These tumors may be classified based on their growth pattern as either papillary tumors (meaning they have a wart-like lesion attached to a stalk) or nonpapillary tumors. Nonpapillary tumors are much less common, but they are more invasive and have a poorer prognosis.
Causes, incidence, and risk factors
As with most other cancers, the exact cause is uncertain. However, several factors may contribute to the development of bladder cancer.
Cigarette smoking increases the risk of developing bladder cancer by a factor of nearly five, compared to non-smokers. As many as 50% of all bladder cancer in men and 30% in women may be attributable to cigarette smoke. This risk does show a gradual decline in people who quit smoking.
About one in four cases of bladder cancer can be attributed to workplace exposure to carcinogens. Arylamines are a group of chemicals most responsible. Dye workers, rubber workers, aluminum workers, leather workers, truck drivers, and pesticide applicators are at the highest risk, although arylamines have been reduced or eliminated in many workplaces.
The association between artificial sweeteners and bladder cancer has been studied and is weak or non-existent.
Women who received radiation therapy for the treatment of cervical cancer have an increased risk of developing transitional cell bladder cancer, as do some people who received the chemotherapy drug cyclophosphamide (Cytoxan).
A chronic (long term) bladder infection or irritation may lead to the development of squamous cell bladder cancer. However, this cancer is very slow growing. Bladder infections do not increase the risk of transitional cell cancers.
In third world countries, infection with a parasite (schistosomiasis) has been linked to the development of bladder cancer.
Bladder cancers are classified or staged based on their aggressiveness and the degree that they are different from the surrounding bladder tissue. There are several different ways to stage tumors. Recently, the TNM staging system has become common. This staging system contains several substages, but it basically categorizes tumors using the following scale:
- Stage 0 - Carcinoma in-situ or non-invasive lesions limited to the bladder mucosa (lining)
- Stage I - Tumor extends through the mucosa, but does not extend into the muscle layer
- Stage II - Tumor invades into the muscle layer
- Stage III - Tumor invades past the muscle layer into tissue surrounding the bladder
- Stage IV - Cancer has spread to regional lymph nodes or to distant sites (metastatic)
Bladder cancer spreads by extending into the nearby organs, including the prostate, uterus, vagina, ureters, and rectum. It can also spread to the pelvic lymph nodes or to other parts of the body, such as the liver, lungs and bones.
While most of the symptoms listed below can be associated with bladder cancer, they can also be associated with non-cancerous conditions. Nevertheless, medical evaluation is critical.
- Blood in the urine
- Urinary frequency
- Painful urination
- Urinary urgency
Additional symptoms that may be associated with this disease:
- Urinary incontinence
- Bone pain or tenderness
- Abdominal pain
- Weight loss
- Lethargy (tiredness)
Signs and tests
A physical examination will be performed, including a rectal and pelvic exam.
Diagnostic tests that may be performed include:
- Urine cytology (microscopic exam of urine to look for cancerous cells)
- Cystoscopy (use of lighted instrument to view inside of bladder)
- Bladder biopsy (usually performed during cystoscopy)
- Intravenous pyelogram - IVP (to evaluate upper urinary tract for tumors or blockage)
The choice of an appropriate treatment is based on the stage of the tumor, the severity of the symptoms, and the presence of other medical conditions.
Generally, stage 0 and I tumors are treated by removing thetumor without removing the rest of the bladder. They sometimes may also be treated by administering chemotherapy directly into the bladder or with immunotherapy. However, because the risk of the cancer returning is so high, people with bladder cancer require constant follow-up for the rest of their lives.
Stage II bladder tumors may be treated by removing the tumor and with BCG immunotherapy. However, most people with stage II and those with stage III tumors require bladder removal. In some patients with stage III tumors who choose not to have surgery or who cannot tolerate surgery, a combination of chemotherapy and radiation may be used.
Most patients with stage IV tumors cannot be cured and surgery is not indicated. In these patients, chemotherapy is often considered.
Chemotherapy for bladder cancer can be administered through a vein or into the bladder. It is usually given by vein to treat patients with stage IV bladder cancer.
Chemotherapy also may be given to patients with stage III cancer after surgery in an attempt to prevent the tumor from returning. (This is called adjuvant chemotherapy.)
Chemotherapy may be given as a single drug or in different combinations of drugs. These include:
The combination of two of these drugs, gemcitabine and cisplatin, has been shown to be as effective with less side effects as an older regimen known as MVAC (methotrexate, vinblastine, doxorubicin and cisplatin) and in many centers has replaced MVAC. The combination of paclitaxel and carboplatin has also been effective and is frequently used.
A Foley catheter can be used to instill the medication directly into the bladder in patients with stage I. The catheter is removed immediately after the medication has been instilled. You are instructed to try to hold the medication in your bladder for at least two hours after treatment. Additionally, you may be asked to rotate from side to side every 15-30 minutes to completely expose the entire bladder wall to the medication.
Several different types of medications may be used for chemotherapy directly into the bladder, such as:
- Doxorubicin (Adriamycin)
Common side effects include bladder wall irritation and pain when urinating. Choice of a specific drug is usually based on the stage of the tumor.
Bladder cancers are often treated by immunotherapy, in which a medication causes your own immune system to attack and kill the tumor cells. Immunotherapy is usually performed using Bacille Calmette-Guerin (commonly known as BCG), which is a solution of genetically altered tubercular bacteria that is not able to produce infection. This medication is administered through a Foley catheter to instill the medication directly into the bladder. Since BCG is a biological agent, special precautions must be taken.
Potential side effects include bladder irritability, urinary frequency, urinary urgency, and painful urination. These are reported by 90% of the people treated with BCG. However, the symptoms usually resolve within a few days after treatment. Rare side effects include blood in the urine, malaise, nausea, chills, joint pain, and itching. Rarely, a systemic tubercular (TB) infection can develop, requiring treatment with anti-tuberculosis medication. Systemic infection is suspected if you develop an elevated temperature that lasts for more than one day.
TRANSURETHRAL RESECTION OF THE BLADDER (TURB)
People with stage 0 or I bladder cancer are usually treated with transurethral resection of the bladder (TURB). This surgical procedure is performed under general or spinal anesthesia. A cutting instrument is then inserted through the urethra to remove the bladder tumor.
Most people with stage II or III bladder cancer will opt for bladder removal (radical cystectomy). Partial bladder removal may be performed if there is only a single lesion with no signs of metastasis. However, only about 10% of the people with bladder cancer meet this criterion.
Radical cystectomy in men usually involves removal of the bladder, prostate, and seminal vesicles. In women, the urethra, uterus, and the front vaginal wall are removed along with the bladder. Often, the pelvic lymph nodes are also removed during the surgery for pathological examination. About half of the people treated with radical cystectomy will be completely cured; the other half shows signs of metastasis at the time of the surgery.
A urinary diversion surgery (a surgical procedure to create an alternate method for urine storage) is usually performed with the radical cystectomy procedure. Two common types of urinary diversion are an ileal conduit and a continent urinary reservoir.
An ileal conduit is a small urine reservoir that is surgically created from a small segment of bowel. The ureters that drain urine from the kidneys are attached to one end of the bowel segment and the other end is brought out through an opening in the skin to create a stoma. The stoma allows the patient to drain the collected urine out of the reservoir.
People who have had an ileal conduit will need to wear an external Urine collection appliance at all times. Possible complications associated with ileal conduit surgery include: bowel obstruction, blood clots, urinary tract infection, pneumonia, skin breakdown around the stoma (the opening in the skin connecting to the ileal conduit), and long-term damage to the upper urinary tract.
CONTINENT URINARY RESERVOIR
A continent urinary reservoir is another method of creating a urinary diversion. In this method, a segment of colon is removed and used to create an internal pouch to store urine. This segment of bowel is specially prepared to prevent reflux of urine back up into the ureters and kidneys, and also to reduce the risk of involuntary loss of urine. Patients are able to insert a catheter periodically to drain the urine. A small stoma is placed flush to the skin. Possible complications include: bowel obstruction, blood clots, pneumonia, urinary tract infection, skin breakdown around the stoma, ureteral reflux, and ureteral obstruction.
This surgery is becoming more common in patients undergoing cystectomy. A segment of bowel is folded over to make a pouch (a neobladder or “new bladder”), then attached to the urethral stump, which is the beginning of where the urine normally empties from the bladder.
This procedure allows patients to maintain some degree of normal urinary control, although there are complications, and the urination is usually not the same as before surgery. For example, this procedure can be associated with leakage of urine at night, the need to intermittently perform manual catheterization, and other complications listed above for the continent urinary reservoir.
Some patients may not be good candidates for this procedure. The patient should discuss the pros and cons of this procedure with their urologist.
Clinical tests are currently underway to evaluate the use of photodynamic therapy in bladder cancer treatment. Photodynamic therapy involves using photosensitizing agents and laser light to detect and kill cancer cells. Other studies are looking at new chemotherapy agents that may be more effective.
You will be closely monitored for progression of the disease regardless of the type of bladder cancer treatment you received. Monitoring may include:
- Cystoscope evaluations every 3 to 6 months after initial treatment for people with stage I disease.
- Periodic urine cytology evaluations for people whose bladders have not been removed.
- Bone scan and/or CT scan to evaluate for metastasis.
- Complete blood count (CBC) to monitor for signs and symptoms of anemia, which would indicate the disease has progressed.
- Monitor for other signs of disease progression, such as fatigue, weight loss, increased pain, decreased bowel and bladder function, and weakness.
The outlook is related to the specific stage of bladder cancer and the type of treatment chosen. The prognosis for stage 0 or I cancers is fairly good, although the risk of the cancer returning is high. However, most of these recurrences can be surgically removed and cured.
For patients with stage III tumors cure rates are less than 50%. For patients with stage IV are rarely cured (although patients with only a few metastatic lesions can be cured in some circumstances).
Bladder cancers may spread into the nearby organs or may travel through the pelvic lymph nodes, and metastasize to the liver, lungs, and bones. Additional complications of bladder cancer include anemia, hydronephrosis (swelling of the ureters causing kidney injury), urinary incontinence, and urethral stricture.
Calling your health care provider
Call your health care provider if you have blood in your urine, or other symptoms of bladder cancer, including urinary urgency, urinary frequency, or painful urination.
Also, call your health care provider for an appointment to be examined if you are over 40 years of age, you are a smoker, or you work in an area of high industrial exposure to potential carcinogens.
Quitting cigarette smoking and eliminating environmental hazards may reduce your risk of developing bladder cancer.
by Dave R. Roger, M.D.
All ArmMed Media material is provided for information only and is neither advice nor a substitute for proper medical care. Consult a qualified healthcare professional who understands your particular history for individual concerns.