ABSTRACT
The acute radiation syndrome is defined in large part by radiation injury in the hematopoietic and gastrointestinal (GI) systems. To identify new pathways involved in radiation-induced GI injury, this study assessed dose- and time-dependent changes in plasma metabolites in a nonhuman primate model of whole abdominal irradiation. Male and female adult Rhesus monkeys were exposed to 6 MV photons to the abdomen at doses ranging between 8 and 14 Gy. At time points from 1 to 60 days after irradiation, plasma samples were collected and subjected to untargeted metabolomics. With the limited sample size of females, different discovery times after irradiation between males and females were observed in metabolomics pattern. Detailed analyses are restricted to only males for the discovery power. Radiation caused an increase in fatty acid oxidation and circulating levels of corticosteroids which may be an indication of physiological stress, and amino acids, indicative of a cellular repair response. The largest changes were observed at days 9 and 10 post-irradiation, with most returning to baseline at day 30. In addition, dysregulated metabolites involved in amino acid pathways, which might indicate changes in the microbiome, were detected. In conclusion, abdominal irradiation in a nonhuman primate model caused a plasma metabolome profile indicative of GI injury. These results point to pathways that may be targeted for intervention or used as early indicators of GI radiation injury. Moreover, our results suggest that effects are sex-specific and that interventions may need to be tailored accordingly.
ABSTRACT
BACKGROUND: As the cost of oncology care continues to rise, composite value models that variably capture the diverse concerns of patients, physicians, payers, policymakers, and the pharmaceutical industry have begun to take shape. OBJECTIVES: To review the capabilities and limitations of 5 of the most notable value frameworks in oncology that have emerged in recent years and to compare their relative value and application among the intended stakeholders. METHODS: We compared the methodology of the American Society of Clinical Oncology (ASCO) Value Framework (version 2.0), the National Comprehensive Cancer Network Evidence Blocks, Memorial Sloan Kettering Cancer Center DrugAbacus, the Institute for Clinical and Economic Review Value Assessment Framework, and the European Society for Medical Oncology Magnitude of Clinical Benefit Scale, using a side-by-side comparative approach in terms of the input, scoring methodology, and output of each framework. In addition, we gleaned stakeholder insights about these frameworks and their potential real-world applications through dialogues with physicians and payers, as well as through secondary research and an aggregate analysis of previously published survey results. RESULTS: The analysis identified several framework-specific themes in their respective focus on clinical trial elements, breadth of evidence, evidence weighting, scoring methodology, and value to stakeholders. Our dialogues with physicians and our aggregate analysis of previous surveys revealed a varying level of awareness of, and use of, each of the value frameworks in clinical practice. For example, although the ASCO Value Framework appears nascent in clinical practice, physicians believe that the frameworks will be more useful in practice in the future as they become more established and as their outputs are more widely accepted. CONCLUSIONS: Along with patients and payers, who bear the burden of treatment costs, physicians and policymakers have waded into the discussion of defining value in oncology care, as well as pharmaceutical companies that seek to understand the impact of these value frameworks on each stakeholder, as they model the value and financial threshold of innovative, high-cost drugs.
