency ablation (RFA) in a living swine liver model.

Methodology

Liver RFA was performed on 10 young swine. Conventional ultrasound and CEUS were performed immediately. After the animals were sacrificed, ablation lesions were removed to histopathologically examine the range of the lesions. Ablation completeness based on three methods were compared using histopathology as the gold standard.

Results

Forty-three ablation lesions were produced in the animals. The horizontal diameter, vertical diameter and ablation lesion area based on conventional ultrasound were all significantly smaller than those based on the gross sample, but no significant differences existed between the results of the CEUS and the gross sample. Histopathology showed that 30 lesions were incompletely ablated and 13 were completely ablated, while CEUS showed that 28 lesions were incompletely ablated and 15 were completely ablated. Compared with histopathology, CEUS had an accuracy of 81.4%, a sensitivity of 83.3%, and a specificity of 76.9%. No significant difference in ablation completeness judgment between CEUS and histopathology was observed.

Conclusion

CEUS provides a real-time radiological foundation for evaluating RFA lesion ranges and completeness in a living swine liver model.

[Long-term Efficacy of Radiofrequency Ablation Combined with Chemotherapy in the Treatment of Patients with Advanced Non-small Cell Lung Cancer --A Retrospective Study]

BACKGROUND

Radiofrequency ablation (RFA) combined with chemotherapy has a certain short-term therapeutic effect for the treatment of advanced non-small cell lung cancer (NSCLC), but whether it can improve the long-term survival rate of patients is still controversy. This study retrospectively analyzed the difference of long-term efficacy between RFA combined with chemotherapy and chemotherapy alone in the treatment of patients with advanced NSCLC.

METHODS

A total of 77 patients with stage IIIb and stage IV NSCLC who underwent radiofrequency ablation and chemotherapy in the Department of Thoracic Surgery, Xuanwu Hospital, Capital University of Medical Sciences from September 2009 to December 2015 were enrolled as the treatment group. Chemotherapy with no radiofrequency ablation was performed in 56 patients with stage IIIb and stage IV NSCLC as the control group. Two groups of patients were followed up by telephone about their living conditions. "Survival" package of R software version 3.4.1 was used for statistical analysis. Two sets of data baseline levels were tested by chi-square test. The bias was processed by Cox regression model and the survival curve was plotted using covariate mean substitution method.

RESULTS

The first-year survival rate of the treatment group was 70.74%, the two-year survival rate was 39.31% and the median survival time was 22.1 months. The one-year survival rate was 54.54% in the control group, the two-year survival rate was 19.49%, the median survival for 18.1 months. The long-term survival rate of the treatment group was better than that of the control group (P<0.05, OR=0.571).

CONCLUSIONS

Radiofrequency ablation of lung cancer combined with chemotherapy can significantly improve the 2-year survival rate of patients with stage IIIb and stage IV NSCLC.

Clinical analysis on 113 patients with lung cancer treated by percutaneous CT-guided microwave ablation

BACKGROUND

Lung Cancer is a primary tumor with poor prognosis. For early stage lung cancer, treatment options include surgical resection and microwave techniques. Percutaneous ablative techniques emerged as best therapeutic options for nonsurgical patients.

METHODS

The aim of this study was to retrospectively analyze the clinical effect of CT-guided microwave ablation (MWA) treatment for patients with lung cancer who were not eligible for surgical resection. MWA was used to treat the tumor lesion of 113 patients with lung cancer who were in our hospital from Jan, 2013 to Jun, 2015. The median diameter of tumors was 3.1 cm (0.7-6 cm). Follow-up were paid to all the patients who received MWA therapy. The average follow-up was 22.1±8.6 months, and the median follow-up was 18 (7-40) months.

RESULTS

All of 113 cases of patients with lung cancer experienced MWA therapy, and their tumors were found to have vacuolization, lower density and much smaller distinct shrinkage of tumor size with varying degrees. The local progression rate or relapse rate of the whole group was 15.9%. The counterpart of patients in the early-stage group was 5.7% (2/35), and the diameter of tumors in the two patients was more than 3 cm. The local progression rate or relapse rate of patients in advanced-stage group was 20.5%, wherein, 81.3% of local progression or relapse occurred to the patients with a tumorous diameter of more than 3 cm. The results indicated that the patients in advanced-stage group were vulnerable to local progression or relapse, the tumorous with greater diameter had higher incidence of local relapse. No mortality occurred within 30 days after surgery, the survival rate of patients in early-stage group at first, second, third year was respectively 97.1%, 94.1% and 84.7%. The counterpart of patients in advanced-stage group was respectively 93.6%, 87.7% and 71.7%. The difference of survival rate between both groups was not statistically significant (P=0.576). No perioperative deaths occurred, and the main complications i.e., fever, pneumothorax, pleural effusion, hemoptysis, pneumonia, and pain were slight and tolerable.

CONCLUSIONS

MWA is an effective, safe and minimally invasive treatment for the patients with lung cancer who cannot be tolerated by surgical resection.

Efficacy of microwave ablation for severe secondary hyperparathyroidism in subjects undergoing hemodialysis

Severe secondary hyperparathyroidism (SHPT) is a serious problem in patients undergoing hemodialysis. The efficacy and safety of microwave ablation (MWA), a minimally invasive treatment, for severe SHPT are as yet unclear. To clarify the role of MWA, we administered it to patients with severe SHPT and assessed its efficacy and safety. This was a prospective, single-center, single-arm, clinical trial. We enrolled patients with severe SHPT attending our hemodialysis center who met the inclusion and exclusion criteria. We then assessed primary outcome measures (serum concentrations of intact parathyroid hormone) and secondary outcome measures (serum concentrations of calcium and phosphorus). Twenty-six patients were enrolled in this study, 10 of whom (38.46%) were responsive to MWA and 16 (61.54%) of whom were not. The main complication was hypocalcemia (10 cases, 38.46%), which had occurred in all cases by one week after administration of MWA. Responding patients with hypocalcemia all achieved normal serum calcium concentrations within seven months and non-responding patients within three months. There were no changes in serum phosphorus concentrations after MWA in either responders or non-responders. Microwave ablation is relatively ineffective in patients with severe SHPT undergoing maintaining hemodialysis and should not be the initial therapy in such cases.

Evaluating Cryoablation of Metastatic Lung Tumors in Patients--Safety and Efficacy: The ECLIPSE Trial--Interim Analysis at 1 Year

INTRODUCTION

To assess the feasibility, safety and local tumor control of cryoablation for treatment of pulmonary metastases.

MATERIALS AND METHODS

This Health Insurance Portability and Accountability Act (HIPAA) compliant, IRB-approved, multicenter, prospective, single arm study included 40 patients with 60 lung metastases treated during 48 cryoablation sessions, with currently a minimum of 12 months of follow-up. Patients were enrolled according to the following key inclusion criteria: 1 to 5 metastases from extrapulmonary cancers, with a maximal diameter of 3.5 cm. Local tumor control, disease-specific and overall survival rates were estimated using the Kaplan-Meier method. Complications and changes in physical function and quality of life were also evaluated using Karnofsky performance scale, Eastern Cooperative Oncology Group performance status classification, and Short Form-12 health survey.

RESULTS

Patients were 62.6 ± 13.3 years old (26-83). The most common primary cancers were colon (40%), kidney (23%), and sarcomas (8%). Mean size of metastases was 1.4 ± 0.7 cm (0.3-3.4), and metastases were bilateral in 20% of patients. Cryoablation was performed under general anesthesia (67%) or conscious sedation (33%). Local tumor control rates were 56 of 58 (96.6%) and 49 of 52 (94.2%) at 6 and 12 months, respectively. Patient's quality of life was unchanged over the follow-up period. One-year overall survival rate was 97.5%. The rate of pneumothorax requiring chest tube insertion was 18.8%. There were three Common Terminology Criteria for Adverse Events grade 3 procedural complications during the immediate follow-up period (pneumothorax requiring pleurodesis, noncardiac chest pain, and thrombosis of an arteriovenous fistula), with no grade 4 or 5 complications.

CONCLUSION

Cryoablation is a safe and effective treatment for pulmonary metastases with preserved quality of life following intervention.

Transient suppression of gap junctional intercellular communication after exposure to 100-nanosecond pulsed electric fields

Gap junctional intercellular communication (GJIC) is an important mechanism that is involved and affected in many diseases and injuries. So far, the effect of nanosecond pulsed electric fields (nsPEFs) on the communication between cells was not investigated. An in vitro approach is presented with rat liver epithelial WB-F344 cells grown and exposed in a monolayer. In order to observe sub-lethal effects, cells were exposed to pulsed electric fields with a duration of 100ns and amplitudes between 10 and 20kV/cm. GJIC strongly decreased within 15min after treatment but recovered within 24h. Gene expression of Cx43 was significantly decreased and associated with a reduced total amount of Cx43 protein. In addition, MAP kinases p38 and Erk1/2, involved in Cx43 phosphorylation, were activated and Cx43 became hyperphosphorylated. Immunofluorescent staining of Cx43 displayed the disassembly of gap junctions. Further, a reorganization of the actin cytoskeleton was observed whereas tight junction protein ZO-1 was not significantly affected. All effects were field- and time-dependent and most pronounced within 30 to 60min after treatment. A better understanding of a possible manipulation of GJIC by nsPEFs might eventually offer a possibility to develop and improve treatments.

Latcripin-13 domain induces apoptosis and cell cycle arrest at the G1 phase in human lung carcinoma A549 cells

Latcripin-13 domain, isolated from the transcriptome of Lentinula edodes C91-3, contains a regulator of chromosome condensation (RCC1) domain/β-lactamase-inhibitor protein II (BLIP-II) and a plant homeodomain (PHD). Latcripin-13 domain has been shown to have antitumor effects. However, the underlying molecular pharmacology is largely unknown. We report here that Latcripin-13 domain induced cell cycle arrest in the G1 phase and caused the apoptosis of human lung carcinoma A549 cells via the GSK3β-cyclin D1 and caspase-8/NF-κB signaling pathways. Western blot analysis showed that Latcripin-13 domain decreased cyclin D1 and cyclin-dependent kinase 4 (CDK4), while it increased the ratio of GSK3β/phosphorylated GSK3β. Importantly, Latcripin-13 domain induced nuclear fragmentation and chromatin condensation in the A549 cells. In addition, treatment of the A549 cells with Latcripin-13 domain resulted in the loss of mitochondrial membrane potential, accompanied by an increase in the Bax/Bcl-2 ratio and activation of caspase-3, -8, and -9. Intriguingly, western blot analysis revealed that NF-κB was significantly downregulated by Latcripin-13 domain. These results demonstrated that Latcripin-13 domain induced apoptosis and cell cycle arrest at G1 phase in the A549 cells, providing a mechanism for the antitumor effects of Latcripin-13 domain.

[Advances in Diagnosis and Treatment of Multiple Primary Lung Cancer]

多原发性肺癌的发病率和检出率逐年升高。目前临床上诊断多原发性肺癌(multiple primary lung cancer, MPLC)主要参照Martini-Melamed标准和美国胸科医师协会(American College of Chest Physicians, ACCP)标准, 综合考虑临床表现、影像学特征、组织学类型和分子遗传学特征。组织学类型不同的MPLC诊断相对容易, 而组织学类型相同的MPLC诊断仍相当困难。DNA倍体分析、基因突变检测、微卫星多态性分析等分子生物学技术为MPLC的正确诊断提供了新手段, 可评估各病灶的克隆性关系, 帮助鉴别MPLC与转移。MPLC的首选治疗方案为根治性手术, 术式应考虑患者肺功能储备等因素, 选择肺叶切除、肺段切除或楔形切除; 对于不能根治性切除的病灶, 可综合化疗、放疗、立体定向放疗(stereotactic ablative radiotherapy, SABR)、射频消融(radiofrequency ablation, RFA)、分子靶向治疗等。

Low immunogenicity in non-small cell lung cancer; do new developments and novel treatments have a role?

Approximately 1.6 million new cases of lung cancer are diagnosed annually (Jemal et al. CA: A Cancer Journal for Clinicians, 61, 69-90, 2011) and it remains the leading cause of cancer-related mortality worldwide. Despite decades of bench and clinical research to attempt to improve outcome for locally advanced, good performance status patients, the 5-year survival remains less than 15 % (Molina et al. 2008). Immune checkpoint inhibitor (ICH) therapies have shown a significant promise in preclinical and clinical trails to date in the treatment of non-small cell lung cancer (NSCLC). The idea of combining these systemic immune therapies with local ablative techniques is one that is gaining momentum. Electrochemotherapy (ECT) is a unique atraumatic local therapy that has had very promising objective response rates and a number of advantages including but not limited to its immunostimulatory effects. ECT in combination with ICHs offers a novel approach for dealing with this difficult disease process.

Feasibility of Intraoperative Nerve Monitoring in Preventing Thermal Damage to the "Nerve at Risk" During Image-Guided Ablation of Tumors

PURPOSE

To assess feasibility of intraoperative neurophysiologic monitoring (IONM) during image-guided, percutaneous thermal ablation of tumors.

MATERIALS AND METHODS

From February 2009 to October 2013, a retrospective review of all image-guided percutaneous thermal ablation interventions using IONM was performed and data was compiled using electronic medical records and imaging studies.

RESULTS

Twelve patients were treated in 13 ablation interventions. In 4 patients, real-time feedback from the monitoring neurologist was used to adjust applicator placement and ablation settings. IONM was technically feasible in all procedures and there were no complications related to monitoring or ablation. All nerves at risk remained intact and of the 11 patients who could be followed, none developed new nerve deficit up to a minimum of 2 months after ablation.

CONCLUSION

IONM is safe and feasible for use during image-guided thermal ablation of tumors in the vicinity of nerves. Outcomes in this study demonstrate its potential utility in image-guided ablation interventions.

Using the Promise of Sonodynamic Therapy in the Clinical Setting against Disseminated Cancers

Sonodynamic therapy (SDT) is a form of ultrasound therapy in which specialized chemotherapeutic agents known as sonosensitizers are administered to increase the efficacy of ultrasound-mediated preferential damage of neoplastic cells. Multiple in vitro and in vivo studies have indicated that SDT has the ability to exhibit profound physical and chemical changes on cellular structure. As supportive as the data have been, assessment of this method at the clinical level has been limited to only solid tumors. Although SDT has shown efficacy against multiple adherent neoplastic cell lines, it has also shown particular promise with leukemia-derived cell lines. Potential procedures to administer SDT to leukemia patients are heating the appendages as ultrasound is applied to these areas (Heat and Treat), using an ultrasound probe to scan the body for malignant growths (Target and Destroy), and extracorporeal blood sonication (EBS) through dialysis. Each method offers a unique set of benefits and concerns that will need to be evaluated in preclinical mammalian models of malignancy before clinical examination can be considered.

Pulmonary radiofrequency ablation (Part 1): current state

The risks involved in surgical treatment and conventional radiotherapy in patients with early lung cancer or lung metastases often make these treatments difficult to justify. However, on the other hand, it is also unacceptable to allow these lesions to evolve freely because, left untreated, these neoplasms will usually lead to the death of the patient. In recent years, alternative local therapies have been developed, such as pulmonary radiofrequency ablation, which has proven to increase survival with a minimal risk of complications. There are common recommendations for these treatments, and although the specific indications for using one technique or another have yet to be established, there are clearly defined situations that will determine the outcome of the treatment. It is important to know these situations, because appropriate patient selection is essential for therapeutic success. This article aims to describe the characteristics and constraints of pulmonary radiofrequency ablation and to outline its role in thoracic oncology in light of the current evidence.

Gelatin microcapsules for enhanced microwave tumor hyperthermia

Local and rapid heating by microwave (MW) irradiation is important in the clinical treatment of tumors using hyperthermia. We report here a new thermo-seed technique for the highly efficient MW irradiation ablation of tumors in vivo based on gelatin microcapsules. We achieved 100% tumor elimination in a mouse model at an ultralow power of 1.8 W without any side-effects. The results of MTT assays, a hemolysis test and the histological staining of organs indicated that the gelatin microcapsules showed excellent compatibility with the physiological environment. A possible mechanism is proposed for MW hyperthermia using gelatin microcapsules. We also used gelatin microcapsules capped with CdTe quantum dots for in vivo optical imaging. Our study suggests that these microcapsules may have potential applications in imaging-guided cancer treatment.

Expression and functional analysis of novel molecule - Latcripin-13 domain from Lentinula edodes C91-3 produced in prokaryotic expression system

The shiitake mushroom Lentinula edodes has health benefits and is used to treat various diseases due to its immunomodulatory and antineoplastic properties. In the present study, the Latcripin-13 domain, isolated from L. edodes, was expressed in Escherichia coli Rosetta-gami(DE3) in the form of inclusion bodies. The Latcripin-13 domain was purified by Ni-His affinity chromatography with high purity and refolded by urea gradient dialysis. The product showed biological activity in A549 cells, a human lung cancer cell line, by flow cytometry and the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) method. The MTT assay and the flow cytometry results revealed that there was a great difference between the Latcripin-13 domain-treated group and the control group (p<0.05). Similarly, cell apoptosis observed by transmission electron microscopy (TEM) supported the flow cytometry results. This work demonstrated that the Latcripin-13 domain can induce apoptosis of A549 cells, which will bring new insights into the development of new antitumor drugs in the future.

Managing lung cancer in high-risk patients: what to consider

Lung cancer patients with medical comorbidity are a challenge for care providers. As with other solid tumors, treatment is stage dependent; but a critical difference is the invasive nature of lung resections and the resulting importance of surgical risk stratification for treatment of early stage disease. External beam radiation was considered the only treatment option for early stage disease in non-operative candidates 10-15 years ago. With recent advances in image-guided technologies, robotics, and the resurgence in interest of sublobar resection there are now numerous treatment options which offer excellent local control and reasonable short and long term survival. Extensive work has been done to clarify interventional risk, and accurately describe anticipated outcomes of these varied treatments in the high risk population. The aim of this article is to review recent literature and provide a better understanding of the considerations used in the management of these patients in the current era.

Intraoperative electrochemotherapy of colorectal liver metastases

BACKGROUND AND OBJECTIVES

Electrochemotherapy is effective in treatment of various cutaneous tumors and could be translated into treatment of deep-seated tumors. With this aim a prospective pilot study was conducted to evaluate feasibility, safety, and efficacy of intraoperative electrochemotherapy in the treatment of colorectal liver metastases.

METHODS

Electrochemotherapy with bleomycin was performed during open surgery, by insertion of long needle electrodes into and around the tumor according to the individualized pretreatment plan.

RESULTS

A 29 metastases in 16 patients were treated in 16 electrochemotherapy sessions. No immediate (intraoperative) and/or postoperative serious adverse events related to electrochemotherapy were observed. Radiological evaluation of all the treated metastases showed 85% complete responses and 15% partial responses. In a group of seven patients that underwent a second operation at 6-12 weeks after the first one, during which electrochemotherapy was performed, the histology of resected metastases treated by electrochemotherapy showed less viable tissue (P = 0.001) compared to non-treated ones.

CONCLUSIONS

Electrochemotherapy of colorectal liver metastases proved to be feasible, safe, and efficient treatment modality, providing its specific place in difficult to treat metastases, located in the vicinity of major hepatic vessels, not amenable to surgery or radiofrequency ablation.

Development and characterization of an enhanced nonviral expression vector for electroporation cancer treatment

Nonviral plasmid DNA gene therapy represents a promising approach for the treatment of many diseases including cancer. Intracellular delivery of DNA can be achieved with the application of electroporation, which facilitates the initial transport of exogenous DNA across the cell membrane into the cytoplasm. However, it does not guarantee further transport of the DNA from the cytoplasm to the nucleus for subsequent mRNA expression, resulting in varying degrees of exogenous gene translation and a major limitation in comparison to viral approaches. To overcome these expression difficulties, we developed a proof-of-concept vector enhanced expression vector (EEV), which incorporates elements from viral systems including nuclear localization sequences and a viral replicase from the Semliki Forest virus. The replicase allows for cytoplasmic mRNA expression and bypasses the need for nuclear localization to generate high levels of gene expression. We have demonstrated that our EEV is capable of achieving high levels of expression in a variety of tissue types. Antitumor effects of pEEV were demonstrated by the delayed growth and increased survival of the nontherapeutic pEEV-treated CT26 tumor model. Using a novel endoscopic electroporation system, EndoVe, we demonstrate and compare, for the first time, both standard cytomegalovirus (CMV) promoter-driven plasmid and EEV gene expression in intraluminal porcine tissues. Our EEV plasmid displays reliable and superior expression capability, and due to its inherent induced oncolytic activity in transfected cells, it may enhance the efficacy and safety of several cancer immunogene therapy approaches.

Enhanced Anti-Cancer Effect of Snake Venom Activated NK Cells on Lung Cancer Cells by Inactivation of NF-κB

In the present study, we investigated anti-cancer effect of snake venom activated NK cells (NK-92MI) in lung cancer cell lines. We used snake venom (4 μg/ml) treated NK-92MI cells to co-culture with lung cancer cells. There was a further decrease in cancer cell growth up to 65% and 70% in A549 and NCI-H460 cell lines respectively, whereas 30–40% was decreased in cancer cell growth by snake venom or NK-92MI alone treatment. We further found that the expression of various apoptotic proteins such as that Bax, and cleaved caspase-3 as well as the expression of various death receptor proteins like DR3, DR4 and Fas was also further increased. Moreover, consistent with cancer cell growth inhibition, the DNA binding activity of NF-κB was also further inhibited after treatment of snake venom activated NK-92MI cells. Thus, the present data showed that activated NK cells could further inhibit lung cancer cell growth.

Electrochemotherapy with bleomycin induces hallmarks of immunogenic cell death in murine colon cancer cells

Electrochemotherapy (ECT) is a local cancer treatment that has been used over the course of more than 2 decades for the removal of cutaneous and subcutaneous tumors. Several lines of evidence support the premise that the immune system is an important factor underlying anticancer treatment efficacy, potentially including patient responses to ECT. The concept of immunogenic cell death (ICD) arose a few years ago, stating that some cancer treatments generate danger-associated molecular patterns (DAMPs) that trigger an adaptive immune response against tumors. Hence, dying cancer cells behave as a therapeutic vaccine, eliciting a cytotoxic immune response against surviving malignant cells. In our study, we sought to evaluate the ability of ECT to generate cancer cell death encompassing the immunostimulatory characteristics of ICD. To this end, we assayed CT26 murine colon cancer cells in vitro in response to either electric pulses (EPs) application only or in combination with the anticancer drug bleomycin (that is ECT) by quantification of calreticulin (CRT) membrane externalization, as well as the liberation of adenosine triphosphate (ATP) and high mobility group box 1 (HMGB1) protein. We show here that cell permeabilizing yet non-lethal electric pulses induce CRT exposure on the cell surface of EP-only treated cancer cells, as well as ATP release. However, the association of electric pulses along with the chemotherapeutic agent bleomycin was mandatory for HMGB1 release coincident with regimen-induced cell death. These data obtained in vitro were then substantiated by vaccination protocols performed in immunocompetent mice, showing that the injection of dying ECT-treated cells elicits an antitumor immune response that prevents the growth of a subsequent administration of viable cancer cells. We also confirmed previous results showing ECT treatment is much more efficient in immunocompetent animals than in immunodeficient ones, causing complete regressions in the former but not in the latter. This supports a central role for immunity in this beneficial outcome. In conclusion, we show that ECT not only possesses an intrinsic cytotoxic property toward cancer cells but also generates a systemic anticancer immune response via the activation of ICD. Hence, ECT may represent an interesting approach to treat solid tumors while preventing recurrence and metastasis, possibly in combination with immunostimulating agents.

Radiofrequency ablation for pulmonary metastases from gastrointestinal cancers

The lung is one of the most common targets of metastases from gastrointestinal (GI) cancers. Surgical treatment (i.e., metastasectomy) is an accepted therapeutic option for pulmonary metastases from GI cancers. However, surgery may be contraindicated in advanced stages of cancer, compromised lung function, and/or comorbidities. This issue has prompted the search for innovative and less invasive ways of treating pulmonary metastases. Image-guided radiofrequency ablation (RFA) has attracted great interest as a minimally invasive approach against intrathoracic malignancies. In this technique, radiofrequency energy is applied via a needle electrode inserted into the target tissue. As the cells are agitated by the applied energy, they release heat, causing denaturation and cell death. Recently, this technique has been used on patients with pulmonary metastatic disease arising from GI cancers such as colorectal cancer, esophageal cancer, and hepatocellular carcinoma, as well as on patients with primary lung cancer. The present review updates the clinical outcomes and advances in RFA therapy of lung metastases from GI cancers.