Bladder cancer: A common form of cancer that begins in the lining of the bladder as a superficial tumor (carcinoma in situ). The most common warning sign is blood in the urine. If there is enough blood to color the urine it may range from slightly rusty to deep red. Other symptoms may be pain during urination and frequent urination or feeling the need to urinate without results.

The diagnosis may be suspected by findings in the medical history and physical examination, urine, and intravenous pyelogram (IVP). Confirmation requires a biopsy usually taken through a cystoscope (a thin lighted tube inserted through the urethra into the bladder).

The bladder is lined with cells called transitional cells and squamous cells. Over 90% of bladder cancers begin in the transitional cells as transitional cell carcinoma. About 8% of bladder cancer patients have squamous cell carcinomas. The tumor may grow through the lining into the muscular wall of the bladder and extend into nearby organs such as the uterus or vagina (in women) or the prostate gland (in men). It also may invade the wall of the abdomen. When bladder cancer spreads beyond the bladder, the malignant cells are frequently found in nearby lymph nodes and may have spread to other lymph nodes or other places including the lungs, liver, or bones.

Risk factors for bladder cancer include age (people under 40 rarely get this disease), race (Whites are at twice the risk of Blacks and Hispanics, with Asians at least risk), gender (men are at 2-3 times higher risk than women), family history of bladder cancer, use of tobacco (a major risk factor), treatment with cyclophosphamide or arsenic (for cancer or another disease), and occupational exposures (to workers in the rubber, chemical, and leather industries, hairdressers, machinists, metal workers, printers, painters, textile workers, and truck drivers).

The type of treatment depends on the growth, size, and location of the tumor. Surgery is common. It may be a transurethral resection (removal or burning away the cancer through a cystoscope), segmental cystectomy (removal of part of the bladder), or radical cystectomy (removal of the entire bladder, the nearby lymph nodes, part of the urethra, and nearby organs that may contain cancer cells). Patients may also have chemotherapy, biological therapy, or radiotherapy.

Prolonged survival in most patients with superficial cancers is achieved by transurethral resection (TUR) with or without intravesical (within-the-bladder) chemotherapy. However, cure is currently not possible for the majority of patients with deeply invasive tumors and for most patients with regional or distant metastases.