The type of bladder cancer means the type of cell the cancer started in. Knowing this helps your doctor decide which treatment you need.
Transitional cell bladder cancer
About 9 out of 10 bladder cancers in the UK (90%) are the transitional cell type. This is also called urothelial cancer.
Transitional cell bladder cancer develops from the cells of the bladder lining (urothelium). These are called transitional or urothelial cells.
When the bladder is empty, these cells are all bunched together. As the bladder fills with urine the cells stretch out into a single layer. These cells come into contact with waste products in the urine that may cause cancer, such as chemicals from cigarette smoke.
Transitional cell bladder cancers can behave in different ways. There are early (superficial) cancers that have not invaded the deeper layers of the bladder. And there are invasive cancers that have. They are treated differently, so it is important to know which kind you have.
Non muscle invasive (superficial or early) bladder cancer
In early (superficial) bladder cancers, the cancer is only in the lining of the bladder. It has not grown into the deeper layers of the bladder wall.
Early bladder cancer usually appears as small growths, shaped like mushrooms. These grow out of the bladder lining. This is called papillary bladder cancer. Your surgeon can remove these growths and they may never come back.
But some types of non muscle invasive (superficial) bladder cancer are more likely to come back. These include carcinoma in situ (CIS) and high grade T1 tumours. T1 stands for the size of the tumour.
Unlike other superficial bladder cancers, areas of CIS are flat. They do not grow out of the bladder wall. In CIS the cancer cells look very abnormal and are likely to grow quickly. This is called high grade. It is more likely to come back than other types of superficial bladder cancer.
High grade T1 tumours
T1 tumours are superficial cancers that have grown from the bladder lining into a layer underneath, called the lamina propria. High grade T1 tumours are superficial cancers, but they can grow very quickly.
Doctors divide early bladder cancer into 3 risk groups. These risk groups describe how likely it is that your cancer will spread further or come back after treatment. Your risk group depends on several factors including the size of the tumour (stage), what the tissue looks like under the microscope (grade) and type of bladder tumour.
The 3 risk groups are low risk, intermediate (medium) risk and high risk.
If you have high risk superficial bladder cancer, your doctor may suggest more treatment than for other superficial bladder cancers. The specialist keeps a close eye on you to make sure the cancer is picked up as early as possible if it does come back.
Invasive bladder cancer
Transitional or urothelial cell bladder cancer can become invasive. This means it has grown into a deeper (muscle) layer of the bladder, or beyond. Some people have invasive bladder cancer when they are first diagnosed.
Invasive bladder cancer needs more intensive treatment than early (superficial) bladder cancer. This is because there is a risk that it could spread to other parts of the body.
Squamous cell bladder cancer
About 5 out of every 100 (5%) bladder cancers are squamous cell cancers. It is usually invasive.
Squamous cells are flat cells that make up the moist, skin-like tissues lining your body organs. This type of bladder cancer develops from these cells.
It is more common in developing countries where a worm infection called bilharzia or schistosomiasis is widespread.
This is a very rare type of bladder cancer. Between 1 and 2 out of every 100 people (1 to 2%) diagnosed with bladder cancer have it. It is usually invasive.
All the moist, skin-like tissues lining your body organs have some gland cells that produce mucus. Adenocarcinoma develops from these cells in the lining of the bladder.
Rarer types of bladder cancer
Very rarely, some people get a cancer of the bladder muscle or other structural tissues rather than the bladder lining. Cancers that start in the bladder muscle are called sarcomas. Doctors treat these differently to bladder cancer.
Small cell cancer of the bladder
This is a very rare type of bladder cancer. If you have it, you may have some of the treatments described in this section – for example, surgery and chemotherapy. But the chemotherapy drugs you have may be different. You must ask your own specialist how your treatment may differ.
Cancer that has spread to the bladder (secondary cancer)
Sometimes cancer that has started elsewhere in the body can spread to the bladder. This can happen with prostate, rectum, ovary, cervix and womb cancer for example.
Cancers that have spread from somewhere else in the body are called secondary cancers. The cancer cells are the same type as the first (primary) cancer. So is the treatment.
If you have cancer that has spread to the bladder, you need to go to the section about your primary cancer.