The future of population monitoring in cancer research.

Population monitoring for cancer research consists of the frequent (or even continuous) gathering of information in a given population that is relevant to that population's cancer risk. This ranges from information on exposure (such as real-time monitoring of radiation dose in a population of radiation workers) or carcinogeninduced phenotypic changes or adducts to information on gene mutations, possible preneoplastic lesions (screening for breast or thyroid abnormalities in the general population or in a high-risk population), and cancer occurrence (monitoring of cancer incidence or mortality through population registries in a geographical area). The main objectives of population monitoring in cancer research are to identify carcinogenic mechanisms by obtaining more precise estimates of the extent to which environmental, lifestyle, and genetic factors contribute to the human cancer burden and to prevent cancer by providing information to evaluate the carcinogenic potential of agents in the absence of sufficient epidemiological data and by identifying high risk groups on which to focus preventive action. With these objectives in mind, it is desirable that, in the future, population monitoring for cancer research be carried out within the framework of well-designed