One of the most common cancers of the urinary tract is bladder cancer. Most bladder cancers are transitional cell carcinomas (TCC), which arise from the lining of the urinary tract called urothelium. Transitional cell carcinoma is thought to be caused by a change in the urothelium, and it can occur anywhere that urothelium is present. TCC can recur after treatment, and patients require lifelong follow-up.
Risk factors for developing bladder cancer include:
- Cigarette smoking
- Occupational exposure to certain chemicals (i.e., aniline dyes and petrochemicals)
- Previous treatment with Cytoxan (cyclophosphamide, a chemotherapy agent)
- Previous pelvic irradiation
Other types of bladder cancer which can occur, although much less frequently, are:
- Squamous cell carcinoma, which is associated with a history of chronic bladder irritation from stones, infection, or long-term catheter use. Most patients have advanced disease at the time of diagnosis and the usual treatment is aggressive surgical intervention.
- Adenocarcinomas of the bladder can arise from the bladder (primary cancer), or arise from another organ (metastatic cancer). Patients diagnosed with adenocarcinoma of the bladder should be evaluated for the source of the cancer prior to treatment. Most of these tumors are invasive and are treated with surgical intervention.
Signs and symptoms
Patients with bladder cancer may have hematuria (blood in the urine), urinary frequency, urgency, and/or painful urination. The blood may be visible to the patient, or may be microscopic and only detected by a urine test. Upon seeing a urologist for these symptoms, a urine sample is collected and examined for abnormal cells which may indicate cancer. A CT urogram or ultrasound is obtained, which allows the urologist to examine the kidneys and ureters for tumors. The urologist will also perform a cystoscopy, which is an in-office procedure using an instrument which is inserted into the urethra and allows the doctor to examine the interior of the bladder for tumor, stones, or suspicious areas. If a suspicious area is discovered, a small amount of tissue is removed from the area (biopsied) and sent to a laboratory for analysis.
Treatment of bladder cancer depends on whether the tumor is superficial (on the surface of the bladder lining) or deep (invading the muscle).
Superficial bladder tumors may be treated with a surgical procedure called transurethral resection of the bladder tumor (TURBT). During this procedure, the urologist inserts a cystoscope and electrocautery device into the urethra and bladder and cauterizes the tumor. Following surgical removal of the tumor, further treatment depends on the "likelihood of recurrence" of the tumor.
A patient is considered to have a high "likelihood of recurrence" based on pathology results (grade of tumor and depth of invasion) the presence of multiple tumors, or a history of previous tumors. Patients with a high likelihood of recurrence will require additional treatment following TURBT. Approximately 3 weeks after surgery, patients receive chemo/immunotherapy by means of a catheter which is placed in the bladder and a chemotherapy agent is flushed into the bladder. The agent is left in the bladder for one to two hours while the patient moves from side to side in order to coat the entire bladder surface. This is performed weekly for six to eight weeks following TURBT. These patients require life-long follow-up which consists of periodic urine tests, CT urogram or ultrasound, and cystoscopy.
Patients with a low "likelihood of recurrence" do not require additional treatment; however, they may require long-term follow-up consisting of periodic urine tests, CT urogram or ultrasound, and cystoscopy.
If the tumor invades the bladder wall (muscle invasive), it is considered a deep tumor and requires more aggressive treatment. A radical cystectomy (removal of the bladder and the surrounding lymph nodes) is the most effective treatment for muscle invasive bladder cancer. This procedure includes the removal of the prostate in men, and the removal of the uterus and ovaries in women. In some cases, a partial cystectomy (removal of only the cancerous portion of the bladder) may be performed.
Following cystectomy, a number of options are available to allow for urinary drainage. Segments of intestine can be used to create an artificial bladder or pouch, which can be connected to the abdominal wall or attached to the uretra. Urine drains freely from the kidneys through the ureters and into the artificial bladder. The artificial bladder must be emptied by increasing abdominal pressure and voding and/or by catheterization every four to six hours.
Patients with TCC that has spread beyond the bladder into lymph nodes or other parts of the body may be candidates for chemotherapy. These patients are referred to a medical oncologist for further treatment.