The Maryland Department of Health
and Mental Hygiene in collaboration with the Frederick County Health
Department is conducting a preliminary statistical analysis of the
cancer case data in the Maryland Cancer Registry.
Objective: Determine if the
rate of all cancers and/or certain types of cancer is higher than
expected and what the likelihood is that an increase in cancer rates
could be due to something other than chance alone in what is
approximately a 1-mile radius from Ft. Detrick.
The process established by the
Maryland Department of Health and Mental Hygiene to evaluate cancer
cluster concerns begins with the local health department evaluating
information about each cancer case thought to be part of a cluster.
The information needed
includes specific information from concerned individuals about the types
of cancers, the names and ages of persons diagnosed with those cancers,
the dates of diagnosis, and the time period that persons diagnosed with
cancer were in the geographic or occupational area of interest.
This step was bypassed in the
current investigation of concerns raised by residents living near Fort
Detrick as there was enough information provided informally to the
Frederick County Health Department by residents, and there is the
possibility that specific case information collected by an external
organization will be provided in the future.
Step 2- Preliminary Investigation
This step is currently underway.
See details below related to the investigation. Preliminary results were presented in October 2010, January 2011 and March 2011.
Preliminary results were
presented during the October 4 Community Cancer Concerns meeting. The
number of cases of cancer observed in the 3 census tracts examined (for
the time period 2000-2007, using the Maryland Cancer Registry source of
data, and for the cancers listed below) were not statistically higher
than what was expected based on Frederick County rates of cancer, but
the number of all cases of cancer observed in the 3 census tracts
examined was statistically greater than the number expected based upon
the Maryland rate for all cancers in the same time period using the same
source of data.
Results presented at the January 3, 2011 Community
Cancer Concerns meeting included an update on the additional analysis
conducted looking at the age of diagnosis of cancers in the 3 census
tracts of interest and further analysis is planned.
Results presented at the March 14, 2011 Community Cancer Concerns meeting included additional analysis using all complete
years in the Maryland Cancer Registry, 1992 to 2008. The analysis was
also expanded by space by adding data from additional census tracts
encompass a distance of approximately 2-miles from the fence line
bordering Fort Detrick Areas A and B.
Summary report of
the analysis of the Maryland Cancer Registry data for the years
1992-2008 presented at the October 3, 2012 Community Cancer Concerns
Step 3- Further Investigation
This step will be guided by the findings from the Step 2 preliminary investigation.
Sources of Data
By law, hospitals, laboratories,
cancer treatment centers, and doctors are required to report all new
cancer cases diagnosed in Maryland (excluding basal and squamous cell
skin cancer) to the Maryland Cancer Registry (MCR) of the Department of
Health and Mental Hygiene.
The MCR records the home
address at the time of diagnosis of cancer. The home address is then
associated with a census tract number since the year 2000. Before the
year 2000, only zip code level groupings of the data are possible. The
zip code areas are much larger than the census tract areas.
The initial analysis of data in the
MCR will evaluate cancer cases that occurred in the geographic area of
analysis based upon census tract level data available for the years
2000-2007. Subsequent analyses will cover the years 1992-1999 and
Geographic Area of Analysis
The initial geographic area defined
for the preliminary statistical analysis of cancer rates is roughly a
1 mile radius from Fort Detrick, Area A and Area B.
In some cases the initial
census tracts examined were more than a mile from the perimeter or fence
line of Fort Detrick Area A and B and in some cases little less than a
The initial 1 mile area was
selected following discussions with cancer data experts and Randy White
and his consultants. Based on feedback from the community
the geographic are of analysis was expanded by another 7 census
tracts extending out approximately 2 miles from the fence line.
Analyzing too large of an
area may “dilute” findings and too small of an area may not have enough
numbers to determine if differences are statistically significant.
Types of Cancer in Analysis
The types of cancer to be evaluated are based upon the off-site well contaminants documented.
Two chemicals detected on
off-site wells, tetrachloroethene (PCE) and trichloroethene (TCE), have
been associated with cancer of the brain, leukemia, lymphoma, and kidney
Due to concerns expressed about exposure to dioxin, liver cancer rates will also be evaluated.
based upon the number of thyroid cases reported at the August 12
Community Meeting, which were more numerous than what might be expected
relative to the other cancers reported at the meeting, thyroid cancer
was also added to the list of specific cancers being examined.
These specific cancers will be evaluated in Step 2 of the investigation.
rates in the smaller geographic area under investigation for the 4
most common cancers (lung, breast, colorectal, and prostate) and the
specific cancers of concern listed above will also be compared to
Frederick County rates and Maryland rates.
Department of Health and Mental Hygiene and the Frederick County Health
Department will perform the additional analysis described in the earlier
reports presented during meetings with the community and cited in the