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The familiality of primary
brain tumors as studied in the Utah Population Database (UPDB)
D. S. Keith, D. T. Blumenthal, L. A. Cannon-Albright
Dept of Biomedical Engineering, University of Utah, Salt Lake
City, UT; University of Utah, Departments of Neurology, Neurosurgery &
Oncology, Salt Lake City, UT; University of Utah, Department of Medical
Informatics, Salt Lake City, UT
Background.
The UPDB is a unique database linking 2.5 million Utah
individuals with genealogical data to 80,000 Utah SEER cancer registry records
since 1973.
The familial nature of cancer has been well studied using this resource.
Here we use similar techniques to investigate 1550 individuals diagnosed with
brain tumors.
Methods.
We estimated the relative risk of brain cancer in relatives of
brain cancer cases using internal age- and sex-specific rates of brain cancer
estimated from UPDB.
We estimated the average relatedness of brain cancer cases (compared to the
average relatedness for 1000 matched control groups) using the Genealogical
Index of Familiality measure, which extends beyond first degree relatives and
looks at all pair wise relationships between cases.
We considered all 1550 brain cancers as a group, the subgroup of 364
astrocytomas and the subgroup of 571 glioblastomas.
Results.
The relative risk for brain cancer in 1st degree relatives of
all brain cancer cases is 2.78 (p=5.1xe-7).
The average relatedness of all brain cancers was significantly higher than
expected in controls (p=0.03).
The relative risk for brain cancer in 1st degree relatives of cases with
astrocytoma was 3.03.
The astrocytoma subgroup also showed significantly higher average relatedness
than controls (p=0.002).
The relative risk of all brain cancers in the first-degree relatives of
glioblastoma cases was 2.60 (p=2.0xe-3).
The glioblastoma subgroup of cases did not show significantly higher average
relatedness than expected in controls (p=0.68).
Conclusions.
The UPDB resource provides strong evidence for a familial
component in brain cancer that seems to extend beyond first-degree
relatives.
The subgroup of astrocytoma showed more evidence for underlying genetic
component than the glioblastoma subgroup.
Study of high-risk pedigrees could allow increased understanding of brain cancer
predisposition genes.
Copyright 2004 American Society of Clinical Oncology All rights
reserved worldwide.
Source: http://www.asco.org/ac/1,1003,_12-002636-00_18-0026-00_19-002418,00.asp
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