Guidelines Summary

Stephanie L. Foster, M.P.H.1,2, Amy M. Lavery, Ph.D.1, Suzanne K. Condon, M.S.M.3, Alisha A. Etheredge, M.P.H.1, Brian S. Kennedy, M.P.P.1, Erik R. Svendsen, Ph.D. 1, Patrick Breysse, Ph.D.3
 1Division of Environmental Health Science and Practice, National Center for Environmental Health, Centers for Disease Control and Prevention
2Office of Innovations and Analytics, Agency for Toxic Substances and Disease Registry
3Office of the Director, National Center for Environmental Health, Centers for Disease Control and Prevention


The Centers for Disease Control and Prevention (CDC) National Center for Environmental Health (NCEH) and the Agency for Toxic Substances and Disease Registry (ATSDR) provide scientific guidance to state, tribal, local, and territorial (STLT) health departments related to environmental health concerns. The guidelines presented here update the 2013 publication, “Investigating Suspected Cancer Clusters and Responding to Community Concerns: Guidelines from the CDC and the Council of State and Territorial Epidemiologists (CSTE)” (1). In general, STLT health departments play the primary role in examining unusual patterns of cancer in communities, including those associated with local environmental concerns. These guidelines expand the approach for these investigations. Occupation-related clusters are not included in these guidelines.

Notable enhancements to the previous guidelines (referred to hereafter as the 2013 Guidelines) include the following:

  • Expanding the name of the guidance document to include examining patterns of cancer and environmental concerns
  • Revising the definition of a cancer cluster and introducing the concept of “unusual patterns of cancer” to describe situations that may warrant further assessment
  • Including specific and standardized approaches to better engage community advocates
  • Providing a standardized template to better document the nature and extent of cancer and environmental concerns
  • Updating approaches to identify and investigate unusual patterns of cancer, including the suggestion for proactive evaluation and routine monitoring
  • Suggesting what information to share with CDC/ATSDR
  • Enhanced appendices describing statistical and geospatial methods supporting the evaluation of unusual patterns of cancer

While the revised guidance includes new methods to better engage with community members and advocates, statistical and other scientific challenges may make it difficult to directly associate factors that may play a role in the cause(s) of unusual patterns of cancer. Although limitations and challenges remain, the revised guidelines propose an approach to identifying and investigating unusual patterns of cancer as part of routine surveillance activities as well as new criteria and decision trees for responding to cancer and environmental concerns.