Cannabis linked to testicular cancer

Scientists find heavy use of marijuana can double risk of tumours among men

The soaring rate of testicular cancer in the UK and other Western countries is linked today to the increased popularity of cannabis. Testicular cancer has more than doubled over the past 30 years and its rise parallels that of the use of cannabis, Britain's most popular illegal drug.

Researchers in the US have found that men who regularly smoke cannabis have a 70 per cent increased risk of testicular cancer. The risk was highest – twice that of those who never used the drug – in those who smoked it at least once a week or had a long history of use, beginning in adolescence.

The study is based on findings from 369 men with testicular cancer who were questioned about their history of cannabis use. The results were compared with 979 men who did not have cancer. Cannabis was linked with testicular cancer independently of smoking, drinking and family history.

Experts from Cancer Research UK said it was the first time a link had been suggested and the size of the study was small. More than three million people smoke cannabis and only a tiny proportion develop the cancer.

The results, published today in the journal Cancer, showed a link between cannabis use and one type of testicular cancer, called nonseminoma, which is aggressive, tends to strike younger men and accounts for 40 per cent of testicular cancer.

Stephen Schwartz, an epidemiologist at the Fred Hutchinson Cancer Research Centre in Seattle, Washington, who led the research, said: "Our study is not the first to suggest that some aspect of a man's lifestyle or environment is a risk factor for testicular cancer but it is the first that has looked at marijuana use."

There were 2,109 cases of testicular cancer in Britain in 2005 and 78 deaths. In 1975 there were 850 cases. Unlike other cancers, it is most common in young men with a peak incidence between the ages of 20 and 40.

The more common, slower growing type, called seminoma, was not linked with cannabis use, even though both types have been growing by 3 to 6 per cent a year since the 1950s in the US, UK and other developed countries.

Although testicular cancer is normally curable when caught early, some patients are not diagnosed until the disease is advanced. Undescended testes in childhood and a family history of the disease are known to increase the risk.

The disease is thought to begin in the womb when germ cells in the foetus (those that will eventually make sperm in the adult) fail to develop properly. Exposure to male hormones in adolescence is thought to trigger development of cancer in the affected cells. Chronic cannabis use is known to reduce sperm quality and increase impotence, which are linked with testicular cancer.

The testes have receptors for tetrahydrocannabinol (THC), the main psychoactive ingredient in cannabis, and the male reproductive system is known to naturally produce a cannabinoid-like chemical that is thought to protect against the disease.

The researchers speculate that cannabis may interfere with this anti-tumour effect, increasing the risk of the cancer developing.

Janet Daling, a member of the research team, said: "It has been suggested that puberty is a window of opportunity during which lifestyle or environmental factors can increase the risk of testicular cancer. This is consistent with the study's findings that the elevated risk of nonseminoma-type testicular cancer in particular was associated with marijuana use prior to age 18."

PROMOTED VIDEO
Life and Style
ebooksA superb mix of recipes serving up the freshest of local produce in a delicious range of styles
Life and Style
ebooksFrom the lifespan of a slug to the distance to the Sun: answers to 500 questions from readers
Arts and Entertainment
Eye of the beholder? 'Concrete lasagne' Preston bus station
architectureWhich monstrosities should be nominated for the Dead Prize?
News
Lizards, such as Iguanas (pictured), have a unique pattern of tissue growth
science
Extras
indybest
News
Anna Nicole Smith died of an accidental overdose in 2007
people
Life and Style
food + drink
Arts and Entertainment
'The Great British Bake Off' showcases food at its most sumptuous
tvReview: Bread-making skills of the Bake Off hopefuls put to the test
Extras
indybest
Independent
Travel Shop
the manor
Up to 70% off luxury travel
on city breaks Find out more
santorini
Up to 70% off luxury travel
on chic beach resorts Find out more
sardina foodie
Up to 70% off luxury travel
on country retreats Find out more
Latest stories from i100
Have you tried new the Independent Digital Edition apps?

ES Rentals

    Independent Dating
    and  

    By clicking 'Search' you
    are agreeing to our
    Terms of Use.

    iJobs Job Widget
    iJobs General

    Digital Project Manager/BA

    £300 Per Day: Clearwater People Solutions Ltd: An experienced Digital/Ecommerc...

    Creative Content Executive (writer, social media, website)

    £30000 - £35000 Per Annum + 25 days holiday and bonus: Clearwater People Solut...

    Test Lead (C#, Java, HTML, SQL) Kingston Finance

    £40000 - £55000 per annum: Harrington Starr: A Global Financial Service Organi...

    Access/Teradata Developer, Banking, Bristol £400pd

    £375 - £400 per day: Orgtel: Access / Teradata Developer - Banking - Bristol -...

    Day In a Page

    Middle East crisis: We know all too much about the cruelty of Isis – but all too little about who they are

    We know all too much about the cruelty of Isis – but all too little about who they are

    Now Obama has seen the next US reporter to be threatened with beheading, will he blink, asks Robert Fisk
    Neanderthals lived alongside humans for centuries, latest study shows

    Final resting place of our Neanderthal neighbours revealed

    Bones dated to 40,000 years ago show species may have died out in Belgium species co-existed
    Scottish independence: The new Scots who hold fate of the UK in their hands

    The new Scots who hold fate of the UK in their hands

    Scotland’s immigrants are as passionate about the future of their adopted nation as anyone else
    Britain's ugliest buildings: Which monstrosities should be nominated for the Dead Prize?

    Blight club: Britain's ugliest buildings

    Following the architect Cameron Sinclair's introduction of the Dead Prize, an award for ugly buildings, John Rentoul reflects on some of the biggest blots on the UK landscape
    eBay's enduring appeal: Online auction site is still the UK's most popular e-commerce retailer

    eBay's enduring appeal

    The online auction site is still the UK's most popular e-commerce site
    Culture Minister Ed Vaizey: ‘lack of ethnic minority and black faces on TV is weird’

    'Lack of ethnic minority and black faces on TV is weird'

    Culture Minister Ed Vaizey calls for immediate action to address the problem
    Artist Olafur Eliasson's latest large-scale works are inspired by the paintings of JMW Turner

    Magic circles: Artist Olafur Eliasson

    Eliasson's works will go alongside a new exhibition of JMW Turner at Tate Britain. He tells Jay Merrick why the paintings of his hero are ripe for reinvention
    Josephine Dickinson: 'A cochlear implant helped me to discover a new world of sound'

    Josephine Dickinson: 'How I discovered a new world of sound'

    After going deaf as a child, musician and poet Josephine Dickinson made do with a hearing aid for five decades. Then she had a cochlear implant - and everything changed
    Greggs Google fail: Was the bakery's response to its logo mishap a stroke of marketing genius?

    Greggs gives lesson in crisis management

    After a mishap with their logo, high street staple Greggs went viral this week. But, as Simon Usborne discovers, their social media response was anything but half baked
    Matthew McConaughey has been singing the praises of bumbags (shame he doesn't know how to wear one)

    Matthew McConaughey sings the praises of bumbags

    Shame he doesn't know how to wear one. Harriet Walker explains the dos and don'ts of fanny packs
    7 best quadcopters and drones

    Flying fun: 7 best quadcopters and drones

    From state of the art devices with stabilised cameras to mini gadgets that can soar around the home, we take some flying objects for a spin
    Joey Barton: ‘I’ve been guilty of getting a bit irate’

    Joey Barton: ‘I’ve been guilty of getting a bit irate’

    The midfielder returned to the Premier League after two years last weekend. The controversial character had much to discuss after his first game back
    Andy Murray: I quit while I’m ahead too often

    Andy Murray: I quit while I’m ahead too often

    British No 1 knows his consistency as well as his fitness needs working on as he prepares for the US Open after a ‘very, very up and down’ year
    Ferguson: In the heartlands of America, a descent into madness

    A descent into madness in America's heartlands

    David Usborne arrived in Ferguson, Missouri to be greeted by a scene more redolent of Gaza and Afghanistan
    BBC’s filming of raid at Sir Cliff’s home ‘may be result of corruption’

    BBC faces corruption allegation over its Sir Cliff police raid coverage

    Reporter’s relationship with police under scrutiny as DG is summoned by MPs to explain extensive live broadcast of swoop on singer’s home