Introduction
Bladder cancer is where cells in the lining of the bladder begin to grow and divide abnormally. Most people who develop bladder cancer are over the age of 60 and the condition affects men much more than women, with men three to four times more likely to develop the condition than women. For men it is one of the top ten commonest types of cancer.
Cancer in the bladder originates in the innermost lining and can invade through the different layers of the bladder. These layers are:
Urothelium
Composed of urothelial cells, this is the innermost layer.
Lamina Propria
This the next layer out, containing blood vessels.
Muscularis Propria
This is the next layer out and contains the muscles that control the bladder.
Perivesical Tissue
This is the outermost layer, composed mainly of fat.
Where cancer has formed in the bladder, it is also described as either non-muscle invasive or 'superficial' (i.e. confined to the first two layers) or muscle invasive, where it is present in the muscularis propria and possibly the perivesical tissue.
Types of bladder cancer
The three most common types of bladder cancer are:
Urothelial carcinoma (also referred to as 'transitional cell carcinoma')
Around 85% of all cases of bladder cancer are urothelial carcinoma. They generally occur in the urothelium layer in the bladder, but can also occur in the kidneys and the tubes connecting the kidneys to the bladder ('ureters').
Squamous cell carcinoma
Squamous cells are flat cells that form the a strong tissue layer on both the outside and inside of organs. Cancer that develops in these cells is much less common than urothelial carcinoma, accounting for less than 2% of all bladder cancers. It is generally a more invasive type of cancer. It is more common in countries where the bilharzia parasitic worm infection (also called schistosomiasis) is present.
Adenocarcinoma
This type forms in glandular cells in the bladder and is often the result of long-term inflammation. It accounts for around 1% of all bladder cancer and is a more invasive type of cancer.
There are also some other rarer types of cancer that affect the bladder - sarcomas, which develop in muscle tissue, and 'small cell carcinoma', 'micropapillary carcinoma' and 'plasmacytoid carcinoma', all three of which are regarded as aggressive types of cancer.
Causes
There are a number known risk factors for bladder cancer. These are:
- Age - most people diagnosed are over 60
- Gender - men are up to four times more likely to develop the condition
- Smoking - smokers are three times as likely to develop bladder cancer
- Chemical exposure - certain chemicals (benzene, aromatic amines and aniline dyes) are linked to the condition. These chemicals are used in some manufacturing processes where dyes are used, and people working in coal mining (exposure to soot), hairdressing, painting and printing can be exposed to these
- Family history - some types of bladder cancer are linked to genetics (especially Lynch Syndrome).
- Chemotherapy/radiotherapy (to pelvic area) - some cancer treatments can increase the risk of the condition (especially a chemotherapy drug called cyclophosphamide used to treat a number of different cancer types)
- Long term urinary tract infections - linked to squamous cell carcinoma
- Bladder stones - where untreated, linked to squamous cell carcinoma
- Urinary catheter - where one has been in place over a long time
Symptoms
The most common symptom is haematuria, that is blood in the urine. It can often occur quite suddenly. Other symptoms linked with bladder cancer include:
- Difficulty urinating
- Burning sensation/pain when urinating (dysuria)
- Frequent need to urinate or frequent feeling of urgency, including at night (nocturia)
All of these symptoms may have another cause, which is why it is important to check these symptoms with a doctor.
Tests / Diagnosis
Your doctor will firstly conduct a review of medical history and a physical examination. In addition, the following tests may be recommended:
- Blood tests
- Urine tests / urinalysis
- Urine cytology
- Cystoscopy - this is the main test where an examination is made of the bladder using a camera, which may involve taking a tissue sample (biopsy).
Further tests may include scans such as a CT scan, bone scan or MRI.