Men with high levels of testosterone ‘could be almost a FIFTH more likely to develop prostate cancer’
- Levels of hormones testosterone and IGF-I could predict risk of cancer
- They may fuel a dangerously rapid growth of cells in the prostate
- Scientists say hormones can be reduced naturally with methods like diet
Men with high levels of testosterone may be almost a fifth more likely to develop prostate cancer.
A study of more than 200,000 British men suggests two hormones, picked up in a simple blood test, can predict their prostate cancer risk.
Men with the most testosterone in their blood, compared to those with the least, were 18 per cent more likely to be diagnosed with prostate cancer.
Those with the highest level of a second hormone, called IGF-I, saw their risk increase by 25 per cent compared to those with the lowest level.
Experts believe the hormones are a red flag for cancer because they fuel the growth of cells in the prostate, which keeps growing for a man’s entire life.
When prostate cells grow and divide faster, there is more chance that errors will creep into their genetic code and mutated cells will be copied and cause cancer.
It is unlikely men will be given drugs to lower these hormones in the future, as that could have unintended side effects.
Men with high levels of testosterone may be almost a fifth more likely to develop prostate cancer. Those with the highest level of a second hormone, called IGF-I, saw their risk increase by 25 per cent. (Stock of prostate cancer cells)
But the findings, set to be presented at the National Cancer Research Institute conference in Glasgow, do suggest men could reduce their hormone levels naturally.
For example men on vegan diets have been found to have lower levels of IGF-I. That may be linked to evidence that men who eat less dairy have a lower risk of prostate cancer.
Dr Ruth Travis, who led the study from Nuffield Department of Population Health at the University of Oxford, said: ‘We were interested in studying the levels of two hormones circulating in the blood because previous research suggests they could be linked with prostate cancer and because these are factors that could potentially be altered in an attempt to reduce prostate cancer risk.
‘This research tells us that these two hormones could be a mechanism that links things like diet, lifestyle and body size with the risk of prostate cancer. This takes us a step closer to strategies for preventing the disease.’
More than 47,000 men a year are diagnosed with prostate cancer in the UK, and almost 12,000 die from it each year.
There is a blood test used to detect prostate cancer, which looks for a protein called PSA which leaks from the prostate, but it is often only given to men suffering symptoms such as frequent urination or blood in the urine.
Researchers are also working on blood tests which can detect fragments of tumours in the blood.
The largest single study to look at hormone levels in the blood, led by the University of Oxford, looked at 200,452 men from the UK Biobank genetic database.
All free from cancer when they began the study, more than 5,400 developed prostate cancer and almost 300 died from it in the seven years they were studied by researchers.
The men were divided into five groups, based on their levels of ‘free’ testosterone, which was not attached to any other chemicals in the blood, and insulin-like growth factor-I, a growth hormone known as IGF-I.
High levels of these hormones were linked to prostate cancer even when other factors, including body weight and socioeconomic status, were taken into account.
Hashim Ahmed, professor of urology at Imperial College London, who was not involved in the research. said: ‘These results are important because they show that there are at least some factors that influence prostate cancer risk that can potentially be altered.
‘In the longer term, it could mean that we can give men better advice on how to take steps to reduce their own risk.’
WHAT IS PROSTATE CANCER?
How many people does it kill?
Prostate cancer became a bigger killer than breast cancer for the first time, official statistics revealed last year.
More than 11,800 men a year – or one every 45 minutes – are now killed by the disease in Britain, compared with about 11,400 women dying of breast cancer.
It means prostate cancer is behind only lung and bowel in terms of how many people it kills in Britain. In the US, the disease kills 26,000 each year.
Despite this, it receives less than half the research funding of breast cancer – while treatments for the disease are trailing at least a decade behind.
How quickly does it develop?
Prostate cancer usually develops slowly, so there may be no signs someone has it for many years, according to the NHS.
If the cancer is at an early stage and not causing symptoms, a policy of ‘watchful waiting’ or ‘active surveillance’ may be adopted.
Some patients can be cured if the disease is treated in the early stages.
But if it diagnosed at a later stage, when it has spread, then it becomes terminal and treatment revolves around relieving symptoms.
Thousands of men are put off seeking a diagnosis because of the known side effects from treatment, including erectile dysfunction.
Tests and treatment
Tests for prostate cancer are haphazard, with accurate tools only just beginning to emerge.
There is no national prostate screening programme as for years the tests have been too inaccurate.
Doctors struggle to distinguish between aggressive and less serious tumours, making it hard to decide on treatment.
Men over 50 are eligible for a ‘PSA’ blood test which gives doctors a rough idea of whether a patient is at risk.
But it is unreliable. Patients who get a positive result are usually given a biopsy which is also not foolproof.
Scientists are unsure as to what causes prostate cancer, but age, obesity and a lack of exercise are known risks.
Anyone with any concerns can speak to Prostate Cancer UK’s specialist nurses on 0800 074 8383 or visit prostatecanceruk.org