How Common is Bladder Cancer?
Bladder cancer is the second most common urologic cancer after prostate cancer accounting for approximately 54,000 new cases each year.
Causes and Risk Factors of Bladder Cancer
The actual causes of bladder cancer are unknown although the disease is associated with exposure to tobacco and certain chemicals, particularly aniline dyes.
The most common sign of bladder cancer is blood in the urine (hematuria), which does not necessarily have to be visible to the naked eye, i.e. visible only microscopically. Other signs and symptoms may include:
- Change in bladder habits, including having to urinate more often:
- Difficulty initiating or stopping urine flow
- Weak or interrupted urine flow
- Painful urination
Diagnostic Tests include:
Urine Cytology: In this test, the urine is examined under a microscope to look for any cancerous or precancerous cells.
Cystoscopy: Using a endoscope– an instrument consisting of a slender tube with a camera lens and light is placed into the bladder through the urethra – the physician can then check the bladder and urethra for possible cancers. Suspicious tissue can sometimes be removed during this procedure (i.e. bladder biopsy) to be analyzed microscopically for signs of cancer.
Diagnosing Bladder Cancer
If bladder cancer is suspected, there needs to be a tissue diagnosis (biopsy) to confirm the diagnosis as well as to determine the stage (spread) of the disease. Staging (size of the tumor, the extent of disease as to whether it has metastasized or spread to other organs) is necessary to determine the most effective therapy. The various stages are:
Stage Ta: the tumor cells remain confined within the bladder and have not invaded the muscle or connective tissue of the bladder wall.
Stage I: the cancer has invaded the layer of connective or supporting tissue under the lining layer of the bladder, but it has not spread to the thick layer of muscle in the bladder wall, the lymph nodes or to any other organs.
Stage II disease, the tumor has invaded the thick muscle layer of the bladder wall, but has not reached the fatty tissue that surrounds the bladder or beyond.
Stage III and IV indicate more serious disease with invasion of the cancer into nearby organs, such as the prostate, uterus or vagina, or to the lymph nodes and more distant organs, such as bones, liver or lungs.
The lower the number of the stage, the less the cancer has spread. To make the diagnosis and to assess the extent of the tumor the following are often necessary:
- Biopsy: Suspicious tissue is removed during a cystoscopy procedure so that it can be analyzed under a microscopic for signs of cancer.
- CT Scan: this is a radiographic scan that looks for visible extension or spread of the disease.
- MRI Scan: Like the CT scan, an MRI may determine if the cancer has spread beyond the bladder into adjacent tissues, nearby lymph nodes or to distant organs.
Treatment Options for Bladder Cancer
Transurethral surgery: This procedure is indicated for the diagnosis of bladder cancer and for subsequent treatment of non-muscle invasive disase. It is performed through a cystoscope like instrument to scrape out the tumor within the bladder when it has not penetrated the bladder wall. Since there is a propensity for recurrence, close follow-up treatment is indicated to ensure early detection of future cancers.
Cystectomy: For cancer that is invasive, a cystectomy may be indicated in which part of the bladder (partial cystectomy) or the entire bladder and nearby lymph nodes and adjacent organs (radical or total cystectomy) may be indicated.
Reconstructive surgery: If the bladder needs to be removed, reconstructive surgery must be performed to create an alternative for storage and removal of urine.
Radiation therapy is occasionally advised in patients who are not suitable surgical candidates. The treatment uses high-energy rays that are delivered externally. External beam radiation therapy administered in conjunction with chemotherapy following local removal of a bladder tumor may on occasion allow for bladder preservation without compromising loco-regional tumor control.
In this treatment, an immunotherapeutic agent such as the live attenuated tuberculous vaccine (BCG) and/or interferon is instilled directly into the bladder (intravesical) through a catheter to treat low-stage bladder cancer or high grade non-invasive tumors (carcinoma in situ).
Chemotherapy involves medication to destroy malignant cells. It can be instilled directly into the bladder which is suitable to treat non-invasive disease and to prevent recurrences. For more advanced disease, chemotherapy is given by mouth and/or by intravenous injection so that the drug can reach cancer cells that have spread beyond the bladder to lymph nodes and other organs.
It is recommended to abstain from smoking – a significant risk factor for developing this disease, and to use appropriate precautions to limit occupational exposure to certain dyes (particularly aniline dyes), rubber and leather, which have been shown to increase the risk of bladder cancer.