When diagnosing non-metastatic infiltrating breast cancer, different risk factors and criteria are taken into account when deciding on the type of surgery that will be performed, as well as additional treatments tailored to each patient’s situation.
Non-metastatic infiltrating breast cancer: definition
Breast cancer is said to be “infiltrating” if cancer cells are present in the tissues surrounding the lobules or ducts of the breast where the tumor was formed. It is not metastatic in that no cancer cell has migrated to another body organ, since the initial site of the tumor.
Nonmetastatic infiltrative breast cancer treatments
A partial mastectomy (lumpectomy) consists of extracting the breast tumor and a small amount of surrounding tissue to retain most of the breast.This surgical procedure is called “conservative”: it is possible if the tumor is sufficiently small, with a margin of healthy tissue around. In the case of non-metastatic infiltrating breast cancer, partial mastectomy includes ganglion surgery: it consists of removing the first lymph node (s) from the armpit near the tumor. A lymph node dissection allows to examine the removed ganglia, to determine if they are affected by cancer cells. Partial mastectomy is frequently followed by radiation therapy.
Unlike partial mastectomy, mastectomy involves removing the entire mammary gland where the tumor has formed. It is practiced when the tumor is too large and does not help to keep the breast. This surgical procedure is said to be non-conservative insofar as the entire breast is removed.Like partial mastectomy, it includes removal of the sentinel lymph node or lymph node dissection, which can be supplemented with radiotherapy.
The goal of the complementary treatments is to prevent the risk of recurrence of breast cancer after surgery.
Risk factors requiring the implementation of a complementary treatment.
Following a mastectomy, several types of treatment are considered in the presence of factors increasing the risk of cancer recurrence. These risk factors include: the size of the tumor, its grade (aggressiveness) established after microscopic examination of tissues / ganglions removed / extracted and the possible involvement of lymph nodes by cancer cells. Two other factors are taken into account: the hormone-sensitive nature of the cancerous tumor (certain tumors are stimulated by the female hormones naturally produced by the body), and the overexpression – or not of the HER2 protein or not. In fact, the gene coding for the HER2 protein is amplified in 20 to 30% of patients with breast cancer.
In the case of conservative surgery (partial mastectomy), and in the presence of one or more risk factors for recurrence: radiotherapy of the affected mammary gland and radiotherapy of ganglionic areas may be performed. Depending on the age of the patient, additional radiation can be performed at the exact location of the removed tumor (tumor bed). In the case of non-conservative surgery, and in the presence of one or more risk factors for recurrence: radiotherapy of the chest wall and ganglionic areas is frequently proposed.
Chemotherapy, which may be associated with targeted therapy if the tumor is called HER2 positive, is performed following surgery. It precedes radiotherapy if it is necessary.
The following chemotherapy drugs are used alone or in combination, and administered intravenously:
- Docetaxel (taxane family)
- doxorubicin ( anthracyclinefamily)
- Epirubicin (anthracycline family)
- Fluorouracil (also called 5-FU)
- Paclitaxel (taxane family)
Hormone therapy is proposed if the tumor analyzed is called “hormone-sensitive”. This term is used to refer to cancer cells whose growth is stimulated by the natural production of estrogen or progesterone. A hormonal treatment then makes it possible to slow down or stop the development of these cancers.
In some particular cases (inflammatory cancer, tumor too large to be operated on), the surgical procedure may be preceded by a so-called neoadjuvant treatment (chemotherapy or hormone therapy).
A clinical examination every six months up to 5 years, then yearly, and a mammogram at 6 months and then annually, are set up to prevent the risk of recurrence. The monitoring rhythm is increased in cases of high metastatic risk.
In the case of non-metastatic infiltrating breast cancer, the 5-year survival rate is 82%.