The stage of evolution of a breast cancer is established during the diagnosis. To define it, examinations are essential, starting with a sample (biopsy) of the tumor that will be analyzed in the laboratory.
Other examinations can be performed, such as an MRI, a scanner ...
The main criterion is the size of the tumor, whether or not lymph nodes are affected by cancer cells, or the presence of metastases elsewhere in the body.
The different stages
There are five stages:
> Stage 0 : we talk about cancer "in situ". It is ductal carcinoma in situ (the cells are located in a galactophore duct and have not migrated to the outside), and lobular carcinoma in situ (the cells are located in the membrane of a lobule). He did not invade the surrounding tissues. Once removed, the cells will not spread.
> Stage 1 : The tumor is 2 centimeters or less, and the cancer has not spread to the lymph nodes.
> Stage 2 : the cancer measures more than 2 cm, without having invaded a ganglion. Or it is less than 5 centimeters and it reaches from 1 to 3 lymph nodes.
> Stage 3 : The cancer has spread to the ganglia and perhaps to the surrounding tissues of the muscle or skin.
> Stage 4 : Cancer has metastasized to other parts of the body.