Bladder Cancer Overview
The bladder is an organ located in the pelvic cavity that stores and discharges urine. Urine is produced by the kidneys, carried to the bladder by the ureters, and discharged from the bladder through the urethra. Bladder cancer accounts for approximately 90% of cancers of the urinary tract (renal pelvis, ureters, bladder, urethra). There are a number of types of bladder surgery procedures and options available today.
Bladder cancer usually originates in the bladder lining, which consists of a mucous layer of surface cells that expand and deflate (transitional epithelial cells), smooth muscle, and a fibrous layer. Tumors are categorized as low-stage (superficial) or high-stage (muscle invasive).
In industrialized countries (e.g., United States, Canada, France), more than 90% of cases originate in the transitional epithelial cells (called transitional cell carcinoma; TCC). In developing countries, 75% of cases are squamous cell carcinomas caused by Schistosoma haematobium (parasitic organism) infection. Rare types of bladder cancer include small cell carcinoma, carcinosarcoma, primary lymphoma, and sarcoma.
Incidence and Prevalence
According to the National Cancer Institute, the highest incidence of bladder cancer occurs in industrialized countries such as the United States, Canada, and France. Incidence is lowest in Asia and South America, where it is about 70% lower than in the United States. Incidence of bladder cancer increases with age. People over the age of 70 develop the disease 2 to 3 times more often than those aged 55–69 and 15 to 20 times more often than those aged 30–54.
Bladder cancer is 2 to 3 times more common in men. In the United States, approximately 38,000 men and 15,000 women are diagnosed with the disease each year. Bladder cancer is the fourth most common type of cancer in men and the eighth most common type in women. The disease is more prevalent in Caucasians than in African Americans and Hispanics.
Causes and Risk Factors
Cancer-causing agents (carcinogens) in the urine may lead to the development of bladder cancer. Cigarette smoking contributes to more than 50% of cases, and smoking cigars or pipes also increases the risk. Other risk factors include the following:
• Chronic bladder inflammation (recurrent urinary tract infections, urinary stones)
• Consumption of Aristolochia fangchi (herb used in some weight-loss formulas)
• Diet high in saturated fat
• Exposure to second-hand smoke
• External beam radiation
• Family history of bladder cancer (several genetic risk factors identified)
• Gender (male)
• Infection with Schistosoma haematobium (parasite found in many developing countries)
• Personal history of bladder cancer
• Race (Caucasian)
• Treatment with certain drugs (e.g., cyclophosfamide—used to treat cancer)
Exposure to carcinogens in the workplace also increases the risk for bladder cancer. Medical workers exposed during the preparation, storage, administration, or disposal of antineoplastic drugs (used in chemotherapy) are at increased risk. Occupational risk factors include recurrent and early exposure to hair dye, and exposure to dye containing aniline, a chemical used in medical and industrial dyes. Workers at increased risk include the following:
• Truck drivers
• Workers in rubber, chemical, textile, metal, and leather industries
Signs and Symptoms
The primary symptom of bladder cancer is blood in the urine (hematuria). Hematuria may be visible to the naked eye (gross) or visible only under a microscope (microscopic) and is usually painless. Other symptoms include frequent urination and pain upon urination (dysuria).
The type of surgery depends on the stage of the disease. In early bladder cancer, the tumor may be removed (resected) using instruments inserted through the urethra (transurethral resection).
Bladder cancer that has spread to surrounding tissue (e.g., Stage T2 tumors, Stage T3a tumors) usually requires partial or radical removal of the bladder (cystectomy). Radical cystectomy also involves the removal of nearby lymph nodes and may require a urostomy (opening in the abdomen created for the discharge of urine). Complications include infection, urinary stones, and urine blockages. Newer surgical methods may eliminate the need for an external urinary appliance.
In men, the standard surgical procedure is a cystoprostatectomy (removal of the bladder and prostate) with pelvic lymphadenectomy (removal of the lymph nodes within the hip cavity). The seminal vesicles (semen-conducting tubes) also may be removed. In some cases, this can be performed in a manner that preserves sexual function.
In women with T2 to T3a tumors, the standard surgical procedure is radical cystectomy (removal of the bladder and surrounding organs) with pelvic lymphadenectomy. Radical cystectomy in women also involves removal of the uterus (womb), ovaries, fallopian tubes, anterior vaginal wall (front of the birth canal), and urethra (tube that carries urine from the bladder out of the body). Segmental cystectomy (partial removal of the bladder), which is a bladder-preserving procedure, may be used in some cases (e.g., patients with squamous cell carcinomas or adenocarcinomas that arise high in the bladder dome). When segmental cystectomy is performed, it may be preceded by radiation therapy.
Urinary Tract Diversion
Until recently, most bladder cancer patients who underwent cystectomy (bladder removal) required an ostomy (surgical creation of an artificial opening) and an external bag to collect urine. Newer reconstructive surgical methods include the continent urinary reservoir, the neobladder, and the ileal conduit.
The continent urinary reservoir is a urinary diversion technique that involves using a piece of the colon (large intestine) to form an internal pouch to store urine. The pouch is specially refashioned to prevent back-up of urine into the ureters (tubes that carry urine out of the kidneys and into the bladder) and kidneys. The patient drains the pouch with a catheter several times a day, and the stoma site is easily concealed by a band aid.
The neobladder procedure involves suturing a similar intestinal pouch to the urethra so the patient is able to urinate as before, without the need for a stoma. In many cases, there is no sensation to void, but some patients experience abdominal cramping as the neobladder fills. Complications of the continent urinary reservoir and neobladder include bowel (intestine) obstruction, blood clots, pneumonia (lung inflammation), ureteral reflux (back-flow), and ureteral blockage.
The ileal conduit is a urinary channel that is surgically created from a small piece of the patient’s bowel. During this procedure, the ureters are attached to one end of the bowel segment and the other end is brought out of the surface of the body to make a stoma. An external, urine-collecting bag is attached to the stoma and is worn at all times.
Complications of the ileal conduit procedure include bowel obstruction, urinary tract infection (UTI), blood clots, pneumonia, upper urinary tract damage, and skin breakdown around the stoma.