A doctor explains the common causes, symptoms and treatment for the disease.

A study from Maastricht University has revealed new insights into the link between diet and bladder cancer.

The research, funded by the World Cancer Research Fund, found that consuming too much saturated and animal fats increased the risk of bladder cancer in men by 37%, while women who ate monounsaturated fatty acids and plant-based oils (such as olive, coconut and sesame oil) decreased their risk of the disease by 27%.

Saturated fats are found in foods such as fatty cuts of meat, sausages and pies, butter, cheese, chocolate, biscuits, cakes and pastries - foods that should be consumed in moderation as part of a healthy diet.

Lead investigator, Dr Anke Wesselius, commented: "These findings suggest that the quality of fat consumed has an impact on the likelihood of developing bladder cancer, and men could see a benefit in reducing levels of animal fats in their diets."

In light of the new research, here are the key causes, symptoms and treatments of bladder cancer.

What is bladder cancer?

"The eleventh most common cancer in the UK, bladder cancer is caused by changes to the cells inside the bladder lining," says Dr Bryony Henderson, lead GP at the digital health provider Livi livi.co.uk).

There are two main types. With transitional cell bladder cancers (also known as urothelial carcinoma), "the cells lining the wall of the bladder can come into contact with waste products that can lead to cancer, like cigarette smoke," she says.

"With squamous cell bladder cancer, these tumours spread through the muscle layer or wall of the bladder to other parts of the body."

Who is most at risk?

Bladder cancer can affect anyone but most commonly it can be found in those over 55, with men three times more like to be diagnosed than women.

Some medical conditions are correlated with the disease, Henderson explains: "People with type-2 diabetes, those who have experienced repeated bladder infections or bladder stones, those who have a paralysis of the nerves in the bladder resulting from having a tube called a catheter inserted on a long-term basis, and patients who have experienced a rare infection called schistosomiasis [are more at risk]."

In addition to the dietary aspects revealed by the new research, other lifestyle risk factors include: "Being exposed to some chemicals through your work like arylamines or PAH," and smoking. "Some of the chemicals from tobacco are passed through urine, which can damage your bladder cells over time," she says.

What are the symptoms of bladder cancer?

"Common bladder cancer symptoms include blood in your urine, dark-coloured urine, need to urinate frequently and urgently, pain or a burning sensation when you pee and pain in the lower tummy," Henderson explains.

In addition, "Pain in your pelvis, pain in your bones, weight loss, or leg swelling", should be investigated, as well as feeling unusually tired or unwell.

While any of these symptoms may be caused by something less serious, it's important to get them checked out. She advises: "If you're showing any of the symptoms of bladder cancer you should get in touch with a GP immediately."

How is it diagnosed?

At an initial appointment your GP may suggest a urine microscopy, where a sample of your urine is checked for blood cells or infections under a microscope.

"It may be suggested that you are referred to a specialist," Henderson says. "If cancer is suspected then this would be requested urgently and you should be seen within two weeks in the NHS."

A specialist may then suggest a cystoscopy, or a CT or MRI scan if a closer look is needed.

"A cystoscopy involves a thin, flexible tube with a camera at one end being passed into your urethra (the tube that carries urine out of your body) and bladder to check for any cancerous cells," Henderson says. "The doctor may also take a small sample from your bladder to test it (this is called a biopsy), or even remove a superficial tumour if one is found."

How is bladder cancer treated?

If you are diagnosed with bladder cancer, a multidisciplinary team will work together to provide your care.

"The treatment you have will depend on the type of bladder cancer that you have," says Henderson. "Treatment options may include tumour removal using a cytoscope that is passed into your bladder or cystectomy surgery to remove your bladder."

A course of chemotherapy or radiotherapy might also be recommended: "Chemotherapy involves a special medicine to kill cancer cells being passed into your bladder by a catheter. Radiotherapy is where high-energy beams of radiation are targeted at your bladder cancer tumours to kill the cancerous cells."

In terms of the outlook for bladder cancer patients, Henderson says: "Your doctor will be able to advise you about the long term outlook as it depends on the stage of your cancer. This is why it is so important to catch any tumour early so treatment can be started."

In stage one about 80% of people survive for five years or more, whereas in stage four this falls to about 10%, according to Cancer Research UK (but the statistics don't take age into account).