Cancer Concerns

Although cancer is a serious and frightening diagnosis, it is a common disease. Current information shows that approximately one out of three Americans will develop cancer in their lifetime, and cancer will affect three out of four families. The risk of developing cancer increases with age, so as the population ages, more cases of cancer are expected in our communities.

The term cancer covers not one but many diseases that share the common feature of abnormal cell growth. It can occur in almost any part of the body. Each cancer type develops differently and has different risk factors. For example, the main risk factor for lung cancer is cigarette smoking, but for skin cancer it is sun exposure. The causes of some common cancers such as breast cancer are still unknown.

Many people believe that something in the environment causes most cancers, but behavior and lifestyle accounts for most of the known cancer risks. Factors such as smoking, poor diet, obesity, heavy alcohol use, sexual and reproductive history, and genetic factors can all contribute to developing cancer. It is estimated that less than 10% of cancers are caused by environmental exposures. In contrast, cigarette smoking alone causes about 30% of cancers. In addition, family history is important and contributes to some types of cancer.

Most cancers take a long time to develop. It is usually decades from the time someone is exposed to something that might cause cancer to the time that cancer is diagnosed. This is one of the reasons that cancer is more common in older adults. In addition, the few chemicals that are linked to cancer must have fairly long and/or concentrated exposures before they may cause cancer.

A cancer cluster is defined as a greater than expected number of cancer cases that occurs within a group of people in a defined geographic area over a specified period of time. When people learn that several friends, family members, or neighbors have found out they have cancer, cancer clusters are often suspected. Cancer clusters are also sometimes suspected when people who work at the same place or have other factors in common get cancer.

If a suspected cluster includes cancers of different types, it is probably not a “true” cancer cluster. For example, if someone reported that there were many people with cancer in their community, but the kinds of cancer included lung, breast, leukemia, and prostate which are cancers known to have different risk factors; this would not be considered a cancer cluster. A confirmed cancer cluster is a relatively rare occurrence and few documented clusters have been able to be linked to an environmental agent. 

To be a cancer cluster, a group of cancer cases must meet the following criteria. Until all of these parameters are met, the group of cancer cases is often referred to as a suspected cancer cluster.

A greater than expected number:
A greater than expected number is when the observed number of cases is higher than one would typically observe in a similar setting (in a group with similar population, age, race, or gender). This may involve comparison with rates for comparable groups of people over a much larger geographic area (e.g., an entire state).

Of cancer cases:
All of the cases must involve the same type of cancer or types of cancer scientifically proven to have the same cause.

That occurs within a group of people:
The population in which the cancers are occurring is carefully defined by factors such as race/ethnicity, age, and gender for purposes of calculating cancer rates.

In a geographic area:
Both the number of cancer cases included in the cluster and calculation of the expected number of cases can depend on how we define the geographic area where the cluster occurred. The boundaries must be defined carefully. It is possible to “create” or “obscure” a cluster by selection of a specific area.

Over a period of time:
The number of cases included in the cluster, and calculation of the expected number of cases, will depend on how we define the time period over which the cases occurred.

It is important to keep in mind that most investigations of suspected cancer clusters do not lead to the identification of an associated environmental contaminant. There are several steps taken, each with an increasing amount of resources needed, to investigate a possible cancer cluster. To learn more about the detailed plan (or protocol) the Florida Department of Health uses, see the 2013 Cancer Cluster Guidelines from the Centers for Disease Control (CDC) found at: https://www.cdc.gov/mmwr/preview/mmwrhtml/rr6208a1.htm?s_cid=rr6208a1_w

2) Assessment – The purpose of this step is to determine whether the suspected cancer cluster is statistically significantly higher than what would be expected. This step uses existing data and requires the determination of the study population, the cancer type(s), comparison population, and statistical methods to be used. 

3) Determining the Feasibility of Conducting an Epidemiologic Study – The purpose of this step is to gather additional information to assess the feasibility of conducting an epidemiologic study to determine whether the cases are associated with a common etiological risk factor (cause). If feasible, the outcome of this step should include a recommended study design.

4) Conduct an Epidemiologic Investigation – The purpose of this step is to determine if the exposure to a specific risk factor or environmental contaminant might be associated with the suspected cancer cluster.

At the end of each step, the information gathered is assessed and a determination is made about whether or not to move to the next step. Each step has criteria to help determine if the next step is warranted.

There is an inherent delay in collecting cancer incidence data. Each facility, laboratory, and practitioner is required to report to the Florida Cancer Data System (FCDS) within six months of each diagnosis and within six months of the date of each treatment. In addition, FCDS data are linked annually to mortality and hospital discharge databases respectively to find any missed cancer report. Consequently, a complete diagnosis year file is not available for surveillance activities and analysis until approximately two years after the close of the year (e.g., the 2015 cancer diagnosis file is available at the earliest January 1, 2018).

Where do I go for additional information? 

• Centers for Disease Control and Prevention (CDC) Cancer Clusters 
• Agency for Toxic Substances and Disease Registry
• National Cancer Institute (NCI) Cancer Clusters
• Cancer Cluster Investigations: When exposure to environmental contaminants is suspected

What is the FCDS (Florida Cancer Data System)?

The FCDS is Florida's statewide cancer surveillance system. The FCDS is legislatively mandated to collect incidence data on all cancers diagnosed in Florida per Section 385.202, Florida Statute (F.S.). The FCDS has been collecting the number of new cancers diagnosed each year (incidence) statewide since 1981. The FCDS is used to observe cancer trends and provide a research base for studies into the possible causes of cancer.

What kind of cancer cases must be reported to FCDS?

Florida statute requires all malignant cancers reportable with the following exceptions: In situ carcinoma of the cervix (CIS), intraepithelial neoplasia grade III of the cervix (CIN III) and intraepithelial neoplasia of the prostate (PIN III) are not reportable. Basal and squamous cell carcinoma of non-genital skin sites are not reportable regardless of extent of disease at the time of diagnosis or the date of first contact with the reporting facility. Reportable on or after diagnosis date of 01/01/2001 are Intraepithelial neoplasia Grade III of vulva (VIN III), vagina (VAIN III) and anus (AIN III) and Myelodysplastic Syndrome (MDS). All patients with an active, benign or borderline brain or central nervous system (CNS) tumor, diagnosed on or after 01/01/2004, whether being treated or not are reportable. All cancer cases diagnosed and/or treated in Florida since 1981 must be reported to the FCDS.

What kind of data is collected?

The FCDS requires that the data collected include diagnosis, stage of disease, medical history, patient demographics, laboratory data, tissue diagnosis, and methods of diagnosis or treatment for each cancer diagnosed or treated in Florida.

Who is required to report cancer cases to FCDS?

Per Section 385.202 F.S., all facilities licensed under Chapter 395 and each freestanding radiation therapy center under Section 408.07; All ambulatory surgical centers as specified by Rule 64D-3.034; Any licensed practitioner (Chapters 458, 459, 464, F.S.) in the state of Florida or any laboratory licensed under Chapter 483 that diagnoses or suspects the existence of a cancer are required to report cancer as a 'reportable disease or condition' per Chapter 381 F.S.