Single-Pass vs 2-Pass Endoscopic Ultrasound-Guided Fine-Needle Biopsy Sample Collection for Creation of Pancreatic Adenocarcinoma Organoids

Cancer organoids: A platform in basic and translational research

An accumulation of previous work has established organoids as good preclinical models of human tumors, facilitating translation from basic research to clinical practice. They are changing the paradigm of preclinical cancer research because they can recapitulate the heterogeneity and pathophysiology of human cancers and more closely approximate the complex tissue environment and structure found in clinical tumors than in vitro cell lines and animal models. However, the potential applications of cancer organoids remain to be comprehensively summarized. In the review, we firstly describe what is currently known about cancer organoid culture and then discuss in depth the basic mechanisms, including tumorigenesis and tumor metastasis, and describe recent advances in patient-derived tumor organoids (PDOs) for drug screening and immunological studies. Finally, the present challenges faced by organoid technology in clinical practice and its prospects are discussed. This review highlights that organoids may offer a novel therapeutic strategy for cancer research.

Comparison of endoscopic ultrasound-guided fine-needle aspiration and fine-needle biopsy to generate pancreatic cancer organoids: Randomized trial

Background and study aims The prognosis for pancreatic cancer remains poor. Molecular diagnostics and customized therapies are becoming increasingly important in clinical routine. Patient-derived, predictive model systems such as organoids have the potential to substantially increase the depth of information from biopsy material by functional and molecular characterization. We compared the extent to which the use of fine-needle aspiration needles (FNA, 22G) or fine-needle biopsy needles (FNB, 22G) influences the generation of pancreatic cancer patient-derived organoids (PDOs) to establish endoscopic standards of organoid technology. Patients and methods Endoscopic ultrasound (EUS)-guided punctures by EUS-FNA and EUS-FNB of pancreatic masses highly suspicious for adenocarcinoma (detected by computed tomography and/or magnetic resonance imaging) were prospectively evaluated. Consecutive patients received EUS-FNA and EUS-FNB in a randomized order without the need to exchange the needle shaft (only the inner needle type (FNA/-B) was exchanged) between the passes. With each needle type, the specimens for histological analysis and for PDOs were obtained separately. Results Fifty patients were enrolled in the study. Histology revealed malignancy in 42 of 50 cases (84%). In total PDOs were generated from 17 patients (34%). Of these, nine were established by FNB only, two by FNA only, and six by both FNA and FNB. Histology revealed malignancy in 13 of 17 PDO cases (76%). In two histologically false-negative cases, PDOs could be established. Conclusions EUS-FNB was superior to EUS-FNA in terms of successful generation of PDOs, although it failed to show statistical significance.

Simultaneous establishment of pancreatic cancer organoid and cancer-associated fibroblast using a single-pass endoscopic ultrasound-guided fine-needle biopsy specimen

Considering the critical roles of cancer-associated fibroblasts (CAFs) in pancreatic cancer, recent studies have attempted to incorporate stromal elements into organoid models to recapitulate the tumor microenvironment. This study aimed to evaluate the feasibility of patient-derived organoid (PDO) and CAF cultures by using single-pass endoscopic ultrasound-guided fine-needle biopsy (EUS-FNB) samples from prospectively enrolled pancreatic cancer patients. The obtained samples were split into two portions for PDO and CAF cultures. PDOs and CAFs were cultured successfully in 54.4% (31/57) and 47.4% (27/57) of the cases, respectively. Both components were established in 21 cases (36.8%). Various clinicopathologic factors, including the tumor size, tumor location, clinical stage, histologic subtype, and tumor differentiation, did not influence the PDO establishment. Instead, the presence of necrosis in tumor samples was associated with initial PDO generation but no further propagation beyond passage 5 (P = 0.024). The "poorly cohesive cell carcinoma pattern" also negatively influenced the PDO establishment (P = 0.018). Higher stromal proportion in tumor samples was a decisive factor for successful CAF culture (P = 0.005). Our study demonstrated that the coestablishment of PDOs and CAFs is feasible even with a single-pass EUS-FNB sample, implying an expanding role of endoscopists in future precision medicine.

Exploring Tumor-Immune Interactions in Co-Culture Models of T Cells and Tumor Organoids Derived from Patients

The use of patient-derived tumor tissues and cells has led to significant advances in personalized cancer therapy and precision medicine. The advent of genomic sequencing technologies has enabled the comprehensive analysis of tumor characteristics. The three-dimensional tumor organoids derived from self-organizing cancer stem cells are valuable ex vivo models that faithfully replicate the structure, unique features, and genetic characteristics of tumors. These tumor organoids have emerged as innovative tools that are extensively employed in drug testing, genome editing, and transplantation to guide personalized therapy in clinical settings. However, a major limitation of this emerging technology is the absence of a tumor microenvironment that includes immune and stromal cells. The therapeutic efficacy of immune checkpoint inhibitors has underscored the importance of immune cells, particularly cytotoxic T cells that infiltrate the vicinity of tumors, in patient prognosis. To address this limitation, co-culture techniques combining tumor organoids and T cells have been developed, offering diverse avenues for studying individualized drug responsiveness. By integrating cellular components of the tumor microenvironment, including T cells, into tumor organoid cultures, immuno-oncology has embraced this technology, which is rapidly advancing. Recent progress in co-culture models of tumor organoids has allowed for a better understanding of the advantages and limitations of this novel model, thereby exploring its full potential. This review focuses on the current applications of organoid-T cell co-culture models in cancer research and highlights the remaining challenges that need to be addressed for its broader implementation in anti-cancer therapy.

Validation of a Novel EUS-FNB-Derived Organoid Co-Culture System for Drug Screening in Patients with Pancreatic Cancer

Cancer-associated fibroblasts (CAFs) have been shown to impact the chemosensitivity of patient-derived tumor organoids (PDTOs). However, the published literature comparing PDTO response to clinical outcome does not include CAFs in the models. Here, a co-culture model was created using PDTOs and CAFs derived from endoscopic ultrasound-guided fine-needle biopsies (EUS-FNBs) for potential use in drug screening applications. Co-cultures were established, and growth was compared to monocultures using image metrics and a commercially available assay. We were able to establish and expand validated malignant PDTOs from 19.2% of adenocarcinomas from EUS-FNBs. CAFs could be established from 25% of the samples. The viability of PDTOs in the mixed cell co-culture could be isolated using image metrics. The addition of CAFs promoted PDTO growth in half of the established co-cultures. These results show that co-cultures can be established from tiny amounts of tissue provided by EUS-FNB. An increased growth of PDTOs was shown in co-cultures, suggesting that the present setup successfully models CAF-PDTO interaction. Furthermore, we demonstrated that standard validation techniques may be insufficient to detect contamination with normal cells in PDTO cultures established from primary tumor core biopsies.

Preclinical models derived from endoscopic ultrasound-guided tissue acquisition for individualized treatment of pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive malignancy with poor outcomes. Although the management strategies have evolved in recent years, the PDAC 5-year survival rate remains at only 9%; it may become the second leading cause of cancer death in the USA by 2030. Only 15-20% of PDAC patients are eligible to undergo surgery; diagnostic biopsies and individualized treatment present a more significant challenge for the remaining group. Endoscopic ultrasound-guided tissue acquisition (EUS-TA) has been widely used in the diagnosis of pancreatic masses. With the advancement of this sampling technique, adequate specimens can be obtained from all patients with PDAC in both early and late clinical stages. Recent data suggest that the specimens obtained from EUS-TA might be used to establish viable preclinical models, which conserve the genetic mutation and preserve the heterogeneity of the original tumors. Additionally, any drug sensitivity evident in the EUS-TA-derived preclinical models might predict the clinical response, thus guiding the prospective therapeutic selection. As we move toward the era of precision medicine, this review provides an update on the role of EUS-TA as a method for obtaining genetic material used in preclinical models that can assess and stratify individuals according to their individual cancer biology.

Patient-specific modeling of stroma-mediated chemoresistance of pancreatic cancer using a three-dimensional organoid-fibroblast co-culture system

BACKGROUND

Cancer-associated fibroblasts (CAFs) are considered to play a fundamental role in pancreatic ductal adenocarcinoma (PDAC) progression and chemoresistance. Patient-derived organoids have demonstrated great potential as tumor avatars for drug response prediction in PDAC, yet they disregard the influence of stromal components on chemosensitivity.

METHODS

We established direct three-dimensional (3D) co-cultures of primary PDAC organoids and patient-matched CAFs to investigate the effect of the fibroblastic compartment on sensitivity to gemcitabine, 5-fluorouracil and paclitaxel treatments using an image-based drug assay. Single-cell RNA sequencing was performed for three organoid/CAF pairs in mono- and co-culture to uncover transcriptional changes induced by tumor-stroma interaction.

RESULTS

Upon co-culture with CAFs, we observed increased proliferation and reduced chemotherapy-induced cell death of PDAC organoids. Single-cell RNA sequencing data evidenced induction of a pro-inflammatory phenotype in CAFs in co-cultures. Organoids showed increased expression of genes associated with epithelial-to-mesenchymal transition (EMT) in co-cultures and several potential receptor-ligand interactions related to EMT were identified, supporting a key role of CAF-driven induction of EMT in PDAC chemoresistance.

CONCLUSIONS

Our results demonstrate the potential of personalized PDAC co-cultures models not only for drug response profiling but also for unraveling the molecular mechanisms involved in the chemoresistance-supporting role of the tumor stroma.

Establishment of Patient-Derived Pancreatic Cancer Organoids from Endoscopic Ultrasound-Guided Fine-Needle Aspiration Biopsies

Background/Aims

Three-dimensional cultures of human pancreatic cancer tissue also known as "organoids" have largely been developed from surgical specimens. Given that most patients present with locally advanced and/or metastatic disease, such organoids are not representative of the majority of patients. Therefore, we used endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) to collect pancreatic cancer tissues from patients with advanced pancreatic cancer to create organoids, and evaluated their utility in pancreatic cancer research.

Methods

Single-pass EUS-FNA samplings were employed to obtain the tissue for organoid generation. After establishment of the organoid, we compared the core biopsy tissues with organoids using hematoxylin and eosin staining, and performed whole exome sequencing (WES) to detect mutational variants. Furthermore, we compared patient outcome with the organoid drug response to determine the potential utility of the clinical application of such organoid-based assays.

Results

Organoids were successfully generated in 14 of 20 tumors (70%) and were able to be passaged greater than 5 times in 12 of 20 tumors (60%). Among them, we selected eight pairs of organoid and core biopsy tissues for detailed analyses. They showed similar patterns in hematoxylin and eosin staining. WES revealed mutations in KRAS, TP53, CDKN2A, SMAD4, BRCA1, and BRCA2 which were 93% homologous, and the mean nonreference discordance rate was 5.47%. We observed moderate drug response correlations between the organoids and clinical outcomes in patients who underwent FOLFIRINOX chemotherapy.

Conclusions

The established organoids from EUS-FNA core biopsies can be used for a suitable model system for pancreatic cancer research.

Endoscopic ultrasound guided interventions in the management of pancreatic cancer

There has been a growing interest in developing endoscopic ultrasound (EUS)-guided interventions for pancreatic cancer, some of which have become standard of care. There are two main factors that drive these advancements to facilitate treatment of patients with pancreatic cancer, ranging from direct locoregional therapy to palliation of symptoms related to inoperable pancreatic cancer. Firstly, an upper EUS has the capability to access the entire pancreas–lesions in the pancreatic head and uncinate process can be accessed from the duodenum, and lesions in the pancreatic body and tail can be accessed from the stomach. Secondly, there has been a robust development of devices that allow through-the-needle interventions, such as placement of fiducial markers, brachytherapy, intratumoral injection, gastroenterostomy creation, and ablation. While these techniques are rapidly emerging, data from a multicenter randomized controlled trial for some procedures are awaited prior to their adoption in clinical settings.

Pancreatic Cancer Patient-Derived Organoid Platforms: A Clinical Tool to Study Cell- and Non-Cell-Autonomous Mechanisms of Treatment Response

For many years, cell lines and animal models have been essential to improve our understanding of the basis of cell metabolism, signaling, and genetics. They also provided an essential boost to cancer drug discovery. Nevertheless, these model systems failed to reproduce the tumor heterogeneity and the complex biological interactions between cancer cells and human hosts, making a high priority search for alternative methods that are able to export results from model systems to humans, which has become a major bottleneck in the drug development. The emergent human in vitro 3D cell culture technologies have attracted widespread attention because they seem to have the potential to overcome these limitations. Organoids are unique 3D culture models with the ability to self-organize in contained structures. Their versatility has offered an exceptional window of opportunity to approach human cancers. Pancreatic cancers (PCs) patient-derived-organoids (PDOs) preserve histological, genomic, and molecular features of neoplasms they originate from and therefore retain their heterogeneity. Patient-derived organoids can be established with a high success rate from minimal tissue core specimens acquired with endoscopic-ultrasound-guided techniques and assembled into platforms, representing tens to hundreds of cancers each conserving specific features, expanding the types of patient samples that can be propagated and analyzed in the laboratory. Because of their nature, PDO platforms are multipurpose systems that can be easily adapted in co-culture settings to perform a wide spectrum of studies, ranging from drug discovery to immune response evaluation to tumor-stroma interaction. This possibility to increase the complexity of organoids creating a hybrid culture with non-epithelial cells increases the interest in organoid-based platforms giving a pragmatic way to deeply study biological interactions in vitro. In this view, implementing organoid models in co-clinical trials to compare drug responses may represent the next step toward even more personalized medicine. In the present review, we discuss how PDO platforms are shaping modern-day oncology aiding to unravel the most complex aspects of PC.

Impact of Endoscopic Ultrasound-Guided Tissue Acquisition on Decision-Making in Precision Medicine for Pancreatic Cancer: Beyond Diagnosis

Precision medicine in cancer treatment refers to targeted therapy based on the evaluation of biomarkers. Although precision medicine for pancreatic cancer (PC) remains challenging, novel biomarker-based therapies, such as pembrolizumab, olaparib, and entrectinib, have been emerging. Most commonly, endoscopic ultrasound-guided tissue acquisition (EUS-TA) had been used for the diagnosis of PC until now. However, advances in EUS-TA devices and biomarker testing, especially next-generation sequencing, have opened up the possibility of sequencing of various genes even in limited amounts of tissue samples obtained by EUS-TA, and identifying potential genetic alterations as therapeutic targets. Precision medicine benefits only a small population of patients with PC, but biomarker-based therapy has shown promising results in patients who once had no treatment options. Now, the role of EUS-TA has extended beyond diagnosis into decision-making regarding the treatment of PC. In this review, we mainly discuss tissue sampling by EUS-TA for biomarker testing and the current status of precision medicine for PC.

The Impact of Recent Advances in Endoscopic Ultrasound-Guided Tissue Acquisition on the Management of Pancreatic Cancer

Over the last few decades, endoscopic ultrasound (EUS)-guided tissue acquisition has become the method of choice for the pathological diagnosis of solid pancreatic lesions. Due to its high diagnostic yield and low complication rate, EUS-guided tissue acquisition has surpassed percutaneous sampling techniques. For many years, EUS-guided fine-needle aspiration (EUS-FNA) was traditionally used to obtain cytological aspirates of solid pancreatic lesions, with sensitivity values ranging from 80 to 90% for the diagnosis of malignancy. Nevertheless, despite numerous technical advances, EUS-FNA still presents some limitations. Therefore, EUS-guided fine-needle biopsy (EUS-FNB) has been introduced to provide tissue core biopsies, allowing histological assessment. A newly developed generation of FNB needles has demonstrated an outstanding diagnostic accuracy of over 95% for solid pancreatic lesions and provides samples appropriate for ancillary testing, such as immunohistochemistry and tumour molecular profiling. As a result, EUS-FNB is rapidly replacing EUS-FNA and is now the recommended technique for EUS-guided tissue acquisition in pancreatic cancer. Furthermore, with the recent expansion of neoadjuvant treatment criteria and with the advent of novel and personalised anti-cancer therapies, EUS-FNB is gaining a pivotal role in pancreatic cancer management and might soon be generalised to all patients, independent of disease stage. In this article, the authors present an updated review of the role of EUS-guided tissue acquisition in pancreatic cancer. Current indications, several technical aspects and new applications of EUS-FNA and EUS-FNB are discussed.

A Prospective Feasibility Trial to Challenge Patient-Derived Pancreatic Cancer Organoids in Predicting Treatment Response

Real-time isolation, propagation, and pharmacotyping of patient-derived pancreatic cancer organoids (PDOs) may enable treatment response prediction and personalization of pancreatic cancer (PC) therapy. In our methodology, PDOs are isolated from 54 patients with suspected or confirmed PC in the framework of a prospective feasibility trial. The drug response of single agents is determined by a viability assay. Areas under the curves (AUC) are clustered for each drug, and a prediction score is developed for combined regimens. Pharmacotyping profiles are obtained from 28 PDOs (efficacy 63.6%) after a median of 53 days (range 21-126 days). PDOs exhibit heterogeneous responses to the standard-of-care drugs, and are classified into high, intermediate, or low responder categories. Our developed prediction model allows a successful response prediction in treatment-naïve patients with an accuracy of 91.1% for first-line and 80.0% for second-line regimens, respectively. The power of prediction declines in pretreated patients (accuracy 40.0%), particularly with more than one prior line of chemotherapy. Progression-free survival (PFS) is significantly longer in previously treatment-naïve patients receiving a predicted tumor sensitive compared to a predicted tumor resistant regimen (mPFS 141 vs. 46 days; p = 0.0048). In conclusion, generation and pharmacotyping of PDOs is feasible in clinical routine and may provide substantial benefit.

Endoscopic Ultrasound-Guided Sampling for Personalized Pancreatic Cancer Treatment

Pancreatic cancer is the most lethal solid malignancy, and the number of patients with pancreatic cancer is increasing. Systemic chemotherapies are often ineffective for such patients, and there is an urgent need for personalized medicine. Unlike other types of cancer, personalized treatments for pancreatic cancer are still in development. Consequently, pancreatic cancer is less sensitive to anticancer drugs and is often refractory to common treatments. Therefore, advances in personalized medicine for pancreatic cancer are necessary. This review examined advances in personalized medicine for pancreatic cancer, including the use of endoscopic ultrasound (EUS)-guided sampling. EUS-guided sampling is widely used for diagnosing pancreatic tumors and is expected to be applied to sampled tissues. Additionally, there has been an increase in clinical research using EUS-guided sampling. The combination of precision medicine using genomic testing and pharmacological profiles based on high-throughput drug sensitivity testing using patient-derived organoids is expected to revolutionize pancreatic cancer treatment.

The Role of Endoscopic Ultrasound in Pancreatic Cancer Staging in the Era of Neoadjuvant Therapy and Personalised Medicine

Precise staging of pancreatic cancer is crucial for treatment choice. In clinical practice, this includes the TNM staging and determination of tumour resectability, based on a multimodality imaging workup. International guidelines recommend multi-detector computed tomography (CT), with a dedicated pancreatic protocol, as the first-line tool for TNM staging and evaluation of tumour-vessel relationships. In non-metastatic disease upon initial CT assessment, both magnetic resonance imaging and endoscopic ultrasound (EUS) may add relevant information, potentially changing treatment sequence. EUS may have distinct advantages in pancreatic cancer diagnosis and staging when compared with other modalities, being particularly valuable in the determination of portal venous confluence involvement (particularly in small and ill-defined/isoattenuating tumours on CT), in locoregional nodal staging and in the detection of ascites. As we step forward to a more frequent use of neoadjuvant chemotherapy and to personalised medicine, the importance of EUS-guided fine-needle biopsy (EUS-FNB) also increases. The recent availability of third-generation biopsy needles significantly increased the diagnostic yield of EUS-guided tissue acquisition, providing diagnostic cell blocks in approximately 95% of cases with only two dedicated passes and allowing ancillary testing, such as immunohistochemistry and molecular profiling of the tumour. In this article, the authors present an updated perspective of the place of EUS and EUS-FNB in the staging algorithm of pancreatic cancer. Data supporting the increasing role of neoadjuvant therapy and the importance of a patient-tailored treatment selection, based on tumoural subtyping and molecular profiling, are also discussed.