The medical debate around whether riding a bike could cause prostate cancer reignited this week after cycling hero Sir Chris Hoy revealed he has an aggressive form of the disease.
Eleven-time Olympic gold medallist Sir Chris, 48, announced at the weekend he has ‘two to four years to live’ due to his terminal illness — with fans taking to social media to express shock and sadness.
Others wanted to know why someone relatively young, and seemingly fit and healthy, could be hit by an illness normally associated with older men.
Could it have been anything to do with regular bike-riding, as some research has previously suggested?
Given one in ten adult men ride a bike — twice the number of women — and it’s most popular with those aged 50 to 60, the ages prostate cancer starts to become a concern, it’s a fair question. But what is the truth?
British cycling legend Sir Chris Hoy has revealed he has incurable prostate cancer , and could have ‘two to four years to live’ – at the age of just 48
Scientists have been exploring the relationship between prostate cancer and cycling for over a decade. Pictured Sir Chris taking part in the Platinum Jubilee Pageant in 2022
Scientists have long worried that cycling could impact the prostate as bike seats put pressure on the perineum — the underside of the pelvis, between the legs.
This, in turn, may irritate the prostate, due to the location of the gland — which helps the body produce semen — which sits inside the pelvis, directly below the bladder.
Researchers have found cycling can increase levels of prostate specific antigen (PSA) in blood tests.
This compound is released by the prostate and, if levels are higher than normal, can be a sign there is something wrong with the gland.
Bouts of cycling have been found to spike levels for up to 48 hours, in some studies.
There is also evidence that regular cyclists are more likely to suffer from prostatitis — which is the medical term for inflammation of the prostate.
However, neither prostatitis or elevated PSA levels, by themselves, are signs someone has prostate cancer, nor are they known to increase the risk of the disease.
In 2014 a study from University College London found men in their 50 who cycle more than nine hours a week were five times as likely to develop prostate cancer as those who cycles less frequently.
Researchers looked at data from over 5,000 cyclists, and also found an increased risk when men this age cycled for just over 3.5 hours per week.
But subsequent studies, such as a 2020 paper published in the Journal of Clinical Urology on data from 8,000 male cyclists, failed to find a link between cycling and increased risk of prostate cancer.
And other research has even suggested cycling could help ward off the disease.
One such study, published earlier this year on over 50,000 men, found that men who exercise regularly, including cycling, have a reduced chance of prostate cancer compared to those who don’t.
The Swedish study, published in January, found men who undertake regular cardiovascular exercise had a third lower chance of developing prostate cancer.
The authors of the worrying 2014 University College London study went as far as to urge men to keep up the cycling for the wider benefits to their health.
‘We would not recommend that people reduce their cycling volume. Cycling has many physical and mental health benefits that at present outweigh any risks it may cause,’ they wrote at the time.
This CRUK chart shows prostate cancer incidence over time among different age groups, whilst older men remain the most likely to get the disease rates have dramatically increased among younger men since the 90s
Regular exercise has been a well-established anti-cancer lifestyle tweak.
It not only combats obesity, with excess fat increasing cancer risk overall, but working out also produces hormones that can help reduce the odds of cancer appearing or growing.
British cancer charity, Cancer Research UK (CRUK), states there are no known lifestyle factors that increase a man’s risk of developing it in their lifetime.
This isn’t to say there aren’t any factors that do increase the risk of getting the disease but these are unchangeable such as family history or ethnicity.
For example, prostate cancer risk is generally higher among Black men compared to those of different backgrounds.
As with most cancers, what precisely causes a specific case of prostate cancer in an individual is generally impossible to determine.
More than 52,000 men are diagnosed with prostate cancer every year on average in the UK, making it the most common cancer in men. Around 12,000 men die every year from the disease — the equivalent of one every 45 minutes
CRUK data show about 55,000 cases of prostate cancer are diagnosed in the UK each year, equivalent to about 150 men every day in Britain.
Prostate cancer is the most common cancer for men in the UK, with those in their late 70s the most likely to be diagnosed with the disease at 825 cases per 100,000 men.
However, cases of the disease have increased dramatically in young groups since the 90s for reasons scientists are still unsure of.
Rates have increased over 600 per cent in this time period among men aged 25-to-49, like Sir Chris, the largest rise of any group.
However the base level among young men remains low at just six cases per 100,000 men this age, up from one case per 100,000 in the 90s.
Rates among 50s have increased by about 350 per cent to about 150 cases per 100,000 men and 163 per cent in the 60s to some 500 cases per 100,000.
Prostate cancer, if it’s caught early, is highly treatable. Overall, 9 in 10 men with the disease will survive for five years or more, and eight in 10 survive a decade.
Outlook is much less positive for advanced prostate cancer, with survival dropping to one to three years.
It is noted that prostate cancer in younger men, for the purposes of cancer diagnoses those under 50 such as Sir Chris, are far more likely to be diagnosed at the advanced stage.
This can be due to a lack of awareness about potential symptoms that delay them seeking help or medics not initially suspecting issues could be caused by prostate cancer in someone so young leading to delayed diagnosis.
A total of 12,000 men die from prostate cancer each year in the UK.
Symptoms of prostate cancer include needing to urinate more frequently, often during the night, needing to rush to the toilet to urinate, having trouble urinations or taking a long time or feeling like your bladder has not emptied when doing so.
Blood in urine or semen can able be a potential sign of the condition.
These symptoms can be triggered by a variety of conditions, not just cancer, but people are urged to report them to their GP regardless so the cause can be investigated.