Triple negative breast cancer represents about 10 to 15% of breast cancers and particularly affects women under 40 years of age. Causes, chances of recovery, survival… Know everything.
15% of patients have so-called “triple negative” breast cancer, the most difficult to treat. Triple-negative breast cancer means he has no no known markers on the surface of cancer cells, likely to respond to known targeted therapy, says theInstitut Curie. What are the causes occurrence of triple negative breast cancer? How do you put the diagnostic ? How to treat it? What life expectancy?
What is the definition of triple negative breast cancer?
THE triple negative breast cancer are made up of cells that have no hormone receptors for estrogen and progesterone. They are characterized by an absence of overexpression of the growth factor HER-2. This subtype of breast cancer is associated with a more unfavorable clinical profilewith a high risk of early metastasis due to the aggressive nature of these tumours, their partial response to chemotherapy and the absence of a therapeutic target, making it possible to propose a specific treatment.
What is the life expectancy?
The 5-year survival rate for triple-negative breast cancer would be 62%.
What causes triple negative breast cancer?
“The onset of cancer is often multifactorial, emphasizes Dr. Elise Deluche, oncologist specializing in breast cancer at Gustave Roussy. The main risk factor identified in triple negative breast cancer is the BRCA1 mutation. 80% of women with a BRCA1 mutation are at risk of developing triple-negative breast cancer but among patients with triple negative breast cancer only 10% carry a BRCA mutation“. However, other risk factors should also be taken into account, they do not specifically define the risk of having triple negative cancer but contribute to the risk of cancer in general:
- Risky lesions called pre-neoplastic lesions such as atypical ductal hyperplasia…
- History of chest irradiation
- Genetic predispositions other than BRCA1 or BRCA2 mutations.
- Hormonal factors linked to hyper-oestrogenia: precocious puberty, lack of breastfeeding, etc.
- Personal risk factors: alcohol, tobacco, high BMI in post menopause…
Who are the women at risk?
Triple-negative breast cancer is diagnosed most often in young, premenopausal women (under 40) and women of Asian or African descent. In some cases, it isa hereditary form of breast cancer, with a genetic mutation (BRCA1 or BRCA2 gene). Many triple-negative breast cancers are diagnosed between two regularly scheduled screening mammograms. “interval cancer”which requires the utmost vigilance.
What are the consequences of triple negative breast cancer?
triple negative breast cancer has a higher risk of metastasis (dissemination of cancerous cells to other organs) and a worse prognosis than the other subtypes of breast cancer. Compared to other breast tumours, metastases more frequently concern the liver and the lungs due to their more hematological than lymphatic distribution (via the blood circulation more than via the lymphatic system).
What tests to diagnose triple negative breast cancer?
As with any breast cancer, screening must be done on the basis of several examinations: physical exam, and screening mammogram. Personal and family history will also be sought. These first examinations can be supplemented, in the event of an anomaly, by additional examinations: breast ultrasound, breast biopsy, blood test, MRI, etc… But it is by tumor biopsy that the diagnosis of triple negative breast cancer will be made. “The immunohistochemical analysis of the status of the hormone receptors of the cells makes it possible to diagnose triple negative breast cancer, continues the specialist”. This analysis is carried out by an anatomopathological laboratory on a piece of breast biopsywhether performed as part of additional examinations or after analysis of the tissues of the surgical specimen“, explains our interlocutor. The three elements sought in order to be able to make the diagnosis of triple negative breast cancer are:
- estrogen receptors,
- progesterone receptors,
- HER2 protein receptors. For the characterization of HER2, genomic analysis can complement immunohistochemical analysis.
In the absence of a response from these three elements (if they come back negative), we can then speak of triple negative breast cancer. Triple-negative breast cancer therefore does not over-express any of the hormone receptors (estrogen, progesterone) or the HER2 receptor. Cancer cells do not contain any known marker on their surface and are therefore not sensitive and influenced by known targeted treatments such as hormone therapy or anti-HER2 treatment (trastuzumab, etc.). Triple-negative breast cancer thus includes several kinds of cancerous tumors of different type and evolution. Most of these tumors are high-grade invasive ductal carcinomas.
What treatment to treat triple negative breast cancer?
Therapeutic management for triple negative breast cancer has similarities to the treatment of all breast cancers. “Treatment often includes breast surgerycontinues our interlocutor. The type of surgery will depend on the size of the tumor, its location, the type of tumor and its possible spread (conservative surgery or lumpectomy, non-conservative surgery or total mastectomy, sentinel lymph node (one to three lymph nodes removed), lymph node dissection (several lymph nodes removed, etc.)“. Chemotherapy is the second mainstay of treatment for triple-negative breast cancerand the chemo-therapeutic combinations are close to those proposed in the different types of hormone-dependent breast cancer. Radiation therapy may also be offered following surgery. Due to the lack of response to hormone receptors and the HER2 receptor, treatment with hormone therapy and anti-HER2 (trastuzumab) would be unnecessary and is therefore not considered in this type of cancer. There is currently no place for routine immunotherapy in the management of triple negative cancer outside of a therapeutic trial.
The risk of recurrence is higher with triple negative breast cancer. Close monitoring is essential during the first 5 years post-diagnosis. “The peak of recurrence would be in the first 3 yearsand would decrease rapidly whereas for other types of breast cancer, the risk of recurrence is lower, but more persistent over the years, concludes Dr. Deluche. A follow-up is generally set up with an alternation of consultations between the surgeon, the oncologist, and the radiation therapist. The gynecologist also has its place in the follow-up because the care must be global. Additional examinations are also carried out regularly (annual mammography, etc.) to ensure that there is no abnormality or recurrence.
Thanks to Dr. Elise Deluche, oncologist specializing in breast cancer at Gustave Roussy.