About 5% to 10% of all cancers are due to inherited (genetic) damage to genetic material (DNA) which is inherited from the parents. These lesions are called inherited mutations. Hereditary Breast Cancer and Hereditary ovarian cancer are due, to the higher rate, to lesions in genes BRCA1 (~ 50%) or gene BRCA2 (~ 35%).
Male carriers of mutations in BRCA2 have an 8% risk of developing breast cancer and 20% risk of prostate cancer by the age of 80. A smaller percentage of cases is due to alterations of genes RAD51C (1.5-4%), PALB2 (~ 3.4% ) and CHECK2 (~ 2.2%). The probability of mutation transfer from parent to each child is 50%. For the Greek population it has been recorded and published a range of pathogenic mutations in the genes BRCA1 and BRCA2.
Indications for genetic testing
People who are carriers of pathogenic mutations have, as mentioned, increased risk of cancer occurrence at a young age. Those who have at least one of the following, should get tested for hereditary cancer:
- A & B degree relatives (mother, sister, grandmother, aunt, first cousin, etc.) who were diagnosed with breast cancer at an age earlier than 45 years.
- A & B degree relatives, who have become ill from ovarian cancer at any age.
- Two or more relatives in the family diagnosed with breast cancer or ovarian cancer.
- The same type of cancer has been diagnosed in different members of the same family.
- More than one cancer types (e.g., breast cancer and thyroid cancer, or endometrial cancer, or stomach cancer, or leukemia) have been diagnosed in the same individual.
- A rare type of cancer has been found in one or more members of the same family.
- Breast cancer emergence in man.
- History of bilateral breast malignancy.
- Patients who have experienced triple negative breast cancer (ER = 0, progesterone receptors = 0, HER2 / new = 0).
The results of genetic testing may help carriers of genetic mutations through various methods to prevent or at least to diagnose the disease at an early stage.
Equally important is for relatives of these individuals to know if they are carriers of genetic manipulation too, and take precaution measures or not.