Abstract C027: A survey of NCI’s extramural microbiome and cancer grant portfolio: Assessing methodologic differences

Abstract

Abstract Background. Over the last decade, studies have reported that changes in composition of microbiome may be associated with certain disease states in humans, raising the possibility that managing microbial communities may become important in disease prevention and control. Human microbiome refers to all microorganisms on or in the human body, their genes, and surrounding environmental conditions. Studies on the microbiome suggest that errors at each step in the microbiome analysis pipeline, such as sample collection, transport, storage, DNA extraction/sequencing, bioinformatics, statistical methods, and covariates can contribute to variation in microbiome results. Use of different methods and tools may also impede comparison of microbiome results across studies. It is imperative that we capture microbiome information with high accuracy so that we can understand the microbiome’s role in cancer. The National Cancer Institute has funded several studies focused on the human microbiome and cancer. The purpose of our study was to present our assessment of consistency of the methods and technologies used by the cancer epidemiology studies for capturing the microbiome. Methods. We reviewed studies funded between 2013-2018 and extracted information on basic covariates such as demographics and diet; type of biospecimens collected; and the methods used for biospecimen collection, storage, shipping, DNA extraction and sequencing, and bioinformatic tools used for microbiome analysis. We identified 46 relevant funded studies and our assessment found widespread differences in methodologies and technologies used, and in important covariate information collected. Results. For the differences in methodologies and technologies, the results suggest that there is a need for standardization and harmonization of microbiome protocols to minimize variation in results for improving rigor and reproducibility of the findings. In addition, majority of the studies included predominantly non-Hispanic white participants. There is a need to include diverse groups of participants as it is probable that the microbial composition could vary within other racial/ethnic groups due to differing exposures. Conclusion. Given the link between microbiome and cancer, our findings emphasize the need for improving rigor and reproducibility of microbiome analyses by using standardized methods and racially diverse samples in future research studies. Note: This abstract was not presented at the conference. Citation Format: Prema Bhattacharjee, Gabriel Lai, Rao Divi, Somdat Mahabir. A survey of NCI’s extramural microbiome and cancer grant portfolio: Assessing methodologic differences [abstract]. In: Proceedings of the Twelfth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2019 Sep 20-23; San Francisco, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl_2):Abstract nr C027.