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Responding to Cancer Cluster Inquiries
OHA Cancer Cluster Inquiry Procedure

A cancer cluster is the occurrence of a greater than expected number of cases of a specific cancer within a community. The community of interest may be defined by geographic area, population, time period, worksite, etc. Cancer clusters may be suspected when several family members, friends, neighbors or co-workers have been diagnosed with cancer.

The priority in responding to a cancer cluster inquiry is determining whether an environmental, occupational or community-level exposure is associated with the cancer cases included in the inquiry. Some factors may indicate that an environmental exposure is associated with the cancer cases. These factors include: cases of one type of cancer, cases of a rare type of cancer, or cases among age groups that do not usually experience a specific cancer. In most instances, even when the number of cancer cases is greater than expected, no common exposure can be identified. This may occur for several reasons, including: 1) most cancer clusters are random occurrences unrelated to environmental exposures; 2) there is no known relationship between the cancer of interest and any identified environmental or occupational exposures; 3) important details about environmental exposures are missing and cannot be obtained; or 4) the number of cases involved in a cluster is too small to draw any meaningful conclusions.

Every year, the Oregon Health Authority (OHA) receives and responds to inquiries about suspected cancer clusters. OHA procedures for responding to cancer cluster inquiries are outlined in Responding to Cancer Cluster Inquiries_2015-03-24.pdfResponding to Cancer Cluster Inquiries.

OHA Cancer Cluster Inquiry Response Forms

Response to Ca Cluster Inquiries - Assessment and Response Guidelines_2015-03-24.pdfAssessment and Response Guidelines

Response to Ca Cluster Inquiries - Informant Interview - Data Collection Form_2015-03-24.pdfInformant Interview - Data Collection Form

Response to Ca Cluster Inquiries - Cancer Case - Data Collection Form_2015-03-24.pdfCancer Case - Data Collection Form

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