Dark history behind dangerous war weapon that’s now used by millions of cancer patients

A devastating weapon of war which killed thousands in World War One actually held the key to revolutionising the treatment of cancer.

In July 1917, nearly 10,000 British soldiers were killed in Belgium trenches after they were attacked by the German army with a deadly new chemical weapon.

Within seconds, their skin was blistering and severely burnt, and it would eventually claim the lives of tens of thousands on the battlefield. But what no one could have anticipated was that buried within the devastation of the attack was actually a breakthrough in developing one of the most renowned treatments for cancer.

And it would lie dormant for over 20 years.

Unbeknown to them, the soldiers that day has been poisoned by something called mustard gas, which went on to become one of the most deadly chemical weapons to be used in battle.

(Daily Mirror/Mirrorpix/Mirrorpix via Getty Images)

Mustard gas - the killer of WW1

Mustard gas is absorbed by the skin - meaning any attempts to scramble for a protective mask would have been useless - and while it's not always immediately fatal, it's known to trigger serious long-term health issues such as breathing problems, eye damage and chronic blistering.

But despite its dark history, mustard gas has managed to turn its legacy around somewhat after researchers at Yale University had a lightbulb moment some two decades after the devastating WW1 attack.

If we rewind a bit, during the war, medics opened up the bodies of those who had been killed by mustard gas in the hopes of understanding the impact the poison had on the body, and they quickly realised the effects went a lot further than just skin deep.

To their horror, doctors discovered the gas had completely wiped out the white blood cells in its victims - but what they didn't realise is that they had accidentally stumbled upon one of the most revolutionary discoveries in modern medicine.

Many were blinded by the gas (Bettmann / Contributor)

Years later, when the world was in the mist of its second world war, fears grew over further deployment of the chemical for a second time around.

So, allied researchers were tasked with finding ways to treat victims of mustard gas attacks to avoid a repeat of all the bloodshed.

A lightbulb moment: the birth of cancer treatment

Yale University researchers Louis Goodman and Andrew Gilman began pouring over the medical files of those killed by the attacks in WW1 when, all of sudden, the breakthrough came.

The fact the gas had completely obliterated all the victims' white blood cells could mean it was also capable of killing off cancerous cells as well, the researchers theorised.

In August 1942, the time came to put their theory to the test. They administered a secret chemical known then only as 'substance x' to a patient called J.D., who was suffering from tumours in his lymph nodes and jaw.

'Substance x' was actually nitrogen mustard, a key component in producing mustard gas.

It turned out their hunch was correct - within a few days, J.D.'s pain had dramatically decreased, and with every treatment he had, his lymph nodes shrank.

At the time, recovery like this in cancer cases was unprecedented and it turns out that Goodman and Gilman's medical trial had actually just developed what we now know as chemotherapy.

Sadly for J.D., his remission wasn't to last and he ended up passing away on 1 December 1942, but the medical breakthrough changed the landscape of modern medicine forever.

From the battlefield to hope

Of course, chemo has come a long way since the days of J.D., Goodman and Gilman, but their work lay out the foundations for what has become the key treatment to fighting cancer over 100 years on.

The discovery would become what we now know as chemotherapy (FatCamera/Getty stock photo)

Nowadays, chemotherapy follows similar principals to the work which was established by the researchers in the 1940s, and is used to treat a range of different cancers by damaging or completely killing the unhealthy cells.

It's an invasive and gruelling treatment due to the fact the drugs can't tell the difference between a healthy cell and a cancer cell, meaning patients are immunocompromised throughout the course of treatment and can be left with grim side effects.

Chemo can be used on its own or alongside other types of treatment such as radiation therapy or surgery with the outlook of curing the cancer or prolonging life.

Over a century has gone by now since the troops in Belgium were killed in the heinous chemical attack, but no one could have ever predicted that a poison which brutally killed thousands would go on to be the key to saving countless lives decades later.