Argon Plasma Coagulation for the Treatment of Superficial Esophageal Carcinoma

Cold Argon Athmospheric Plasma for Biomedicine: Biological Effects, Applications and Possibilities

Currently, plasma medicine is a synthetic direction that unites the efforts of specialists of various profiles. For the successful formation of plasma medicine, it is necessary to solve a large complex of problems, including creating equipment for generating cold plasma, revealing the biological effects of this effect, as well as identifying and justifying the most promising areas of its application. It is known that these biological effects include antibacterial and antiviral activity, the ability to stimulate hemocoagulation, pro-regenerative properties, etc. The possibility of using the factor in tissue engineering and implantology is also shown. Based on this, the purpose of this review was to form a unified understanding of the biological effects and biomedical applications of argon cold plasma. The review shows that cold plasma, like any other physical and chemical factors, has dose dependence, and the variable parameter in this case is the exposure of its application. One of the significant characteristics determining the specificity of the cold plasma effect is the carrier gas selection. This gas carrier is not just an ionized medium but modulates the response of biosystems to it. Finally, the perception of cold plasma by cellular structures can be carried out by activating a special molecular biosensor, the functioning of which significantly depends on the parameters of the medium (in the field of plasma generation and the cell itself). Further research in this area can open up new prospects for the effective use of cold plasma.

Argon plasma coagulation for superficial squamous cell carcinoma in the residual esophagus after esophagectomy

BACKGROUND

Patients after esophagectomy for esophageal squamous cell carcinoma (SCC) occasionally develop metachronous SCC in the residual esophagus. Although most of these second primary lesions are detected as superficial cancer at follow-up endoscopy, it is often difficult to perform endoscopic resection for these lesions near the site of anastomosis.

METHODS

The objective of this study was to evaluate the effectiveness of argon plasma coagulation (APC) for superficial SCC in the residual esophagus after esophagectomy. Twelve patients (involving 15 s primary lesions) received APC for superficial SCC in the residual esophagus after esophagectomy. These lesions were difficult to perform endoscopic resection and they were treated using APC.

RESULTS

There was no treatment-related complication. Complete remission (CR) was achieved in 13 (86.6%) of the 15 lesions: CR was achieved in 11 lesions (73.3%) after the first APC course, and in another 2 lesions (13.3%) after two or more APC courses. Of the 2 patients with persisting residual tumor, 1 patient received 12 times repeated-APC courses over 6 years, and eventually achieved local control without metastasis, the other patient received radiotherapy and cervical esophagectomy after treatment failure with APC. All patients survived except for one patient who died of old age and another patient who died of tongue cancer.

CONCLUSIONS

APC was a safe treatment that was easy to perform. APC was concluded to be an effective treatment for superficial SCC in the residual esophagus after esophagectomy when endoscopic resection was difficult.

Usefulness of argon plasma coagulation for superficial esophageal squamous cell neoplasia in patients at high risk or with limited endoscopic resectability

BACKGROUND/AIMS

Endoscopic resection is the standard treatment for superficial esophageal squamous-cell neoplasia (SESCN). However, we encounter patients in whom endoscopic resection is difficult to perform. We retrospectively studied the usefulness of argon plasma coagulation (APC) in patients with SESCN.

MATERIALS AND METHODS

The study comprised 45 patients with SESCN (81 lesions) who underwent APC in our hospital from March 1999 through August 2016. Clinicopathological characteristics, treatment time, the presence or absence of metastasis and recurrence, adverse events, and outcomes were studied.

RESULTS

The median follow-up was 40 months. The median age was 70 years. The tumor diameter was 10 mm or longer in 48 lesions and less than 10 mm in 33 lesions. The median treatment time was 22 minutes. The reasons for selecting APC were as follows: technical difficulty caused by the presence of metachronous multiple lesions in the radiation field after chemoradiotherapy or close proximity to the ulcer scar remaining after endoscopic treatment in 49 lesions (60.4%), and the presence of underlying diseases in 26 lesions (32.0%). Adverse events occurred in 2 patients (4.4%) who had hypoxemia due to over-sedation. Two lesions (2.5%) recurred locally but could be locally controlled by additional APC. No patient had metastasis or recurrence or died of esophageal neoplasia. The 3-year overall survival rate was 87.0%, and the 3-year recurrence-free survival rate was 97.2%.

CONCLUSION

APC can be a useful treatment option for SESCN in patients with a limited life expectancy, poor performance status, or technical difficulty in resection of superficial neoplasms.

Decomposing the subclonal structure of tumors with two-way mixture models on copy number aberrations

Multistage tumorigenesis is a dynamic process characterized by the accumulation of mutations. Thus, a tumor mass is composed of genetically divergent cell subclones. With the advancement of next-generation sequencing (NGS), mathematical models have been recently developed to decompose tumor subclonal architecture from a collective genome sequencing data. Most of the methods focused on single-nucleotide variants (SNVs). However, somatic copy number aberrations (CNAs) also play critical roles in carcinogenesis. Therefore, further modeling subclonal CNAs composition would hold the promise to improve the analysis of tumor heterogeneity and cancer evolution. To address this issue, we developed a two-way mixture Poisson model, named CloneDeMix for the deconvolution of read-depth information. It can infer the subclonal copy number, mutational cellular prevalence (MCP), subclone composition, and the order in which mutations occurred in the evolutionary hierarchy. The performance of CloneDeMix was systematically assessed in simulations. As a result, the accuracy of CNA inference was nearly 93% and the MCP was also accurately restored. Furthermore, we also demonstrated its applicability using head and neck cancer samples from TCGA. Our results inform about the extent of subclonal CNA diversity, and a group of candidate genes that probably initiate lymph node metastasis during tumor evolution was also discovered. Most importantly, these driver genes are located at 11q13.3 which is highly susceptible to copy number change in head and neck cancer genomes. This study successfully estimates subclonal CNAs and exhibit the evolutionary relationships of mutation events. By doing so, we can track tumor heterogeneity and identify crucial mutations during evolution process. Hence, it facilitates not only understanding the cancer development but finding potential therapeutic targets. Briefly, this framework has implications for improved modeling of tumor evolution and the importance of inclusion of subclonal CNAs.

Salvage Endoscopic Argon Plasma Coagulation After Chemoradiotherapy for Inoperable Esophageal Cancer

PURPOSE

The purpose of this study is to evaluate the effectiveness of salvage endoscopic argon plasma coagulation (APC) therapy for local failure occurring after definitive chemoradiotherapy (CRT) in patients with inoperable esophageal cancer.

PATIENTS AND METHODS

A total of 47 patients with esophageal squamous cell carcinoma received CRT from January 2009 through November 2011 in our hospital. Thirty-five of these patients were excluded because of long-term disease-free status or because they received salvage surgery, systemic chemotherapy, or best supportive care. The other 12 patients had local relapse (n=8) or residual lesions (n=4) after definitive CRT and received salvage APC therapy. Local failures after definitive CRT were divided into 2 groups: the superficial growth group (n=6) and the submucosal growth group (n=6). The primary endpoints were relapse-free survival and overall survival after 60 months of follow-up.

RESULTS

Six patients in the superficial growth group and 1 patient in submucosal growth group had a complete response after salvage APC. The rates of both relapse-free survival and overall survival were higher in the superficial growth group than in the submucosal growth group. No complications occurred after APC.

CONCLUSIONS

Salvage APC is a potentially curative treatment for patients who have local failure associated with superficial tumors after CRT for esophageal squamous cell carcinoma.

Argon and helium plasma coagulation of porcine liver tissue

Objective

Argon plasma coagulation (APC) and helium plasma coagulation (HPC) are electrosurgical techniques that provide noncontact monopolar electrothermal haemostasis. Although these techniques have been widely used clinically during the last three decades, their in vivo effects on liver tissue remain unclear.

Methods

We investigated the effects of different power levels (10–100 W) of APC and HPC on liver coagulation in 11 Landrace pigs. Capillary blood flow and capillary blood flow velocity were recorded with a combined laser Doppler flowmeter and spectrophotometer. The temperature, clinical biochemical parameters, blood gas parameters, bile duct-sealing effect, and coagulation depth were measured.

Results

APC and HPC significantly reduced the capillary blood flow and capillary blood flow velocity compared with baseline flow. No significant temperature change was measured on the liver surface immediately after coagulation. The clinical biochemical and blood gas parameters were not different before and after coagulation. The coagulation depth was positively correlated with the device power setting.

Conclusions

These results prove that APC and HPC provide sufficient superficial haemostasis. No significant systemic effects occurred following coagulation. The depth of the coagulation effect can be controlled through selection of the output power level.

Argon plasma coagulation for superficial esophageal squamous-cell carcinoma in high-risk patients

AIM: To evaluate the usefulness and safety of argon plasma coagulation (APC) for superficial esophageal squamous-cell carcinoma (SESC) in high-risk patients.

METHODS: We studied 17 patients (15 men and 2 women, 21 lesions) with SESC in whom endoscopic mucosal resection (EMR), endoscopic submucosal dissection (ESD), and open surgery were contraindicated from March 1999 through February 2009. None of the patients could tolerate prolonged EMR/ESD or open surgery because of severe concomitant disease (e.g., liver cirrhosis, cerebral infarction, or ischemic heart disease) or scar formation after EMR/ESD and chemoradiotherapy. After conventional endoscopy, an iodine stain was sprayed on the esophageal mucosa to determine the lesion margins. The lesion was then ablated by APC. We retrospectively studied the treatment time, number of APC sessions per site, complications, presence or absence of recurrence, and time to recurrence.

RESULTS: The median duration of follow-up was 36 mo (range: 6-120 mo). All of the tumors were macroscopically classified as superficial and slightly depressed type (0-IIc). The preoperative depth of invasion was clinical T1a (mucosal cancer) for 19 lesions and clinical T1b (submucosal cancer) for 2. The median treatment time was 15 min (range: 10-36 min). The median number of treatment sessions per site was 2 (range: 1-4). The median hospital stay was 14 d (range: 5-68 d). Among the 17 patients (21 lesions), 2 (9.5%) had recurrence and underwent additional APC with no subsequent evidence of recurrence. There were no treatment-related complications, such as bleeding or perforation.

CONCLUSION: APC is considered to be safe and effective for the management of SESC that cannot be resected endoscopically because of underlying disease, as well as for the control of recurrence after EMR and local recurrence after chemoradiotherapy.

Endoscopic ablation therapy for gastrointestinal superficial neoplasia

AIM

  In Japan, endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) have been widely accepted and standardized for the treatment of gastrointestinal superficial neoplasia.

METHODS

  In contrast, mucosal ablation techniques are more common in Western countries and a variety of endoscopic ablation modalities, including argon plasma coagulation (APC), photodynamic therapy (PDT) and lasers, are used.

RESULTS

  Recently developed modalities such as radiofrequency ablation (RFA) and cryotherapy are also available for the treatment of superficial lesions such as dysplasia of Barrett's esophagus.

CONCLUSION

  Although we should understand that the completeness of destruction of neoplastic tissue can only be judged at follow up, endoscopic ablation is a viable alternative to endoscopic resection for dysplasia and early-stage malignancies, especially for poor candidates of surgery or endoscopic resection.

New endoscopic and surgical treatment options for early esophageal adenocarcinoma

Although the outcome for advanced stage esophageal cancer is poor, the early detection and treatment of early stage disease is usually associated with a much better outcome. Until recently, esophagectomy has been the treatment of choice in fit patients. However, morbidity is significant, and this has encouraged the development of newer endoscopic treatments that preserve the esophagus. These techniques include ablation and mucosal resection. Promising results are described, and endoscopic methods might provide a reasonable alternative for the treatment of early esophageal cancer. However, follow-up remains short and endoscopic treatment does not deal with potential lymphatic spread. Hence, careful selection is required. Minimally invasive techniques for esophageal resection have also been shown to be feasible, although there is only limited evidence that they reduce postoperative morbidity. Better data are still required to demonstrate improved outcomes from endoscopic treatment and minimally invasive esophagectomy.

The safety and effectiveness of endoscopic and non-endoscopic approaches to the management of early esophageal cancer: a systematic review

INTRODUCTION

Traditionally, management of early cancer (stages 0-IIA) has comprised esophagectomy, either alone or in combination with chemotherapy and/or radiotherapy. Recent efforts to improve outcomes and minimize side-effects have focussed on minimally invasive, endoscopic treatments that remove lesions while sparing healthy tissue. This review assesses their safety and efficacy/effectiveness relative to traditional, non-endoscopic treatments for early esophageal cancer.

METHODS

A systematic review of peer-reviewed studies was performed using Cochrane guidelines. Bibliographic databases searched to identify relevant English language studies published in the last 3 years included: PubMed (i.e., MEDLINE and additional sources), EMBASE, CINAHL, The Cochrane Library, the UK Centre for Reviews and Dissemination (NHS EED, DARE and HTA) databases, EconLit and Web of Science. Web sites of professional associations, relevant cancer organizations, clinical practice guidelines, and clinical trials were also searched. Two independent reviewers selected, critically appraised, and extracted information from studies.

RESULTS

The review included 75 studies spanning 3124 patients and 10 forms of treatment. Most studies were of short term duration and non-comparative. Adverse events reported across studies of endoscopic techniques were similar and less significant compared to those in the studies of non-endoscopic techniques. Complete response rates were slightly lower for photodynamic therapy (PDT) relative to the other endoscopic techniques, possibly due to differences in patient populations across studies. No studies compared overall or cause-specific survival in patients who received endoscopic treatments vs. those who received non-endoscopic treatments.

DISCUSSION

Based on findings from this review, there is no single "best practice" approach to the treatment of early esophageal cancer.