Molecular pathological epidemiology

Molecular pathological epidemiology (MPE, also molecular pathologic epidemiology) is a discipline combining epidemiology and pathology. It is defined as "epidemiology of molecular pathology and heterogeneity of disease". Pathology and epidemiology share the same goal of elucidating etiology of disease, and MPE aims to achieve this goal at molecular, individual and population levels. Typically, MPE utilizes tissue pathology resources and data within existing epidemiology studies. Molecular epidemiology broadly encompasses MPE and conventional-type molecular epidemiology with the use of traditional disease designation systems. Data from The Cancer Genome Atlas projects indicate that disease evolution is an inherently heterogeneous process. Each patient has a unique disease process (“the unique disease principle”), considering the uniqueness of the exposome and its unique influence on molecular pathologic process. This concept has been adopted in clinical medicine along with precision medicine and personalized medicine. In MPE, investigators dissect interrelationships between exposures (e.g., environmental, dietary, lifestyle and genetic factors); alterations in cellular or extracellular molecules (disease molecular signatures); and disease evolution and progression. Investigators can analyze genome, methylome, epigenome, metabolome, transcriptome, proteome, microbiome, immunity and interactome. A putative risk factor can be linked to specific molecular signatures. MPE research enables identification of a new biomarker for potential clinical utility, using large-scale population-based data (e.g., PIK3CA mutation in colorectal cancer to select patients for aspirin therapy). The MPE approach can be used following a genome-wide association study (GWAS), termed "GWAS-MPE approach". Detailed disease endpoint phenotyping can be conducted by means of molecular pathology or surrogate histopathology or immunohistochemistry analysis of diseased tissues and cells within GWAS.