Trials have started for a new test for prostate cancer that involves analysing saliva.

Prostate cancer is the most common cancer in men in the UK. It often has no symptoms, which makes it difficult to diagnose in the early stages when treatment outcomes are more likely to be successful. Detecting prostate cancer earlier is, therefore, an important health care goal.

At present, there is no single reliable test for prostate cancer. There is a blood test that detects a protein in the blood called prostate-specific antigen (PSA), a high PSA reading may indicate a problem with the prostate, but this test is not always accurate and can give false positives or miss more aggressive forms of the disease.

For this reason, PSA results are combined with biopsies and physical examinations to get an overall diagnosis, which is time-consuming and invasive. The new test will involve taking a sample of saliva and looking at the DNA to identify the presence of high-risk genes that are thought to affect one in every 100 men.

The new DNA test was created by a group of international scientists based at the Institute of Cancer Research (ICR) in London. They studied more than 140,000 men and looking at their DNA identified 63 new genetic variations that can increase the risk of prostate cancer. The DNA test combines those variants with more than 100 others previously linked to prostate cancer and can provide information on a man’s inherited risk of developing prostate cancer. Men who are deemed to be at higher risk of prostate cancer would then be scanned and have a prostate biopsy, so researchers hope it could prevent unnecessary procedures. It would also inform men of their individual genetic risk factor for prostate cancer.

In the first phase of the trial, 300 men will be taking part but it is hoped the trial will expand to include 5,000 men next year.
Carl Alexander from Cancer Research UK said the study was “an exciting example” of how research can find clues in our genes to help us uncover those more likely to develop the disease.

What is the prostate?

Many men who are diagnosed with prostate cancer admit they had never even heard of their prostate before. But given that 1 in 8 men develop prostate cancer at some point in their lives, it’s important to know a bit about it.

Firstly, only men have a prostate gland. The prostate is usually the size and shape of a walnut and grows bigger as you get older. It sits underneath the bladder and surrounds the urethra. Its main job is to help make semen – the fluid that carries sperm.

As with all cancers, prostate cancer develops when cells in the prostate start to grow in an uncontrolled way. It is often slow-growing cancer and many men may never have any symptoms or know they have the disease. However, some forms of the disease can be more aggressive and if left untreated can spread outside the prostate gland. One symptom can be difficulty passing urine. Men with prostate cancer that’s spread to other parts of the body might have pain in the lower back or pelvis area, blood in the urine or unexplained weight loss. Other conditions could also be responsible for these symptoms but it is important to speak to your GP to find out what’s causing the symptoms and not ignore them.

Prostate cancer in the UK: facts and figures

(Source: Prostate Cancer UK).

• Prostate cancer is the most common cancer in men.
• 1 in 8 men will get prostate cancer in their lifetime.
• Over 47,000 men are diagnosed with prostate cancer every year.
• More than 11,000 men die every year from prostate cancer.
• Men aged 50 or over, men with a family history of prostate cancer are at a higher risk
• Black males are at a higher risk then white or Asian males, the reasons are unclear but could be genetic.
• Over 330,000 men are living with and after prostate cancer.

Rachel Kayani