Genetic studies in breast cancer

Hereditary breast cancer

Genetic studies

Between 5% and 10% of breast cancers are inherited and are part of what are known as hereditary cancer syndromes. Specific mutations in certain genes, such as BRCA1 and BRCA2 as well as other less prevalent genes, increase the risk of breast cancer and other associated cancers such as cancer of the ovary, pancreas, or prostate in men, in those who are carriers.

The identification of the BRCA1 and BRCA2 mutations has enabled great strides to be made in the prevention and early detection of breast cancer.

Who should undergo these genetic tests?

Women (and men) with a past history of breast cancer or with close relatives who have had breast, ovarian, or prostate cancer, or other types of cancer.
Those who have had breast cancer at an early age (under the age of 50).
Patients with breast and ovarian cancer.
Women with a male relative with breast cancer.
People of Jewish descent from Eastern Europe.
All women with a past history of ovarian cancer, regardless of their family history.

What is the test and what implications does it have?

Genetic testing is not just a blood test, it is a diagnostic process that reveals important information, often involving the patient and their family, and requires genetic counselling.

The doctor specialising in genetic counselling will review the entire family history, looking for a history of cancer and other risk factors to be able to request the test with the patient’s agreement. If the tests are indicated for the patient and the patient wishes to undergo the study, the genetic test will be performed on a blood sample which will be processed with the results reported within only a few weeks.

If the test is positive, it is vital to interpret the results for the person tested through subsequent genetic counselling, to analyse all available options. It should be noted that a positive result implies that there is a gene mutation predisposing the family to cancer and it may be necessary to extend the study to other members of the family.

Is being a carrier of the mutation synonymous with cancer?

Being a carrier of an oncogenic germline mutation does not mean cancer will be inherited but, it does imply a greater susceptibility to developing it, in other words, being at greater risk of suffering from it when compared to the population who do not carry the mutation.

If the test is positive, it is vital to interpret the results for the person tested through subsequent genetic counselling, to analyse all available options. It should be noted that a positive result implies that there is a gene mutation predisposing the family to cancer and it may be necessary to extend the study to other members of the family.

How likely is a child to inherit the family mutation?

Specific genetic alterations (mutations) in certain genes are found in all cells, transmitted through germ cells (eggs and sperm), giving subsequent generations a greater chance of developing certain types of cancer.

Their transmission, in most cases, follows a pattern of inheritance called autosomal dominant. This means that the altered allele is the dominant one, and only one copy is required for the disease to express itself. This makes the chances of inheriting one of these mutations as high as 50%.

Benefit of genetic studies

Deciding whether to undergo genetic testing is a personal choice, but it does allow measures to be taken for prevention and early diagnosis, both for the patient and their family.

Consultants

Dr. Trigo, José Manuel
Director of Oncology, Research and Innovation

Dr. Jiménez Rodríguez, Begoña
Specialist in Medical Oncology
Clinical Dedication in Breast and Gynecological Cancer

Dr. Sedano Ferreras, Paula
Radiotherapy Oncology Specialist

Dr. García Baltar, José Antonio
Especialista en Radiofísica Hospitalaria

Dr. Rebollo García, Natividad
HC Marbella Radiology Specialist

Dr. Escobar, Ángela
Ginecología y Obstetricia, especialista en la Unidad de Mama

Dr. Bellinvia, Anna Alessandra
HC Marbella Radiology Specialist

Dr. Gerchunoff, José Ignacio
Finecología y obstetricia, especialista en la Unidad de Mama

Dr. Arrazola, Tomás
Especialista en Farmacia Hospitalaria
Especializado en terapia contra el cáncer, certificado por la Sociedad Americana de Farmacéuticos de Hospital