Family health history information is a useful and accurate tool for assessing an individual's risk of developing various diseases. Family health history charts -- known as pedigrees -- are also an important tool that is often used in genetic evaluation. While specific personal genetic screening tests may be useful in some situations, research on family history data shows that family health history information may be a more useful initial disease risk assessment tool.
A group of researchers led by Charis Eng, MD, PhD, Chair and Founding Director of the Genomic Medicine Institute (GMI) of the Cleveland Clinic, and Founding Director and Attending Clinical Cancer Geneticist of GMI's Center for Personalized Genetic Healthcare, investigated the concordance and relevance between family health history-based risk assessment (FHRA) and SNP-based risk assessment through a DTC personal genomic screening (PGS) test. The DTC genetic tests for this study were conducted by Navigenics to assess each participant's personal risk of developing three common types of cancer. Dr. Eng and her colleagues then compared FHRA with Navigenics PGS for breast cancer (22 females), prostate cancer (22 males), and colorectal cancer (44 individuals).
The researchers found that although both FHRA and PGS placed an average of 40% in the same risk categories, there was little concordance between the two for breast, prostate, or colon cancer risks. For instance, the use of FRHA methods classified eight individuals as being at high risk for breast cancer, but only one of the eight was classified as high-risk when assessed via PGS. Overall, FHRA assigned 22 individuals to the hereditary risk category (i.e., due to a high risk mutation in a cancer-predisposing gene), but PGS identified only one of these individuals as high-risk. The researchers also assessed nine individuals with hereditary risk for colorectal cancer, five of whom had proven mutations defining inherited colorectal cancer syndromes. None of the nine were classified as high-risk when assessed through PGS risk analysis.
"Our research findings indicate that family health history assessment is currently a better predictor of cancer risk when compared with personal genomic testing methods," said Dr. Eng. "However, the personal genomic screening tests could potentially become more effective and accurate if combined with family health history information and used as a complementary tool for cancer risk assessment."
"Evaluation of family health history still remains to be the gold standard in personal disease risk assessment," said Eng. "Until further research is conducted to prove that personal genomic screening can accurately predict a person's risk, it is imperative that health care practitioners rely on family history as the primary tool that they use to clinically evaluate each patient's personal risk of developing cancer."
Furthermore, Eng points out that, "A personal family health history report can be completed at little to no cost, and this type of information is typically readily accessible and easily gathered by the patient." She concluded by stating her belief that, "In effect, family health history could potentially be considered as a 'secret weapon' in the integration of personalized medicine and genetic knowledge into clinical practice."
This research was presented at the American Society of Human Genetics 60th Annual Meeting, which was held November 2-6, 2010, in Washington, D.C.
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