Bladder Cancer
What is bladder cancer ?
Bladder cancer is a common disease. It ranges from a superficial disease located superficially on the inside of the bladder with a low risk of progressing to a muscle invasive or metastatic disease. In general 75% of new cancer diagnoses are superficial disease. It is usually diagnosed between the ages of 50-80.
What are the risk factors for bladder cancer ?
Bladder cancer has been associated with exposure to a number of environmental factors.
Smoking is the most consistent and common risk factor associated with bladder cancer.
Association with heterocyclic amines is found in several at "risk" industries including rubber manufacturing , petrochemical, dyestuffs and textile printing
There has also been noted associations with cyclophosphamide exposure, previous pelvic radiotherapy and schistosomiasis infections.
What are the signs and symptoms of bladder cancer ?
The most common symptom is the development of haematuria ( blood in the urine). This may be either macroscopic (visible to the eye) or microscope (only detected by laboratory testing).
The amount of bleeding is not necessarily proportional to the severity of the cancer. With cancer the bleeding is not always constant and may actually disappear before returning some time later.
It may be found as an incidental finding discovered on ultrasound or CT scanning or during a cystoscopy ( examination of the bladder with a telescope) .
Urine cytology ( examination of the urine for cancer cells) may also be performed . This is most useful for high grade lesions.
How is bladder cancer diagnosed ?
A cystoscopy needs to be performed with resection of the tumour down to the muscle of the bladder. The resected material is then removed and sent for histological analysis by a pathologist.
Most bladder cancer is a type described as a transitional cell carcinoma. Squamous cell carcinoma and adenocarcinoma are less common types.
|
|
| Bladder Cancer at Cystoscopy |
Transitional cell carcinoma is graded between 1-3 and is described as well, moderately or poorly differentiated and this tends to reflect its aggressiveness.
Staging TMN system
Staging reflects the degree of spread of the cancer which has important implications for treatment and overall outcomes.
The TMN staging system is based on
T(tumour),
M; (metastatic) spread outside the bladder to other organs
N; (lymph node involvement)
Ta involves the submocusa
T1 lamina propria invasion
T2 Muscle invasion
T3 invades the fat surrounding the bladder
T4 invasion of adjacent organs
|
|
In general most bladder cancers are superficial (involving the mucosa or submucosa) and have not spread elsewhere. Only 10-20% of superficial cancers progress over time. After resection there is a high risk of tumour recurrence approaching 50%. This can be modified with the use of chemotherapy or immunotherapy (BCG) treatments which are placed in the bladder for a short period either immediately or for a 6 week course in the short term after surgery..
Muscle invasive cancers are generally very aggressive. Without treatment there is a mortality rate of up to 90% within 2 years.
Staging of the cancer is performed by the pathologists' assessment of the removed bladder cancer. Determination of whether the cancer has spread outside the bladder is generally performed for higher risk cancers and involves the use of imaging techniques such as Computerised Tomography of the chest, abdomen and pelvis and nuclear medicine studies ie bone scan.
Treatment for Superficial Bladder Cancer
Cystoscopy with diathermy of bladder cancer
A telescope (cystoscope) can be passed into the bladder. These have channels that permit small instruments to be passed into the bladder for the purpose of removing tissue and stopping bleeding.
TUR(Trans-Urethral Resection)
This involves removal of the cancer with a resectoscope. This is passed through the urethral meatus (eye of the penis) into the bladder and a cutting loop used to excise the cancer. The cancer is then removed through the resectoscope. This does not involve making an incision into the body.
Following this a catheter may be placed into the bladder which is usually removed the next day.
Drug therapy after TUR is commonly prescribed for patients with tumors that are large, multiple or high grade to prevent recurrence of cancer.
|
|
| Transurethral Resection |
Intravesical drug therapy /Immunotherapy
Medication is placed directly into the bladder (intravesical) via a urethral catheter in order to lower the recurrence rate of bladder tumors. This is usually used for multiple CIS (carcinoma in situ) , large cancers (>5 cm), or high grade cancers.
About 50-75% of patients with superficial bladder cancer have a very good response to intravesical therapy.
Commonly used intravesical drugs are:
Mitomycin C which disrupts the normal DNA function in cancer cells.
Bacille Calmette-Guerin (BCG) forces the immune system to respond to the BCG drug in the lining of the bladder, thus forcing the body's immune system to help fight off the cancer
Treatment for Muscle Invasive Bladder Cancer
Radical cystectomy
Radical cystectomy is performed when cancers invade the bladder's muscular wall. In men the bladder is removed with the prostate, seminal vesicles, adjacent lymph nodes and if the prostate is involved then the urethra may also be excised. In women the uterus, ovaries, anterior vaginal wall and urethra are removed.
Dissection and excision of the adjacent lymph nodes is also performed.
Surgical reconstruction to replace the removed bladder then needs to be performed. There are different forms of reconstruction and this can involve either the creation of a conduit or the creation of a neobladder.
Ileal conduit
This procedure has been routinely performed since the 1950's. The internal pouch which holds the urine is made from a small portion of intestinal tract. One end is closed with sutures while the other end is attached to skin on the front side of the abdomen. A stoma is the open end of the conduit attached to the skin. An external appliance (ostomy bag) covers the stoma to collect urine. The ureters are implanted into the back of the ileal conduit
Catheterizable Continent Diversion Pouch
This is a reservoir of bowel with a stoma that is catheterizable for emptying the bladder. The urine is siphoned out of the urinary reservoir with a small catheter every 4-6 hours. The catheterizable pouch may require surgical repair at some point after surgery due to the wear and tear of frequent catheterization. This type of reconstruction is not performed on patients with a history of bowel disease.
Neobladder
A neobladder is a new bladder made of intestines. This internal (new bladder) is connected to the urethra and ureters. After this reconstruction the patient needs to relearn how to void. The advantage is that there is no stoma or ostomy on the abdomen. Some disadvantages of this type of reconstruction are possibility of scar tissue formation at the connection of the urethra and new bladder and incontinence.
Radiation Therapy
The type of radiation used to treat cancer is actually a special high energy x-ray that is more powerful than x-rays used for imaging studies. Radiation therapy is planned and executed in a way to kill cancer cells or alter their ability to reproduce while the surrounding healthy cells are minimally affected .
Historically, radiation therapy has been used for muscle invasive bladder cancer but current treatment can involve a combined approach of both radiation and chemotherapy.
The role of radiation therapy in combination with chemoradiaton therapy (combined chemotherapy and radiation therapy) is to kill the bladder cancer cells both in the bladder and outside the bladder. Local lymph nodes are frequently radiated as part of the therapy to treat the microscopic cancer cells which may be in the nodes.
Chemotherapy
Chemotherapy is the use of medications that interfere with the replication and normal cell function resulting in tumour shrinkage or cancer cell death. The use of two or more chemotherapy drugs together has been found to be more effective than a single drug alone. There are several types of chemotherapy which can be used. The most common chemotherapeutic drug used in bladder cancer is cisplatin and gemcitabin.
In patients with muscle invasive bladder cancer chemotherapy may be given as a treatment before or after surgery.
Comprehensive Medical Care for Bladder Cancer at Urology Associates includes multidisciplinary care with the expertise of specialist oncologists and radiation oncologists and the input of the nursing team and stomal therapist of Cabrini Hospital.