Cancer from A to Z

Causes
 

There are no absolute methods to prevent bladder cancer. Refraining from smoking is the best way to lower your risk of getting bladder cancer. People who are exposed to aromatic amines in their work environment are advised to always follow safe work habits. Other healthy practices, such as drinking plenty of fluids (mainly water) and eating a diet high in fruits and vegetables have been shown to protect against bladder cancer.

 
Risk Factors
Although the exact cause of bladder cancer is unknown, studies have found the following to be risk factors for developing the disease:

Age: The chance of contracting bladder cancer increases with age, and is uncommon in people under the age of 40.

Tobacco: Tobacco use is a major risk factor in bladder cancer. Smokers, including pipe and cigar smokers, are two to three times more likely than nonsmokers to get the disease.

Race: Bladder cancer occurs twice as often in Caucasians than it does in black people and Hispanics. Asians have the lowest rate of developing the disease.

Gender: Males are two to three times more likely than females to get bladder cancer.

Family history: People with a family history of bladder cancer are more likely than those with no family history of it to get the disease. Studies are underway to determine whether certain genes increase the risk of getting the disease.

Personal history of bladder cancer: Bladder cancer has a 50-80% recurrence rate, the highest of any cancer - including skin cancer. Bladder cancer survivors have an increased chance of getting the disease again.

Occupation: Workers exposed to elevated amounts of carcinogens in the workplace are more at risk. This includes the rubber, chemical, and leather industries, along with hairdressers, machinists, metal workers, printers, painters, textile workers and truck drivers.

Infections: People infected with certain parasites have an increased risk of bladder cancer. These parasites tend to be common of more tropical climates.

Treatment with cyclophosphamide or arsenic: These drugs are sometimes used in the treatment of cancer and other conditions, and raise the risk of developing bladder cancer.

Bladder cancer can be diagnosed by cystoscopy, imaging or cytologyprocedures. People considered at high risk should undergo one or more of these procedures on a regular basis so that the cancer is found at an early, more treatable stage.

People at high risk for bladder cancer are:

• At least 50 years old with hematuria (blood in the urine)
• Under age 50 with visible hematuria

Cystoscopy is the most common and reliable test for bladder cancer. A thin tube with a camera (cystoscope) is inserted into the bladder through the urethra to view the suspicious area. The cystoscope can also be used to take a tissue sample for biopsy, and to treat superficial tumors without surgery. However, cystoscopy is not perfect. Flat lesions (carcinoma in situ) and small papillary tumors can be missed. MD Anderson recommends that cystoscopy be combined with other tests listed below for the most accurate diagnosis possible.

Imaging studies such as a CT scan, ultrasound or intravenous pyelogram (IVP) supplement the information provided by cystoscopy. IVP involves injecting a dye that shows up on an X-ray as it travels through the urinary system.

Urine-based tests use a urine sample to determine the presence of cancer. Cytology is the oldest urine test, which involves looking at the sample under a microscope for the presence of abnormal cells. There are several types of urine tests available that focus on specific bladder cancer "markers." The urologist will choose the most appropriate urine test for each patient.

Different types of treatment are available for bladder cancer. Some treatments are standard and some are being tested in clinical trials. Before starting treatment, patients may want to think about taking part in a clinical trial.

 
Surgery
Surgery to remove the bladder is called a cystectomy. Virtually all cystectomies for cancer are radical, meaning that the entire bladder is removed. Partial cystectomies are rare, but may be appropriate for very carefully selected patients. Minimally invasive surgery techniques such as laparoscopy are still considered experimental, and are not routinely performed at this time.

In men, the bladder, prostate and lymph nodes are removed in a cystectomy. Surgical advances are allowing surgeons to spare the nerve bundles responsible for erection. In women, the bladder, uterus and part of the anterior vaginal wall are removed, but the vagina can now be spared in some cases.

For some early-stage or superficial bladder cancers, a procedure called transurethral resection (TUR) may be used. A resectoscope, which is a thin tool with a wire loop on the end, is threaded through the urethra to scrape the tumor from the bladder wall. The resectoscope can also be used to deliver an electrical current to burn the tumor away.

 
Bladder Reconstruction Surgery
When the bladder is removed, there are procedures known as urinary diversions to restore urinary function. Urinary diversions are done at the same time as a cystectomy. There are three types of urinary diversion:

Ileal neobladder: part of the ileum (small intestine) is used to make a new bladder, allowing for "normal" urination. This procedure works best on men. It provides good daytime urinary control, with about a 20% chance of nighttime incontinence. Some women may have trouble completely emptying the neobladder and may sometimes need to use a catheter.

Ileal conduit: a piece of small intestine is used to create a “pipe” that connects ureters to the surface of the skin in the navel. Urine is directed to a urostomy bag worn on the outside of the body. It is a simple and efficient procedure, but some patients may have issues with wearing an external appliance.

Continent reservoir: intestinal tissue is used to create an internal pouch that is connected to the navel. The patient uses a catheter to drain the pouch. This procedure is done less frequently than the other two.

 
Chemotherapy
Chemotherapy plays a major role in the treatment of metastatic bladder cancer that has spread to the lymph nodes, lungs, liver and other parts of the body. In patients who have metastases at diagnosis, chemotherapy is the frontline treatment.

The "gold standard" chemotherapy for metastatic bladder cancer is a combination of four drugs known as MVAC: methotrexate, vinblastine, adriamycin and cisplatin. MVAC has provided good response rates since the 1980s. In recent years, the MVAC treatment regimen has been decreased from four weeks to two weeks, with less toxic side effects for the patient and an improved response rate of 50% and higher.

Another chemotherapy regimen is a combination of gemcitabine and cisplatinum. It is less toxic than MVAC, with similar response rates. Both chemotherapies have an average survival rate of 14 months.

Chemotherapy is also used in conjunction with surgery for patients who are at high risk for metastasis. Data suggest that bladder tumors that have invaded the muscle wall and have the potential to spread can benefit from chemotherapy before surgery (neoadjuvant therapy).

 
Radiation Therapy
Although surgery is the frontline treatment for bladder cancer, radiation treatment does have a role in certain patients. Simultaneous radiation and chemotherapy with cisplatin may be used instead of surgery in an effort to save the bladder. However, only about 40% of patients who undergo bladder-sparing treatment will be able to keep their bladder and not have the cancer come back.

The best candidates for radiation therapy:

• Have locally resected tumors
• Have only one tumor site
• Can tolerate chemotherapy and 35 radiation treatments
• Must undergo rigorous follow-up after treatment

 
Immunotherapy
In recent years, a significant amount of cancer research has been devoted to immunotherapy, which uses the body's own defense mechanisms to fight cancer. All cells have protein markers, called antigens, on their surfaces that identify them as either "normal" or "foreign." The presence of foreign antigens (such as cancer cells) in the body provokes a sophisticated chemical reaction involving lymphocytesand other cells that defend the body against disease. Some of these defender cells produce antibodies, which seek out and destroy specific antigens.

Immunotherapies are designed to manipulate the antigen/antibodyimmune response by targeting antigens on specific types of tumor cells. As researchers identify more of these tumor-specific antigens, they are working to develop therapeutic agents that target only those cells.

 
Radiation therapy is used with patients with locally advanced disease in combination with chemotherapy with the aim of preserving the bladder, as an adjuvant after surgery in the case of poor prognosic factors in anatomical pathology or to treat symptoms in the case of bleeding.

The following technological means and type of radiation therapy are used with this disease.

• Virtual CT simulation
• Intensity modulated radiation therapy (IMRT)
• Volumetric Modulated Arc Therapy (VMAT)

Immunotherapy & Bladder Cancer
For superficial bladder cancer, another type of immunotherapy has become the standard of care.

Intravesical immunotherapy involves filling the bladder with a solution containing Bacillus Calmette-Guérin (BCG), a bacterial organism that is sometimes used to treat tuberculosis. The BCG, delivered through a catheter, stimulates an immune response within the bladder to destroy any remaining cancer cells. Intravesical immunotherapy is performed after the bladder wall has been scraped to remove superficial tumor cells. The treatment success rate with intravesical BCG is 70% to 80%.