Epidemiology: the art and science of reducing cancer risk and promoting health and wellbeing.
Cancer is a leading cause of mortality worldwide in countries of all income levels. The incidence of cancer is expected to increase rapidly as populations grow, age, and adopt lifestyle behaviors that increase cancer risk. It is estimated that about 40% of cancer cases can be prevented by changes in lifestyle and modification of risk factors. But how do we know this? How can we describe people’s chances of ill health, and measure the impact of changes in lifestyle and environment? For this we turn to epidemiology ─ the science underpinning public health and clinical medicine.
Epidemiology describes the occurrence of health-related states or events, quantifies the risk of disease and outcomes such as prognosis, survival, and mortality. It can postulate and test causal mechanisms for disease in populations. The function of epidemiology is to provide evidence to guide public health policy and clinical practice to protect, restore, and promote health of individuals and populations.