Non-small cell lung cancer (8th edition of the IASLC TNM classification for lung cancer). All about lung cancer at different stages of its development International classification of lung cancer

lung cancer deaths than women taking placebo. Among women who smoked (former and current smokers), 3.4% of those who took hormones died of lung cancer compared to 2.3% of women who took placebo.

With the experience of smoking tobacco, the likelihood of developing lung cancer in a person increases. If a person stops smoking, this likelihood steadily decreases as damaged lungs are repaired and contaminants are gradually removed. In addition, there is evidence that lung cancer in never smokers has a better prognosis than in smokers, and therefore patients who smoke on the time of diagnosis, have a lower survival rate than those who quit smoking a long time ago.

Passive smoking(inhalation of tobacco smoke from another smoker) is the cause of lung cancer in non-smokers. Studies in the US, Europe, UK and Australia have shown significant increases in relative risk among those exposed to secondhand smoke. Recent studies have shown that the smoke exhaled by a smoker is more dangerous than inhaling it directly from a cigarette. 10-15% of lung cancer patients have never smoked.

Radon is a colorless and odorless gas formed during the decay of radioactive radium, which in turn is a decay product of uranium present in the Earth's crust. Radioactive radiation can damage genetic material, causing mutations that sometimes lead to cancer. Exposure to radon is the second cause of lung cancer in the general population, after smoking, with an increase in risk of 8% to 16% for every 100 Bq/m³ increase in radon concentration. The concentration of radon in the atmosphere depends on the location and composition of the underlying soils and rocks. For example, in areas such as Cornwall in the UK (where granite is available), radon

A big problem and buildings need to be well ventilated to reduce radon concentrations.

Rusty bodies in asbestosis. Stained with hematoxylin and eosin

2.4. Viruses

Viruses are known to cause lung cancer in animals, and recent evidence suggests that they can cause it in humans. Such viruses are human papillomavirus, JC virus , monkey virus 40(SV40), BK virus and cytomegalovirus. These viruses can influence the cell cycle and suppress apoptosis, promoting uncontrolled cell division.

2.5. dust particles

Research by the American Cancer Society has found a direct link between exposure to dust particles and lung cancer. For example, if the concentration of dust in the air increases by only 1%, the risk of developing lung cancer increases by 14%. In addition, it was found that the size of dust particles is important, since ultrafine particles are able to penetrate into the deep layers of the lung.

	3. Classification of lung cancer
2.3. asbestosis	by stages
Asbestos can cause various lung diseases.	According to the national classification, lung cancer
diseases, including lung cancer. There is mutual	is divided into the following stages:
the lingering effect of tobacco smoking and asbestosis in	Stage I - tumor up to 3 cm at its largest
incidence of lung cancer. Asbestosis can also
cause cancer of the pleura, called mesothelioma (co-	dimension, is located in one segment of the lung
which should be differentiated from lung cancer).	whom or within the segmental bronchus.

3.1

There are no metastases.

Stage II - a tumor up to 6 cm in greatest dimension, located in one lung segment or within the segmental bronchus. There are single metastases in the pulmonary and bronchopulmonary lymph nodes.

Stage III - a tumor larger than 6 cm with a transition to the adjacent lobe of the lung or germination of the adjacent bronchus or main bronchus. Metastases are found in the bifurcation, tracheobronchial, paratracheal lymph nodes.

Stage IV - the tumor goes beyond the lung with spread to neighboring organs and extensive local and distant metastases, cancerous pleurisy joins.

According to TNM classification, tumors are determined by:

T - primary tumor:

Tx - insufficient data to assess the primary tumor, or tumor cells are found only in sputum or bronchial washings, but not detected by bronchoscopy and / or other methods

T0 - primary tumor is not determined

Tis - non-invasive cancer (carcinoma in situ)

Tl - tumor up to 3 cm in greatest dimension, surrounded by lung tissue or visceral pleura without sprouting proximal to the lobar bronchus during bronchoscopy (the main bronchus is not affected)

T2 - a tumor of more than 3 cm in the largest dimension or a tumor of any size, germinating the visceral pleura, or accompanied by atelectasis, or obstructive pneumonia, spreading to the root of the lung, but not capturing the entire lung; According to bronchoscopy, the proximal edge of the tumor is located at least 2 cm from the carina.

TK - a tumor of any size, passing to the chest wall (including a tumor of the upper sulcus), diaphragm, mediastinal pleura, pericardium; tumor less than 2 cm short of the carina, but without involvement of the carina, or tumor with concomitant atelectasis or obstructive pneumonia of the entire lung.

T4 - a tumor of any size directly passing to the mediastinum, heart, large vessels, trachea, esophagus, vertebral bodies, carina (individual tumor nodes in the same lobe or tumor with malignant pleural effusion)

N - regional lymph nodes

Nx - insufficient data to assess the status of regional lymph nodes

N0 - no evidence of metastatic involvement of regional lymph nodes

N1 - there is a lesion of the peribronchial and / or lymph nodes of the lung root on the side of the lesion, including the direct spread of the tumor to the lymph nodes.

N2 - there is a lesion of the lymph nodes of the mediastinum on the side of the lesion or bifurcation lymph nodes.

N3 - damage to the lymph nodes of the mediastinum or the root of the lung on the opposite side: prescale or supraclavicular nodes on the side of the lesion or on the opposite side

M - distant metastases

Mx - insufficient data to determine distant metastases

M0 - no signs of distant metastases

M1 - there are signs of distant metastases, including individual tumor nodes in another lobe

G - histopathological gradation

Gx - degree of cell differentiation cannot be assessed

G1 - high degree of differentiation

G2 - moderate degree of differentiation

G3 - poorly differentiated tumor

G4 - undifferentiated tumor

3.1. Histological classification of lung cancer

According to histological Classification of lung cancer is divided into the following types:

I. Squamous cell (epidermoid) cancer

a) highly differentiated

b) moderately differentiated

c) undifferentiated

5589 0

The prevalence of the tumor process is one of the main factors determining the choice of treatment method, the volume of surgical intervention and prognosis.

The stage of the disease depends on the size and extent of the primary tumor, its relationship to the surrounding organs and tissues, as well as on metastasis - the location and number of metastases.

Various combinations of factors characterizing the prevalence of the tumor process make it possible to distinguish between the stages of the disease.

The classification of lung cancer by stages makes it possible to evaluate the effectiveness of organizational measures to detect this disease and to ensure the exchange of information on the results of treating patients with different methods.

The classification of lung cancer by stages adopted in the USSR and recommended for use in 1985 cannot currently satisfy clinicians, since it contains a number of such subjective coding criteria as “ingrowth ... in a limited area”, “removable and non-removable metastases in the lymph nodes mediastinum”, “germination over a considerable extent”, which does not allow one to unambiguously judge the stage and unify treatment tactics.

Even stage IV includes both locoregional and generalized tumor processes. This classification, in our opinion, is significantly inferior to international ones both from a scientific and practical point of view.

Progress in the development of diagnostic methods, the accumulation of clinical material, and new possibilities of therapy lead to a revision of established ideas. Thus, the International classification of lung cancer according to the TNM system (1968), based mainly on long-term results of treatment, was revised 4 times - in 1974, 1978, 1986 and 1997.

The fundamental differences in the latest classification (1986), widely recommended by the International Cancer Union, include the allocation of preinvasive cancer (Tis), as well as microinvasive cancer and its classification as T1, regardless of location, specific pleurisy - to T4, metastases in the supraclavicular lymph nodes - to N3. Such rubrication is more in line with ideas about the significance of the nature and extent of the tumor.

The proposed gradation by stages in the TNM system is quite clearly defined, suggesting the selection of groups of patients who are indicated for surgical or conservative antitumor treatment (in relation to non-small cell forms of lung cancer). This gives grounds to currently give preference to this particular classification and contributes to the international integration of scientific research.

Until recently, this International Classification of Lung Cancer according to the TNM system of the fourth revision, published by a special committee of the International Anti-Cancer Union in 1986, was used. The addition of numbers to the symbols T, N and M indicates a different anatomical prevalence of the tumor process.

The rule of the TNM system is to apply two classifications:

Clinical classification of TNM (or c TNM), based on the results of clinical, radiological, endoscopic and other studies. The symbols T, N and M are determined before the start of treatment, as well as taking into account additional data obtained using surgical diagnostic methods.

Post-surgical, pathohistological classification (or pTNM), which is based on information established before the start of treatment and supplemented or modified by data obtained during surgery and the study of the surgical preparation.

International classification of lung cancer according to the TNM system (1986)

T - primary tumor;
TX - insufficient data to assess the primary tumor, the presence of which is Proved only on the basis of the detection of cancer cells in sputum or bronchial washings, the tumor is not visualized radiologically and during bronchoscopy;
T0 - primary tumor is not determined;

Tis - intraepithelial (preinvasive) cancer (carcinoma in situ);
T1 - microinvasive cancer, a tumor up to 3 cm in the largest dimension, surrounded by lung tissue or visceral pleura, without damage to the latter and bronchoscopic signs of invasion proximal to the lobar bronchus;
T2 - a tumor more than 3 cm in the greatest dimension, or extending to the main bronchus at least 2 cm from the carina of the tracheal bifurcation (carina trachealis), or growing into the visceral pleura, or accompanied by atelectasis, but not of the entire lung;

T3 Tumor of any size directly invading the chest wall (including lung apex tumor), diaphragm, mediastinal pleura, pericardium, or tumor invading the main bronchus less than 2 cm from the tracheal carina, but without involvement of the latter, or tumor with atelectasis or pneumonia of the entire lung;
T4 Tumor of any size directly invading the mediastinum, heart (myocardium), great vessels (aorta, common trunk of the pulmonary artery, superior vena cava), trachea, esophagus, vertebral body, tracheal carina, or tumor with malignant cytologically confirmed pleural effusion;
N - regional lymph nodes;

NX - regional lymph nodes cannot be assessed;
N0 - no metastases in regional lymph nodes;
N1 - metastatic lesion of the intrapulmonary, ipsilateral bronchopulmonary and / or lymph nodes of the root of the lung, including their involvement by direct spread of the tumor itself;

N2 - metastatic lesion of the ipsilateral lymph nodes of the mediastinum and / or bifurcation;
N3 - damage to the contralateral mediastinal and / or root lymph nodes, prescale and / or supraclavicular lymph nodes on the side of the lesion or the opposite side;
M - distant metastases;

MX - distant metastases cannot be assessed;
MO - no distant metastases;
Ml - distant metastases are present.

PUL - light;
PER - abdominal cavity;
MAR - bone marrow;
BRA - brain;
OSS - bones;
SKI - skin;
PLE - pleura;
LYM - lymph nodes;
ADP - kidneys;
HEP - liver;
OTN - others.

PTNM - post-surgical pathohistological classification

The requirements for determining the categories pT, pN, pM are similar to those for determining the categories T, N, M.

G - histopathological gradation:

GX - the degree of cell differentiation cannot be assessed;
G1 - high degree of differentiation;
G2 - moderate degree of differentiation;
G3 - poorly differentiated tumor;
G4 - undifferentiated tumor.

R-classification:

RX - presence of residual tumor cannot be assessed;
R0 - no residual tumor;
R1 - microscopically determined residual tumor;
R2 - macroscopically detectable residual tumor.

While recognizing the importance and convenience of the International Classification, a number of its shortcomings should be noted. So, for example, the symbol N2 is not specific enough, since it determines the state of all mediastinal lymph nodes - upper and lower (bifurcation) tracheobronchial, paratracheal, anterior mediastinum, etc.

Meanwhile, it is important to know which and how many of the listed lymph nodes contain metastases. As you know, the prognosis of treatment depends on this.

This classification does not provide for situations that often arise in practice when there are two or more peripheral nodes in a lobe or lung (multinodular form of bronchioloalveolar cancer, lymphoma), pericardial effusion, involvement of the phrenic and recurrent nerves, etc. are not classified.

In this regard, in 1987 the International Society for the Study of Cancer (UICC) and in 1988 the American Committee (AJCC) proposed the following additions to this classification (Mountain C.F. et al., 1993).

I. Multiple nodes in one lung

T2 - if in one share at T1 there is a second node;
T3 - if in one share at T2 there is a second node;
T4 - multiple (more than 2) nodes in one lobe; if at T3 there is a node in the same lobe;
M1 - the presence of a node in another lobe.

Grouping of lung cancer by stages, according to the International classification according to the TNM system (1986)

II. Large vessel involvement

T3 - damage to the pulmonary arteries and veins extrapericardially;
T4 - damage to the aorta, the main branch of the pulmonary artery, intrapericardial segments of the pulmonary artery and veins, superior vena cava with esophageal compression syndrome, trachea.

III. Involvement of the phrenic and recurrent nerves

T3 - germination of the primary tumor or metastases in the phrenic nerve;
T4 - germination of the primary tumor or metastases in the recurrent nerve.

IV. Pericardial effusion

T4 - tumor cells in the pericardial fluid. The absence of tumor cells in the fluid obtained from two or more punctures, and its non-hemorrhagic nature, is not taken into account when determining the symbol.

V. Tumor nodules on or outside the parietal pleura

T4 - tumor nodules on the parietal pleura;
M1 - Tumor nodules on the chest wall or diaphragm, but outside the parietal pleura.

VI. Bronchioalveolar cancer (BAD)

In 1997, the International Cancer Union proposed a new International Classification of Lung Cancer according to the TNM system of the fifth revision, which was published under the editorship of L.H. Sobin and Ch. Wittekind.

The characteristics of the symbols T, N and M have not changed significantly, except for:

T4 - a separate (second) tumor node in the same lobe;
M1 - single tumor nodes in different lobes (ipsilateral and contralateral);
pNO - histological examination of the root and mediastinal lymphadenectomy surgical preparation should include the study of 6 lymph nodes or more. Grouping by stages has undergone significant changes.

Until recently, in small cell lung cancer, the systematization proposed in 1973 by Veteran's Administration Lung Cancer Study Group was used:

Localized process - damage to the hemithorax, ipsilateral medial and supraclavicular lymph nodes, contralateral root nodes, specific
exudative pleurisy on the affected side;
a common process is the defeat of both lungs and metastases in distant organs.

Subsequently, this systematization, which is of little use for practice, was corrected. G. Abrams et al. (1988) suggested that the defeat of the contralateral root lymph nodes be classified as a "common process", and R. Stahcl et al. (1989), K.S. Albain et al. (1990) - exclude ipsilateral pleurisy from the category of "localized process".

Rice. 2.49. Lung cancer IA (a) and IV (b) stages (scheme).

Rice. 2.50. Lung cancer IIA (a) and IIB (b, c) stages (scheme).

Rice. 2.51. Lung cancer stage IIIA (a, b) (scheme).

Rice. 2.52. Lung cancer stage IIIB (a, 6) (scheme).

Meanwhile, many years of research conducted at the Moscow Research Institute of P.A. Herzen, showed that small cell lung cancer also has a locoregioparous stage of development, in which surgical treatment with adjuvant polychemotherapy is justified (Trachtenberg A.Kh. et al., 1987, 1992).

Other domestic and foreign thoracic surgeons and oncologists came to this conclusion (Zharkov V. et al., 1994; Meyer G.A., 1986; Naruke T. et al., 1988; Karrer K. et al., 1989; Ginsberg R.G., 1989; Shepherd F.A. et al., 1991, 1993; Jackevicus A. el al., 1995).

The use of the International TNM classification for small cell lung cancer makes it possible to objectively judge the degree of spread of the primary tumor and the nature of metastasis to the lymph nodes and organs, which makes it possible to obtain a more complete picture of the contingent of treated patients and the course of its various histological types.

In the literature, there is no generally accepted systematization by stages of primary malignant non-epithelial lung tumors. This allowed us, based on the study of prognostic factors in a large group of patients, to use the modified International Classification of Lung Cancer according to the TNM system for sarcomas.

The systematization by stage of most sarcoma variants is based on the size of the primary tumor, the number of tumor nodes, relation to neighboring organs and structures, spread to the bronchi, the presence and localization of metastases in the intrathoracic lymph nodes and / or distant organs.

Stages of lung sarcoma

I stage- solitary tumor node or infiltrate up to 3 cm in the largest dimension with a peripheral clinical and anatomical form; tumor of the segmental and/or lobar bronchus in the central clinical and anatomical form; absence of regional metastases.

II stage- solitary tumor node or infiltrate more than 3 cm, but less than 6 cm in the greatest dimension, germinating or not involving the visceral pleura in the peripheral form; the tumor affects the main bronchus, but not closer than 2 cm to the carina with a central form; metastases in pulmonary, bronchopulmonary and ipsilateral root lymph nodes.

IIIA stage- Tumor node or infiltrate more than 6 cm in the largest dimension or any size, growing into the mediastinal pleura, chest wall, pericardium, diaphragm in the peripheral form; the tumor affects the main bronchus with a central clinical and anatomical form at a distance of less than 2 cm from the carina; metastases in ipsilateral mediastinal lymph nodes.

IIIB stage- a tumor node or infiltrate of any size, growing into the tissue of the mediastinum, aorta, common trunk of the pulmonary artery, superior vena cava, myocardium, esophagus, trachea, opposite main bronchus; metastases in the contralateral mediastinal and / or root, supraclavicular lymph nodes; multiple nodes or infiltrates in the lung; specific pleurisy.

IV stage- a tumor node or infiltrate of any size, the presence or absence of damage to the intrathoracic lymph nodes, but with metastases in distant organs; a multinodular form of the disease or multiple infiltrates in one lobe or in several lobes of one or two lungs.

Since the degree of tumor differentiation in sarcoma is an independent prognostic factor, when the final stage is established, category G should be added, which determines further treatment tactics after surgery.

For example, if surgery is sufficient for T2G1NIM0, then adjuvant anticancer therapy is also indicated for T2G3N1M0. Clinical observations have shown that the degree of tumor differentiation in sarcomas is of significant importance when its size is more than 3 cm in the largest dimension.

In this regard, we consider it extremely important to propose a practically significant grouping of lung sarcomas according to stages, taking into account the post-surgical (pTNM) histological gradation of the tumor (G).

After histological confirmation of malignant non-Hodgkin's lymphoma of the lung, it is necessary to examine the patient to exclude extrathoracic manifestations of the disease.

After that, staging is carried out according to the Ann Arbor stage classification (Carbone P. et al., 1971; L "Hoste R. et al., 1984):

Stage I E - defeat only the lung;
Stage II 1E - damage to the lung and lymph nodes of the root;
Stage II 2E - damage to the lung and medial lymph nodes;
Stage II 2EW - damage to the lung with involvement in the process of the chest wall, lyaphragm.

It is also extremely important to divide non-Hodgkin's lymphomas of the lung, according to the International Working Classification and Non-Hodgkin's Lymphoma Pathologic Classification Project into lymphomas consisting of small or large cells, which determines the prognosis and choice of treatment tactics.

Carcinoid tumors according to the prevalence of the process are classified as

Lung cancer is a fairly common disease among the general population in the world. Features of its distribution are due to smoking, the release of toxic and carcinogenic substances into the environment, harmful working conditions and better development of diagnostic methods at this stage of life.

It must be said that this condition is characterized by high secrecy, being able to disguise itself as various other diseases and is often determined by chance or with a more detailed diagnosis of another disease. Like most oncological diseases, lung cancer has a large number of varieties, which are divided according to their clinical and pathomorphological properties.

General principles of classification

Lung cancer can be classified according to the following criteria:

1. Anatomically.
2. TNM classification.
3. According to morphological features.

The anatomical classification of lung cancer includes the principles of distribution of cancer according to the structures that are affected by the oncological process. According to this classification, there are:

1. Central lung cancer.
2. Peripheral lung cancer.

TNM classification implies classification by tumor size (T score), presence/absence of lymph node lesions (N), and presence/absence of metastases (M score). The morphological classification includes varieties of the tumor process, where each is characterized by its own pathomorphological features. They also distinguish the classification of lung cancer according to the degree of spread of the process:

1. local distribution.
2. Lymphogenic.
3. Hematogenous.
4. Pleurogenic.

In addition, with certain forms of lung cancer (for example, sarcoma), a classification by stage can be distinguished.

Anatomical classification

This technique is based on the principles of classifying the tumor process according to the anatomical localization and the nature of tumor growth in relation to the bronchus.

As already mentioned above, there is a central form (bronchogenic) and peripheral. However, according to the anatomical classification according to Savitsky, atypical forms are also added to these 2 varieties. In turn, each of the above forms is divided into its subspecies.

Central or bronchogenic lung cancer usually occurs in the large bronchi of the lungs. It distinguishes: endobronchial cancer, exobronchial and branched cancer. The difference between these varieties is based on the nature of the growth of the tumor process. In endobronchial cancer, the tumor grows into the lumen of the bronchus and looks like a polyp with a bumpy surface. Exobronchial cancer is characterized by growth in the thickness of the lung tissue, which leads to a long-term intact patency of the affected bronchus. Peribronchial cancer forms a kind of "clutch" of atypical tissue around the affected bronchus and spreads along its direction. This variety leads to a uniform narrowing of the lumen of the bronchus.

Peripheral cancer affects either the lung parenchyma or the subsegmental branches of the bronchi. It includes:

1. "Round" form of peripheral cancer.
2. Pneumonia-like tumor.
3. Pancoast cancer (apex of the lung).
4. bronchoalveolar cancer.

The round shape is the most common variety (about 70-80% of cases of peripheral lung cancer) and is located in the lung parenchyma. Pneumonia-like lung cancer occurs in 3-5% of cases and looks like an infiltrate without clear boundaries, located in the lung parenchyma. Bronchoalveolar lung cancer is a highly differentiated tumor that spreads intraalveolarly using the alveoli themselves as stroma. Atypical forms of lung tumors are mainly due to the nature of metastasis. The most common type of this form is mediastinal lung cancer, which is a multiple metastasis of the tumor in the intrathoracic lymph nodes in the absence of a clarified primary oncological focus.

TNM classification

This classification was first introduced in 1968 and is periodically reviewed and revised. At the moment, there is a 7th edition of this classification.

As mentioned above, this classification includes three main principles: tumor size (T, tumor), lymph node involvement (N, nodulus) and metastasis (M, metastases).

Usually the following degrees of classification are distinguished:

Tumor size:

• T0: signs of the primary tumor are not determined;
• T1: Tumor less than 3 centimeters, no visible extension or bronchus lesions;
• T2: tumor size more than 3 centimeters or the presence of a tumor of any size with invasion into the visceral pleura;
• T3: the tumor can be of any size with the condition of its spread to the diaphragm, chest wall, mediastinal side of the pleura;
• T4: tumor of any size with significant spread to the tissues and structures of the body + confirmed malignant nature of the pleural effusion.

By the defeat of the lymph nodes:

• N0 metastases in the regional bed of the lymph nodes are absent;
• N1 intrapulmonary, pulmonary, bronchopulmonary lymph nodes or lymph nodes of the root of the lung are affected;
• N2 damage to the lymph nodes of the mediastinal basin or bifurcation lymph nodes;
• N3 addition to the existing lesion of the lymph nodes, an increase in the supraclavicular lymph nodes, lymph nodes of the mediastinum and root.

Classification considering lung metastasis:

• M0 - distant metastases are absent;
• M1 are determined by signs of the presence of distant metastases.

Pathological classification

This technique makes it possible to evaluate the cellular structure of the tumor and its individual physiological principles of functioning. This classification is needed in order to choose the right method of influencing a particular type of tumor in order to treat a patient.

According to pathomorphological features, there are:

1. Large cell lung cancer.
2. lung adenocarcinoma.
3. Squamous cell carcinoma.
4. Small cell cancer.
5. Solid lung cancers.
6. Cancer affecting the bronchial glands.
7. Undifferentiated lung cancer.

A tumor with a large cell structure is a cancer in which its cells have large, clearly visible under a microscope, dimensions, cytoplasm and pronounced dimensions. This cellular lung cancer can be divided into 5 subcategories, among which the most common are:

• giant cell form;
• light cell form.

The giant cell type of the disease is a tumor with cells of giant, bizarre shapes with a large number of nuclei. In the clear cell form, the cells have a characteristic appearance with a light, "foamy" cytoplasm.

Adenocarcinoma affects the cells of the epithelial series. Its structures are able to produce mucus and form structures of various shapes. Due to the predominant damage to the cells of the glandular layer of the epithelium, this variety is also known as glandular lung cancer. This type of tumor can have different degrees of differentiation of its structures, and therefore both varieties of highly differentiated adenocarcinoma and its low-differentiated varieties are distinguished. It must be said that the degree of differentiation has an important influence on the nature of the tumor process and the course of the disease itself. Thus, poorly differentiated forms are more aggressive and more difficult to treat, while highly differentiated ones, in turn, are more susceptible to treatment.

Squamous cell carcinoma also belongs to the group of tumor processes that originate from epithelial cells. Tumor cells have the appearance of a kind of "thorns". This type has its own peculiarity - its cells are able to produce keratin, in connection with which peculiar “growths” or “pearls” are formed, which is a hallmark of squamous cell carcinoma. It is thanks to these characteristic growths that squamous cell carcinoma has also received the name "keratinizing" or "cancer with pearls."

The small cell form is characterized by the presence in its structure of cells of small sizes of various shapes. Usually there are 3 subspecies:

1. "Oatmeal".
2. From intermediate cells.
3. Combined.

The group of solid lung cancers is characterized by the location of their structures in the form of "strands" or trabeculae, separated by connective tissue. This species also belongs to low-grade tumor processes.

The pathomorphological subgroup of the classification of pulmonary tumors can also include such a form as neuroendocrine lung cancer. This variety is quite rare compared to other types of lung tumors and is characterized by slow growth. At the heart of a neuroendocrine tumor is the triggering of tumor changes in cells of a special type - neuroendocrine. These cells have the ability to synthesize various protein substances or hormones and are distributed throughout the human body. They are also known as the "APUD-system" or diffuse neuroendocrine system.

Under the influence of various reasons, the programs of natural growth and aging in these cells are disrupted, and the cell begins to divide uncontrollably and becomes tumorous.

Despite the fact that neuroendocrine tumor processes spread quite slowly throughout the body, they are included in the list of diseases that require close attention of medical personnel. The reason for this is that these tumors have practically no characteristic clinical signs and therefore are difficult to diagnose in the early stages, as a result of which the patient develops an already inoperable lung cancer.

According to their classification, they distinguish:

• Carcinoid neuroendocrine tumors of the lung.
• small cell forms.
• large cell forms.

Neuroendocrine pulmonary tumors also have different degrees of differentiation and malignancy. The degree of malignancy is determined by the number of divisions of the tumor cell (mitosis) and its ability to grow (proliferation). The indicator of the ability of a malignant cell to divide is called G, and the indicator of the proliferative activity of the tumor is Ki-67.

According to these indicators, 3 degrees of malignancy of a neuroendocrine tumor are determined:

1 degree, or G1, where the G and Ki-67 index is less than 2 (that is, the tumor cell is capable of less than 2 divisions).
2 degree or G2, where the number of mitoses is from 2 to 20, and the proliferation index is from 3 to 20.
3 degree or G3, at which the cell is capable of more than 20 divisions. The proliferation index at this stage is also above 20.

Diagnosis of neuroendocrine tumors of the lungs consists in the use of radiation methods (CT, MRI, plain radiography of the chest organs), sputum examination for atypical cells. There are also specific methods aimed at identifying the neuroendocrine characteristics of the process. Most often, 2 methods are used for this:

1. Electron microscopy of the tumor biopsy.
2. Determination of immunological markers.

With the help of an electron microscope, it is possible to see a characteristic “granularity” in tumor cells, which is neuroendocrine granules, which is characteristic only for cells of the APUD system. Immunological or "neuroendocrine markers" are usually determined by immunohistochemistry. This method consists in processing sections of the material under study with special antibodies to the desired substance. As a rule, for neuroendocrine tumors such substances are synaptophysin and chromogranin-A.

Lung cancer - the prevalence of this disease over the past decades has increased faster than malignant tumors of other organs. At the beginning of the last century, only a few dozen cases of the disease were described, and at the beginning of this century, the disease is the most frequently diagnosed malignant tumor.

The correct classification of lung cancer makes it possible to get an idea of ​​the tumor itself, its growth and size, localization and extent of spread. Based on the characteristics of a malignant neoplasm, it is possible to predict the course of the disease and the results of treatment. Treatment tactics depend on the stage of the disease. Today they distinguish:

• histological classification
• clinical and anatomical
• International classification according to the TNM system

Histological classification

Histological classification is decisive in the prognosis and treatment. Depending on the elements of the bronchial epithelium, the following types of lung cancer are distinguished:

• Squamous - the most common form, occurs in 50-60% of patients, in men 30 times more often. It mainly affects long-term smokers. Most of the tumors are localized in the central regions, which negatively affects the diagnosis. The primary detection of a tumor occurs mainly when the symptoms are pronounced or there are complications.
• Small cell carcinoma (adenocarcinoma, glandular) accounts for 20-25% of all lung tumors, affects women twice as often as men, and is localized in the peripheral parts of the lungs in 80% of cases. The tumor is characterized by slow growth and its size may remain unchanged for several months. However, such a tumor is among the most aggressive.
• Large cell - so called because of the large round cells that are clearly visible under a microscope. There is another name - undifferentiated carcinoma.
• Mixed - squamous and adenocarcinoma, adenocarcinoma and small cell, etc.

Classification by localization

Equally important is the clinical and anatomical classification, which also determines the choice of treatment plan. According to her distinguish:

• central cancer - accounts for 65% of all lung tumors, affects large bronchi (segmental, lobar, main). The ratio of the newly discovered central and peripheral is 2:1. The right lung is affected more often.
• peripheral - affects the smaller bronchi
• atypical

These malignancies differ in location, symptoms and clinical manifestations.

Also of particular importance are the features of the growth of malignant tumors. A tumor that spreads into the lumen of the bronchus (exophytic cancer) poses a threat in terms of obstruction, which will lead to blockage of the lumen and pneumonia. A tumor with endophytic growth does not create obstacles for bronchus patency for a long time. There is also peribronchial growth, in which the tissue is located around the bronchus.

International TNM classification

The TNM classification developed by the International Cancer Union is used worldwide. With its help, the spread of the tumor and the prognosis of treatment are determined.

• T - the size of the tumor and the degree of germination in the surrounding tissues,
• N - the presence of affected lymph nodes
• M - the presence or absence of metastases in other organs

According to the TNM classification, there are 4 degrees of lung cancer.

• I degree - a tumor of a small size, lymph nodes and pleura are not affected
• II degree - a tumor of 3-5 cm, there are metastases in the bronchial lymph nodes
• IIIA degree - the tumor can be of any size, the pleura, chest wall are involved in the process, there are metastases in bronchial lymph nodes or mediastinal nodes on the opposite side
• IIIB degree - the tumor affects the organs of the mediastinum
• Grade IV - there are metastases in the other lung, metastasis to distant organs is observed

Forecast

Treatment prognosis varies depending on the stage of the disease. has the best result, but almost 2/3 of patients are diagnosed with a stage II-III tumor during the initial visit. The forecast in this case is not so optimistic; of great importance is the presence of metastases, the spread of which to other organs allows only palliative treatment. However, in the absence of metastasis, there is a chance of success with a radical operation. When diagnosing the last stage of the disease, 80% of patients die during the first year, and only 1% have a chance to live more than 5 years.

The classification of lung cancer is based on several principles. The division is based on belonging to the histological structure, macroscopic localization, international TNM standards and disease stages.

The most important way for doctors to divide the disease is histological. Each tumor consists of cells of different origin, this determines all its properties.

Lung cancer can be one of the following:

1. Squamous - the most common type of disease. It is more common in males, as it is directly related to smoking. A constant inflammatory process, hot smoke in the bronchi provoke cell division, in which mutations occur. Most often, such tumors are localized in the region of the lung root, therefore, it has a severe clinical picture.


2. Small cell carcinoma, or adenocarcinoma, is a rarer form. Has genetic mechanisms of development. Women are more likely to get cancer. Neoplasms are located on the periphery of the organ and are asymptomatic for a long time. But they have a rather severe prognosis.
3. Non-small cell carcinoma is a rare disease, is a formation of a small size. It occurs in adults and the elderly and actively metastasizes, since it is based on immature cancer cells.
4. A mixed form of lung cancer is a histological variant of the structure of the formation, in which there are several types of cells in one neoplasm.

Extremely rare variants of the disease are tumors of the organ from the auxiliary elements of its structure: sarcomas, hemangiosarcomas, lymphomas. All of them have fairly aggressive growth rates.

Tumors of any organ are subdivided by oncologists into several subtypes:

• Highly differentiated - cells in the composition are close to mature, have the most favorable prognosis.
• Moderately differentiated - the stage of development of elements is closer to the intermediate one.
• Poorly differentiated lung cancers are the most dangerous, develop from immature cells and often metastasize.

The options listed above have their own mechanisms of development and risk factors. Histology in lung cancer also determines the methods of treatment of the disease.

Clinical forms of lung cancer

It is very important to determine the macroscopic location of lung cancer, the classification implies the division of the disease into central and peripheral variants.

The central types of lung cancer are located in the thickness of the organ, closer to the main bronchi. They are characterized by such features:

• Accompanied by cough and shortness of breath.
• They have a large size.
• They are more commonly referred to as squamous cell tumors.
• The clinical picture emerges quickly.
• Easier to diagnose.
• Spread bronchogenically or with lymph flow.

Characterization of peripheral neoplasms:

• Small size.
• They belong to adenocarcinomas.
• They have few symptoms.
• Metastases spread mainly through the blood.
• They are found in the later stages.

The listed features of localization affect not only the diagnostic process, but also the choice of treatment tactics. Sometimes surgery is not possible due to the location of the tumor.

Classification of lung cancer by TNM

In the conditions of modern medicine, doctors are forced to classify diseases according to international standards. In oncology, the basis of tumor division is the TNM system.

The letter T stands for tumor size:

• 0 - the primary tumor cannot be found, so it is not possible to determine the size.
• is - cancer "in place". This name means that the tumor is located on the surface of the bronchial mucosa. Well treated.
• 1 - the largest size of the formation does not exceed 30 mm, the main bronchus is not affected by the disease.
• 2 - the tumor can reach 70 mm, involves the main bronchus or grows into the pleura. Such formation may be accompanied by atelectasis of the lung or pneumonia.
• 3 - the formation is more than 7 cm, passes to the pleura or diaphragm, less often involves the walls of the chest cavity.
• 4 - such a process already affects nearby organs, the mediastinum, large vessels or even the spine.

In the TNM system, the letter N stands for lymph node involvement:

• 0 - the lymphatic system is not involved.
• 1 - the tumor metastasizes to the lymph nodes of the first order.
• 2 - the lymphatic system of the mediastinum is affected from the side of the primary tumor.
• 3 - Distant lymph nodes are involved.

Finally, the letter M in the classification denotes distant metastases:

• 0 - no metastases.
• 1a - foci of dropouts in the opposite lung or pleura.
• 1b - metastases in distant organs.

As a result, the characteristics of the tumor may look like this: T2N1M0 - a tumor from 3 to 7 cm, with metastases in the lymph nodes of the first order without affecting distant organs.

Stages of lung cancer

Classification of lung cancer by stages is necessary to determine the prognosis. It is domestic and widely used in our country. Its disadvantage is subjectivity and a separate division for each organ.

The following stages are distinguished:

• 0 - the tumor was accidentally discovered during diagnostic measures. The size of the neoplasm is extremely small, there is no clinical picture. The shell of the organ and the lymphatic system are not involved.
• 1 - the size is less than 30 mm. Corresponds to T1 form according to the international system. It does not affect the lymph nodes. The prognosis is good with any type of treatment. Finding such a formation is not easy.
• 2 - the size of the primary focus can reach 5 cm. In the lymph nodes along the bronchi there are small foci of dropouts.
• 3A - the formation affects the pleura. The size of the tumor in this case is not important. Usually at this stage there are already metastases in the lymph nodes of the mediastinum.
• 3B - the disease involves the organs of the mediastinum. The tumor can germinate blood vessels, esophagus, myocardium, vertebral bodies.
• 4 - there are metastases in distant organs.

In the third stage of the disease, a favorable outcome occurs only in a third of cases, and in the fourth stage, the prognosis is unfavorable.

Each method of division of the disease has its own purpose in clinical medicine.