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Classification of cancer
Last reviewed: 23.04.2024
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The clinical classification of the cancer of the TNM International Cancer Union (ICPM) is necessary to develop a methodology for the uniform presentation of clinical data. Clinical description and histological classification of cancer can play a significant role: in planning treatment; forecasting; evaluation of treatment outcomes; exchange of information between medical centers; contribute to the further study of cancer. The division of tumors into groups by the so-called "stages" of the process is based on the fact that with localized tumors the survival percentage is higher than with lesions that extend beyond the organ.
The classification of TNM cancer is based on the clinical and histopathological determination of the anatomical spread of the tumor. An important task of the clinician is to determine the prognosis of the disease and plan the most effective course of treatment, which requires an objective assessment of the anatomical prevalence of the tumor. TNM meets these requirements.
[Grouping by stages
The classification of cancer by the TNM system provides a fairly accurate description of the anatomical spread of the disease. Four degrees for T, three degrees for N and two degrees for M constitute 24 categories of TNM. For the analysis and compilation of tables, these categories need to be grouped into the appropriate number of groups by stages.
Carcinoma in situ corresponds to stage 0. Cases with the presence of distant metastases - stage IV. Stages II (A, B) and III (A, B) reflect variants of the local regional prevalence of the tumor process: different combinations of tumor size (T) and regional lymph node involvement (N).
Cancer classification TNM: general rules
The TNM system, adopted to describe the anatomical spread of the lesion, is based on three components:
T (tumor - tumor) - the spread of the primary tumor; N (nodes - lymph node) - absence or presence of metastases in regional lymph nodes and the degree of their lesion;
M (metastases - organ metastases) - the absence or presence of distant metastases.
To these three components are added figures indicating the extent of the prevalence of the malignant process: T0, T1, T2, T3; N0, N1, N2, N3; M0, M1. In all cases, general principles are used: T - primary tumor:
Tx - it is not possible to estimate the size and local distribution of the primary tumor; T0 - primary tumor is not detected; Tis - preinvasive carcinoma (carcinoma in situ); T1, T2, T3, T4 - reflects the increase in the size and / or local distribution of the primary tumor; N - regional lymph nodes;
Nx - insufficient data for assessment of regional lymph nodes;
N0 - no regional metastases;
N1, N2, N3 - reflect a different degree of metastatic lesions of regional lymph nodes; M - distant metastases;
Mx - insufficient data for the definition of distant metastases;
M0 - no signs of distant metastases;
M1 - there are distant metastases.