Chemicals in weed killer could be driving rise in prostate cancer

More than a dozen chemicals used in commonly used weed killers may raise the risk of prostate cancer, alarming research suggested today. 

Tests on almost 300 pesticides found 22 had 'direct' links with the disease, with four shown to raise the likelihood of death. 

One is the main ingredient in the popular spray Roundup, which was earlier this year also blamed for causing one American man's blood cancer. 

Just a handful of the 22 identified, however, are currently legal in the UK. 

US researchers claimed the probe showed how important the environment was as a risk factor for the illness, which kills more than 11,500 men in the UK every year. 

But they acknowledged the paper was merely observational and cannot prove causality. 

Dr Simon John Christoph Soerensen, study lead author and prostate cancer expert at Stanford University, said his research could 'potentially explain' some of the 'geographic variation' in prostate cancer incidence and deaths across the United States.

'By building on these findings, we can work towards reducing the number of men affected by this disease.'

According to the World Health Organization (WHO), more than 1,000 different pesticides are used globally. 

They are used in agriculture to control weeds, insect infestation and disease carriers like mosquitoes, ticks, rats and mice. They also enable farmers to protect crop quantity and quality.

Some are also used to make products bought by gardeners to protect their crops at home, such as RoundUp. 

Pesticide consumption has grown almost 60 per cent since 1990 reaching 2.66bn kg (5.86bn lbs) by 2020.

But the elderly, children and unborn babies are especially susceptible to the adverse effects of pesticides. 

In the study, researchers assessed data on annual estimated usage of the 295 pesticides between 1997 to 2001. 

They then compared it against prostate cancer diagnoses and deaths between 2011 and 2015, to account for the slow-growing nature of most prostate cancers.

The same was done for pesticide use between 2002 to 2006 and prostate cancer outcomes from 2016 to 2020. 

Writing in the journal Cancer, the researchers said 19 of the 22 pesticides associated with prostate cancer had never been linked to the disease before. 

But just eight of these 22 are currently authorised for use in the UK. 

Of these included the agricultural weedkiller 2,4-dichloroacetic acid, better known as 2,4-D.

Animal studies have shown exposure to it during pregnancy is associated with lower body weight and changes in offspring behavior.

Other research has shown there is an increased link to lymphoma, and long-term exposure may result in kidney and liver damage. 

Another, glyphosate — the main ingredient in Roundup — is also a known endocrine disruptors, which can interfere with hormone systems. 

Endocrine disruptors have also been linked to an array of health problems including birth defects and developmental disorders.

Glyphosate is found in Roundup's 'Fast Action Ready to Use' weedkiller and 'Ready to Use Path weedkiller' in the UK.

Its makers —Monsanto and its owner Bayer AG— however, have repeatedly assured the public that their product is safe and does not pose a threat to human health.

Earlier this year, however, Pennsylvania groundskeeper John McKivison, 49, won a multi-billion-dollar lawsuit against Bayer after he had been diagnosed with non-Hodgkin’s lymphoma in 2020, which he and attorneys successfully argued was a result of using Roundup for two decades.

According to the researchers, four of the 22 pesticides were also associated with prostate cancer deaths.

While available in the US, none of the four — trifluralin, cloransulam-methyl, thiamethoxam and diflufenzopyr — are legally used in the UK.

One in eight men will develop prostate cancer at some point in their lives, charities say. More than 52,000 men in Britain are diagnosed each year.

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But thousands are diagnosed once it has already spread, making it the second most common cause of cancer death in men after lung cancer.

Experts are in agreement that early detection is key to boosting survival rates. 

Unlike other forms of cancer – which can be very difficult to diagnose in their early stages – prostate cancer has a relatively effective screening method.

PSA tests check for high levels of a protein that indicates the prostate is not functioning as it should.

The risk of prostate cancer increases with age, with most cases diagnosed in men aged 50 or older, the NHS says. 

A high PSA score is not always a sign of cancer — it can also be triggered by an enlarged prostate, an infection, by sexual activity or even riding a bike.

However, patients with high results are usually sent for scans to identify the cause.

But the majority of men under 50 do not have their PSA tested unless they have symptoms. 

Charities have been advocating for years to have this rule changed – particularly for men with underlying risk factors.  

Symptoms of the disease include needing to urinate more often, having to wait longer before you can pass urine, erectile dysfunction, blood in urine, weight loss or any new and unexplained lower back pain.

WHAT IS PROSTATE CANCER?

How many people does it kill?

More than 11,800 men a year - or one every 45 minutes - are 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 men each year.

Despite this, it receives less than half the research funding of breast cancer and treatments for the disease are trailing at least a decade behind.

How many men are diagnosed annually?

Every year, upwards of 52,300 men are diagnosed with prostate cancer in the UK - more than 140 every day.   

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 is 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 fool-proof. 

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