Cancer Investigations

• Cancer is very common. It is a leading cause of death in Michigan, second only to heart disease. In the United States, it is estimated that one in every three people will be diagnosed with cancer in their lifetime.
• Cancer is not a single disease. Cancer includes more than a hundred different diseases, each with their own causes and risk factors.
• Different cancers have different latency periods. A latency period is the time it takes after an exposure for cancer to develop and be diagnosed.
• Cancer rates may change over time or feel like they are increasing for the following reasons:
  • Aging population: People are living longer. Cancer rates are highest among older people.
  • Better screening practices: Improvements in technology and guidelines may result in more cases being identified.
  • Better treatment: Cancer treatment advancements improve outcomes with fewer people dying (for example, earlier mammograms).

Despite recent advancements, there is much that we do not know about cancer. While science has identified certain factors that may increase one’s risk of developing cancer, we do not yet know why one person might get cancer while another person does not (see MDHHS fact sheet – What factors increase your cancer risk?). There are preventative steps you can take to lower your personal cancer risk (see MDHHS – Cancer Prevention – What you can do). To learn more about cancer, visit the MDHHS Cancer Section homepage.  

A cancer cluster is an unusual number of cancer cases in a group within the same location during a window of time.

• An unusual number: There is a greater than expected number of cases.
• Of cancer cases of the same type or with the same cause: All cases involve the same type of cancer or different types of cancer that science has proven to have the same cause.
• Occur in a group: All cancer cases occur among a group of unrelated people with similar characteristics (for example, age, occupation or sex).
• Within the same location: The group lives in the same area or works in the same place.
• During a window of time: Cancer cases occur over a defined period of time (such as, 2015-2020).

Identifying a true cluster of cancer is rare. Most of the time, it is just a coincidence that cancer occurs in several people in a small area or group. Our program investigates unusual patterns of cancer in relation to environmental exposures (chemical or contaminant). It is possible that an unusual number of cancer cases may be seen in a location for reasons unrelated to an environmental exposure. 

There are several reasons why you might contact the Cancer Investigation Program, including:

• You are concerned that the number of people with a cancer diagnosis in your neighborhood, workplace, school or some other defined area is unusual.
• You are concerned about an exposure within your local environment that might be affecting the health of your friends, family or neighbors.
• You would like to learn more about how exposures in the environment may contribute to cancer risk.