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Risk Factors and Causation
Risk factors change the likelihood of an outcome, while evidence of causation asks whether a factor helps produce it.
#A risk factor concerns the chance of an outcome
NCI explains cancer risk factors as characteristics or exposures linked to an increased chance of developing cancer. They include aspects of age, family history, behaviour and the environment. It also notes that it is usually not possible to explain exactly why one person develops cancer and another does not.
This cancer example introduces the difference between a factor affecting risk and an explanation of one person's illness. It is not a personal prediction or a basis for blame. This page assigns no risk percentage, evaluates no individual exposure and supplies no screening or prevention plan.
Evidence: NCI: risk factors and evidence
#An association is a starting point, not proof by itself
NCI describes epidemiology studies comparing groups who develop cancer with those who do not. An observed link between a behaviour or substance and cancer can reflect chance or a different underlying factor. Such a study, on its own, does not prove that the suspected factor causes cancer.
When many studies find a similar association and a possible biological mechanism explains it, confidence in the relationship can increase. NCI describes cell, animal and human studies contributing different evidence. The distinction does not mean established causes are unknowable; it means a single observed link needs careful interpretation.
Evidence: NCI: risk factors and evidence / NCI: research on causes of cancer
#Measurement and alternative explanations matter
NCI describes challenges in assessing past exposures, including imperfect recall, uncertainty in exposure estimates and the difficulty of identifying which part of a complex exposure matters. Rare outcomes or uncommon exposures may require very large studies to detect an association. Even a genetic association can need more research to identify the particular change and its biological role.
These limits help explain why research findings can differ without every difference being a contradiction. They do not let this page determine what caused an individual's illness or whether a specific product is safe. Mynd provides evidence education, not personal risk assessment or regulatory certification.
Evidence: NCI: research on causes of cancer
Source note
The sections above were checked against the linked sources. No clinical review has been performed. This is general research education, not a clinical guideline.