Superficial Bladder Cancer

Superficial Bladder Cancer

Bladder cancer (also called transitional cell carcinoma – TCC, or urothelial carcinoma – UC) is a cancer of the urothelial lining and/or muscle of the bladder. In a small number of people, the entire urothelium, from the kidneys to the urethra can be at risk, so the investigations that are done when bladder cancer is discovered sometimes include investigation of the entire urothelium. This is true for high-grade superficial cancer of the bladder, and all muscle invasive bladder cancers.

There are two forms of the disease – superficial bladder cancer and muscle-invasive bladder cancer. Although strictly the same disease, they are very different in the way they are managed and treated, and these will be considered separately. This article will discuss superficial bladder cancer.

Superficial bladder cancer (non-muscle invasive bladder cancer)

This affects the superficial (inside) lining of the bladder. Most bladder cancers (about 85%) are this kind. They behave in a much less aggressive manner than bladder cancers that invade the muscle of the bladder. They do have a tendency to occur in different areas of the bladder over time, and need long-term observation. Most will stay superficial, but in some of the higher grade tumours, there is a risk of them later becoming muscle invasive.

What causes superficial bladder cancer?

There is often no obvious cause. All bladder cancers are more common in men than women, and many are caused by smoking. Chemicals from cigarette smoke are excreted in the urine, and these cause damage to the bladder over many years, in some people resulting in cancer of the bladder. As many as 30% of bladder cancers are attributed to smoking.

Other chemicals have been associated with an increased bladder cancer risk, and include:

• Aniline dyes
• Benzidine
• beta-naphthylamines
• 4-Aminobiphenyl
• Xenylamine
• O-toluidine
• Polycyclic hydrocarbons

There are a number of industrial occupations that are associated with these chemicals and bladder cancer, and these include the paint, dye, rubber, paper, petrochemical and smelting industries.

Other factors that may be linked to an increased risk of bladder cancer include:

1. a family history of bladder cancer
2. treatment with pioglitazone for diabetes (although there is some debate about this)
3. early menopause, including removal of the ovaries for medical reasons
4. previous chemotherapy with cyclophosphamide or cisplatin
5. pelvic radiotherapy for other cancers
6. repeated bladder infections
7. long term bladder stones

How is superficial bladder cancer investigated?

If a person has blood in the urine, it is usual to have an investigation known as a cystoscopy, where a telescope is passed into the bladder via the urethra. You can read more about this here. A form of imaging of the other parts of the urinary tract is required, either an ultrasound if there is non-visible blood, or a CT if the patient had seen blood.

The picture above shows the cystoscopic view of a small superficial bladder tumour.

The pathology report gives us important information about the tumour, which helps decide future management, including:

• The exact type of tumour
• The grade of the tumour (grade 1/2/3)
• The depth of invasion of the tumour

These factors are vital to know before further management can be planned. In general the management plan :

If the tumour is low grade and non-invasive, you will just need regular looks inside the bladder (first one at 3-months) to watch for any recurrence of the tumour. This is usually done with a flexible cystoscope, and is done periodically according to a rigid protocol.

If the tumour is high grade but non-invasive, you may need to have a course of chemical treatment inside the bladder, given as an out-patient procedure. Generally this is done with an agent called BCG, but mitomycin and gemcitibine can also be used in some settings. You will also need regular surveillance of the bladder into the future with cystoscopies.

Can superficial bladder cancer become invasive?

Yes this can occur, but it is generally very rare with low grade and very superficial tumours. Those that are higher grade or involve the second lining of the bladder (the lamina propria) do have more tendency to later become invasive. There is also a form of tumour called carcinoma-in-situ that is high risk for becoming invasive. It is these types of tumour particularly that need to be treated with chemicals into the bladder (intravesical treatment) to reduce the chance of this happening.