Written by Bladder cancer is the most common cancer of the urinary tract. Bladder cancer occurs most commonly between the ages of 50 and 70. It is twice as common in men as in women. Cancer-causing agents (carcinogens) in the urine may lead to the development of bladder cancer.
The bladder is a hollow organ in the lower abdomen (pelvis). It collects and stores urine, liquid waste produced by the kidneys. Urine passes from each kidney into the bladder through a tube called ureter and leaves the bladder through the urethra. The wall of the bladder has several layers. A layer of urothelial cells (also called transitional cells) lines the inside of the the kidney, ureter, bladder, and urethra. This layer is called the urothelium or transitional epithelium. Beneath the urothelium, there is a thin zone of connective tissue called the lamina propria. The next deeper layer is a wider zone of muscle tissue called muscularis propria. Beyond this muscle, another zone of fatty connective tissue separates the bladder from other nearby organs. As the cancer penetrates through these layers into the wall of the bladder, it becomes harder to treat.
Types
Most bladder cancers starts in the layer of cells which form the lining of the bladder. These are called transitional cell carcinoma or urothelial carcinoma. Other bladder cancer are squamous cell carcinoma and adenocarcinoma. Squamous cell carcinoma starts from one of the types of cell in the bladder lining. Adenocarcinoma starts from glandular cells which produce and release fluids such as mucus. Rare types of bladder cancer include small cell carcinoma, carcinosarcoma, primary lymphoma, and sarcoma.
Tumors are categorized as low-stage (superficial) or high-stage (muscle invasive). If a bladder cancer affects only the inner lining of the bladder, it is known as non-invasive cancer or superficial cancer, or carcinoma in situ. Most bladder cancers are superficial. If the bladder cancer has grown deeper into the bladder wall and extends into the muscle layer or its surrounding tissues, it is called invasive cancer. Nearly all adenocarcinomas and squamous cell carcinomas are invasive.
Causes
The exact causes of bladder cancer are unknown . Smoking is believed to be an important cause of bladder cancer. Exposure to certain toxic chemicals and drugs may also result in cancer. The risk of cancer increases with age.
Exposure to carcinogens in the workplace and the use of cyclophosphamide or arsenic drugs increase the risk for bladder cancer. Aromatic amines, an organic chemicals used in dye industry, is linked with bladder cancer. Workers in the rubber, chemical, leather, textile, paints and printing industries are also at increased risk.
People with a family history
of bladder cancer may have an increased risk of developing the disease. Those whose diets include large amounts of fried meats and animal fats are also at higher risk of bladder cancer. Frequent bladder infections, bladder stones, and other urinary tract problems that irritate the bladder increase the risk of developing a cancer, more commonly squamous cell carcinoma.
Symptoms
Common symptoms of bladder cancer include :
* Blood in the urine (hematuria). Sometimes, blood clots can form which may cause painful muscle spasms in the bladder.
* Pain or burning during urination without evidence of urinary tract infection
* Pelvic pain
* Frequent urination, or feeling the strong urge to urinate without producing much urine
* Slowing of your urinary stream
Infections, benign tumors, bladder stones or other problems can also cause these symptoms. When any of these symptoms is noticed, consult a doctor, preferably a urologist so that he can diagnose and treat any problem as early as possible.
Diagnosis
Often, bladder cancer is asymptomatic until there is advanced disease. Therefore, in such cases, screening must be performed to detect the tumor. The most widely used screening tests are medical interview, physical examination, urinalysis, urine cytology, and cystoscopy. These tests are also used to diagnose bladder cancers symptomatic patients as well.
The doctor will review the patient’s medical condition, work history, habits and lifestyle
so that he can develop and assess the risk for bladder cancer. A complete physical examination is performed including rectal or vaginal exam. The physician
may insert a gloved finger into the vagina, rectum or both to feel for any lumps that might indicate a tumor or another cause of bleeding.
Urinalysis :
It is a collection of tests for finding abnormalities in the urine such as blood, protein, sugar (glucose), and solids. Any abnormal findings should be investigated with more definitive tests.
Urine cytology (Urine tests) :
Abnormal cells or tumors in the bladder wall slough off cells that are suspended in the urine and excreted from the body during urination. In this test, a sample of the urine is examined under a powerful microscope to look for abnormal cells that might suggest cancer. A urine culture may be done to rule out an infection. The presence of certain antibodies and other markers may indicate cancer.
Cystoscopy :
It is the method of examining bladder and urethra using cystoscope, which is a thin, narrow tube with a light and a camera on the end. Cystoscope is inserted into the bladder through the urethra to examine any abnormalities such as tumors. The camera transmits pictures to a video monitor, allowing direct viewing of the inside of the bladder wall. With the cystoscope, sample tissues can be removed and it is examined under a microscope to detect cancer.
If bladder cancer is suspected, further tests are performed. These includes :
Pyelography :
It is a series of x-rays of the kidneys, ureters, and bladder. The doctor will inject a special dye into a vein (intravenous pyelography or IVP) or into the urethra (retrograde pyelography) and x-ray film of the urinary tract is taken. The dye highlights the organs of the urinary tract and makes seeing certain abnormalities easier.
CT (Computerized tomography) Scan :
Similar to an x-ray film, CT gives a 3-dimensional view of the bladder, urinary tract (especially the kidneys), and pelvis to look for masses and other abnormalities. In most cases, before the test, a contrast dye is injected into a vein to highlights the organs. The greatest risk with this procedure is a possible allergic reaction to the dye.
Biopsy :
Biopsy is the removal of tissue to look for cancer cell. It is the only sure way to tell whether cancer is present. Tiny samples of the bladder wall are removed, usually during cystoscopy. The samples are examined under a microscope. Small tumors are sometimes completely removed during the biopsy process.
If bladder cancer is identified, certain other tests may be performed to find whether it has invaded the bladder wall or spread to other parts of the body. It is called staging and the tests may include CT scan, ultrasound scan, magnetic resonance imaging (MRI), sonogram, bone scan or chest x-ray.
Ultrasound Scan :
This scan can show the size and how far the tumor has spread to other organs. In this painless test, a handheld device run over the surface of the skin uses sound waves to examine the contours of the bladder and other structures in the pelvis.
Chest x-ray film :
A simple x-ray film of the chest is taken to check whether the bladder cancer has spread to the lungs.
Magnetic resonance imaging (MRI) :
Instead of X-rays, MRI uses a powerful magnetic field and radio waves to create the image of urinary tract.
Bone scan :
This imaging test is used to determine whether cancer has spread to your bones. In this method a tiny amount of a radioactive substance is injected into the veins. A special scanner then takes pictures of all your bones.
Stages
The chances of recovery are determined by the stage of the disease. Staging is essential for better treatment and usually it can be determined at the time of diagnosis. Staging is based on imaging studies (such as CT scans, x-ray films, or ultrasound) and biopsy results.
The main features of each stage of the bladder cancer are :
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Stage 0 - cancer cells are found only on the surface of the inner lining of the bladder. This is called noninvasive cancer or superficial cancer or carcinoma in situ.
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Stage 1 - cancer cells has started to grow into the connective or supporting tissue beneath the bladder lining. They have not spread to the muscular bladder wall.
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Stage 2 - cancer cells has invaded the muscular bladder wall and spread to the muscle of the bladder.
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Stage 3 - cancer cells have spread through the muscular bladder wall to the surrounding tissues. They may have spread to the prostate in men or to the uterus or vagina (in women).
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Stage 4 - cancer has extend to the wall of the abdomen or to the wall of the pelvis. They may have spread to lymph nodes and other parts of the body far away from the bladder, such as the liver, lungs, or bones