Reported disease clusters of any kind, including suspected cancer clusters, are investigated by epidemiologists (scientists who study the frequency, distribution, causes and control of diseases in populations). Epidemiologists use their knowledge of diseases, environmental science, lifestyle factors and biostatistics to try to determine whether a suspected cluster represents a true excess of cancer cases.

Please follow this link to read more about cancer cluster investigations.

http://www.bccancer.bc.ca/PPI/cancerclusters.htm