INTERVIEW. Dr. Suzette Delaloge is a medical oncologist and researcher specializing in breast cancer and cancer prevention. Trained in France and Canada, she headed the breast cancer group at Gustave Roussy from 2004 to 2021, before leading the personalized prevention program "Interception" until 2026.
Appointed president of the National Cancer Institute (INCa) in July 2026, she discusses in this interview several misconceptions and false information surrounding breast cancer, from wearing a bra to aluminum salts in deodorants, including fasting and sugar consumption.
Breast cancer is the most common and deadliest cancer among women in France, with 61,000 new cases diagnosed and more than 12,000 deaths each year.
AFP Are mammograms more dangerous than beneficial?
Dr. Suzette Delaloge Current data shows that if you have a mammogram every two years for about fifteen years (with organized screening from 50 to 74 years old - editor's note), there is a very small risk of breast cancer that would be linked to exposure to radiation, on the order of one woman in ten thousand.
But this risk is infinitely less than the benefits, since mammography will reduce the risk of dying from breast cancer by 20%.
Does wearing a bra increase the risk of developing breast cancer?
No. This idea was shared in the media quite a few years ago, but numerous studies have shown the opposite. Wearing a bra, regardless of the type, is not dangerous.
Do the aluminum salts in deodorants cause cancer?
We had biological data showing that there were aluminum deposits inside breast tumors. Many studies have therefore been conducted over the past fifteen years and have never shown a real increase in the risk of breast cancer with deodorants containing aluminum salts. Nevertheless, most manufacturers have removed alumina from deodorants as a precaution.
«"Fasting doesn't treat cancer, and neither does cutting out sugar."»
Should you fast and stop eating sugar when you have cancer?
Fasting doesn't cure cancer, and neither does cutting out sugar. We know that a diet high in fat and especially sugar is a potential risk factor for developing cancer. But once you have cancer, starving yourself won't help.
If a patient is fasting, extreme caution is necessary, and it absolutely must be medically supervised. The risk is malnutrition, which affects 301% of cancer patients. This is something we actively combat because a malnourished patient will experience more side effects from treatments and have a less effective immune system at fighting cancer cells.
Can chemotherapy kill patients?
Chemotherapy remains an essential treatment for certain cancers. When it is offered, it is because there is a truly significant benefit.
Unfortunately, all medications carry the risk of side effects. In particularly vulnerable individuals, some chemotherapies can have fatal side effects. This represents slightly less than 11% of people with very serious cancers. But this is extremely rare.
«"Fake news is everywhere, so we need to remain cautious."»
In what situations should a person with cancer be wary?
People with cancer are in a vulnerable position, and many people take advantage of this, particularly through commercial approaches. Fake news is everywhere, so it's important to be cautious. Even vitamins can be dangerous because they can interfere with the effectiveness of treatments.
We shouldn't be afraid to say that there are a number of supportive care options that are very helpful. If it's harmless, not dangerous, and there's no strong evidence against it, then it's not a problem. However, for some people, we know it's ineffective, that it will cost money, that it can have side effects, and even worsen the situation. It's really important not to forget to talk to healthcare professionals; that's what they're there for.
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