Precision health refers to the tailoring of disease prevention, screening, diagnosis, and treatment to the unique characteristics of an individual. It does not literally mean the creation of drugs or medical devices customized to a patient, but rather the ability to classify individuals into subpopulations that differ in their susceptibility to a particular disease, in the biology or prognosis of those diseases they may develop, or in their response to a specific treatment. Preventive or therapeutic interventions can then be concentrated on those who will benefit, sparing expense and side effects for those who will not.
Natural history of disease refers to the progression of a disease process in an individual over time, in the absence of treatment. It includes four stages: susceptibility, subclinical disease, clinical disease, and recovery/disability/death. Disease progression is driven by multiple factors, and end-stage disease is only a tip of iceberg. There exists individual variability in the disease progression with various driving factors at different stages. Prediction of disease progression is essential for precision health, and long-term follow-up studies are required to elucidate risk predictors of disease progression. The prediction of the risk of disease progression and the benefit of healthcare management is essential for the daily practice of healthcare workers.
Predictive medicine entails predicting the probability of disease and instituting preventive measures in order to either prevent the disease or significantly decrease its impact upon the patient by limiting disability or preventing mortality. It is intended for both healthy individuals (disease prediction) and for those with diseases (treatment prediction) with the purpose to predict susceptibility to a particular disease and to predict progression and treatment response for a given disease.
The predictors include modifiable and unmodifiable biosignatures. Age, gender, race, and genotypes are unmodifiable predictors; while anthropometric characteristics, dietary intake, lifestyle habits, and infection markers are modifiable predictors. Along with the rapid development in biomedical technology (genomics, transcriptomics, proteomics, glycomics, lipidomics, metabolomics, microbiomics, and medical images), each individual will have a virtual cloud of billions of biosignatures in coming years. Through the analysis of this health data cloud using artificial intelligence, it becomes possible to predict health status and treatment response by monitoring self-parameters.
Risk calculators, are widely used in precision health and predictive medicine. They
integrate several predictors into one measure of absolute risk using a regression model, usually in the form of risk score. Uncertainty about clinical interpretation of a single abnormal laboratory parameter can be improved using this method,
allowing for appropriate recognition of clinically important risk in persons with several but seemingly marginal risk factors that may otherwise not raise clinical concerns.
Many risk calculators have been developed and validated for the prediction of major cancers and cardiometabolic diseases in Taiwan. In our REVEAL-HBV/HCV Study, we have derived risk calculators for the prediction of cirrhosis and hepatocellular carcinoma in patients affected with chronic hepatitis B or C. These prediction models including age, gender, family history of liver cancer, viral infection biomarkers, liver inflammation index, alcohol consumption. These risk calculators have very good performance assessed through the area under the receiver operating characteristic curve (AUROC), calibration plots, and Brier scores. They are useful for patient-physician communication, clinical decision on follow-up examination and antiviral therapy, and national health resource allocation.
In the EVB-NPC Study, we have developed the risk calculator for predicting nasopharyngeal carcinoma (NPC), a unique cancer for Chinese populations. The calculator incorporated biosignatures including Epstein-Barr virus (EBV) infection markers, family NPC history and cigarette smoking. New EBV biomarkers have been identified to improve the early diagnosis of NPC.
In the GELAC Study, we have identified 28 variants at 25 independent loci for the prediction of lung adenocarcinoma. A polygenic risk score was derived and had good performance for predicting lung adenocarcinoma in East Asians, especially in never smokers.