Abstract
Malignancies are the 2nd most common cause of death in the population, after cardiovascular diseases. Breast cancer is the most common malignancy found in women, its incidence in the Czech Republic is 6-7%.
In 70-75% of the cases, the carcinoma is of sporadic kind, in 5-10% of the women hereditary breast carcinoma is diagnosed, which developes as a result of one of hereditary carcinoma disposition factors. The heredity of these factors is autosomally dominant, meaning that a mutation of one (usually tumour-suppressing) gene is passed from one generation to the next.
This mutation is present in all somatic cells in the carrier. A mutation or elimination of the 2nd allele in the target issue is then sufficient to trigger the multistep process at the end of which the malignancy develops.
Hereditary malignancies differ from sporadic malignancies in their early age of onset. Bilateral tumours in paired organs, duplicities and the same types of tumours or specific types of tumours characteristic for the particular disposition occurring in the first- and second-degree relatives are typical as well.