This Way Of Training The Body To Attack Cancers Could Lead To New Treatments

Complex tumours can evade the body's immune system. British scientists think they have found a way of finding a way around that, although new drugs may be years away.

A discovery about the way tumours develop has led to hope for a new generation of cancer treatments.

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The British-led study, published yesterday in the journal Science, found that even complex cancers may have a weak spot that could be exploited.

Cancers mutate as they grow. That means that our immune system struggles to fight them.

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Cells in our immune system, known as T-cells, recognise the cancer from biological markers on the tumour's surface and attack it.

But as the cancer grows, parts of it mutate, and the markers change. The T-cells can't easily recognise the new markers. As the cancer becomes more complex, with lots and lots of different parts each with different markers, the T-cells are overwhelmed.

Immunotherapy, using the immune system to fight cancer, has taken off in the last few years. But it relies on the immune system being able to spot the cancer cells.

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The complexity of some cancers makes that very difficult. So although the treatments themselves are often very effective when they work, in some patients and some tumours they are less effective because they can't recognise the complex bits of the cancer.

What the new study has shown is that even the most complex tumours have some markers which are the same throughout, and that some T-cells target these universal markers.

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What the researchers hope is that, in future, cancer treatments could tell your immune system to target these universal markers, so that it will naturally fight the cancer everywhere in your body.

Cancer cells in human tissue. By Dr Cecil Fox (Photographer) [Public domain or Public domain], via Wikimedia Commons / Via commons.wikimedia.org

Dr Sergio Quezada of UCL, one of the authors of the study, compared the immune system's fight with cancer to police officers trying to catch criminals. "Genetically diverse tumours are like a gang of hoodlums involved in different crimes - from robbery to smuggling," he said. "And the immune system struggles to keep on top of the cancer – just as it's difficult for police when there's so much going on.

"Our research shows that instead of aimlessly chasing crimes in different neighbourhoods, we can give the police the information they need to get to the kingpin at the root of all organised crime – or the weak spot in a patient's tumour – to wipe out the problem for good."

For instance, if doctors can recognise the universal markers in a patient's tumour, they could isolate the T-cells which attack them, and grow them in huge numbers.

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Then they could put them back into the patient's body, where they would fight the cancer. Professor Charles Swanton, another of the study's authors, said that the universal markers are an "Achilles heel" for complex cancers.

"It's incredibly exciting," he told the Cancer Research UK website, "and although it's early days, it offers hope that we might just be able to turn the tide against advanced cancer – something we desperately want for our patients." He said that he thinks that preliminary human trials could be just two or three years away.

Other scientists have expressed cautious excitement, but new drugs will be some years away.

"Whether this can be applied in general is early days yet," Professor Peter Lane, a T-cell specialist at the Institute of Immunology and Immunotherapy, told BuzzFeed News. "It's an extension of what people have been finding out over the last few years.

"I think it's an interesting idea, and there's no doubt that immunotherapy for cancer has been the major talking point in cancer for the last five years. There have been some spectacular results."

It's not clear how long it will be before this leads to new treatments, he said. "Getting stuff into people is often quite glacial because of regulatory steps, but I admire their enthusiasm [in saying that trials could be two years away].

"It depends how much regulators are prepared to bypass regulatory requirements. Sometimes in terminal cancer you can get past this stuff quite quickly, because the alternative is worse."

"It's really exciting," Professor Tim Elliott, of the Centre for Cancer Immunology at Southampton University, told BuzzFeed News. "A major step forward, I think. It points towards potential vaccines, and it also tells us which tumours are likely to respond to these immunotherapies."

He said that preliminary trials could indeed be two or three years away. But, he said, "you need to sequence the whole genome from every individual, so the note of caution is that bigger trials will be hard work".