The status of cancer cluster investigations undertaken by state health departments.

A survey of state health departments indicates the number of cancer cluster reports received is associated with the size of the state, the presence of a population-based tumor registry, and the existence of a centralized system for response. Cancer cluster investigations, have generally been unproductive in terms of etiologic discoveries yet they may have important benefits in terms of public education, allaying public anxiety about environmental concerns and engendering good will toward government agencies.