How are suspected cancer clusters investigated?
State and local health departments respond to cancer cluster reports and inquiries about suspected clusters. A CDC survey (http://www.cdc.gov/nceh/clusters/status.htm) revealed that most state health departments strategies for cluster response are based on CDCs Guidelines for Investigating Clusters of Health Events (http://www.cdc.gov/mmwr/preview/mmwrhtml/ 00001797.htm) with some modifications. Usually, a local or state health department starts by gathering information about the suspected cancer cluster including expected cancer rate, types of cancer, number of cases, and the age, sex, race, address, occupation, and age at diagnosis of the individuals with cancer. Information may be verified by contacting patients and relatives or by obtaining medical records. This information is then compared to census data and state cancer registry data to determine if there is a higher than expected number of cases. Most investigations do not proceed beyond evaluation of the gathered information; h
