What Is It?
Bladder cancer is a malignant tumor (an uncontrolled growth of abnormal cells) that develops in the urinary bladder, the balloonlike organ that stores urine. About 90 percent of cancers in the bladder are transitional cell carcinomas that arise from cells that normally form the bladder lining. The remaining 10 percent of bladder cancers are either squamous cell carcinomas (6 percent to 8 percent) or adenocarcinomas (2 percent).
In 70 percent to 80 percent of patients with bladder cancer, the malignant tumor is discovered when it is still a limited, superficial problem. These superficial bladder cancers usually appear as an isolated patch of abnormal cells on the bladder lining or as an odd fingerlike projection along the bladder’s inner wall. Less often, the tumor is diagnosed when it already has progressed to become invasive bladder cancer. At this stage, the tumor may have invaded deeply into the muscle of the bladder wall and possibly metastasized (spread) to nearby lymph nodes or distant organs.
The causes of bladder cancer are only partly understood. It is thought that the majority of transitional cell carcinomas result from carcinogens such as tobacco smoke and chemicals in the environment. Indeed, cigarette smoking is the biggest risk factor for bladder cancer, although only about half of all bladder-cancer patients have ever been smokers. Smokers have a risk of bladder cancer that is two to four times greater than that of nonsmokers. In the past, bladder cancer was associated with exposure to certain industrial chemicals, but exposure to such chemicals has been reduced dramatically by modern workplace safety laws. These industrial carcinogens include aniline dyes, polycyclic aromatic hydrocarbons (such as 2-naphthylamine, 4-aminobiphenyl or benzidine), polychlorinated biphenyls or chemicals used in aluminum manufacturing. These chemicals are used in the aluminum, rubber, chemical and leather industries, as well as by dry cleaners, chimney sweeps, hairdressers, painters, printers, textile workers, machinists and truck drivers. In developing countries, where people are at risk of contracting schistosomiasis (a parasitic infection that affects the bladder), bladder cancer has a different pattern. Schistosomiasis increases the risk of bladder cancer, but these cancers are usually squamous cell carcinoma rather than transitional cell carcinoma.
There are several unusual aspects to bladder cancer that are essential to understand. The bladder is a hollow organ with a muscular wall lined by a layer of mucosal tissue called epithelium. Cancers of the bladder can grow from this superficial lining on the inner surface into the cavity of the bladder. These cancers are called noninvasive because they have not invaded any tissue. Noninvasive cancers are less likely to spread to other organs. In the bladder, however, noninvasive cancers can become invasive and potentially fatal over time so appropriate treatment is necessary. Bladder cancer is considered invasive if it grows into the mucosal lining of the bladder or deeper into the bladder’s muscular wall. The cancer cells have the potential to get into the bloodstream or the lymphatic vessels and spread throughout the body.
A second unusual aspect of bladder cancer is that it tends to recur. After bladder cancer is treated, there is a significant likelihood that additional cancers will occur in other locations: within the bladder itself, in the ureters (the tubes that drain the urine from the kidneys into the bladder) or in part of the kidney called the renal pelvis. This means that once you have had one episode of bladder cancer, you need to be monitored for recurrences.
Currently in the United States, bladder cancer is the fourth most common cancer among men and the ninth most common among women. About 56,000 new cases are diagnosed annually, most of them in adults older than 55. Caucasians are two times more likely to develop bladder cancer than are African-Americans, and the illness is three times more likely to strike men than women. Ultimately, bladder cancer kills approximately 12,000 Americans each year.
Symptoms of bladder cancer include:
- Hematuria (blood in the urine) — This symptom is the first sign of bladder cancer in 80 percent to 90 percent of patients. Hematuria may appear as an obvious red color in the urine, or it may turn the urine a rusty shade.
- Painful urination — This is also called dysuria.
- Frequent urination — Urinating more often than normal, considering your fluid intake, can be a sign of bladder cancer.
Your doctor will review your medical history, especially any history of kidney stones or urinary-tract infections, because these conditions also can cause blood in the urine. Your doctor also will ask about your history of cigarette smoking, your occupation and your diet.
If you don’t smoke now, but did in the past, it is important to tell your doctor. Even though you have quit smoking, your risk of bladder cancer remains high for more than 10 years after your last cigarette.
After reviewing your symptoms and risk factors, your doctor will perform a thorough physical examination, including a rectal examination and, in women, a pelvic examination. Your doctor also will order laboratory tests, including a complete blood count (CBC), a urine test to check for microscopic amounts of red blood cells, and a urine culture to rule out infection. In addition, a urine sample may be sent to a special lab to look for atypical cells and cancer cells.
The main test when looking for bladder cancer is cystoscopy, a procedure in which your doctor inserts a medical instrument through your urethra into your bladder so that the lining of your bladder can be inspected visually. Your urethra is the opening through which you urinate. With cystoscopy, your doctor can see whether or not there are tumors growing in the bladder. During cystoscopy, your doctor either will take a biopsy of the tumor or remove it entirely, if that is possible. A biopsy is cutting out a small piece of tissue so that it can be examined under a microscope to look for cancer cells. In many cases, two cystoscopies will be performed, the first to take a biopsy and determine whether cancer is present and the second to carefully remove any cancer that was found during the first procedure.
In some cases, additional tests may be necessary to determine how far the cancer has spread. At the very least, an examination should be performed of the renal pelvises and the ureters. This is done with a special X-ray study called an intravenous pyelogram (IVP) in which dye is injected into the blood and X-rays are taken of the kidneys and ureters as the dye filters through the kidneys and drains into the bladder. An IVP is performed to look for other tumors in the upper urinary tract. Other tests may include an ultrasound, computed tomography (CT) scan or magnetic resonance imaging (MRI) scan, which allow your doctor to see the bladder wall as well as the kidneys and the lymph nodes near the bladder.
Once it develops, bladder cancer will continue to grow and possibly spread until treatment is provided.
To reduce your risk of bladder cancer, don’t smoke. If you already smoke, ask your doctor about proven ways to help you quit.
If you work in an occupation in which there is a high risk of exposure to chemicals that can cause bladder cancer, find out about the types of equipment that are available to reduce your exposure, then use this equipment faithfully while you are on the job. If you need more information about specific types of exposure or specific protective equipment, contact the National Institute for Occupational Safety and Health (NIOSH), part of the U.S. Centers for Disease Control and Prevention. It also is believed that people who drink a lot of water on a daily basis have a lower risk of bladder cancer than people who consume only small quantities of fluids. This is thought to be because carcinogens in the urine are diluted in people who drink more water.
Treatment of bladder cancer depends on the stage (extent of spread) of the tumor. The stage is determined by: 1) the extent of local tumor invasion — whether the tumor involves only the bladder lining, or whether it has invaded the bladder muscle, tissues around the bladder or nearby pelvic organs; 2) whether the cancer has spread to nearby lymph nodes; and 3) whether the cancer has metastasized to distant sites in other areas of the body.
Once the stage of the tumor has been determined, treatment follows three different courses.
- Superficial tumors — Superficial tumors are cancers that involve only the bladder lining, with no invasion of bladder muscle or deeper structures and no spread to lymph nodes or distant organs. These tumors are usually treated with a transurethral resection, performed through a cystoscope. In this procedure, the doctor may use either a small wire loop to remove the tumor or a localized electric current to burn it away (a process called fulguration). After transurethral resection, some high-risk patients also receive intravesical therapy (medications instilled inside the bladder), using one of the following drugs: bacillus Calmette-Guerin (Pacis, TheraCys, TICE BCG), thiotepa (sold as a generic), mitomycin (Mutamycin), valrubicin (Valstar) or doxorubicin (Adriamycin, Rubex).
These treatments can reduce the likelihood that recurrent tumors will develop, although they do not appear to reduce the likelihood that the cancer will progress to a more advanced and dangerous stage.
- Carcinoma in situ — Carcinoma in situ, a form of noninvasive cancer, exists only within the very thin, most superficial lining of the bladder. It grows neither outward into the bladder’s cavity nor inward to invade the bladder lining or muscle wall. Carcinoma in situ is considered to pose a greater risk than other noninvasive cancers of transforming into a dangerous invasive cancer. It is often difficult or impossible to remove in its entirety. Therapy with BCG can eradicate carcinoma in situ in some patients and is an important part of treatment for this condition.
- Tumors invading the bladder muscle — In this case, bladder cancer has spread to the bladder muscle, but not to the lymph nodes or distant organs. Standard treatment is radical cystectomy — surgical removal of the bladder, together with nearby lymph nodes and adjacent pelvic organs. In men, this procedure includes removal of the prostate gland and seminal vesicles. In women, it includes removal of the uterus, fallopian tubes, ovaries and part of the vagina. Because a radical cystectomy removes the urinary bladder, the surgeon must create an alternate way for the body to hold and pass urine. In some patients, the surgeon will use part of the small bowel to create a conduit that drains the urine from the ureters to an opening in the abdomen called a stoma. The urine is then collected in a bag that covers the stoma. An alternative is to use part of the intestine to construct a new storage area for urine (this is called either a Koch pouch or a Mainz or Indiana pouch). This pouch is then connected to a stoma that is constructed in such a way that the urine cannot leak out unless a catheter is inserted through it. In other cases, the surgeon will create a pouch that he or she can connect to the urethra so that urine leaves the body through the same opening as it did before the surgery. Such a pouch is called a neobladder. Which alternative is best for you depends on your specific circumstances as well as your personal preferences. Each procedure has its own advantages and disadvantages.
As an alternative to radical cystectomy, a segmental or partial cystectomy is sometimes used in patients (about 5 percent to 10 percent of cases) who have very localized, less aggressive tumors. In a segmental cystectomy, only the diseased portion of the bladder is removed, so the patient can still urinate more or less normally after the procedure. One alternative to surgery is radiation therapy combined with chemotherapy. Many studies of this approach have been conducted and favorable results have been reported, although only certain patients are eligible for such an approach. The advantage of this approach is that most patients can keep their own bladders. However, it is not clear whether radiation therapy combined with chemotherapy is as effective as surgery and therefore this approach is not widely accepted. On the other hand, if a patient is not a good candidate for any type of surgery, then radiation therapy, probably combined with chemotherapy, should be considered.
- More extensive tumors — Tumors that have invaded beyond the bladder wall are usually treated with radical cystectomy if the entire tumor can be removed. If the tumor cannot be removed, chemotherapy and/or radiation therapy is sometimes given prior to surgery in an attempt to shrink the tumor and render it removable. Similarly, if cancer is found to have invaded through the bladder wall at the time of surgery or if it has spread to lymph nodes, then chemotherapy after surgery may reduce the likelihood that the cancer will come back later.
- Metastatic bladder cancer — Bladder cancer that has spread to other organs or to distant lymph nodes is considered metastatic. Metastatic bladder cancer is almost always a fatal disease. However, it is very sensitive to chemotherapy and there is strong evidence that chemotherapy can prolong the lives of patients with metastatic disease. Most patients will have their tumors shrink at least partially with chemotherapy. A small proportion of patients may even be cured. The standard chemotherapy in this setting was, until recently, a combination of four drugs: methotrexate (sold as a generic), vinblastine (Velban), doxorubicin (Adriamycin, Rubex) and cisplatin (Platinol) — the combination is referred to as MVAC. However, a recent study showed that a two-drug combination of gemcitabine (Gemzar) and cisplatin is roughly equivalent and is better tolerated. Other drugs commonly used to treat bladder cancer include paclitaxel (Taxol), ifosfamide (IFEX) and carboplatin (Paraplatin).
When To Call A Professional
Call your doctor immediately if you notice blood in your urine, or if your urine turns the color of rust. Also, call your doctor if you begin to urinate more often than normal (compared to your fluid intake), or if urination is painful or uncomfortable in any way.
The prognosis depends on the stage of bladder cancer and the type of treatment used. Overall, up to 80 percent of patients with superficial tumors survive for at least five years after diagnosis. For patients whose tumors have invaded the bladder muscle, the five-year survival rate may be as high as 75 percent. Patients with more invasive tumors or metastatic tumors generally have a poorer prognosis, with five-year survival rates of 40 percent or less.
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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.