Radioactive self-expanding stents for palliative management of unresectable esophageal cancer: a systematic review and meta-analysis

Best Practices in Esophageal, Gastroduodenal, and Colonic Stenting

Endoscopic stenting is an area of endoscopy that has witnessed noteworthy advancements over the last decade, resulting in evolving clinical practices among gastroenterologists around the world. Indications for endoscopic stenting have progressively expanded, becoming a frequent part of the management algorithm for various benign and malignant conditions of the gastrointestinal tract, from esophagus to rectum. In addition to expanded indications, continuous technological enhancements and development of novel endoscopic stents have resulted in an increased success of these approaches and, in some cases, allowed new applications. This review aimed to summarize best practices in esophageal, gastroduodenal, and colonic stenting.

Advanced Endoscopy for Thoracic Surgeons

The thoracic surgeon, well versed in advanced endoscopy, has an array of therapeutic options for foregut pathologic conditions. Peroral endoscopic myotomy (POEM) offers a less-invasive means to treat achalasia, and the authors' preferred approach is described in this article. They also describe variations of POEM, such as G-POEM, Z-POEM, and D-POEM. In addition, endoscopic stenting, endoluminal vacuum therapy, endoscopic internal drainage, and endoscopic suturing/clipping are discussed and can be valuable tools for esophageal leaks and perforations. Endoscopic procedures are advancing rapidly, and thoracic surgeons must maintain at the forefront of these technologies.

Futuristic Developments and Applications in Endoluminal Stenting

Endoscopic stenting is a well-established option for the treatment of malignant obstruction, temporary management of benign strictures, and sealing transmural defects, as well as drainage of pancreatic fluid collections and biliary obstruction. In recent years, in addition to expansion in indications for endoscopic stenting, considerable strides have been made in stent technology, and several types of devices with advanced designs and materials are continuously being developed. In this review, we discuss the important developments in stent designs and novel indications for endoluminal and transluminal stenting. Our discussion specifically focuses on (i) biodegradable as well as (ii) irradiating and drug-eluting stents for esophageal, gastroduodenal, biliary, and colonic indications, (iii) endoscopic stenting in inflammatory bowel disease, and (iv) lumen-apposing metal stent.

The modern approach to esophageal palliative and emergency surgery

Thoracic surgeons currently have multiple options and strategies to guide treatment in esophageal palliative and emergency conditions. To guide the selection of an individualized palliative approach, physicians, including thoracic surgeons, must take into consideration many factors including prognosis, performance status and comorbidities of patients. For dysphagia more specifically, esophageal stent placement is the most widely used intervention for rapidly relieving dysphagia in inoperable esophageal cancer patients. The combination of esophageal stent placement with other therapies has an impact on palliative care. Innovations including radioactive stents, drug-eluding stents and biodegradable stents will require further evaluation and validation studies. Currently, patients with inoperable esophageal cancer have access to oncological and biological therapies that are improving their prognosis. A shift toward restaging and potential curative intent is occurring in current clinical practice. In acute intrathoracic esophageal perforation cases, high index of suspicion, multidisciplinary team expertise, antibiotics and hybrid treatment strategies, have significantly improved outcomes of patients in recent years. Hybrid treatment strategies denote the combination of minimally invasive interventions for source control and endoluminal procedures to seal the esophageal perforation. Endoluminal procedures as treatment of acute intrathoracic esophageal perforation include stent placement, over-the-scope clip and endoluminal vacuum therapy. Future perspective in the management of esophageal perforation seems to be the combination of endoluminal therapies tailored to the specific clinical scenario. Thoracic surgeons benefit from mastering endoluminal therapies and advanced endoscopic techniques. An understanding of these rapidly evolving therapies, i.e., outcomes, limitations and innovations, is required to optimally manage esophageal palliative and emergency conditions.

Inhibition of Endoplasmic Reticulum Stress-Mediated Autophagy Enhances the Anticancer Effect of Iodine-125 Seed Radiation on Esophageal Squamous Cell Carcinoma

Autophagy has been reported to play a radioresistance role in high-dose-rate irradiation. However, its mechanisms and roles in continuous low-dose-rate (CLDR) irradiation have not been clearly understood. Iodine-125 (I-125) seed brachytherapy is a modality of CLDR irradiation and has been used in the treatment of various cancers. In this study, we investigated the mechanisms and roles of autophagy induced by I-125 seed radiation in human esophageal squamous cell carcinoma (ESCC) cell lines (Eca-109 and EC-109) and a xenograft mouse model. The results of this work showed that I-125 seed radiation induced a dose-dependent increase in autophagy in both cell lines. In Eca-109 cells, I-125 seed radiation-induced endoplasmic reticulum (ER) stress, manifesting as the increased levels of intracellular Ca2+ and Grp78/BiP, and activated PERK-eIF2α, IRE1, and ATF6 pathways of the unfolded protein response. Knockdown of PERK led to the decreased expression of autophagy marker, LC3B-II. Inhibition of autophagy by chloroquine or knockdown of ATG5 enhanced I-125 seed radiation-induced cell proliferation inhibition and apoptosis. Interestingly, chloroquine did not aggravate ER stress but promoted apoptosis via the mitochondrial pathway. The animal experiment showed that inhibition of autophagy by chloroquine improved the efficacy of I-125 seed radiation. In summary, our data demonstrate that I-125 seed CLDR radiation induces ER stress-mediated autophagy in ESCC. Autophagy plays a pro-survival role in I-125 seed CLDR irradiation, and chloroquine is a potential candidate for use in combination therapy with I-125 seed radiation treatment to improve efficacy against ESCC.

Meta-analysis of efficacy and complications of intraluminal radioactive stent and common covered stent in treatment of advanced esophageal cancer

BACKGROUND

The main symptom of advanced esophageal cancer is dysphagia. Because there is no indication for surgery, in order to improve the patient's symptoms and quality of life, esophageal stent therapy has become the main palliative treatment. Based on the results of many studies, it can be speculated that intraluminal radioactive stent is better since it combines the function of ordinary stent and brachytherapy.

AIM

To evaluate the difference in the curative effect and complications between intraluminal radioactive stent (iodine 125 particle scaffold) and common covered stent in patients with mid-advanced esophageal cancer.

METHODS

A computer search of the electronic databases PubMed (1989/2020-03), Web of Science (2000/2020-03), Wiley Online Library (1992/2020-03), CNKI database (1978/2020-03), Wanfang database (1997/2020-03), and VIP database (2000/2020-03) and a manual search of Cochrance library were performed to retrieve articles using the method recommended by the Cochrance System Evaluator's Manual (version 4.2.2). The Oxford's 2011 evidence level assessment was used to evaluate the quality of the included articles, and Meta-analysis was performed using Revman 5.3 software.

RESULTS

Ten articles were finally included, with a total of 943 patients involved. Among the patients, 449 were implanted with an intraluminal radioactive stent and 494 were implanted with a common covered stent. A meta-analysis of 10 articles showed that the average survival time of the intraluminal radioactive stent group was 3.91 mo longer than that of the common covered stent group (95%CI: 1.68-6.13, Z = 3.44, P = 0.0006), and the median survival time was 3.12 mo longer 95%CI: 1.78-4.47, Z = 4.57, P = 0.0001). The dysphagia scores of the two groups of patients were significantly reduced within 1 and 3 mo after the stent was placed (P < 0.05), but there was no statistical difference between the two groups (P > 0.05). After stenting, there was no statistically significant difference in the incidence of pain (odds ratio [OR] = 0.89, 95%CI: 0.65-1.21, Z = 0.77, P = 0.44), bleeding (OR = 0.80, 95%CI: 0.52-1.22, Z = 1.03, P = 0.30), perforation (OR = 1.16, 95%CI: 0.55-2.43, Z = 0.39, P = 0.70), or stent displacement (R = 0.66, 95%CI: 0.31-1.38, Z = 1.10, P = 0.27) between the intraluminal radioactive stent group and the common covered stent group; but there was a statistical difference in the incidence of restenosis [OR = 0.61 , 95%CI (0.42-0.87), Z = 3.73 P = 0.006] between them.

CONCLUSION

The use of intraluminal radioactive stent in the treatment of advanced esophageal cancer can prolong the average survival time and median survival time of patients, and signficantly reduce the incidence of restenosis after surgery; however, the two types of stents have no significant difference in relieving the symptoms of dysphagia within 1-3 mo or in reducing postoperative complications such as pain, hemorrhage, perforation, and stent displacement.

Iodine‑125 seed radiation induces ROS‑mediated apoptosis, autophagy and paraptosis in human esophageal squamous cell carcinoma cells

Iodine-125 (¹²⁵I) seed brachytherapy has been proven to be a safe and effective treatment for advanced esophageal cancer; however, the mechanisms underlying its actions are not completely understood. In the present study, the anti-cancer mechanisms of ¹²⁵I seed radiation in human esophageal squamous cell carcinoma (ESCC) cells (Eca-109 and KYSE-150) were determined, with a particular focus on the mode of cell death. The results showed that ¹²⁵I seed radiation significantly inhibited cell proliferation, and induced DNA damage and G2/M cell cycle arrest in both ESCC cell lines. ¹²⁵I seed radiation induced cell death through both apoptosis and paraptosis. Eca-109 cells were primarily killed by inducing caspase-dependent apoptosis, with 6 Gy radiation resulting in the largest response. KYSE-150 cells were primarily killed by inducing paraptosis, which is characterized by extensive cytoplasmic vacuolation. ¹²⁵I seed radiation induced autophagic flux in both ESCC cell lines, and autophagy inhibition by 3-methyladenine enhanced radiosensitivity. Furthermore ¹²⁵I seed radiation induced increased production of reactive oxygen species (ROS) in both ESCC cell lines. Treatment with an ROS scavenger significantly attenuated the effects of ¹²⁵I seed radiation on endoplasmic reticulum stress, autophagy, apoptosis, paraptotic vacuoles and reduced cell viability. In vivo experiments showed that ¹²⁵I seed brachytherapy induced ROS generation, initiated cell apoptosis and potential paraptosis, and inhibited cell proliferation and tumor growth. In summary, the results demonstrate that in ESCC cells, ¹²⁵I seed radiation induces cell death through both apoptosis and paraptosis; and at the same time initiates protective autophagy. Additionally, ¹²⁵I seed radiation-induced apoptosis, paraptosis and autophagy was considerably mediated by ROS.

A New Fully Covered Irradiation Stent Versus a Partially Covered Irradiation Stent for Unresectable Malignant Dysphagia: A Single-Center Experience

PURPOSE

To assess the efficacy and safety of a newly developed fully covered irradiation stent (FCIS) compared with a partially covered irradiation stent (PCIS) in patients with unresectable malignant dysphagia.

MATERIALS AND METHODS

Data of 195 patients [158 (81.0%) males, median age of 75 years (range 49-89 years)] who underwent FCIS or PCIS placement for unresectable malignant dysphagia from January 2012 to November 2017 were retrospectively analyzed. The median follow-up time was 181 days (range 4-547 days). Outcomes were measured in terms of recurrent dysphagia (primary), technical success, clinical success, overall survival, and adverse events. Recurrent dysphagia was analyzed by Fine-Gray regression model.

RESULTS

The technical success rate was 97.8% (87/89) in the FCIS group and 99.1% (105/106) in the PCIS group (P = 0.59). The clinical success rate was 100.0% in both groups. There was no statistically significant difference in the recurrent dysphagia rate between the FCIS and PCIS groups (21.8% vs. 28.6%; P = 0.12). Compared with PCISs, FCISs were associated with a decrease in tissue/tumor growth rate (11.5% vs. 21.9%; P = 0.01), while stent migration rates were statistically comparable (11.5% vs. 5.7%; P = 0.23). The median overall survivals were comparable between the FCIS and PCIS groups (164 days vs. 162 days; P = 0.70). A dysphagia score of 4 and metastasis were risk factors for survival. No significant differences were observed in the rates of adverse events, including chest pain, fistula formation, hemorrhage, and aspiration pneumonia (P > 0.05).

CONCLUSION

For patients with unresectable malignant dysphagia, this newly developed FCIS can provide efficacy and safety comparable to those of a PCIS. Compared with PCIS, this FCIS is more successful in preventing tissue/tumor growth, with a comparable stent migration rate.