What Are the Stages of Bladder Cancer?

The stages of bladder cancer are determined by how far the cancer has spread within the bladder and to other parts of the body. The main staging system for bladder cancer is the TNM system, which takes into account the following factors:

T stage (tumor stage): This describes the size and location of the tumor within the bladder. The T stages range from Ta to T4a:

- Ta: Non-invasive papillary carcinoma (the cancer is confined to the inner lining of the bladder and has not invaded the bladder wall).

- T1: Invasion of the subepithelial connective tissue.

- T2: Invasion of the muscularis propria (the muscular layer of the bladder wall).

- T3: Invasion of the perivesical fat (the fatty tissue surrounding the bladder).

- T4a: Invasion of adjacent organs (such as the prostate, uterus, or rectum).

N stage (nodal stage): This describes whether the cancer has spread to nearby lymph nodes. The N stages range from N0 to N3:

- N0: No regional lymph node involvement.

- N1: Metastasis to a single regional lymph node.

- N2: Metastasis to multiple regional lymph nodes.

- N3: Metastasis to lymph nodes outside the pelvis (such as the inguinal or para-aortic lymph nodes).

M stage (metastasis stage): This describes whether the cancer has spread to other parts of the body (distant metastases). The M stages range from M0 to M1:

- M0: No distant metastasis.

- M1: Distant metastasis (the cancer has spread to other organs beyond the bladder and regional lymph nodes).

Based on the TNM stage, bladder cancer is classified into stages ranging from stage 0 to stage IV:

Stage 0: Non-invasive papillary carcinoma (Ta, N0, M0).

Stage I: Tumor invades the subepithelial connective tissue (T1, N0, M0).

Stage II: Tumor invades the muscularis propria (T2, N0, M0).

Stage III: Tumor invades the perivesical fat (T3, N0 or N1, M0).

Stage IV: Tumor invades adjacent organs (T4a, any N, M0) or has distant metastases (any T, any N, M1).

The stage of bladder cancer helps determine the appropriate treatment and prognosis for the individual patient.