Stages of breast cancer

In clinical medicine, the stages of oncological diseases, including the stages of breast cancer, are clearly defined, since the development of the disease occurs in stages, and treatment methods must be adequate to the intensity and nature of the pathological process.

The answer to the question of how many stages of breast cancer oncologists distinguish is given by the international classification of malignant tumors TNM Classification of Malignant Tumors. According to it, breast cancer has five stages.

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Breast Cancer Staging Classification

TNM Classification of Malignant Tumors (latest 7th edition, 2009) concerns cancerous tumors of any localization, and thus it is a classification of breast cancer stages. It systematizes the main symptoms of cancer: T - Tumor (tumor), N - Nodus (nodes, i.e. lymph node damage) and M - Metastasis (metastases). Depending on the degree of their manifestation, it determines the stages of the disease.

The Tis (Tumor in situ) designation is used in the case of a compact tumor that does not affect other tissues located in the immediate vicinity. The T1-T4 designations refer to the size of the malignant neoplasm, as well as the level of damage to tissues and organs located near the tumor. These are stages 1, 2, 3, and 4 of breast cancer.

In addition, if the pathological process has not affected the regional lymph nodes, the designation N0 is used. The defeat of the lymph nodes - their size, total number and localization - is designated N1-N3. And the process of cancer metastasis has the following gradations: Mx (it is impossible to detect metastases), M0 (there are no distant metastases) and M1 (there are distant metastases).

Accordingly, stage 0 breast cancer is a very small tumor that has not yet had time to affect other tissues and lymph nodes.

If stage 1 breast cancer is diagnosed, it means that the tumor size does not exceed 2 cm in diameter, and its cells have already penetrated into the surrounding tissues, i.e. the process of tumor invasion is underway. However, the lymph nodes are not affected.

Stage 2 of breast cancer is characterized by an increase in neoplasia to 5 cm and the beginning of its spread to the cells of the hypodermis - the lower (fat) layer of the skin. This stage has variants - 2A and 2B. At 2A, there are no metastases, and at 2B, in the armpit area on the side of the tumor, single metastases are found that are not connected either to each other or to neighboring tissues.

Based on the clinical picture of oncopathology, 0, 1 and 2A are early stages of breast cancer. 2B, 3 are later, and 4 is considered the latest stage of this disease.

Stage 3 breast cancer also has two "substages" - 3A and 3B. In case of 3A, the transverse size of the tumor is more than 5 cm, there are several metastases (in the armpit area) and enlarged lymph nodes that are fused with each other or nearby tissues. The nipple may be retracted, there may be serous or bloody discharge from it.

At stage 3B, the tumor becomes even larger, and the intrathoracic lymph nodes and chest wall may be affected. Oncologists distinguish the so-called inflammatory form of breast cancer, which develops very quickly and often "disguises" itself as mastitis. The characteristic signs of such cancer are changes in the skin on the chest, its hyperemia and hyperthermia.

Stage 4 breast cancer is defined when the lesion covers the entire gland, as well as all lymph nodes (axillary, intrathoracic, subclavian and more distant). The skin and subcutaneous tissues of the breast ulcerate, and tumor metastases, spread by lymph flow, can be found in the lungs, adrenal glands, liver, bone tissue and even the brain.

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Breast cancer diagnostics

Breast cancer is diagnosed using the following methods:

• clinical blood test (including biochemical and tumor markers);
• mammography (x-ray of the breast);
• Ultrasound of the mammary gland, chest, abdominal cavity;
• ductography (x-ray of the chest with a contrast agent, performed in case of destruction of milk ducts, which are associated with serous or bloody discharge from the nipples);
• biopsy (puncture, fine-needle aspiration, stereotactic or surgical) of the mammary gland and lymph nodes;
• histological and immunohistochemical examination of biopsy;
• magnetic resonance imaging (MRI);

• chest x-ray;
• Ultrasound or computed tomography (CT) of the chest, abdominal cavity and pelvis;
• osteoscintigraphy (radioisotope examination of bones).

It is necessary to emphasize the special importance of immunohistochemical examination of tumor tissue samples for breast cancer diagnostics. This is the so-called FISH test, which provides the oncologist with information about the number of genes in tumor cells that participate in the synthesis of the HER2/neu receptor. It has been established that in oncological tumors of the mammary glands, there is a high probability of increased activity of the HER2 gene - the membrane protein-phosphotransferase of the epidermal growth factor receptor. It is the activation of the synthesis of this protein that leads to hyperexpression - an increase in the number of HER2 receptors on the outer membrane of tumor cells and their increased reproduction by division.

By determining the number of HER2/neu receptors in tumor cells, it is possible to predict the further development of neoplasia and use the necessary chemotherapeutic drugs to stop the division of pathological cells.

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Treatment of stages of breast cancer

Treatment of breast cancer stages depends on the results of the patient's examination and her health condition and should take into account all factors of the development of pathology. Today, the following treatment methods are used in breast oncology:

• chemotherapy;
• surgical removal of the tumor;
• radiation therapy (radiotherapy);
• hormonal therapy;
• targeted therapy;
• combination therapy.

Chemotherapy is carried out using cytotoxic (cytostatic) drugs that disrupt the division mechanism of pathological cells and thereby lead to the cessation of their proliferation. Such drugs include: platinum drugs (Cytoplastin, Cisplatin, Carboplatin, Triplatin, etc.); drugs of the taxon group (Paclitaxel, Taxan, Paclitax, Paxen, etc.); drugs of the vinca alkaloid group (Vincristine Vinorelbine, Vinblastine, Maverex); oxazaphosphorine derivatives (Endoxan, Mafosfamide, Trofosfamide, etc.); fluoropyrimidine carbamate derivatives (Capecitabine, Xeloda), etc.

In this case, chemotherapy for breast cancer can be used as the only treatment method, as well as to reduce the size of the tumor before its surgical removal and to stop the formation of metastases after surgery.

Surgical intervention - removal of the tumor and part of the surrounding tissue (lumpectomy) or removal of the entire breast (mastectomy) - is performed in most clinical cases of breast oncology, especially if early stages of breast cancer are diagnosed.

Radiation therapy for breast cancer, as with other tumors, is designed to cause mutation and death of cancer cells through exposure to radiation. Radiation therapy can complement chemotherapy and surgical removal of breast tumors.

According to experts, hormonal therapy of breast tumors is advisable to be carried out after their removal only in patients with hormone-dependent tumors, that is, if the cancer cells have receptors for estrogens and progesterone. In this case, drugs from the aromatase inhibitor group (cytochrome P450-dependent enzyme) are prescribed - Anastrozole, Letrozole or Exemestane.

Targeted therapy aimed at the tumor and its metastases is based on the ability of recombinant monoclonal antibodies of the IgG1 class (similar to those produced by human immune cells) to selectively bind to the HER2/neu molecular receptors on the outer shell of cancer cells and stop their growth. Among the most widely used drugs in this group, oncologists name Trastuzumab and Epratuzumab.

Combined treatment of stages of breast cancer involves individual selection and simultaneous or sequential use of all the methods listed above.

Treatment of stage 0 breast cancer

In the treatment of stage 0 breast cancer, the affected sector of the breast (sectoral resection) or lumpectomy (see above) is used. These operations may be accompanied by lymph node dissection - removal of nearby lymph nodes.

In addition, a course of radiation therapy is prescribed, and in the case of increased tumor expression of HER2, targeted therapy using recombinant monoclonal antibodies.

Treatment of stage 1 breast cancer

In the treatment of stage 1 breast cancer, lumpectomy with removal of the axillary lymph node is performed. To eliminate the remaining tumor cells and prevent its recurrence, adjuvant (postoperative) radiation, hormonal or chemotherapy is prescribed after surgery. And in the case of tumor overexpression of HER2, adjuvant targeted therapy should be used.

Treatment of stage 2 breast cancer

A mandatory stage of treatment for stage 2 breast cancer is partial removal of the affected organ tissue (lumpectomy) or complete removal of the gland (mastectomy), which depends on the individual clinical picture of the disease. In this case, the affected regional lymph nodes are also subject to removal. Patients with tumors larger than 5 cm undergo a course of chemotherapy twice: before and after surgery.

According to indications, postoperative courses of radiation or hormonal therapy are carried out.

In the case of a mastectomy, breast augmentation surgery is performed over time.

Treatment of stage 3 breast cancer

The beginning of the treatment of stage 3 breast cancer is a complex attack on cancer cells using cytotoxic drugs (chemotherapy) and oncological hormone therapy. And only after positive results is a decision made to perform surgery. The positive result of surgeons is consolidated by a repeated course of chemotherapy or targeted ionized radiation.

However, in case of tumor necrosis, bleeding or abscess formation, treatment begins with surgery (palliative radical mastectomy). And only after that, chemo- and radiation therapy are used.

In case of hormone-dependent neoplasms, long-term use of aromatase inhibitors (hormone therapy) is indicated, and in case of tumor overexpression of HER2 receptors (for more details, see the section Diagnosis of breast cancer) – the use of monoclonal antibodies.

Treatment of stage 4 breast cancer

Oncologists generally admit that treatment of stage 4 breast cancer – recurrent and metastatic tumor process – in most cases is palliative, that is, aimed at alleviating the condition of patients. However, full-fledged complex therapy at this stage of the disease can prolong life.

First of all, to reduce the level of intoxication of the body, a sanation mastectomy is necessary, which consists of the most complete removal of necrotic and ulcerated tissues. And to combat metastases, the entire arsenal of anti-cancer methods is used: complex chemotherapy, radiation and hormonal therapy.

In addition, supportive treatment of concomitant pathological processes must be mandatory. Thus, in case of anemia and thrombocytopenia, the administration of appropriate medications and blood transfusion are indicated; in case of bone metastases, the prescription of bisphosphonate drugs, etc.

The development of the disease goes through several stages, and the stages of breast cancer are clearly defined. Therefore, it is necessary to seek medical help in time and not allow incurable stages of oncological diseases.