Patient-Derived Xenograft vs. Organoids: A Preliminary Analysis of Cancer Research Output, Funding and Human Health Impact in 2014–2019

SIMPLE SUMMARY: Given ongoing issues with public opinion against the use of animals in biomedical research, scant research resources, high drug costs, low translational success rates, and the length of time that it currently takes for new drugs to reach the market, we undertook a preliminary analysis of cancer research involving animals, compared to studies using non-animal, human-relevant approaches, carried out between 2014–2019. We collated research studies in the United States and across the European Union, which had used animal models or non-animal, patient-derived cell-based models to study breast, lung and colorectal cancers, and looked for evidence of impacts of this research on human health. We noticed that the number of publications focused on human organoid models shows a growing trend over time. We also saw that there is evidence of increasing funding support for the human cell-based methods, although these still lag behind the animal-based research. Overall, we found that more could be done to promote the use of human-relevant methods and we call for the major funding organizations to prioritize the use of non-animal methods. ABSTRACT: Cancer remains a major threat to mortality and morbidity globally, despite intense research and generous funding. Patient-derived xenograft (PDX) models—where tumor biopsies are injected into an animal—were developed to improve the predictive capacity of preclinical animal models. However, recent observations have called into question the clinical relevance, and therefore the translational accuracy, of these. Patient-derived organoids (PDO) use patient tumor samples to create in vitro models that maintain aspects of tumor structure and heterogeneity. We undertook a preliminary analysis of the number of breast, colorectal, and lung cancer research studies using PDX or PDO published worldwide between 2014–2019. We looked for evidence of impacts of this research on human health. The number of publications that focused on PDO is gradually increasing over time, but is still very low compared to publications using PDX models. Support for new research projects using PDO is gradually increasing, a promising indicator of a shift towards more human-relevant approaches to understanding human disease. Overall, increases in total funding for these three major cancer types does not appear to be translating to any consequential increase in outputs, defined for this purpose as publications associated with clinical trials. With increasing public discomfort in research using animals and demands for ‘alternative’ methods, it is timely to consider how to implement non-animal methods more effectively