Cohorts

A cohort is a defined population observed over time, either prospectively or retrospectively. In some cohorts, members share a characteristic such as an occupational exposure or medical condition, while some other cohorts are samples of the general population. In addition, some DCEG cohorts were first enrolled in clinical or prevention trials, but continue to be followed as a general population cohort.

Cohort members are often surveyed to gather information on lifestyle factors such as diet and nutrition, exercise, use of alcohol or tobacco, because these factors can be related to cancer risk. They are followed over time to gather updates on their general health. In addition, in some studies, members agree to donate biospecimens such as blood, buccal cell, and urine.

For cancer studies that require large numbers of subjects and biospecimens, DCEG investigators often participate in large consortia (collaborative partnerships) that pool data and biospecimens across numerous cohorts. For example, the NCI Cohort Consortium includes investigators responsible for more than 40 high-quality cohorts, involving more than 4 million people.

Following are examples of DCEG cohort studies:

Cohorts

General population cohorts

Occupational cohorts

Environmental Exposure Cohorts

Medical Conditions or Treatment Cohorts