Urothelial Cancer of the Bladder and Upper Tracts

Executive Summary

  • Urothelial cancer may occurs anywhere urine is in contact with the lining of the urinary system.

  • Bladder is the most common location for urothelial cancer. Urothelial cancer may also occur in the renal pelvis, ureter and urethra.

  • Urothelial cancers vary from ‘nuisance’ tumors that pose little risk through to aggressive cancers that may be rapidly lethal.

  • Treatment is highly individualized and based on assessment of risk.

  • Urothelial cancers that have metastasized are incurable. Treatment of cancers that have not spread is focused on preventing recurrences of cancers and progression to metastatic disease. This may require removal of the bladder.

  • Post-treatment surveillance is always necessary. Surveillance with cystoscopy, sometimes life-long, is necessary patients who do not require removal of their bladder.

  • Treatment always involves transurethral resection of the tumor. Additional treatments will vary based on the risk of the tumor and range from medications administered into the bladder through to major surgery and chemotherapy.

Background & Terminology

Kidneys filter blood and produce urine. The urine drains through a collecting system and eventually leaves the body through the urethra (the last part of the drainage system). The collecting system is a series of pipes which are much like the plumbing in a home. The collecting system starts in the kidneys and ends with the urethral meatus. The inside of these ducts are lined by a layer of cells that is called the urothelium. The individual cells are called transitional cells or urothelial cells (these terms are used interchangeably). When the lining of a hollow organ such as the bladder is in contact with fluid, we call the lining a mucosa (e.g. the lining of the mouth is also a mucosa, but is lined by a different type of cell than in the bladder). The urothelium (i.e. the mucosa) is constantly being renewed - dead cells being shed in the urine, much like the skin is always undergoing renewal. Just as sun exposure can predispose to skin cancer, the composition of the urine can predispose to urothelial cancers. Cancer is the unregulated growth of cells which cause problems with the function of the urinary system and also have the ability to spread to other organs (e.g. lung, liver, lymph nodes, etc.).

Urothelial cancer is therefore cancer that arises in the lining of the urinary system. It is also called transitional cell cancer.

Urothelial cancer may arise anywhere the urothelium exists - from the start of the collecting system in the kidney, the ureters which conduct urine from kidney to bladder, within the bladder itself to the urethra which conducts urine from the bladder to the tip of the urethral meatus.

Note: Other types of cancers involving the urinary collecting system may occur but they are much less common.. These include tumors such as squamous cell cancer, sarcomas and others. Their evaluation and management may differ significantly from urothelial cancer.

Quick Facts About Urothelial Cancer

Urothelial cancer is common. 5000 new cases per year in Canada. #4 cancer in men. #8 cancer in women.

Anyone can develop urothelial cancer. However, the major risks are age, any history of cigarette exposure, male gender, Caucasian ethnicity.

Bladder cancer (in common usage) is urothelial cancer involving bladder and is by far the most common type of urothelial cancer. Urothelial cancer of the upper tracts (renal pelvis and ureters) are much less common. The ratio of bladder to upper tract cancer is 50:1. The reason for this is that the majority of the urothelium resides in the bladder. Urothelial carcinoma of the urethra is less common but may occur as an extension from the bladder or less commonly arising from the prostatic urethra.

 

Causes of Urothelial Cancer

Similar to just about any other type of cancer, these tumors may result from bad luck. However, urothelial cancer is much ore common in older individuals and in those that have exposure to cigarette smoke. Urothelial carcinoma may occur in patients of any age and in the absence of a smoking history.

 

Structure of the Bladder Wall

It is helpful to understand the structure of the bladder wall because invasion into and beyond that wall is critical in how bladder cancer is managed. Urothelial carcinomas that show invasion into the underlying structures are almost high risk high grade and pose a significant risk of spreading.

To use an analogy, one can think of the bladder wall as being similar to a carpeted floor. The surface of the floor is the side which is in contact with the urine (and forms the inside of the bladder). Starting from from the inside-out, the layers of the bladder are:

 

Diagnosis

Bladder cancer is most commonly diagnosed when there is blood in the urine (hematuria). Virtually all patients who have hematuria require evaluation. In fact, urologists generally approach the work up of evaluation by assuming that urothelial cancer is present and then doing the testing to exclude it.

 

Risk Assessment

Just like any cancer, urothelial cancers may be life-threatening. However, some may be more nuisance and non-life-threatening. Assessing risk is essential in management. Regardless of the level of risk, all urothelial cancers should be treated so that the risk can be fully assessed.

Urothelial cancers that have metastasized (spread outside the urinary system) are invariably high grade and are incurable. The prognosis is months to a a few years at best. Metastatic urothelial cancer is a terrible disease and the primary goal in the management of urothelial cancer is to prevent this occurrence.

Risk assessment means:

  • Assessing the current state of affairs.

  • Predicting the likely future behavior of the tumor: the risk of recurrence (the cancer comes back) and progression (the tumor invades more deeply into the surrounding tissues or metastases).

Assessment of bladder cancers is often ore straight forward than for upper tract urothelial cancer

Management of Bladder Cancer

All patients with bladder cancer start with:

  1. Imaging (CT or MRI or other type).

  2. Transurethral resection of bladder tumor (TURBT).

Untreated bladder cancer, especially high grade tumors, may be lethal. This section addresses what happens after that the initial evaluation and TURBT have been completed..

The treatment of bladder cancer is individualized based on the risk associated with the tumor with further consideration of the patient's circumstances. Bladder cancers are highly variable - some are associated with much more aggressive behavior than others. The following are general guidelines and your treatment may differ based on your circumstances.

See above: ‘Classification - Putting It All Together’.

All patients require surveillance (periodic rechecks) after initial treatment. Cystoscopy is the cornerstone of surveillance - there is no substitute. Urine tests cannot replace cystocopy.

Clinically Localized: Non-Muscle Invasive Bladder Cancer (NMIBC)

NIMBC are those confined to the mucosa or lamina propria (the 'carpet or underlay') - they do not invade into the muscular layer of the bladder. They are designated by the stages Ta or T1, respectively. These tumors are frequently curable without major surgery but can, none the less, progress to very dangerous muscle-invasive disease. In many cases, the tumors are more 'nuisance' than 'life threatening', but knowing exactly what sort of risk the tumor brings with it will help individualize treatment.

The goals of treatment are to prevent recurrence (tumor comes back) and progression (tumor becomes high grade or muscle invasive) of the cancer (see Predicting Future Behavior above). Preventing cancer progression is the most important goal since progression in bladder cancer may be lethal and almost always requires radical treatment.

Patients with NMIBC are split into 3 groups for the purposes of management:

  1. Low risk NMIBC: first presentation, stage Ta, low grade, less than 3 cm, no CIS.

  2. Intermediate risk NMIBC: anything that is not low or high risk.

  3. High risk NMIBC: any of stage T1, high grade (grade 3/3), any CIS, a mix of criteria (need all of multiple, recurrent and large (>3 cm), Ta, grade 1 or grade 2 tumor).

  4. Very high risk NMIBC: high risk patients who have multiple high risk features or those with additional factors including age >70, multiple papillary tumors, tumor diameter >3 cm

Recommendations for intravesical treatment and the frequency and nature of surveillance are what vary between treatments. With increasing risk, the intensity of surveillance and the use of additional (adjuvant treatments) increase as well.

Intravesical Treatment for NMIBC: Medication Instilled Into The Bladder

Intravesical means ‘into the bladder’. Intravesical treatment (IVT) is a treatment where medication is placed into the bladder by way of a temporary catheter. The medication coats the inner surface of the bladder with the goal of reducing the risk of recurrence and progression. Treatments that are given after the primary treatment (in this case TURBT) are known as adjuvant treatments. Therefore, short hand for this treatment is ‘adjuvant IVT’.

Adjuvant IVT is almost exclusively used in non-muscle invasive bladder cancer. It is almost never used for muscle invasive bladder cancer.

There are a variety of adjuvant IVT’s that are in use. The primary ones are BCG and gemcitabine. IVT’s not using BCG are sometimes administered at the time of surgical removal of the tumor and are called ‘post-operative intravesical installation of chemotherapy’.

 

Clinically Localized: Muscle-Invasive Bladder Cancer

Bladder cancers that have invaded into the muscle layer may still be curable. Muscle-invasive bladder cancers (MIBC) are invariably high grade and have a high risk of spreading if not treated aggressively. About 1 in 3 to as many as 1 in 2 patients who do not appear to have evidence of spread at the time of initial assessment will in reality have cancer that has already spread but is not yet detectable because the amount of cancer that has spread is below the threshold of detection. What this means is that about up to 1 in 2 patients who appear to have clinically localized bladder cancer will die from their cancer within 5 years despite best efforts at cure. Muscle invasive bladder cancer is a life-threatening disease.

The 2 primary options for treatment of MIBC are:

  1. Radical cystectomy: Removal of the bladder and surrounding organs (prostate in males and uterus in females) plus pelvic lymph nodes plus urinary diversion/reconstruction is considered the standard treatment for muscle invasive bladder cancer. Often combined with chemotherapy before surgery (neoadjuvant chemotherapy) and sometimes chemotherapy after surgery (adjuvant chemotherapy). There are rare circumstances where removal of part of the bladder is possible (partial cystectomy).

  2. Radiation combined with adjuvant chemotherapy after TURBT. This is also known as ‘trimodal therapy’ or ‘TMT’ and is an option only in very selective circumstances. In those select circumstances it can be as effective as radical cystectomy.

Chemotherapy is not capable of curing bladder cancer on its own. It is always used as an adjunct to radiation or surgery. Chemotherapy utilized on its own is restricted to patients who are incurable.

Management of patients with MIBC is highly specialized and it is beyond the scope of this website to describe all of the important nuances. Some general information follows.

Quantitative Risk Assessment Tools

Sometimes classifying patients with NMIBC into low, intermediate and high risk is not satisfactory. These tools can be used in those circumstances.

TAT1 TUMORS - NMIBC PREDICTION OF RECURRENCE AND PROGRESSION

The European Association of Urology has provided a set of tools for predicting recurrence and progression. It utilizes a scoring system based on the 6 most significant clinical and pathological factors.

IMPORTANT: This tool does NOT take into account the beneficial effects of adjuvant intravesical therapy. The Cueto risk tool does take this into account.

Factor Recurrence Progression
Number of tumours
Single 0 0
2-7 3 3
≥8 6 3
Tumour diameter
<3 cm 0 0
≥3 cm 3 3
Prior recurrance
Primary 0 0
≤ 1 recurrance/year 2 2
> 1 recurrance/year 4 2
category
Ta 0 0
T1 1 4
Concurrent CIS
No 0 0
Yes 1 6
Grade
G1 0 0
G2 1 0
G3 2 5
Total Score 0-17 0-23
 
Recurrence Score Probability of recurrence at 1 year Probability of recurrence at 5 years
% (95% CI) % (95% CI)
0 15 (10-19) 31 (24-37)
1-4 24 (21-26) 46 (42-49)
5-9 38 (35-41) 62 (58-65)
10-17 61 (55-67) 78 (73-84)
 
Progression Score Probability of progression at 1 year Probability of progression at 5 years
% (95% CI) % (95% CI)
0 0.2 (0-0.7) .8 (0-1.7)
2-6 1 (0.4-1.6) 6 (5-8)
7-13 5 (4-7) 17 (14-20)
14-23 17 (10-24) 45 (35-55)

Note that we offer the full spectrum of bladder cancer surgery and treatments:

On the Web

General Information on Cancer

UNDERSTANDING CANCER - Metrovan Urology info on the principles of diagnosis, staging, prognosis and more.

American Cancer Society

BC Cancer Agency: Good general website from the British Columbia Cancer Agency. Has contact information on locations.

National Cancer Institute: Excellent source of understandable and mainly unbiased information. Several very good brochures on every stage of prostate cancer.

National Comprehensive Cancer Network: peer-reviewed expert content/prostate cancer guidance on evidence-based cancer diagnosis and management. Best for Prostate and Kidney Cancer. The most in-depth information is located in the physician section and requires registration.