Blue light is not a treatment for bladder cancer but is a new method of detecting early (superficial) bladder cancer. It is also called fluorescence cystoscopy.

It works by making it easier for the doctor to see areas of cancer in the bladder. This may be useful in helping doctors to:

• remove more of the cancer in the bladder
• detect a type of bladder cancer called bladder cancer-in-situ (CIS)
• choose the most appropriate treatment for each person.

Doctors diagnose bladder cancer and monitor the bladder after treatment using a small, flexible, fibre-optic telescope called a cystoscope. During cystoscopy a white light is used to show up areas of the bladder that may be abnormal. But this type of light doesn't always show up all of the cancer in the bladder.

Blue light cystoscopy can show up cancers in the bladder that might be missed by standard white light cystoscopy. Firstly, a chemical, which glows brightly when blue light is shone on it, is put into the bladder. The chemical, called hexaminolevulinate (HAL or ALA), is left in the bladder for at least an hour while it is absorbed by any cancer cells. After this the doctor uses a cystoscope fitted with a blue light to show up areas of cancer in the bladder.

Cancers in the lining of the bladder often grow back after they are removed. Doctors may use additional treatments to reduce the risk of this happening. How the bladder looks at cystoscopy helps the doctor to decide if extra treatment may be needed as well as which treatment to give. Some doctors think that blue light cystoscopy may help them to choose the best treatment for each patient.

Because blue light cystoscopy is so new there are still a number of questions about how best to use it and we don't yet know for sure whether it helps to improve the treatment for early bladder cancer. There are also some concerns that it may mean some people are given treatment that they don't need.

Sometimes doctors see changes in parts of the bladder of people with bladder cancer that look like cancer. But, once they are removed they turn out to be non cancerous. When this happens it is called a false positive. Doctors want to avoid false positives because they mean people having treatment, such as operations to remove the ‘cancers’ that they don't need. Some doctors are concerned that the number of false positives seems to be a bit higher with blue light cystoscopy than with white light cystoscopy.

Further research trials are planned to find out how best to use blue light cystoscopy. In the meantime there are very few centres in the UK where it is available. Your specialist will be able to talk over with you if it is appropriate for you and whether you could be referred to one of these centres.

References

• Jocham D et al 2005. Improved detection and treatment of bladder cancer using hexaminolevulinate imaging: A prospective, phase III multicenter study. The Journal of Urology 174(3) 862-866.
• Steinberg G 2005 Editorial comment. The Journal of Urology 174(3) 866.