Bladder Cancer

written by Dr George Lee Eng Geap on 19 April 2011

Bladder cancer is the sixth most common cancer in the developed world. In recent decades there has been a steady increase in the incidence of bladder cancer. However, the treatments have been increasingly successful and survival rates are improving. But what are its symptoms? How should it be treated?

 
What is bladder cancer?
The bladder is a hollow muscular organ that stores urine until ready for release. The urine is produced in the kidneys. It flows through tubes called the ureters into the bladder. The bladder stores urine until urination is ready. Bladder cancer occurs when the tissues in the bladder transform into uncontrolled growth.
 
Bladder cancer is associated with cancer-causing agents in cigarette smoke and various industrial chemicals. Cigarette smoking alone has been estimated to cause 50 percent of all bladder cancer cases. Long-term workplace exposure to chemical compounds such as paints and rubber are also associated with bladder cancer.
 
What are the symptoms of bladder cancer?
Painless blood in the urine is the most common symptom. It occurs in nearly all cases of bladder cancer. In the majority of cases, the blood is visible during urination. In some cases, it is invisible except under a microscope, and is usually discovered when analyzing a urine sample as part of a screening examination.
 
Blood in the urine has many possible causes. For example, it may result from an infection of the urinary tract or stones in the kidney or bladder. A diagnostic investigation is necessary to determine whether bladder cancer is present. However, in some patients, the existence of the microscopic blood in the urine may be normal. Other symptoms of bladder cancer may include frequent urination and pain upon urination.
 
How is bladder cancer diagnosed?
When attending a urology clinic, the clinician will go through the medical history and conduct a physical examination. The doctor will ask the patient about past exposure to known causes of bladder cancer, such as cigarette smoke or industrial exposure to chemicals. Majority of the patients will have imaging investigations of the kidneys, ureter and bladder to check for problems in these organs.
 
Diagnostic tools to check for bladder cancer also include various types of urinalysis. In one type, the urine is examined under a microscope to look for cancer cells that may have been shed into the urine from the bladder lining.
 
The doctor's most important diagnostic tool is cystoscopy, which is a procedure that permits direct viewing of the inside of the bladder. Majority of these investigations are carried out by a flexible telescope that allows the procedure to be carried out under local anaesthesia. First, a topical anesthetic gel is applied, so the patient will feel little or no discomfort. The doctor then inserts a viewing instrument called a cystoscope through the urethra and into the bladder, to examine the organs for the cause of the bleeding.
 
If tumors are present, the doctor will recommend a separate procedure (resection) for the removal of the tumors, which cannot usually be done under local anesthesia. Trans Urethral Resection of the bladder Tumour (TURBT) is a surgical procedure to remove the tumor under general anesthesia or regional anesthesia. The tumours are removed by a wire loop at the end of the telescope. The removed tissue is sent to another specialist for examination.
 
The tissue will be graded according to how much cells differ in appearance from normal cells. The more deviated the tumour are from the norm, the more aggressive the tumours are. The most widely used grading systems classify tumors into three main grade, G1, G2, and G3 according to their increasing aggressiveness. 
High-grade tumors are the most aggressive and the most likely to progress into the muscle. The bladder cancer tissues will also be assessed for the depth of tomour penetrating the bladder wall. 
 
Stages Ta, Tis and stage T1 are the non-muscle-invasive stages. Most Ta tumors are low grade, and most do not progress to invade the bladder muscle. 
Stage T1 tumors are much more likely to become muscle invasive, depending on the degree of differentiation. 
The Tis stage classification is reserved for a type of high-grade cancer called carcinoma in situ (CIS). If untreated, CIS may progress to muscle-invasive disease.
 
How is bladder cancer treated?
Ta and T1 Bladder Cancer: Transurethral resection of the bladder (TURBT) is the usual treatment method for patients who, when examined with a cystoscope, are found to have abnormal growths stage Ta and/or stage T1. Alternative methods, such as laser therapy, compare favorably with TURBT in terms of treatment results.
 
 Following the procedure, therapeutic agents are put directly into the bladder through a catheter in the urethra, are retained for one to two hours and are then urinated out. This is proven to prevent recurrence. The main therapeutic agents currently available are doxorubicin, mitomycin C and bacillus Calmette-Guérin (BCG). 
 
BCG, is a live but weakened vaccine strain of bovine tuberculosis. It is also used to immunize humans against tuberculosis. The therapeutic agents produce side effects of painful urination and the need to urinate frequently. BCG therapy also carries a risk of flu-like symptoms and a small risk of systemic infections.
 
Once thoroughly removed, further treatments for Ta and T1 bladder cancer are repeated cystoscopic inspection. Depending on the grade of the tumour, your doctor may consider additional treatments of the above therapeutic agents to prevent future recurrences. During the first one to two years surveillance is carried out on a three monthly basis but then can gradually be reduced to twice and eventually even once per year thereafter.
 
T2 and possibly some G3 or CIS Bladder cancer: Surgical removal of the bladder may be an option for patients with CIS or high-grade T1 cancers that have persisted or recurred after initial intravesical treatment. After the cystectomy, urinary reconstruction or urostomy (stoma bag) may be necessary to drain the urine. Cystectomy is considered a major pelvic operation, which carries the risk of bleeding, bowel leakage and deep vein thrombosis immediately after the operation. In the long term, continence and erectile dysfunction may also be the complications. 
 
The decision for either urostomy or continence reconstruction depends on the stage of the disease and the surgeon expertise.
 
FREQUENTLY ASKED QUESTIONS
 
What are some risk factors for bladder cancer?
Smokers develop bladder cancer at two to three times the rate of non-smokers. People who work with dyes, metal, paints, leather, rubber and organic chemicals may be at a higher risk. People who have chronic bladder infections may also be at higher risk.
 
Can screening tests detect bladder cancer?
The presence of blood in the urine may be a sign of bladder cancer but this is non-specific and may point to other problems of the urinary tract as well.