An experimental trial for a lung cancer therapy is to be tested on patients in the UK later this year. The treatment, combining stem cells and gene therapy, could dramatically increase survival rates for lung cancer sufferers.
In some cases, during tests of the treatment carried out on mice, the therapy completely removed the cancer.
The combination of stem cells and gene therapy is the first of its kind. It will initially be given to human volunteers to make sure it is safe and then to a further 56 NHS patients to see if it works on cancerous growth in humans.
If it is successful, the treatment could increase the survival rates of lung cancer sufferers, which kills around 35,400 people a year in the UK alone – that is 97 people every day and one person every 15 minutes.
How the therapy works
The treatment uses stem cells taken from a donor and then altered to activate an anti-carcinogen called ‘TRAIL’. Patients will receive almost a billion of these cells over three infusions.
The stem cells naturally migrate towards the tumour. Once there, they activate a ‘kill-switch’, destroying the cancer cells and the tumour, but leaving healthy tissue untouched.
The tests on mice show that the cells reduce and in some cases completely clear tumours from otherwise healthy lung tissue.
One of the main advantages of this treatment is that the modified cells can be used practically ‘off-the-shelf’, which makes the treatment quicker and cheaper. Also, the cells do not trigger an immune response from the patients, even though the cells have originated from a donor.
Human trials have been made possible by £2m worth of funding from the Medical Research Council. Over the next three years, 100 billion of the cells will be created at a £2.1m state-of-the-art manufacturing lab that will be built at the Royal Free Hospital in London.
Who is at risk from lung cancer?
Around 23,000 men and 18,000 women are diagnosed with lung cancer each year. The disease accounts for 6% of all deaths in the UK, 13% of all new cancer cases and more than a fifth of all cancer deaths.
The majority of lung cancer cases are among smokers, who account for over 80% of those affected – although one in eight of all lung cancer deaths are among people who have never smoked.
Passive smoking (second-hand smoking), exposure to and inhalation of asbestos dust and fibres, exposure to radon gas and other chemicals, together with diet and family history can all increase the risk of developing the disease.
Smoking and asbestos
Smoking significantly increases the risk of lung cancer, but combine smoking with exposure to asbestos and the two toxins multiply the risk of developing lung cancer later in life.
Research demonstrates that there is a multiplicative effect between asbestos, smoking and lung cancer. This means that the damage caused by a combination of these two risk factors is substantially greater than that caused by either smoking or asbestos exposure alone.
One study, published in the American Journal of Respiratory and Critical Care Medicine, analysed data sets of 456 patients who were diagnosed with lung cancer of stage 1 or 2. Factoring in potential modifiers – like age, race and smoking history – researchers determined a direct association between increased risks of lung cancer development among smokers who also were exposed to asbestos.
Inhalation of the chemicals within cigarette smoke, as the lungs already face scarring from asbestos, can also lead to additional respiratory complications.
Why does asbestos cause lung cancer?
Inhaled asbestos fibres become trapped in the lungs. Over long periods of time, the asbestos fibres accumulate and cause inflammation and scarring. After many years, often decades, the asbestos fibres cause enough irritation and cellular damage to generate tumours.
It can be difficult to attribute lung cancer to asbestos exposure and if the sufferer is a smoker it is often assumed that smoking is the cause.
Why is lung cancer survival in the UK so poor?
Half of people with lung cancer die within six months of diagnosis, according to a report from Macmillan Cancer Support which looked at variations in cancer survival rates.
In the report, the cancer charity carried out an analysis of almost 85,000 cancer patients’ experiences of the NHS in England from 2004 to 2011.
They looked in detail at what happened to people with one of four types of cancer – breast, prostate, lung or brain cancer – after they were diagnosed.
The report suggests that poor survival rates from lung cancer are a result of a wide variety of factors, which include:
- Uncertainty among people as to when to seek help, not recognising the symptoms and not seeking help until it is too late
- Reluctance to seek help due to the symptoms thought to be smoking – and self-inflicted
- Difficulty amongst GPs in identifying suspicious symptoms early enough
- Time taken to progress from first appointment through to diagnostic tests onto treatment, is too lengthy in some areas
- A wide variation in quality and provision of cancer services across the country – as a result, not all patients are receiving the optimal treatment; for example, the proportion of patients who are receiving surgery varies from between 9.8% and 17% between different UK cancer networks
- Decades of under-investment in people and equipment. Whilst many aspects of these problems have been addressed over the last 10 years, there is still limited capacity for specialist surgery, specialist oncology and specialist nursing in many area
- Lack of screening programmes. Many other cancers have benefited from the development of screening programmes
- Patients in the UK may be generally less healthy, with more co-existing illnesses, and therefore less likely to be fit for such things as major surgery
Macmillan Cancer Support report – Lung cancer survival stats reveal poor outlook