Breast cancer: preventive mastectomy greatly reduces mortality in women at risk

Breast cancer preventive mastectomy greatly reduces mortality in women at

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    In women carrying the BRCA1 or BRCA2 genes, who are more likely to develop breast cancer, the use of a preventive mastectomy would drastically reduce the risk of mortality, as confirmed by a new study.

    Faced with the very high risk of developing breast cancer, women carrying the BRCA1 or BRCA2 genes may be offered a preventive double mastectomy, also called risk-reducing mastectomy (RRM), i.e. an operation aiming to remove both breasts before the disease sets in. These two main genes BRCA 1 or BRCA 2 are responsible for almost 80% of breast cancers of genetic origin. Such surgery is not an obvious choice to make, but according to a latest study, it would be extremely effective.

    Indications for preventive mastectomy

    Many still remember the media storm caused by the announcement, in May 2013, of the double mastectomy that Angelina Jolie had chosen to undergo. The American actress who carries a BRCA1 gene mutation, which her mother, who died of breast cancer, also carried, then explained her personal choice in order to avoid an 87% risk of one day developing cancer. of the breast (with a 30% risk of mortality) and a 50% risk of developing ovarian cancer (the actress had also decided to have her ovaries removed). This announcement had a global impact on the therapeutic choice of women carrying these mutations.

    Breast removal does not completely eliminate the risk of cancer because it is virtually impossible to completely remove the mammary gland. However, among women at high genetic risk, as was the case for Angelina Jolie, several studies have shown a significant drop in the occurrence of cancers. And today, a new study makes it possible to quantify this reduction in risk.

    80% lower risk of breast cancer with the intervention

    The Lawrence Bloomberg faculty team followed more than 1,600 women carrying the BRCA1 or BRCA2 genes for six years, coming from nine different countries. Half of them had undergone a preventive mastectomy. At the end of the test, the researchers counted:

    • 20 breast cancers and 2 deaths in the group that opted for MRR;
    • 100 breast cancers and 7 deaths in the control group.

    Preventive mastectomy has reduced the risk of breast cancer by 80%. A reduction which was known, but which is confirmed today and which allows women to perhaps consider this option with a little more serenity.

    “The decision to undergo a risk-reduction mastectomy is often difficult for a woman to make. The more we are able to provide them with reliable data when they have to make this choice, the more informed they will be,” declared Kelly Metcalfe, head of this study.

    In France, 2 women out of 1,000 are affected

    However, MRR is not that common. In France, there are approximately 2 women in 1,000 who carry a mutation in the BRCA1 and BRCA2 genes, according to the National Cancer Institute. Detection is done by examinations, in the case where heredity or a history of cancer in the family may lead the person to consult.

    According to the Breast Institute, women at high risk of breast cancer are subject to close monitoring: consultation every 6 months, annual imaging monitoring (MRI, mammography, +/-ultrasound) with biopsy at the slightest doubt. But when the risk is very high, as is the case in women carrying a BRCA1 or BRCA2 genetic mutation, a mastectomy is sometimes requested by the patient. “It is in fact today the only effective method to prevent breast cancer.”

    A choice that remains that of each patient

    But for the moment, this intervention is proposed but not yet recommended. A course of action that could evolve in light of the latest figures? ““With more studies like ours, we will eventually know if these guidelines need to be changed.” concludes the first author.

    Especially since traditionally administered treatments can have a more lasting impact on women’s lives than an intervention: pain, fatigue, chronic motor function disorders, urinary problems, psychological consequences, etc. Enough to make MRR a real option?

    Although preventive mastectomy is not subject to any specific regulations in France, the National Cancer Institute has issued recommendations in October 2009. In any case, each woman is unique, and each case must be examined individually. It is up to doctors to assess the relevance of a preventive mastectomy. And it is then up to each woman concerned to decide knowingly what she wants.