Question: What is a cancer “cluster” and how many purported “cancer clusters" are reported to state health departments each year?
Answer: The cited article states “The term cancer cluster implies that more cases of cancer (usually of the same type) are identified within a certain group of people, geographic area and time period than are expected, based on the size and age of the population. Usually the term refers to a highly localized situation such as a school, neighborhood, or workplace, although it is sometimes used to refer to a broader geographic area or larger subgroup of the population.” “It is reported that more than 1,000 suspected cancer clusters are reported to state health departments each year.” (Thun MJ and Sinks T. Understanding cancer clusters. 2004 CA Cancer J Clin 54:273-280)