In bladder cancer staging, which factor is used to classify stages?

• A. TNM staging factors
• B. Tumor size only
• C. Lymph node count only
• D. Metastasis only

Answer: (A)

Staging uses the TNM system, which describes three key aspects of bladder cancer: how deeply the tumor invades the bladder wall (T), whether regional lymph nodes are involved (N), and whether there is distant metastasis (M). This approach is best because it combines local invasion, nodal status, and spread to distant sites into one framework, producing stages that reflect prognosis and guide treatment. Tumor size alone doesn’t capture how deep the invasion goes or the spread to nodes or distant sites; lymph node count alone misses the extent of local invasion and distant metastasis; and metastasis alone ignores the depth of invasion and nodal involvement. By integrating T, N, and M, clinicians classify the cancer in a way that accurately maps disease severity and informs management.