Endoscopic ultrasound-fine needle injection for oncological therapy

The Role of Endoscopy in the Palliation of Pancreatico-Biliary Cancers: Biliary Drainage, Management of Gastrointestinal Obstruction, and Role in Relief of Oncologic Pain

Therapeutic endoscopy permits many and various treatments for cancer palliation in patients with bilio-pancreatic cancers, enabling different options, supporting patients during their route to oncologic treatments, and trying to improve their quality of life. Therefore, both endoscopic and endoscopic ultrasound (EUS)-guided techniques are performed in this scenario. We performed a literature review focusing on the role of endoscopy in the palliation of those advanced pancreatic and biliary cancers developing malignant biliary obstruction (MBO), gastric outlet obstruction (GOO), and pain unresponsive to medical therapies. Therefore, we explored and focused on the clinical outcomes of endoscopic procedures in this scenario. In fact, the endoscopic treatment is based on achieving biliary drainage in the case of MBO through endoscopic retrograde cholangiopancreatography (ERCP) or EUS-guided biliary drainage (EUS-BD), while GOO is endoscopically treated through the deployment of an enteral stent or the creation of EUS-guided gastro-entero-anastomosis (EUS-GEA). Furthermore, untreatable chronic abdominal pain is a major issue in patients unresponsive to high doses of painkillers, so EUS-guided celiac plexus neurolysis (CPN) or celiac ganglia neurolysis (CGN) helps to reduce dosage and have better pain control. Therefore, therapeutic endoscopy in the palliative setting is an effective and safe approach for managing most of the clinical manifestations of advanced biliopancreatic tumors.

Endoscopic ultrasound role in pancreatic adenocarcinoma treatment: A review focusing on technical success, safety and efficacy

The impressive technological advances in recent years have rapidly translated into the shift of endoscopic ultrasound (EUS) from diagnostic modality into an interventional and therapeutic tool. Despite the great advance in its diagnosis, the majority of pancreatic adenocarcinoma cases are inoperable when diagnosed, thus demanding alternative optional therapies. EUS has emerged as an easy, minimally invasive modality targeting this carcinoma with different interventions that have been reported recently. In this review we summarize the evolving role of interventional therapeutic EUS in pancreatic adenocarcinoma management.

Evaluation of the feasibility of intrapancreatic delivery of drug-loaded microparticles via EUS-guided fine needle injection using a swine model

Background and study aims  Patients with pancreatic cancer often have locally advanced or metastatic disease and are not candidates for curative surgery. Polymer-based microparticles (MPs) represent a drug delivery system that offers sustained release of a chemotherapeutic drug after intralesional injection for local tumor management. The aim of this study was to determine the feasibility of endoscopic ultrasound-guided fine-needle injection (EUS-FNI) of drug-loaded MPs tagged with a fluorophore and fiducial markers for locating the injection site. Secondary aims were to determine the tissue-specific effects of MPs. Methods  Five pigs underwent EUS with selection of an injection site within the pancreas that was marked by placing fiducial markers prior to the MPs injection. EUS-FNI of either blank microparticles (BMPs), containing no drug, or gemcitabine-loaded microparticles (GMPs) was performed. A saline flush containing Spot Endoscopic Marker was used to expel any residual MPs in the needle shaft and tattoo the injection site. Results  A green fluorescent protein flashlight was used to successfully identify the site of MP injection sites in the dissected pancreas. Frozen sections of pig pancreas demonstrated a defined deposit, confirming the delivery of the MPs. Finally, fluorescence microscopy showed activation of caspase-mediated cell death in pancreases of animals that received injections of GMPs. Conclusions  This pilot study demonstrated that fiducial marker placement and pancreatic EUS-FNI of MPs was successful in all pigs with no animals demonstrating pancreatitis. Further studies are needed to determine the role for intralesional injection of drug-loaded MPs in borderline resectable or unresectable pancreatic cancer.

Targeting Ligand Specificity Linked to Tumor Tissue Topological Heterogeneity via Single-Cell Micro-Pharmacological Modeling

Targeted therapy has held promise to be a successful anticancer treatment due to its specificity towards tumor cells that express the target receptors. However, not all targeting drugs used in the clinic are equally effective in tumor eradication. To examine which biochemical and biophysical properties of targeted agents are pivotal for their effective distribution inside the tumor and their efficient cellular uptake, we combine mathematical micro-pharmacological modeling with in vivo imaging of targeted human xenograft tumors in SCID mice. The mathematical model calibrated to experimental data was used to explore properties of the targeting ligand (diffusion and affinity) and ligand release schemes (rates and concentrations) with a goal to identify the properties of cells and ligands that enable high receptor saturation. By accounting for heterogeneities typical of in vivo tumors, our model was able to identify cell- and tissue-level barriers to efficient drug uptake. This work provides a base for utilizing experimentally measurable properties of a ligand-targeted agent and patient-specific attributes of the tumor tissue to support the development of novel targeted imaging agents and for improvement in their delivery to individual tumor cells.

The Emerging Role of Endoscopists in Treating Unresectable Pancreatic Cancer

Pancreatic adenocarcinoma is the eighth leading cause of cancer deaths worldwide in men and ninth leading cause in women. Surgical resection offers the only chance of potential cure; however, only 9.4% of patients present at the localized, resectable stage, whereas the rest present at the locally advanced or metastatic, unresectable stages. Because of the guarded outcomes following systemic chemoradiation and the associated systemic toxicities, locoregional therapies have recently gained popularity. Various endoscopic techniques (endoscopic ultrasound [EUS]-guided ablative therapies, fine-needle instillation of antitumor agents, stereotactic body radiation therapy with EUS-guided fiducial marker placement, and EUS-guided brachytherapy) have been explored over the past several years. Endoscopic therapy plays a role in the treatment of unresectable pancreatic adenocarcinoma. Its minimal invasiveness and increased precision of delivering oncologic treatments under EUS guidance render it as a favorable option for patients who do not benefit from surgical resection. New endoscopic therapies are currently under investigation, and the emerging role of the endoscopist in the treatment of unresectable pancreatic cancer continues to grow.

State-of-the-art endoscopic procedures for pancreatic cancer

Pancreatic cancer is the twelfth most common cancer worldwide, taking the fourth place in cancer-related mortality in western countries. Despite significant efforts in understanding the tumor biology of pancreatic cancer and introducing new technologies and therapies to improve the detection, staging and treatment of this disease, pancreatic cancer continues to have a high and almost unchanged mortality. In the last few decades, the development of techniques such as endoscopic retrograde cholangio pancreatography and endoscopic ultrasound have allowed us to directly access the pancreaticobiliary system and fight pancreatic cancer and its complications from different fronts. Our goal with this review is to discuss the most cutting-edge endoscopic techniques available in our armamentarium to diagnose, stage and treat pancreatic cancer.

Photodynamic therapy for cancer of the pancreas – The story so far

Pancreatic cancer has long been a leading cause of cancer death. Few patients are suitable for surgery and for those who are not, the response to treatment is generally poor. No more than about 10% survive for more than a year. Recent research has focused on focal treatment for local disease control. This review covers the development of one of the most promising options, photodynamic therapy (PDT).

This review covers pre-clinical and clinical studies. Laboratory work was designed to understand the effect of PDT on the normal pancreas and surrounding tissues and on transplanted cancers in the hamster pancreas to ensure safety prior to clinical application. Essentially all clinical studies have been undertaken in University College Hospital, London. Phase-I studies used the photosensitisers mTHPC and verteporfin in patients with localised but inoperable cancers.

Laboratory results showed that normal pancreas, bile duct, liver, stomach and major blood vessels could tolerate PDT without any unacceptable effects on the structure and function of these organs. Necrosis that healed safely was documented in transplanted cancers. The clinical trials showed that focal necrosis could be produced in inoperable cancers with acceptable levels of complications, but considerable refinements of treatment delivery and monitoring are required before the technique will be ready for assessment in controlled clinical trials.

PDT is showing promise for the minimally invasive treatment of localised pancreatic cancers, but it is still at an early stage of development. Much more work will be necessary to optimise techniques for applying PDT to these cancers and for combining it with other therapeutic options such as chemotherapy.