Empowering prevention of BreastCancer*
Early diagnosis and primary prevention are crucial to breast cancer control. The deCODE BreastCancer™ test can be used as an aid to deciding on optimal strategies for screening and prevention of breast cancer.
The American Cancer Society (ACS) recommends that women over 40 years old should have an X-ray mammogram every year and should continue to do so for as long as they are in good health. In the UK, women in the age range of 50 to 70 years are invited for screening by mammography every 3 years. Women who are at higher-than-average risk of breast cancer may be considered for earlier start ages of mammographic screening and/or enhancement of screening programs by including magnetic resonance imaging (MRI) scans. According to the ACS, high-risk women with a 20% lifetime risk (or a relative risk of 1.65 based on the deCODE BreastCancer™ test) should have a yearly breast MRI added to the usual yearly mammography beginning at age 40. MRI can detect many more early tumors before they spread than can standard mammography, but it is only recommended for higher-risk women. The ACS also recommends that physicians consider breast MRI for patients who have a modestly high risk for breast cancer based on lifetime risks of 15 to 20% (relative risks of 1.25 to 1.65). The deCODE BreastCancer™ test can be used to help patients and physicians decide on what is the optimal screening strategy.
Women who are at high risk of breast cancer may benefit from preventative treatment with tamoxifen, a drug that modifies the effects of estrogen on breast tissue and reduces the risk of breast cancer. The use of tamoxifen has significant drawbacks, so it is not suitable for use by everyone. According to the American Society of Clinical Oncology (ASCO), higher risk women (defined as having a greater than 1.66% 5-year risk) should consider with their physicians whether to use
tamoxifen (or similar drugs that also block the effects of estrogen, which can drive small tumors into larger tumors) as a preventive measure. The average 55-year-old woman has a 1.2% risk of developing breast cancer over the next 5 years. If her deCODE BreastCancer™ result showed a genetic risk of 1.4, her total 5-year risk of 1.7 would make her a candidate for preventive therapy, whereas based on conventional risk factors, she would be considered to have an average risk. The breast cancer genetic risk assessment provided by the deCODE BreastCancer™ test can help patients and physicians to weigh up the risks and benefits of using tamoxifen to prevent breast cancer.
Some forms of hormone replacement therapy (HRT) used over long periods of time can increase the risk of breast cancer. The deCODE BreastCancer™ test can help patients and physicians weigh up the risks and benefits of using HRT for treating menopausal symptoms.
Patients who are identified as being at high risk of breast cancer may be considered for risk-reducing surgery, either bilateral mastectomy, oophorectomy, or both. Clearly, such drastic treatments are recommended only for patients found to be at extremely high risk. Taken individually, no genotype in the deCODE BreastCancer™ test confers sufficiently high risk for risk-reducing surgical interventions to be recommended. However, some of the SNP variants in the deCODE BreastCancer™ test have been shown to modify the risk of breast cancer in patients who are known carriers of high-penetrance mutations in the BRCA1 and/or BRCA2 genes. Therefore, the deCODE BreastCancer™ test can be used as an aid to clinical decision making in conjunction with a BRCA1 or BRCA2 genetic test. The test is also useful to use in parallel to BRCA1 and BRCA2 testing since it may reinforce that patients who are negative for BRCA1 and BRCA2 may still be at increased risk for later-onset breast cancer by the results of the test, by family history and/or clinical parameters, or both.