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."

News
John Travolta is a qualified airline captain and employed the pilot with his company, Alto
people'That was the lowest I’d ever felt'
Life and Style
healthIt isn’t greasy. It doesn’t smell. And moreover, it costs nothing
News
i100

Other places that have held independence referendums
Arts and Entertainment
Jack Huston is the new Ben-Hur
film

It scooped up an unprecedented 11 Academy Awards when it was first remade in 1959

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
Pharrell dismissed the controversy surrounding
musicThe singer said 'the last thing I want to do is degrade'
News
news

Arts and Entertainment
Blossoming love: Colin Firth as Stanley and Emma Stone as Sophie, in 'Magic in the Moonlight'
film

Actors star in Woody Allen's 'Magic in the Moonlight'

News
A male driver reverses his Vauxhall Astra from a tow truck
newsThe 'extremely dangerous' attempt to avoid being impounded has been heavily criticised
News
peopleThe Times of India said actress should treat it as a 'compliment'
Arts and Entertainment
Maxine Peake plays Hamlet at Manchester's Royal Exchange
theatreReview: Maxine Peake brings emotional ferocity to Shakespeare's starring part
News
news

Watch this commuter wage a one-man war against the Circle Line
Property
Home body: Badger stays safe indoors
lifeShould we feel guilty about keeping cats inside?
Life and Style
fashion

Olympic diver has made his modelling debut for Adidas

Travel
travel

...and the perfect time to visit them

Sport
Jonas Gutierrez (r) competes with Yaya Toure (l)
football

Newcastle winger reveals he has testicular cancer - and is losing his trademark long hair as a result

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

    SEN Teacher

    Negotiable: Randstad Education Birmingham: SEN Teacher required with immediate...

    Maths Teacher

    Negotiable: Randstad Education Reading: Maths Teacher required for a College i...

    Year 1 Teacher required in Haverhill

    £21000 - £35000 per annum: Randstad Education Cambridge: Teacher required for ...

    Lecturer - Construction

    Negotiable: Randstad Education Reading: Construction Lecturer needed for a Col...

    Day In a Page

    Mystery of the Ground Zero wedding photo

    A shot in the dark

    Mystery of the wedding photo from Ground Zero
    His life, the universe and everything

    His life, the universe and everything

    New biography sheds light on comic genius of Douglas Adams
    Save us from small screen superheroes

    Save us from small screen superheroes

    Shows like Agents of S.H.I.E.L.D are little more than marketing tools
    Reach for the skies

    Reach for the skies

    From pools to football pitches, rooftop living is looking up
    These are the 12 best hotel spas in the UK

    12 best hotel spas in the UK

    Some hotels go all out on facilities; others stand out for the sheer quality of treatments
    These Iranian-controlled Shia militias used to specialise in killing American soldiers. Now they are fighting Isis, backed up by US airstrikes

    Widespread fear of Isis is producing strange bedfellows

    Iranian-controlled Shia militias that used to kill American soldiers are now fighting Isis, helped by US airstrikes
    Topshop goes part Athena poster, part last spring Prada

    Topshop goes part Athena poster, part last spring Prada

    Shoppers don't come to Topshop for the unique
    How to make a Lego masterpiece

    How to make a Lego masterpiece

    Toy breaks out of the nursery and heads for the gallery
    Meet the ‘Endies’ – city dwellers who are too poor to have fun

    Meet the ‘Endies’ – city dwellers who are too poor to have fun

    Urbanites are cursed with an acronym pointing to Employed but No Disposable Income or Savings
    Paisley’s decision to make peace with IRA enemies might remind the Arabs of Sadat

    Ian Paisley’s decision to make peace with his IRA enemies

    His Save Ulster from Sodomy campaign would surely have been supported by many a Sunni imam
    'She was a singer, a superstar, an addict, but to me, her mother, she is simply Amy'

    'She was a singer, a superstar, an addict, but to me, her mother, she is simply Amy'

    Exclusive extract from Janis Winehouse's poignant new memoir
    Is this the role to win Cumberbatch an Oscar?

    Is this the role to win Cumberbatch an Oscar?

    The Imitation Game, film review
    England and Roy Hodgson take a joint step towards redemption in Basel

    England and Hodgson take a joint step towards redemption

    Welbeck double puts England on the road to Euro 2016
    Relatives fight over Vivian Maier’s rare photos

    Relatives fight over Vivian Maier’s rare photos

    Pictures removed from public view as courts decide ownership
    ‘Fashion has to be fun. It’s a big business, not a cure for cancer’

    ‘Fashion has to be fun. It’s a big business, not a cure for cancer’

    Donatella Versace at New York Fashion Week