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Generally, cancer in children is rare and Hodgkins disease in children and
adults is also rare. However there appears to be an association between
childhood mixed cellularity and adult, nodular sclerosis subtypes.
Since these two subtypes are associated with a known viral agent, and
share other epidemiologic characteristics, it would be interesting to exam
the relationship of childhood disease and maternal infection with EBV.
Because this disease has a prolonged incubation period between infection
and presentation of clinical symptoms, it seem feasible that exposure for
children could occur in utero or during the birth process.
Hypotheses: There is no difference between EBV infection in
mothers of
children with Hodgkins disease, vs matched control of mothers of children
without Hodgkins disease.
Methodology: A case-control design will be used. Cases will
include
mothers of children with Hodgkins disease diagnoses between age 5-10.
Controls will be selected from women who gave birth at the same hospital
as the cases in a range of 3 months before - 3 months after the birth of a
case. Medical records of cases and control will be reviewed for hx of
EBV. Blood sample will be obtain from cases and controls to assess
presence of EBV. Presence of EBV infection in cases will then be compared
to evidence of EBV in the children diagnosed with mixed cellularity
Hodgkins Lymphoma. Viral markers will be used to compare the viral stain
present in EBV positive mothers and their EBV positive children with
Hodgkins diseases.
The article by Neilly et al. (1995) reported findings based on
1359 cases of HD in the United Kingdom. The cases were identified through
the Scotland and Newcastle Lymphoma Group (SNLG) registry and included
patients from 1979 to 1992. A distinct pattern emerged when the
researchers were analyzing all cases of HD. The data showed a significant
peak of cases presenting in the month of March. Further analyses separated
the four subclasses of HD. The analyses showed that the cases of Nodular
Sclerosis (NS) and the cases of Mixed Cell (MC) presented with the disease
in patterns related to seasonality (most cases presenting in March).
However, cases with Lymphocyte Depletion (LD) and cases with Lymphocyte
Predominant (LP) did not present in patterns related to time of year. It
is intriguing to note that the onset of the two classes where most HD
patients are grouped, Nodular Sclerosis (30-60% of HD cases) and Mixed
Cell (20-40% of HD cases), have strong associations with the month of
March. This area of research can have very important implications for our
knowledge of the etiology and risk factors of Hodgkin's disease.
This proposal will therefore attempt to replicate this study by
analyzing information from cancer registries in North America. There are
several excellent cancer registries such as the SEER (Surveillance,
Epidemiology and End Results) by the National Cancer Institute which has
collected information regarding cancer patients since 1973 and is
estimated to capture 14% of the population in United States. The database
will be analyzed following the same strategy as outlined in the report by
Neilly et al. (1995). The analysis will look at the subclasses of HD,
month of presenting, and demographics such as age, race and gender of
patient. To control for possible confounding due to climate differences,
information regarding geographic location will be added into the analyses
as well. Since Scotland and Newcastle (UK) are located between the 55th
and 60th parallel this would equal the geographic position of Northern
Canada. However, the climate in Scotland and Newcastle are milder due to
the Atlantic Ocean. A climate index, based on average temperature,
precipitation and humidity, will be used to differentiate the factors of
separate climates. It will be interesting to also investigate HD onset and
climate factors.
The potential findings of this study can have very consequential
relations to the understanding of HD especially risk factors that are
potentially associated with infectious agents.. Since the etiology and the
risk factors for HD are still unclear, a study like this can provide
simple but yet important epidemiologic data to guide future research into
new directions. This study can also easily be done by using information
already gathered in the cancer registries.
Reference
Neilly, I. J., Dawson, A. A., Bennett, B., & Douglas S. (1995). Evidence
for a seasonal variation in the presentation of Hodgkins disease.
Leukemia & Lymphoma. (18):325-328.