Cellular Classification of Bladder Cancer

More than 90% of bladder carcinomas are transitional cell carcinomas derived from the uroepithelium. About 6% to 8% are squamous cell carcinomas, and 2% are adenocarcinomas.[1] Adenocarcinomas may be either of urachal origin or of nonurachal origin; the latter type is generally thought to arise from metaplasia of chronically irritated transitional epithelium.[2] Pathologic grade, which is based on cellular atypia, nuclear abnormalities, and the number of mitotic figures is of great prognostic importance.

References:

1. Mostofi FK, Davis CJ, Sesterhenn IA: Pathology of tumors of the urinary tract. In: Skinner DG, Lieskovsky G, eds.: Diagnosis and Management of Genitourinary Cancer. Philadelphia, Pa: WB Saunders, 1988, pp 83-117.
2. Wilson TG, Pritchett TR, Lieskovsky G, et al.: Primary adenocarcinoma of bladder. Urology 38 (3): 223-6, 1991.

Stage Information for Bladder Cancer

Note: This Stage Information section has been updated to include information from the seventh edition (2010) of the American Joint Committee on Cancer's AJCC Cancer Staging Manual. The PDQ Adult Treatment Editorial Board, which is responsible for maintaining this summary, is currently reviewing the new staging categories to determine whether additional changes need to be made to other parts of the summary. Any necessary changes will be made as soon as possible.

The clinical staging of carcinoma of the bladder is determined by the depth of invasion of the bladder wall by the tumor. This determination requires a cystoscopic examination that includes a biopsy, and examination under anesthesia to assess the size and mobility of palpable masses, the degree of induration of the bladder wall, and the presence of extravesical extension or invasion of adjacent organs. Clinical staging, even when computed tomographic and/or magnetic resonance imaging scans and other imaging modalities are used, often underestimates the extent of tumor, particularly in cancers that are less differentiated and more deeply invasive.[1,2,3]

Definitions of TNM

The American Joint Committee on Cancer has designated staging by TNM classification to define bladder cancer.[4]

Table 1. Primary Tumor (T)a

Table 2. Regional Lymph Nodes (N)a,b

Table 3. Distant Metastasis (M)a

Table 4. Anatomic Stage/Prognostic Groupsa

An older, less frequently used staging system was derived by comparing clinical estimates of stage with the pathologic stage of radical cystectomy specimens.[2,3] To better ensure uniform staging and reporting of clinical results, the use of the modern TNM classification described above is recommended.

References:

1. Consensus conference. Magnetic resonance imaging. JAMA 259 (14): 2132-8, 1988.
2. Marshall VF: The relationship of the preoperative estimate to the pathologic demonstration of the extent of vesical neoplasms. J Urol 68(4): 714-723, 1952.
3. Skinner DG: Current state of classification and staging of bladder cancer. Cancer Res 37 (8 Pt 2): 2838-42, 1977.
4. Urinary bladder. In: Edge SB, Byrd DR, Compton CC, et al., eds.: AJCC Cancer Staging Manual. 7th ed. New York, NY: Springer, 2010, pp 497-505.