Lung cancer staging
Staging and grading
Staging describes the diagnostic procedure following the diagnosis of a malignant tumor. In addition to histology, staging plays a decisive role in the choice of therapy and the statements about the prognosis.
Staging assesses the spread of the tumor in the organism.
As part of staging, the so-called Grading. The tumor cells are classified according to their differentiation. Differentiation in this case means to what extent the cells from the biopsy obtained are still similar to the original cells from which they originated (bronchial cells). There are four different levels:
G1 - the tumor cells are well differentiated, i.e. they are similar to the original tissue except for minor changes
G2 - moderately differentiated cells
G3 - poorly differentiated cells
G4 - the cells are undifferentiated, i.e. no longer recognizable as a former bronchial cell.
The grading says something about the aggressiveness and the growth rate of the tumor. The more undifferentiated the cells are, the faster and more aggressively they grow into the surrounding tissue.
To assess the spread of solid tumors, the so-called TNM classification used, based on which the disease is divided into different stages.
T stands for tumor and evaluates the local tumor spread in the tissue, N stands for node and evaluates the involvement of the lymph nodes, M. stands for metastasis and refers to the presence of settlements of the tumor in the organism. Numbers are assigned to each of the letters, e.g. at T mostly 4 degrees of dispersion.
Based on the TNM classification, the Stage division from I to IV. Stage I. means localized tumor without lymph node involvement and without metastases, stage IV the presence of metastases. In the stadiums II and III tumors with greater local spread and / or differently pronounced lymph node involvement are classified.
A simpler classification is often used for small cell lung cancer; there are only two stages:
- limited disease (approx. 35% at diagnosis): limitation to one half of the lung without involvement of the lymph nodes or the pleura (pleura, serous skin around the lungs).
- Extended disease (approx. 65%) all other stages.
