A DRUG that is already available on the NHS in Scotland for bladder and lung cancer has had "dramatic benefits" for some patients with head and neck cancer in the first clinical trial of its kind.

The global study, which included patients from the Western General hospital in Edinburgh, reported that 36 patients given the immunotherapy drug pembrolizumab saw their tumours partially or completely disappear.

Some are still cancer free three years after first receiving the drug, which is also known by the brand name Keytruda.

Mr Jim McCaul, one of Scotland's leading head and neck surgeons, said: "It's an incredible breakthrough. For some patients there's a really long-lasting effect. 

"The next step is working out why it works for some people and not others and trying to harness that benefit for everybody. 

"In terms of a leap forward it's the best thing we've had in decades."

The drug works by preventing cancer cells from camouflaging themselves, enabling the body's immune system to detect and attack them.

HeraldScotland: President Jimmy Carter

It was previously hailed as a 'wonder drug' when a US clinical trial for lung cancer was cut short in 2016 after results showed that pembrolizumab cut the risk of death or tumours spreading by 50% compared to chemotherapy. 

Former US President Jimmy Carter also credited it with making his tumours "vanish" after skin cancer spread to his brain, a condition which would usually be fatal.

HeraldScotland: Professor Kevin Harrington

Professor Kevin Harrington, a radiation oncologist who led the international trial at the Institute of Cancer Research in London, said: “Head and neck cancer is extremely hard to treat once it comes back or spreads, and the outlook for patients once other therapies have stopped working is very poor.

“Our findings show that the immunotherapy pembrolizumab extends the life of people with advanced head and neck cancer overall, and in a group of patients has really dramatic benefits."

Head and neck cancer is the fourth most common form of the disease among men in Scotland and was the eighth most common cause of cancer deaths for men and women combined in 2017, when it claimed 521 lives.

It includes cancers affecting the tongue, throat, salivary glands, lips and sinuses, which are generally very difficult to treat.

Scotland's rate of head and neck cancer is also 24% higher than the UK average, largely due to higher alcohol consumption and smoking.

However, the sexual revolution of the 1960s and subsequent changes in sexual practices, especially in relation to oral sex, have been blamed for the increasing prevalence of the disease worldwide as it can also be caused by the human papillomavirus (HPV) - better known as a cause of cervical cancer.

In Scotland, mortality from head and neck cancer has increased by 20% for women and 17% for men in the past decade, making it one of the fastest growing causes of cancer death.

In the west of Scotland, incidence and mortality rates are even higher. 

Mr McCaul, who is based at the Queen Elizabeth University Hospital in Glasgow, added: "It could be our population in the west has the most to gain from this."

The study, published today [Sat] in the Lancet, followed 495 patients in 20 countries with very advanced head and neck cancer which had spread and become resistant to platinum chemotherapy, the first-line treatment for the disease.

Half the participants were given pembrolizumab and the others received a standard treatment of chemotherapy or the drug, cetuximab.

It found that 37% of patients given pembrolizumab survived for a year or more, compared to 26.5% of patients in the control group, and there were also fewer side effects.

Median survival terms were 8.4 months and 6.9 months respectively, but a minority of patients - 36 - responded unusually well to the new drug.

In this group, patients continued to respond to treatment for more than 18 months on average and some are still alive three years on.

Derek Kitcherside, from Leicester, is among the trial's longest survivors. The 69-year-old, who was first diagnosed with head and neck cancer in 2011, was recruited after he suffered a relapse in 2014 when tumours spread to his right lung.

Mr Kitcherside said: "The standard treatments of radiotherapy and chemotherapy weren’t really doing much for me this time around. My tumours were still getting larger and I was told there wasn’t much more the doctors could do.

“I was really lucky to get a place on The Royal Marsden’s pembrolizumab trial and started treatment in May 2015. I travelled down from Leicester every three weeks for two years.

"My tumour was shrinking all the time and I felt a bit better every time I went - it made a huge difference to my life and I was able to return to normality.

“Now I have CT scans every nine weeks, which are still showing stable disease and slight tumour shrinkage each time. It’s remarkable how I’ve responded to the drug and I don’t think I’d be here without it.”

The scientists now want to develop tools to predict the patients likely to have the best response.

Prof Harrington said: “I would like to see pembrolizumab approved for use in the clinic, so that people with advanced head and neck cancer can be offered the chance of a longer life and improved quality of life.

"There is also an urgent need to work out how we can identify in advance which patients are likely to benefit, given that some of these people may do much better than they do on standard treatment.”