deCODE BreastCancer™
The first test measuring genetic risk of the common forms of breast cancer. Complements standard risk modeling tools. More complete assessment of risk and more personalized and effective screening, prevention and treatment.
Better screening & prevention
How can deCODE BreastCancer™ help?
Comprehensive risk assessment
deCODE BreastCancer™ detects genetic risk that is independent of and complementary to the risk factors used in standard clinical risk assessment tools. The results are presented as a numerical value of individual risk relative to the population average, by which the scores of traditional risk modeling tools can be multiplied.
Informing prophylactic therapy
Approximately 14% of women of European descent aged 55 and older who take the deCODE BreastCancer™ test will receive a score placing them at or above a 1.7% absolute risk of developing breast cancer within the following five years. This is the threshold used by the American Society of Clinical Oncology for consideration of the use of tamoxifen (or similar drugs) as preventive therapy. deCODE BreastCancer™ also provides information on whether a woman is more likely to develop estrogen-positive or estrogen-negative breast cancer.
Modification of BRCA-associated risk
The risk conferred by four of the SNPs detected by the deCODE BreastCancer™ test interacts in a multiplicative manner with that conferred by the highly penetrant mutations in the BRCA1 and BRCA2 genes. The results can thereby indicate increased lifetime risk in women positive for the BRCA1 or BRCA2 gene mutations.
The association to the risk of breast cancer has been validated in large case-control studies in multiple populations
The deCODE BreastCancer™ test measures 16 genetic markers that have been associated with risk of breast cancer in large case-control studies in multiple populations (1-28). The risk conferred by each marker has been separately derived, replicated, and validated. These studies have involved more than 30,000 patients and several times that number of control subjects, and have been published in peer-reviewed scientific journals. The risk conferred by each marker, is independent of that conferred by the other markers in the test. The results of the test are therefore derived by multiplying together the risk conferred by the at-risk allele of each SNP. The validity of multiplying together the risk conferred by the different markers is based upon the fact that neither deCODE nor other researchers have been able to observe any significant interaction or overlap in impact between the markers (2,4,14,44,45).
Multiple risk factor integration – including genetic risk – provides more complete risk assessment
Through our deCODEhealth interface we provide physicians with a risk calculator that integrates their patients’ test results with Gail model scores, providing a more complete overall risk assessment. Integrating the impact of both genetic, environmental, and behavioral risk factors is critical for providing a comprehensive risk assessment, as the common forms of breast cancer occur as a result of genetic as well as environmental, behavioral, and other risk factors such as age and family history. It is also important to note that the deCODE BreastCancer™ test provides the most accurate and comprehensive measurement of validated genetic risk factors available at the time; not all the genetic risk factors are yet known, and as we and others discover new risk factors we will integrate them into the test.
deCODE BreastCancer™ is not a BRCA test
deCODE BreastCancer™ does not measure the known, rare mutations in genes such as BRCA1, BRCA2, TP53, and PTEN that confer high risk of familial and/or early-onset breast cancer but which account for a very small proportion of breast cancer cases. However, the results of deCODE BreastCancer™ can modify the risk conferred by BRCA mutations. BRCA- modifying results from the deCODE BreastCancer™ test are reported separately, to enable doctors to directly calculate risk for women who are known BRCA1 or BRCA2 mutation carriers.
deCODE BreastCancer™ is not a determinative test
The diagnosis or confirmation of breast cancer cannot be made by this test. Diagnosis of breast cancer is based on breast examination, mammogram, MRI and biopsy. deCODE BreastCancer™ is a risk test, not a determinative Mendelian genetic test; therefore, high risk results would not mean that the patient will definitely develop breast cancer while a low risk result would not mean that the patient has no risk of developing breast cancer.
At present, the test results fully apply only to women of European descent, as the large-scale studies required to validate all of the markers in populations of other continental ancestries are not yet complete. deCODE and other leading research institutions around the world are actively engaged in advancing this work, and deCODE seeks collaborations and publishes its findings in order to accelerate this process.
The deCODE BreastCancer™ test is performed using the Illumina I-select BeadChip. This technology has greater than 99.9% accuracy and is based on a proprietary Illumina technology using DNA amplification, hybridization and fluorescent detection.
This content was last reviewed on April 07, 2011.