Tnm classification of malignant tumors. Cancer stages. Basic principles of TNM classification

When deciding on the choice of the optimal treatment plan for a patient, specialists are interested in how far the neoplasm is spread. For this, the international classification of malignant tumors is used. Its main indicators are:

T - means that the tumor is primary, its stages are indicated;
N - the presence of metastases in neighboring lymph nodes;
M - the presence of distant metastases - for example, in metastases in the lungs. liver or other organs.

To clarify the stage of the tumor, the following indexing is used: T1 indicates that the tumor is small, and T4 is already significant (in each case, the growth of the tumor into different layers of the organ and its spread to neighboring ones is taken into account). If the nearest lymph nodes are unchanged, then N0 is set. If they have metastases - N1. In the same way, the absence (MO) or presence (Ml) of metastases to other organs is noted. Next, a more specific description of the stages of cancer of each organ will be given. Thus, if cancer is detected at an early stage and without metastases, then T1 N0 MO is set in the medical history.

Classification of tumors according to the TNM system

The TNM System for describing the anatomical extent of a neoplasm is based on 3 components:
T Prevalence of the primary tumor N Presence, absence and prevalence of metastases in the lymph nodes M Presence or absence of distant metastases.
The number next to the component indicates the extent of the malignancy:
TO, T1, T2, TZ, T4 N0, N1, N2, N3 MO, M1
Thus, the TNM System is a short guide for describing the prevalence of specific malignancies.
Basic rules for the classification of neoplasms of any localization
1. In all cases, histological confirmation of the diagnosis is required. Cases where confirmation is not possible should be described separately.
2. For each of the localizations, there are two classifications, namely:
a) clinical classification (cTNM or TNM): classification before treatment, which is used to select and evaluate the effectiveness of treatment. It is based on pre-treatment findings by physical examination, as well as on the results of radiological and endoscopic examination methods, preoperative biopsies and diagnostic interventions;
b) pathoanatomical classification (pTNM); post-surgery classification to select additional therapy, obtain additional information about the prognosis of treatment, as well as statistical reporting of treatment outcomes. This classification is based on data obtained before the start of treatment, which are further supplemented or modified based on the results of surgical intervention and post-mortem examination. Morphological assessment of the prevalence of the primary tumor is carried out after resection or biopsy of the neoplasm. The defeat of regional lymph nodes (category pN) is assessed after their removal. In this case, the absence of metastases is designated as pNO, and the presence is denoted by one or another pN value. Excisional lymph node biopsy without histological examination of the primary tumor is not a sufficient basis for establishing a pN category and belongs to the clinical classification. The presence of distant metastases (rM) is determined by microscopic examination.
3. After determining the categories T, N and M and / or pT, pN and pM they are grouped into one or another stage of the disease. The established categories of TNM, as well as the stage of the disease, should remain unchanged in the medical records. The data of clinical and pathoanatomical classifications can be combined in cases where the information presented in them complements each other.
4. If in a particular case there is doubt in determining the exact value of the category T, N or M, it is necessary to choose a category with a lower value. The same rule applies when choosing the stage of cancer.
5. In cases of multiple primary tumors of one organ, category T is assigned the maximum value among these tumors. In this case, the multiple nature of the formation or the number of primary tumors should be indicated in brackets after the T value, for example, T2(t) or T2(5). In the case of simultaneous bilateral (bilateral) primary neoplasms of paired organs, each of them should be classified separately. In tumors of the liver, ovary, and fallopian (fallopian) tubes, multiplicity is a criterion for category T, while in lung cancer, multiplicity can be a criterion for both category T and M.

Classification of tumors clinical TNM

T - Primary tumor
TC Primary tumor cannot be assessed
TO No evidence of primary tumor
Tis Carcinoma in situ
T1-T4 Increased size and/or spread of the primary tumor
N - Regional lymph nodes
NX Regional lymph nodes cannot be assessed
N0 No metastases in regional lymph nodes
N1-N3 Increased involvement of regional lymph nodes
M - Distant metastases*
MO No distant metastases M1 Distant metastases present
* Category MX is considered inappropriate, because evaluation of distant metastases can only be based on physical examination data (MX category cannot be determined).
Subcategories in the TNM Classification
Subcategories of some main categories are used when additional clarification is needed (eg Ha, T1b or N2a, N2b).

Classification of tumors pathoanatomical

The germination of the primary tumor in the lymph nodes is regarded as a metastasis in the lymph nodes.
Tumor deposits (satellites), such as macro- and microscopic nests or nodules in the zone of lymphatic vessels draining the primary tumor without histological signs of residual lymph node tissue in such formations, may be a continuation of the primary tumor, unrelated nodes, the result of venous invasion (V1/ 2) or complete replacement of the lymph node tissue with tumor tissue. If the pathologist suspects that such a nodule is a lymph node tissue replaced by tumor cells (usually it has smooth contours), he must designate this phenomenon as a metastasis in the lymph node. In this case, each nodule must be recorded as a separate lymph node in the final value of the pN category.
Metastasis in any non-regional lymph node should be considered as distant metastasis.
If the pN category criterion is size, then only the metastasis is measured, not the entire lymph node.
In the presence of only micrometastases in regional lymph nodes, i.e. metastases, the maximum size of which does not exceed 0.2 cm, add (mi) to the pN value in brackets, for example, pN1(mi). It is necessary to indicate the number of removed and metastasized lymph nodes.

sentinel lymph node

The sentinel lymph node is the first lymph node that receives lymph from the primary tumor. If there are tumor cells in the tissue of this node, then they can be in other lymph nodes. If there are no tumor cells in the sentinel node, then most likely they are absent in other lymph nodes (rarely there are several sentinel lymph nodes).
When taking into account the state of the "sentinel" lymph node, the following designations are used:
pNX(sn) Sentinel lymph node cannot be assessed,
pNO(sn) No sentinel node metastasis,
pN 1 (sn) Metastasis in the "sentinel" lymph node.

Histological classification of tumors

The histological grade of malignancy (Grade, G) for neoplasms of most localizations is indicated as follows:
GX Tumor grade cannot be determined;
G1 Highly differentiated tumor;
G2 Moderately differentiated tumor;
G3 Poorly differentiated tumor;
G4 Undifferentiated tumor.
Note: Under certain conditions, categories G3 and G4 can be combined as G3-4, i.e. "poorly differentiated - undifferentiated tumor". In the classifications of bone and soft tissue sarcomas, the terms "high grade" and "low grade" are used. Special systems for assessing the degree of malignancy have been developed for diseases: breast cancer, uterine cancer, prostate cancer and liver cancer.

Additional criteria for classifying tumors

For some special cases in the TNM and pTNM Systems, there are additional criteria, denoted by the symbols T, Y, V and A. Although their use does not change the established stage of the disease, they indicate cases that require separate additional analysis.
Symbol T Used to indicate the presence of multiple primary tumors in the same area.
Symbol Y. In cases where the tumor is assessed during or immediately after complex treatment, the values ​​of the cTNM or pTNM categories are accompanied by the Y prefix. The values ​​of ycTNM or ypTNM characterize the prevalence of the tumor at the time of the study. The Y prefix takes into account the spread of the tumor before the start of complex treatment.
Symbol V. Recurrent tumors. evaluated after a relapse-free period, denoted by the prefix V.
The character "a". This prefix indicates that the tumor was classified after autopsy.
L - Invasion of the lymphatic vessels
LX Invasion of lymphatic vessels cannot be assessed
L0 No invasion of lymphatics L1 Invasion of lymphatics
V - Venous invasion
VX Venous invasion cannot be assessed
V0 No venous invasion
VI Microscopically detected venous invasion V2 Macroscopically detected venous invasion
Note: macroscopically detected tumor invasion of the vein wall, but without tumor invasion into its lumen, belongs to category V2.
Rp - Perineural invasion
RnS Impossible to assess perineural invasion RnO No perineural invasion Pn1 Perineural invasion present
The C-factor, or the factor of certainty, reflects the reliability and validity of the classification, depending on the diagnostic methods used. Its use is optional.

Classification of tumors and definitions of C-factor

C1 The classification is based on the results of standard diagnostic procedures (examination, palpation, routine radiography and endoscopic examination of the lumen of hollow organs in order to detect tumors in some organs).
C2 Classification is based on the results of special diagnostic studies (radiography in special projections, tomography, computed tomography, ultrasonography, lymph and angiography, scintigraphy, magnetic resonance imaging, endoscopy, cytological and histological studies). C3 The classification is based on the results of exploratory surgery with biopsy and cytology. C4 Data on the prevalence of the process were obtained after a full surgical intervention with a histological examination of the remote mass
C5 Classification based on autopsy data.
Note: A C-factor value can be assigned to any of the categories T, N, and M. For example, an observation can be described as T3C2, N2C1, M0C2.
Thus, the clinical classification of cTNM usually corresponds to the certainty factor C1, C2 and C3, while the pathological classification of pTNM usually corresponds to the value of C4.

Classification of tumors category R

The presence or absence of residual tumor after treatment is indicated in category R.
Some investigators believe that the R category can only be used for primary tumors and their local or regional tumor growth. Others apply this category more broadly, incl. to designate distant metastases, therefore, when using the R category, these features must be noted.
Usually, using the TNM and pTNM classifications, they describe the anatomical extent of the tumor without taking into account the treatment performed. These classifications can be supplemented by the R category, which describes the state of the tumor after treatment. It reflects the effectiveness of therapy, the impact of additional treatments on the outcome of the disease, and in addition is a prognostic factor.

R category values:
RX Residual tumor cannot be assessed
R0 No residual tumor
R1 Microscopically detected residual tumor
R2 Macroscopic residual tumor

The TNM system is used to describe and document the anatomic extent of a disease. For the purpose of combining and analyzing data, categories can be grouped into stages. The TNM System defines carcinoma in situ as stage 0. Tumors that do not extend beyond the organ from which they originate are in most cases classified as stages I and II. Locally advanced tumors and tumors with involvement of regional lymph nodes are classified as stage III, and tumors with distant metastases are classified as stage IV. The stages are set in such a way that, as far as possible, each of the resulting groups is more or less homogeneous in terms of survival and that the survival rates in groups for neoplasms of different sites are different.
When grouped into stages using the pathoanatomical classification pTNM, in cases where the tissue under study was removed for pathoanatomical examination in order to determine the maximum value of categories T and N, category M can be both clinical (cM 1) and pathoanatomical (pM1). If there is histological confirmation of distant metastases, the pM1 category and stage will be pathologically confirmed.
Although tumor extent, as described by the TNM classification, is a significant predictor of cancer, many other factors also have a strong influence on disease outcome. Some of these are included in grouped disease stages, such as grade (for soft tissue sarcoma) and age of patients (for thyroid cancer). These classifications remain unchanged in the seventh edition of the TNM Classification. The newly revised classifications of esophageal and prostate cancer retained the stage grouping based on the principle of tumor extent, and added a prognostic grouping system that included a number of prognostic factors.

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Classification of the International Cancer Union according to the TNM system.

The TNM classification below applies only to adenocarcinoma. Transitional cell carcinoma of the prostate is classified as a tumor of the urethra.

T — primary tumor.

TX- insufficient data to evaluate the primary tumor.
T0- the primary tumor is not defined.
T1- the tumor is not clinically manifested, is not palpable and is not visualized by special methods.
T1a- the tumor is incidentally detected during histological examination and makes up less than 5% of the resected tissue.
T1b- the tumor is incidentally detected during histological examination and makes up more than 5% of the resected tissue.
T1s- the tumor is diagnosed with a needle biopsy (performed due to a high level of prostate-specific antigen).
T2- the tumor is limited to the prostate gland or extends into the capsule.
T2a- the tumor affects half of one lobe or less.
T2b- the tumor affects more than half of one lobe, but not both lobes.
T2c The tumor affects both lobes.
Note. Tumor diagnosed by needle biopsy in one or both lobes, but not palpable and not visualized, is classified as T1c.
T3 The tumor has spread beyond the capsule of the prostate gland.
T3a- the tumor extends beyond the capsule (unilateral or bilateral).
T3b- The tumor has spread to the seminal vesicle(s).
Note. Tumor extension to the apex of the prostate or into the capsule (but not beyond) of the prostate is classified as T2, not T3.
T4 An indisplaceable tumor or a tumor that has spread to adjacent structures (but not to the seminal vesicles): bladder neck, external sphincter, rectum, levator ani, and/or pelvic wall.

N - regional lymph nodes.

The regional lymph nodes for the prostate are the pelvic lymph nodes located below the bifurcation of the common iliac arteries. Category N does not depend on the side of localization of regional metastases.

NX- insufficient data to evaluate regional lymph nodes.
N0 There are no metastases in regional lymph nodes.
N1- there are metastases in regional lymph nodes.

M - distant metastases.

MX- it is not possible to determine the presence of distant metastases.
М0 There are no signs of distant metastases.
M1- Distant metastases.
M1a- damage to non-regional lymph nodes.
M1b- damage to the bones.
M1c- other localizations of distant metastases.

pTNM Pathological classification.

Depending on the combination of criteria T, N, M and G, the stage of the disease is determined:

Summary

Material prepared

18.03.2016 10:34:45

Staging of neoplasms into groups depending on their prevalence is necessary to take into account data on tumors of a particular localization, treatment planning, prognostic factors, evaluation of treatment results and control of malignant neoplasms. In other words, determining the stage of cancer is necessary in order to plan the most effective treatment tactics, as well as for the work of extras.

TNM classification

The TNM classification for describing the prevalence of neoplasms is based on 3 components:

• The first - T(lat. Tumor- tumor). This indicator determines the prevalence of the tumor, its size, germination in the surrounding tissues. Each localization has its own gradation from the smallest size of the tumor ( T0), up to the largest ( T4).
• Second component - N(lat. nodus- node), it indicates the presence or absence of metastases in the lymph nodes. Just as in the case of the T component, each tumor localization has its own rules for determining this component. The gradation comes from N0(absence of affected lymph nodes), up to N3(widespread involvement of the lymph nodes).
• Third - M(Greek Metastasis- movement) - indicates the presence or absence of distant metastases to various organs. The number next to the component indicates the extent of the malignancy. So, М0 confirms the absence of distant metastases, and M1- their presence. After the designation M, the name of the organ in which the distant metastasis was detected is usually written in brackets. For example M1 (oss) means that there are distant bone metastases, and M1 (bra)- that metastases were found in the brain. For other organs, the designations given in the table below are used.

Also, in special situations, an additional letter designation is placed before the TNM designation. These are additional criteria, denoted by the symbols “c“, “r”, "m", "y", "r" and "a".

- Symbol "s" means that the stage is established according to non-invasive examination methods.

- Symbol "r" says that the stage of the tumor was established after surgery.

- Symbol "m" used to refer to cases where several primary tumors are located in the same area at once.

- Symbol "y" used in cases where the tumor is evaluated during or immediately after anticancer treatment. The prefix "y" takes into account the prevalence of the tumor before the start of complex treatment. Values ycTNM or ypTNM characterize the prevalence of the tumor at the time of diagnosis by non-invasive methods or after surgery.

- Symbol "r" used in the evaluation of recurrent tumors after a relapse-free period.

- Symbol "a", used as a prefix, indicates that the tumor was classified after autopsy (postmortem examination).

Histological classification of cancer stages

• GX- the degree of differentiation of the tumor cannot be determined (few data);
• G1- highly differentiated tumor (non-aggressive);
• G2- moderately differentiated tumor (moderately aggressive);
• G3- poorly differentiated tumor (highly aggressive);
• G4- undifferentiated tumor (highly aggressive);

Only after the tumor has been classified according to the TNM system can staging be performed. Determining the degree of spread of the tumor process according to the TNM system or by stages is very important for the selection and evaluation of the necessary treatment methods, while the histological classification allows you to obtain the most accurate characteristics of the tumor and predict the prognosis of the disease and the possible response to treatment.

Cancer staging: 0 - 4

Traditionally Cancer stages are usually denoted from 0 to 4.. Each stage, in turn, can have the letters A and B, which divides it into two more sub-stages, depending on the prevalence of the process. Below we will analyze the most common stages of cancer.

We would like to draw attention to the fact that in our country many people like to say "degree of cancer" instead of "stage of cancer." Questions are posted on various sites about: “4 degree of cancer”, “survival with 4 degrees of cancer”, “cancer degree 3”. Remember - there are no degrees of cancer, there are only stages of cancer, which we will discuss below.

Stages of cancer on the example of a tumor of the intestine

stage 0 cancer

At stage 0 cancer, the boundaries of the tumor do not extend beyond the epithelium that gave rise to the neoplasm. With early detection and timely initiation of treatment, the prognosis for stage 0 cancer is almost always favorable, that is, stage 0 cancer in the vast majority of cases is completely curable.

stage 1 cancer

stage 2 cancer

The second stage of cancer is considered the most common stage of cancer, at which cancer is diagnosed. The prognosis for stage 2 cancer depends on many factors, including localization and histological features of the tumor. In general, stage II cancer is successfully treated.

stage 3 cancer

The third stage of cancer does not provide for distant metastases to various organs, which is a positive thing and determines a favorable prognosis.

stage 4 cancer

Rarely, there are cases when stage 4 cancer can be diagnosed even in the absence of distant metastases. Large, poorly differentiated, fast-growing tumors are also often referred to as stage 4 cancers. There is no cure for stage 4 cancer, as well as in stage 3 cancer. At the fourth stage of cancer, the disease takes on a chronic course, and only the introduction of the disease into remission is possible.

It is always important for physicians to have a standardized description of colorectal cancer, and there are several reasons for this. First of all, the patient's prognosis directly depends on the degree of spread of the tumor during the initial diagnosis. Tumors that have distant spread (metastases) to other organs are more aggressive and common than small tumors that are confined to the intestinal wall. Secondly, the common system allows physicians to communicate very important information to each other and adhere to an accurate treatment plan. It also makes it possible to determine which patients need special investigations, surgery or chemotherapy. For example, surgery alone may be sufficient to treat small tumors, while more advanced tumors may require a combination of surgery and chemotherapy. The stage of the tumor is the language in which doctors describe the nature of the tumor, as well as the degree of its local and distant spread.

Tumor staging is based on three criteria: the depth of tumor ingrowth into the intestinal wall (T), the presence of spread of tumor cells in the lymph nodes (N) and, finally, the presence or absence of metastases (M). These three components form the TNM system for colorectal cancer staging (see tables below).

Stage T (tumor)- depth of tumor ingrowth into the intestinal wall. The lower the value of this stage, the less invasive tumor growth. Stage T0 tumor can still be considered fairly benign, since the growth of this tumor is limited only to the intestinal mucosa. Stage T4 tumor means that the tumor has sprouted not only all layers of the intestinal wall, but also neighboring organs.

Stage N (lymphnodes)- indicates the number of lymph nodes in which cancer cells were found. Stage N0 means that no cancer cells were found in any of the lymph nodes in the post-mortem examination. The Nx stage means that the number of affected lymph nodes is unknown. This may be at the stage of examination before surgery, when it is impossible to determine whether the lymph nodes are affected or not. Until a post-mortem examination is performed, the stage is considered as Nx.

Stage M (metastases)- indicates whether the tumor has distant screenings - metastases.

Tumor stage according to TNM system

General tumor stage

To understand how the stage is set, look in the table for the headings T, N, and M. Each column contains numbers or the word "any". The second line in the table corresponds to stage I, the columns contain the following data: stage T 1 or 2, stages N and M - 0. This means that if the tumor grows only into the intestinal wall (stage T1 or T2) and there are no cancer cells in any lymph node cells (stage N0) and no distant metastases (stage M0), then the tumor will be classified as a stage I cancer. A tumor that grows through the intestinal wall (stage T3 or T4) but does not involve lymph nodes or distant metastases is stage II, and so on.

Staging plays a very important role in determining treatment tactics. Stage I tumors are usually treated with surgery alone, while stage III tumors are usually treated with both surgery and chemotherapy. Thus, tumor staging is a very important step in preoperative diagnosis. In order to determine the stage before surgery, many studies may be required. Computed tomography (CT), chest x-ray, ultrasound (ultrasound), magnetic resonance imaging (MRI) and positron emission tomography (PET) are very informative tests to help determine the extent of tumor spread. However, the most accurate method for determining the stage of a tumor is to examine the part of the intestine removed during surgery using a microscope.

It is very important that patients understand the principles of tumor staging and how it is done in order to competently discuss treatment options and prognosis with the doctor.

Classification of breast cancer is carried out by WHO according to the TNM system, on the basis of which the stage of breast cancer is determined as stage 1, 2, 3 or 4. Also, for the diagnosis and choice of treatment tactics, classifications according to ICD 10, according to histology, tumor growth rate, and determining the risk group for surgery are used.

Classification of breast cancer according to ICD 10

C50 Malignant disease of the breast.
C50.0 Nipple and areola.
C50.1 Central part of the mammary gland.
C50.2 Upper inner quadrant.
C50.3 Lower inner quadrant.
C50.4 Upper outer quadrant.
C50.5 Infero-outer quadrant.
C50.6 Axillary region.
C50.8 Spread over more than one of the above areas.
C50.9 Location, unspecified.
D05.0 Lobular carcinoma in situ
D05.1 Intraductal carcinoma in situ

Histological classification of breast cancer

At the moment, the WHO histological classification of 1984 is used.

A. Non-invasive cancer (in situ)

Intraductal (intracanalicular) cancer in situ;

Lobular (lobular) cancer in situ.

B. Invasive cancer (infiltrating carcinoma)

ductal;

Lobular;

Mucous (mucinous);

Medullary (cerebral);

tubular;

Apocrine;

Other forms (papillary, squamous, juvenile, spindle cell, pseudosarcomatous, etc.).

C. Special (anatomical and clinical) forms

Paget's cancer;

Inflammatory cancer.

The most commonly diagnosed histological forms of cancer are: squamous cell carcinoma;
Paget's disease (a special kind of squamous cell carcinoma in the area of ​​the nipple of the gland); adenocarcinoma (glandular tumor). The most favorable prognosis for the course and treatment are: tubular, mucous, medullary and adenocystic cancer.

If the pathological process does not extend beyond one duct or lobule, then the cancer is called non-infiltrating. If the tumor spreads to the lobules lying around, then it is called infiltrating. Infiltrating cancer is the most frequently detected form (ductal form in 50-70% of cases and lobular form in 20%).

Read more about the treatment and prognosis of breast cancer on our website.

Classification by tumor growth rate

The growth rate of a breast tumor is determined using radiation diagnostic methods, the growth rate of cancer makes it clear how malignant the process is.

Rapidly growing cancer (the total mass of tumor cells becomes 2 times larger in 3 months).

Average growth rate (doubling of mass occurs within a year).

Slow-growing (2-fold increase in tumor occurs in more than a year).

TNM classification of breast cancer

T - definition of the primary tumor node.

N - involvement of lymph nodes.

M - the presence of metastases.

Primary tumor (T)

Tx - insufficient data to evaluate the primary tumor.

That - the primary tumor is not determined.

Tis, cancer in situ.

Tis (DCIS) – preinvasive carcinoma (ductal carcinoma in situ).

Tis (LCIS) - non-infiltrating intraductal or lobular carcinoma (lobular carcinoma in situ).

Tis (Paget "s) - Paget's cancer of the nipple of the breast in the absence of a tumor in the mammary gland.

T1 - Tumor ≤ 2cm in greatest dimension.

T1mic - microinvasive cancer (≤ 0.1 cm in greatest dimension).

T1a - tumor 0.1 - 0.5 cm.

T1b - tumor 0.5 - 1.0 cm.

T1c - tumor 1 - 2 cm.

T2 - tumor 2.1 - 5 cm.

T3 - tumor > 5 cm.

T4 Tumor of any size with direct extension to the skin or chest wall (fascia, muscle, bone).

T4a: Tumor invades the chest wall but does not grow into the pectoral muscles;

T4b: tumor with skin ulceration and/or edema (including orange peel symptom) and/or metastases in the skin of the breast of the same name;

T4c: combination of T4a and T4b;

T4d: Primary edematous form of cancer, inflammatory breast cancer (without a primary focus).

Regional lymph nodes (N)

The localization of the affected regional lymph nodes and the prevalence of the tumor process are assessed using palpation, ultrasound, CT, MRI, PET) and pathoanatomically (according to the results of histological examination of the lymph nodes after surgery).

Clinical classification

Nx - insufficient data to assess the state of regional lymph nodes.

No - there are no signs of metastatic involvement of regional lymph nodes.

N1 - metastases in the displaced axillary lymph nodes or lymph node on the side of the lesion.

N2 - metastases in the axillary lymph nodes fixed to each other, on the side of the lesion, or clinically detectable (on examination, ultrasound, CT, MRI, PET, but not on lymphoscintigraphy) metastases in the internal lymph nodes of the mammary gland on the side of the lesion in the absence of clinically defined metastases in the axillary lymph nodes:

N2a - metastases in the axillary lymph nodes on the side of the lesion, fixed to each other, or to other structures (skin, chest wall)

N2b - metastases, determined only clinically (during examination, ultrasound, CT, MRI, PET, but not with lymphoscintigraphy), in the internal lymph nodes of the mammary gland in the absence of clinically detectable metastases in the axillary lymph nodes on the side of the lesion;

N3 - metastases in the subclavian lymph nodes on the side of the lesion with / without metastases in the axillary lymph nodes, or clinically detectable metastases (on examination, ultrasound, CT, MRI, PET, but not on lymphoscintigraphy) in the internal lymph nodes of the mammary gland on the side of the lesion at the presence of metastases in the axillary lymph nodes or metastases in the supraclavicular lymph nodes on the side of the lesion with / without metastases in the axillary or internal lymph nodes of the mammary gland:

N3a: metastases in the subclavian lymph nodes on the side of the lesion;

N3b: metastases in the internal lymph nodes of the mammary gland on the side of the lesion;

N3c: metastases in the supraclavicular lymph nodes on the side of the lesion.

Pathological classification of breast cancer

PNx - insufficient data to assess the state of regional lymph nodes (nodes removed earlier, or not removed for post-mortem examination).

РNo - no histological signs of regional lymph node metastases, no additional studies were performed on isolated tumor cells.

If there are only isolated tumor cells in the regional lymph nodes, this case is classified as No. Single tumor cells in the form of small clusters (no more than 0.2 mm in the largest dimension) are usually diagnosed by immunohistochemical or molecular methods. Isolated tumor cells usually do not show metastatic activity (proliferation or stromal reaction)

PNo(I-): no histological signs of regional lymph node metastases; negative results of immunohistochemical research.

РNo(I+): no histological signs of regional lymph node metastases; positive results of IHC in the absence of accumulations of tumor cells more than 0.2 mm in the largest dimension according to IHC

PNo(mol-): no histological signs of regional lymph node metastases; negative results of molecular research methods.

РNo(mol+): no histological signs of regional lymph node metastases; positive results of molecular research methods.

PN1 - metastases in 1-3 axillary lymph nodes on the side of the lesion and / or in the internal lymph nodes of the mammary gland on the side of the lesion with microscopic metastases, determined by excision of the sentinel lymph node, but not detected clinically (during examination, ultrasound, CT, MRI, PET, but not lymphoscintigraphy):

PN1mi: micrometastases (> 0.2 mm, but
- pN1a: metastases in 1-3 axillary lymph nodes on the side of the lesion;

РN1b: microscopic metastases in the internal lymph nodes of the mammary gland on the side of the lesion, detected by excision of the sentinel lymph node, but not detected clinically (by examination, ultrasound, CT, MRI, PET, but not by lymphoscintigraphy);

PN1c: metastases in 1-3 axillary lymph nodes and in the internal lymph nodes of the mammary gland on the side of the lesion with microscopic metastases detected by excision of the sentinel lymph node, but not detected clinically (by examination, ultrasound, CT, MRI, PET, but not by lymphoscintigraphy).

PN2 - metastases in 4 - 9 axillary lymph nodes, on the side of the lesion, or clinically detectable metastases (on examination, ultrasound, CT, MRI, PET, but not on lymphoscintigraphy) in the internal lymph nodes of the mammary gland on the side of the lesion in the absence of axillary metastases lymph nodes:

N2a - metastases in 4 - 9 axillary lymph nodes on the side of the lesion, one of which is > 2 mm;

N2b - clinically detectable metastases (on examination, ultrasound, CT, MRI, PET, but not on lymphoscintigraphy), in the internal lymph nodes of the mammary gland on the side of the lesion, in the absence of metastases in the axillary lymph nodes.

PN3 - metastases in 10 or more axillary lymph nodes on the side of the lesion; or metastases in the subclavian lymph nodes on the affected side; or clinically detectable (by examination, ultrasound, CT, MRI, PET, but not by lymphoscintigraphy) metastases in the internal lymph nodes of the mammary gland on the side of the lesion in the presence of one or more axillary lymph nodes affected by metastases; or lesions of more than 3 axillary lymph nodes with clinically negative but microscopically proven metastases in the internal lymph nodes of the mammary gland; or metastases in the supraclavicular nodes on the side of the lesion:

PN3a: metastases in 10 or more axillary lymph nodes, one of which is > 2 mm or metastases in the subclavian lymph nodes on the side of the lesion;

PN3b: clinically detectable (by examination, ultrasound, CT, MRI, PET, but not by lymphoscintigraphy) metastases in the internal lymph nodes of the mammary gland on the side of the lesion in the presence of one or more axillary lymph nodes affected by metastases; or lesions of more than 3 axillary lymph nodes and internal lymph nodes with clinically negative (on examination, ultrasound, CT, MRI, PET, but not on lymphoscintigraphy), but microscopically proven metastases in the internal lymph nodes of the mammary gland on stencinal biopsy;

PN3c: metastases in the supraclavicular lymph nodes on the side of the lesion.

Distant metastases (M)

Mx - insufficient data to assess the presence of distant metastases

Mo - no signs of distant metastases.

M1 - there are distant metastases, including skin lesions outside the gland, in the supraclavicular lymph nodes.

Stages of breast cancer

Based on the TNM system, the stages of breast cancer are determined. Depending on the stage, choose the tactics of treatment. The stages of breast cancer are presented in the table.

Risk groups for resectable breast cancer

Before performing breast surgery, a risk group is determined. Borderline women should not be considered a minimum or maximum risk. Borderline women with low estrogen receptor levels should be assigned to the appropriate risk group based on other individual prognostic factors.

Classification into subtypes to determine the tactics of treating breast cancer