Groundbreaking survey of Belgians' willingness to be tested for breast cancer genes

Hereditary breast cancer and carrier status

5 to 10% of all breast cancers are caused by a breast cancer gene: these are alterations in certain genes. Currently, a dozen breast cancer genes have been identified. They increase the risk of breast cancer to varying degrees.  

Two breast cancer genes stand out: BRCA1 and BRCA2 increase the risk of breast cancer by 60 to 80%. According to international research, between 0.3% and 0.5% of the European population is a carrier of BRCA1 or BRCA2. In Belgium, it is estimated that 33,000 to 55,000 people are carriers of either gene (= 0.3% to 0.5% of 11 million inhabitants). At least half of them simply do not know this.

These genes not only increase the risk of breast cancer in women by 60 to 80%, but also ovarian cancer by 40% (BRCA1) or 20% (BRCA2), breast cancer in men by 1% (BRCA1) to 7% (BRCA2) and prostate cancer risk by 15% (BRCA2). They cause untold suffering, especially in women, often at a young age.

Genetic test

BRCA1 and BRCA2 can be detected with a genetic test based on a simple blood draw. Genetic tests are offered only to adults and on the basis of "informed consent." They can only be performed at one of the 8 approved genetic centers in our country.

These genetic breast cancer tests are available today only to persons with breast cancer who meet certain criteria, and, to first- and second-degree relatives of carriers of a breast cancer gene. Always on a voluntary basis.

Every genetic test should be preceded and, if desirable, also followed by professional counseling. In the event of an unfavorable result, the carrier is asked to inform his relatives, as they too have the right to a genetic test whenever they wish. However, this happens far too infrequently. Half of the carriers do not inform anyone or not all the relatives involved. This is not followed up.

When a person is a carrier but has not yet developed cancer, preventive measures can be taken to avoid the cancer. Women can opt for six-monthly follow-up (alternating mammography and MRI) or double mastectomy. If a carrier has a desire to have children, pre-implantation diagnostics can be used to select embryos that do not carry the gene.

When a cancer patient refuses to be tested, the relatives lose their right to be tested and remain willfully in the dark.

Pink Ribbon and IVOX research

A representative survey of 1,000 Belgians (1) on knowledge and willingness for a genetic screening test revealed the following:

• 65% are not well informed about the existence of hereditary breast cancer;

• 87% would like to know if they are carriers of high-risk breast cancer genes because preventive treatment can be provided;

• 13% don't want to know;

• even when the preventive treatment is explained (e.g., double mastectomy), 81% still want the genetic test, and only 19% do not;

• those who have had breast cancer themselves, or have a neighbor with breast cancer, are less likely to be tested: 24% would not;

• 92% of respondents want to be better informed about hereditary breast cancer genes;

• 88% think the government should offer these tests to anyone who wants them.

Policy question to government

Pink Ribbon asks that the government shine its light on our request to give every person with breast cancer and all relatives of that person the opportunity to be tested for the high-risk breast cancer genes BRCA1 and BRCA2. Now too many carriers of these genes remain in the dark about this.

(1) Ivox survey, July 2025, commissioned by Pink Ribbon among 1,000 respondents with a breast cancer diagnosis in their immediate vicinity