Human genetics > Hereditary tumourous diseases counselling
Familial breast and ovarian cancer
Since the actress Angelina Jolie announced that she carries a BRCA1 mutation and has therefore decided to have a prophylactic mastectomy (breast tissue removal operation), the issue of familial breast and ovarian cancer has been brought to the attention of the general public. However, a familial (genetic) tumor predisposition is present only in a small percentage of breast cancer cases (5-10%).
A hereditary cancer predisposition is considered when several family members are affected by breast and/or ovarian cancer, the disease occurs at a particularly young age, or if women develop both of the diseases. Likewise, an additional occurrence of male breast cancer in the family can also be an indication of a predisposition.
On the basis of the medical history and the present medical findings reported during the consultation, we will check whether the test criteria are fulfilled and thus a genetic test can be offered. If in your family, e.g.
at least one woman had breast cancer before she was 36 years old
at least two women had breast cancer, with one woman before the age of 50
at least three women had breast cancer regardless of the age of onset of the disease,
at least one woman had breast cancer and one woman had ovarian cancer, or
at least one male and one female had breast cancer regardless of the age of onset of the disease
a consultation at our cancer risk clinic would be useful for you.
We can also provide you with a risk assessment for the existence of a hereditary predisposition to breast and ovarian cancer in the family using proven risk assessment programmes. This can also lead to a risk assessment for healthy women, which can be used to guide the frequency of early detection measures.
If the test criteria are fulfilled or if a characteristic tumour pathology is present, molecular genetic testing of the two tumour suppressor genes BRCA1 and BRCA2 can generally be offered to the person concerned (using a blood sample). Mutations in these two risk genes account for approximately 25% of familial breast carcinomas and are by far the most frequent causes of hereditary breast and ovarian cancer. In addition, there are other genes that are associated with a significantly increased risk of breast cancer. These are partly associated with other tumour syndromes and it is important that these are taken into account by the family history, the pathology of the tumour and possibly the physical examination. Within the framework of the German Consortium for Familial Breast and Ovarian Cancer, currently a total of nine other risk genes associated with breast and/or ovarian cancer can be tested.
If a genetic change is detected, further, healthy family members can be tested predictively in order to be able to better assess their individual risk of disease. In the case of patients with a family cancer predisposition, an intensified early detection programme is available depending on the mutation found.
You can find useful information on various aspects of genetic testing for familial breast cancer and the clinical consequences, as well as the importance for the family in the online information leaflet MammaMia, which can be found in the links.
Evidence of a mutation in one of the risk genes will enable customised therapy of the patients in the future. Thus, in the case of recurrent ovarian carcinoma, maintenance therapy with a PARP inhibitor is only permitted if a BRCA1 or BRCA2 mutation is present in the patient.
Familial colon cancer
Colon cancer is one of the most common cancers in Western Europe, and about 6% of the German population is affected by it during their lifetime. Colon cancer often occurs sporadically in older age (> 60 years), and there are usually only individual cases within a family. However, in about 25% of colon cancer cases, there is a positive family history, that is, more than one family member has been affected by colon cancer. According to current knowledge, at least 5% of all colon cancers are hereditary.
The two most common hereditary colon cancer diseases are the familial disease adenomatous polyposis (FAP) and HNPCC (hereditary nonpolyposis colorectal cancer disease), also known as Lynch syndrome. HNPCC is associated with a high risk for intestinal and endometrial carcinomas (uterine mucosal cancer). Furthermore, it carries a risk of certain other cancers, e.g. cancer of the stomach, ovaries or urinary tract. The early onset of hundreds to thousands of adenomatous polyps throughout the colon is characteristic of FAP. Generally, this polyposis begins in the second decade of life. An individual polyp shows a low degeneration frequency, but due to the large number of polyps, colorectal carcinomas occur in nearly all cases.
Various genes are responsible for hereditary colon cancer. If the family history as well as the pathological findings indicate a hereditary predisposition, we can order a diagnostic genetic test - usually in the person concerned - using a blood test. If a mutation (gene defect) is detected, further family members can be tested predictively in order to be able to better assess their individual risk of disease.
When should a hereditary form of colon cancer be considered?
We consider a hereditary form of colon cancer if
those concerned develop the disease at a young age (< 50 years old),
the disease occurs in several family members and
an accumulation of specific types of cancer occur within a family.
In such cases, detailed genetic counselling should be given. Within the framework of the genetic counselling, a detailed pedigree is created and the criteria for the diagnosis of the individual forms of familial colon cancer are discussed. An important prerequisite for genetic counselling is accurate information on cancer in the family, in particular the pathological examination results. This allows a better assessment of the individual risk of disease and the resulting recommendations for early detection measures, and makes it possible to carry out further useful investigations. In doing so, we work closely with specialists from other medical disciplines.
In addition to familial breast and ovarian cancer and familial colon cancer, there are other, rarer hereditary syndromes, which are associated with an increased risk of developing a tumourous disease. Examples include Gorlin syndrome (increased risk for basal cell carcinomas) or von Hippel-Lindau syndrome (increased risk for renal cell carcinomas). The occurrence of different tumourous diseases (in a person or even within a family) can indicate the presence of a genetic cause, especially in the case of a young age of onset of the disease, such as, for example, in Cowden syndrome (PTEN gene) or Li-Fraumeni syndrome (TP53 gene). Multiorgan diseases such as neurofibromatosis or tuberous sclerosis, which often have neurological symptoms, are also broadly related to the spectrum of genetic cancers. We also offer genetic counselling for these other syndromes. In collaboration with the Center for Rare Diseases in Tübingen, we work closely with experts from the other medical disciplines, such as dermatology, neurology and child and adolescent medicine.