To date, breast cancer in France remains the leading cause of cancer death in women. Detected at an early stage, it can be cured in nine out of ten cases. This year marks the 28e edition of “Pink October”, the campaign against breast cancer, which aims to encourage screening and inform women. When should a mammogram be done? What are the proven risk factors? Who are the women concerned? This annual meeting is an opportunity to take stock of the main questions that we ask ourselves.
What does breast cancer represent in France?
Breast cancer is most common in women. According to a study from the French network of cancer registries (Francim), around 58,000 new cases (less than 1% of which concern men) are detected each year in metropolitan France – ie a third of cancers affecting women. It is also the deadliest female cancer, with more than 12,000 deaths per year.
Is systematic screening necessary?
Every two years, women between 50 and 74 years old (the age group most at risk) are invited, by mail, to carry out a screening mammogram. This exam is 100% covered by Social Security, with no advance on costs.
Like any medical act, this method of screening has both benefits and limitations. Several disadvantages are highlighted, in particular:
- overdiagnosis and overtreatment: the diagnosis and treatment of cancerous lesions that may not necessarily have developed into cancer;
- X-ray exposure can, in some cases, increase the likelihood of radiation-induced cancer. This is one of the reasons why screening is recommended only every two years and from the age of 50;
- interval cancers: these are cancers that appear between two screenings. It is indeed possible to develop a tumor very quickly, in the months following an examination. However, these situations are rare.
For the head of the pathology department and of the diagnostic and theranostic medicine pole at the Institut Curie, Anne Vincent-Salomon, the benefit / risk balance is nevertheless largely in favor of screening. “These exams are unpleasant and stressful. But they make it possible to identify small and less advanced tumors. However, the earlier breast cancers are detected, the greater the chances of a cure ”, she explains. Detected at an early stage, this cancer can be cured in nine out of ten cases.
The specialist also recalls that cancers detected early allow – in general and except in cases where the tumor is said “Triple negative” Where “HER2 positive” – less heavy and less aggressive treatments, with fewer sequelae (less need for total mastectomy and / or chemotherapy).
Why is it important to have regular breast self-examination?
“A serious tumor can develop between two screening mammograms. It is therefore essential to monitor her breasts by self-tapping regularly. The two are complementary ”, insists Anne Vincent-Salomon. This self-examination is also strongly recommended for women under 50, who do not benefit from routine screening every two years. Do not hesitate to consult your doctor or gynecologist if you notice:
- a lump in a breast or armpit;
- redness or an orange-skinned appearance of a breast;
- nipple retraction or deviation;
- breast discharge.
In parallel and in addition, from the age of 25, it is recommended to perform a clinical examination of the breasts (palpation) once a year. This quick and painless examination can be performed by a general practitioner, a gynecologist or a midwife. “Whatever your age, you must remain vigilant and be followed by a doctor or a gynecologist”, summarizes Anne Vincent-Salomon.
Does breast cancer only affect women aged 50 and over?
The median age at diagnosis is 63 years. Nevertheless, each year, nearly 3,000 women under 40 are diagnosed with breast cancer, i.e. 5% of patients affected by this type of cancer, points out the Institut Curie. “Young women are therefore concerned, just like older women”, says the specialist, who adds that “Breast cancers that occur in women under 40 are generally more aggressive than in older women”.
What is the part of heredity in breast cancer?
Only 5% to 10% of breast cancers are hereditary, that is to say attributable to a certain number of hereditary genetic mutations, according to Medicare figures. Note that it is not because a woman in your family has had breast cancer that you necessarily have genetic predispositions. In addition, being a carrier of a mutation in one of these genes does not necessarily result in the development of cancer, but it increases the risk of developing one. “Consulting a specialist doctor makes it possible to assess the genetic risk and, if this risk is proven, to set up specific monitoring”, explains Anne Vincent-Salomon. That means :
- a clinical examination every six months from the age of 20;
- annual monitoring radiological examinations (breast MRI and / or mammography, depending on the case, sometimes supplemented by an ultrasound) from the age of 30.
What are the other proven risk factors?
Breast cancer is a multifactorial disease. This means that several factors influence the risk of its occurrence. In addition to age and genetic predispositions, certain lifestyle factors play a role, such as: being overweight or obese (especially after menopause), lack of physical activity or alcohol consumption.
Personal history is also important: after breast cancer, a woman is about four times more likely to develop a tumor on the other breast compared to women who have never had one. The risk is also increased after ovarian and / or endometrial cancer. Other non-modifiable risk factors: having had precocious puberty and / or late menopause.
Do hormonal treatments for menopause increase the risks?
Published data in the scientific journal The Lancet, in August 2019, confirmed that women who take hormone replacement therapy (HRT) for menopause have an increased risk of developing breast cancer. All types of HRT are associated with an increased risk of breast cancer, except topical treatments.
Five years of HRT from the age of 50 increases the risk of one more case for every fifty women treated with continuous estrogen-progestogen therapy. The increase is smaller with the combined treatment with intermittent progestins (an additional case for seventy women treated) and smaller with estrogen alone, but this treatment is reserved for women whose uterus has been removed.
The results of the study also suggest that the risk for ten years of treatment is twice as great as for five years.
Do hormonal contraceptives increase the risk?
A large Danish study (1.8 million women followed over almost eleven years on average), whose results were published in December 2017, shows a 20% increase in the risk of developing breast cancer in women taking hormonal contraception or ‘having done recently. The authors of this work estimate that additional breast cancer will be discovered among 7,690 women taking this type of contraception for a year. A harmful effect that must however be considered with regard to the protective effect of these drugs on the risk of ovarian, endometrial and colorectal cancer. It is also an effective method of contraception.
Note that the magnitude of the risk is linked to the duration of use. If the risk does not increase significantly when taking hormonal contraception for less than a year, it increases by 26% after more than ten years of taking. The increased risk persists for at least five years after stopping treatment. No risk was found in women who had previously used hormonal contraception for less than five years.