Heredity and cancer: the brochure CRA reminds when to consult

The brochure of the Association for Research on Cancer (ARC) is devoted to the link between genetics and cancer, and emphasizes family situations that motivate a cancer genetics consultation.

Some people may be from birth mutations predisposing to cancer. This is known as a genetic predisposition, transmitted by heredity, said the CRA in the brochure.

For example, there are two genes, BRCA1 and BRCA2, associated with an increased risk of developing breast cancer. A person with a mutation in one of these two genes may be seen from 10% (the level of risk of the general population) to 50% to 80%.

In case of suspicion of risk for a given cancer, a person may be directed by an oncologist or his attending physician, to a cancer genetics consultation. The oncogénéticien, specialist in both cancer and genetics, is responsible in the first instance to assess the patient's risk restoring family history of the disease.

It is able to offer, if any, monitoring or even appropriate care. When the risk is particularly high, genetic tests can be used to search for genetic mutations.

"Making a genetic test is not a trivial process," insists the CRA. The booklet therefore recalls that "some situations particularly motivate the use of a specialized genetic counseling"

- When three cancer cases are found in the same location related in the same parental branch people;

- When two cancer cases are found in first-degree relatives of people, as soon as one of them occurred at an early age (before age 50) or when one of them was a cancer Breast Hit both breasts at once or having taken a multifocal form;

- When a single case of cancer occurred before age 35, even in the absence of family history;

- When several cases of cancer have occurred in the same person of the family;

- When associated with cancer predisposing disease (familial adenomatous polyposis, ataxia telangiectasia ...) are in the family.

Thus, 5% to 10% of breast and / or ovarian cancer are linked to a genetic predisposition, as about 3% of cancers of the colon and rectum, and 10% of prostate cancers arise in the context family.

Sometimes the transmission for diseases at risk of cancer development. This is the case of family polyposis coli, which can progress to colorectal cancer if polyps are not removed surgically. Similarly, ataxia telangiectasia, hereditary disease causing problems with balance and coordination of movement is associated with an increased risk of leukemia and brain cancer risk.