Breast cancer is relatively common and affects approximately 12% of all women at some time in their life. About 5-10% of women with breast cancer have an inherited form of the disease. The underlying cause is a change (mutation) in the genetic material (DNA), in the sections of DNA known as genes.
BRCA1 and BRCA2
For a number of years it has been possible to carry out DNA testing for mutations in the high-risk genes. These high-risk genes, with names derived from the English words BReast CAncer, are called BRCA1 and BRCA2. These mutations also confer an increased risk for ovarian cancer.
In Western Europe, one particular variant in the CHEK2 gene (the CHEK2*1100delC risk variant) is common. In the Netherlands, 1 person in 100 (1%) carries this CHEK2 risk variant and this mutation appears to occur more frequently in families with multiple cases of breast cancer (5%). Being a carrier of this variant confers only a slightly increased risk of breast cancer in women who do not have breast cancer in the family, whereas women in breast cancer families face a greatly increased risk of breast cancer. This is probably due to having this variant in combination with other unknown risk genes, and to environmental risk factors (lifestyle, etc.).
Women with a mutation in BRCA1 or BRCA2 are advised to undergo annual breast examination by a specialist and a yearly MRI from the age of 25, and an annual MRI and mammography conducted by an outpatient clinic for hereditary tumors (PET) from age 30. Between the ages of 60 to 75 years you can participate in the population screening program.
From age 35-40 years preventive removal of the ovaries and fallopian tubes should be seriously considered by women who are known carriers of a BRCA mutation shown by DNA research.
The clinical geneticist or genetic counsellor will discuss this and other advice with you and arrange for a referral to the outpatient clinic hereditary tumours (PET).
The LUMC has assembled a multidisciplinary team for this condition consisting of clinical geneticists (including Prof. Dr. C.J. van Asperen), gynaecologists (including Dr. K.N. Gaarenstroom), (plastic) surgeons (including Dr. B.G. Molenkamp, Prof. Dr. R.A.E.M. Tollenaar) and pathologists (Prof.dr. V.T.H.B.M. Smit).
Psychological support during the process of genetic testing is also available (Prof. A. Tibben, mw. drs. L. van der Meer and Mw. dr. J. Gopie).
There is abundant information available via the websites http://www.brca.nl/ and http://www.borstkanker.nl/. In addition to this site, useful and reliable information can be found at http://www.erfelijkheid.nl/. This website is also very useful for medical professionals.
In the LUMC we are investigating families which carry DNA variants in the BRCA1 and BRCA2 genes whose clinical significance remains unclear; in other words, it is not yet certain whether these DNA variants actually cause the disease. In addition, we will retrospectively analyze families with breast cancer in which no BRCA1 or BRCA2 mutation was previously found to determine whether these families carry mutations in other genes. If necessary, a family member will be informed of any relevant finding.
Finally, we will consider the psychological consequences of a BRCA1 or BRCA2 mutation in women in relation to the decision to opt for preventive (breast/ovarian) surgery, and what the long-term level of satisfaction is with this operation. To learn more about our research, please visit the website https://www.hebon.nl/ or the research page of the Department of Clinical Genetics website at the LUMC.