T1m-mucosal involvement
T1sm-submucosal involvement
T2-muscularis propia involvement
T3-adventitial involvement
T4-ajacent organ involvement
T4a means the cancer has grown into the tissue covering the lungs (pleura), the outer covering of the heart (pericardium), the muscle at the bottom of the rib cage (diaphragm), or the tissue lining the abdomen (peritoneum)
T4b means that the cancer has spread into other nearby structures such as the windpipe (trachea), a spinal bone (vertebra) or a major blood vessel (the aorta).
There are 4 possible stages describing whether the lymph nodes contain cancer – N0 to N3.
N0 means there are no lymph nodes containing cancer cells.
N1 means there are cancer cells in 1 or 2 nearby lymph nodes.
N2 means there are cancer cells in 3 to 6 nearby lymph nodes.
N3 means there are cancer cells in 7 or more nearby lymph nodes.
Metastasis (M) describes whether the cancer has spread to a different part of the body.
There are 2 stages of metastasis.
M0 means the cancer has not spread to other organs.
M1 means the cancer has spread to other parts of the body.