Drug screening in gastro-esophageal adenocarcinoma and the advantages of the organoid model: a literature review

Abstract

Gastro-esophageal adenocarcinomas (GEA) are among the fastest rising malignancies in North America. Despite advances in cancer prevention and treatment for other cancers, the number of GEA cases continues to rise and prognosis remains bleak with five-year survival rates of only 20%. Additionally, many GEA patients won’t respond to first line therapy, many may develop therapeutic resistance, or will show disease recurrence. Previous drug screen models failed clinical trials due to the failure of the model to adequately recapitulate the primary sample. A new model, the patient-derived organoid (PDO), has become the newest method of investigating and testing numerous characteristics of the in vivo tumor. Initial studies have demonstrated the organoid’s advantages: PDOs are highly heterogeneous, may be maintained in culture indefinitely, and have the capability to model carcinogenesis and therapeutic response. However, limitations exist and questions remain that have yet to be addressed. Indeed, one of the challenges of using organoids is knowing whether the organoids are recapitulating normal or tumor tissue. Additionally, there seem to be limits on immortality of the organoids and the heterogeneity. Finally, without the stroma and Tumor Microenvironment (TME) in culture, the model is limited in its ability to test the response to immunotherapy-based drugs. Current research aims to develop a clinical pipeline utilizing organoids regularly as a diagnostic tool to evaluate therapeutic response, identify emergence of chemoresistance and perform targeted drug screens. Overall, PDOs are a burgeoning method of investigating GEA and are a powerful translational tool from bench to bedside.