For those of us navigating Sniper’s Alley in our late-60s, the recent news of an experimental cancer vaccine to stop the recurrence of bowel cancer is uplifting stuff.
Not because this vaccine will save many lives — it is just a trial — but because it is a harbinger of good news to come about cancer in particular.
Cancer vaccines are the latest and best examples of a gold rush of new therapies that promise to make most cancers just another affliction that can be treated and survived.
A few weeks ago, an experimental cancer vaccine was shown to have halved the death rate of melanoma patients.
For five decades, since Richard Nixon declared a ‘war on cancer’ in 1971, progress against this most insidious of enemies has been disappointing.
As death rates from heart disease, infections, accidents and other causes plummeted, death rates for cancer remained stubbornly high.
Since cancer increases with age, it is the leading cause of death in Britain
Contrary to popular belief and to the views of many doctors, cancers are not mainly the wages of sin: they are the wages of age. Smoking, sunburn and some aspects of diet aside, there is little you can do to head off the exponentially increasing probability that cancer will strike as you get older.
Cumulative random mutations are ‘the major contributors to cancer overall, often more important than either hereditary or external environmental factors’, as one study put it.
Since cancer increases with age, it has become the default cause of death for my generation and is the leading cause of death in Britain.
Yet the tide has been slowly turning — offering considerable cause for optimism. More and more people who get cancer are in remission for longer and longer. The ‘age-standardised death rate’ from cancer — a statistical tool that allows comparisons between populations with different age structures — has fallen steadily now for 40 years as better diagnosis, surgery and treatment come to the rescue.
The big three killers — lung, colon and breast — have seen age-standardised deaths in Britain per 100,000 people almost halve since 1980.
In the case of lung cancer, the decline of smoking, accelerated by the uptake of vaping, has been a huge factor. But prevention by lifestyle changes has proved much harder for other cancers.
Prostate and pancreatic cancer, the next two biggest killers, both kill slightly more people per 100,000 than they did in 1980 — even when standardised for age.
Again and again, the promise of wonder drugs for all cancers has been disappointing. The reason for this is that cancers evolve ways to disable the weapons sent into battle against them.
Until recently, even when cancer was treatable the treatment was often brutal. On top of surgery, months of radiotherapy and chemotherapy made the lives of patients almost as bad as the disease itself.
That is now changing as new and kinder generations of treatment come into service.
There are promising new drugs including ‘antibody drug conjugates’ or ADCs, which combine an antibody that homes in on cancer cells with a chemical that kills them.
Then there’s growing excitement over ‘checkpoint inhibitors’ which disable the mechanism that stops the immune system from attacking its own body. Otherwise your immune system does not have permission to kill your cancer because it thinks the tumour is part of you. Hence the recently announced melanoma trial, done by Merck and
Moderna, which combines a checkpoint inhibitor called pembrolizumab (brand name Keytruda) with a vaccine that provokes the immune system to attack specific antigens (a type of protein) on the tumour.
In early results from the clinical trial with 157 patients, this combination increased the survival rate of those treated from 56 per cent to 75 per cent over nearly three years.
It is these cancer vaccines that perhaps show the greatest promise. Their history is a typical example of how hard it is for new ideas to be taken seriously.
Katalin Kariko, the Hungarian-American biochemist who set out in the 1990s to make vaccines for cancer out of the molecule called messenger RNA, had to overcome extreme scepticism within the scientific establishment.
As her experiments failed again and again, she faced pay cuts, demotion and denial of tenure. Yet last year she won the Nobel Prize, along with her colleague Dr Drew Weissman.
It was Covid, not cancer, that eventually shot mRNA vaccines to fame – and notoriety.
Two firms, Moderna in Boston, US, and BioNTech in Mainz, Germany, used Dr Kariko’s ideas and turned them into an unprecedentedly rapid way of making vaccines against the spike protein of the SARS-CoV-2 virus.
It has revolutionised the sluggish world of vaccine development. In elderly people, especially, these Covid vaccines saved many lives. But governments overclaimed for the Covid vaccines, wrongly saying they would prevent transmission of the virus, and tried to make vaccine passports a condition of work in various professions.
This has caused a disastrous backlash against all vaccines and mRNA ones in particular. That is a worry because it is against cancer that mRNA vaccines will truly win their spurs, as Dr Kariko and Dr Weissman originally intended.
It would be wrong to raise the hopes too high of those with cancer today. Many advances will take years to come to clinical fruition. Others will peter out in disappointment.
Nobel Prize-winning biochemist Katalin Kariko had to overcome scepticism in the scientific establishment after setting out to make cancer vaccines out of the molecule messenger RNA
But in a time of almost mandatory pessimism, it is all too easy to forget just how much better our lives are still getting every day. The things that dominate our news media – wars in Ukraine and Gaza, the authoritarianism of China, the economic stagnation of Britain – cannot and do not stop the steady improvement of our lives by innovation.
In biomedicine, Britain has an extraordinary track record. It was here that natural selection, the structure of DNA, DNA sequencing, IVF, genetic fingerprinting and cloning were first discovered or invented.
With its global headstart in genomics, Britain could play a leading role in the cancer vaccine revolution. The NHS and Genomics England have set up a Cancer Vaccine Launch Pad to attract clinical trials of cancer vaccines to the UK. Trials of colorectal, lung, liver, kidney and pancreas cancer vaccines have begun. Former vaccine tsar Dame Kate Bingham points out that cancer vaccines will be cheaper than continuing to treat late-stage cancer patients with drugs.
‘Cancer vaccines can be used therapeutically post-surgery and post-chemo. But ultimately we could use cancer vaccines prophylactically, like we do with childhood vaccines against infectious diseases,’ she says.
‘For example, we could do a blood biopsy to detect any circulating tumour DNA before any lesion can be imaged and then immediately vaccinate.’
Eventually, perhaps all middle-aged people could be vaccinated for the top five cancers.
Dame Kate has warned, however, that the NHS is not making the most of this opportunity. Speaking at The Great National Cancer Vaccine Summit in May she said there has been a 40 per cent reduction in new clinical trials since 2017.
Yet as a recent analysis by Macmillan Cancer Support shows, Britain lags behind most comparable nations in five-year survival rates for common cancers. This is largely because the way we ration healthcare here is through delay: the gap between seeing a GP and seeing a specialist or getting a biopsy is longer in the NHS than in most healthcare systems. Every day counts with cancer.
But a ‘not-invented-here’ mentality also doesn’t help. A string of proton-beam imaging and treatment centres, developed by Professor Karol Sikora with private money, have been largely boycotted by the NHS.
The genomic knowledge at our fingertips today is extraordinary, like turning on a light in a library. Defeating cancer is therefore eminently possible. So long as we apply that knowledge wisely, the possibilities are immense.
