Lyn Barrington assumed that her cough was just a chest infection. But when, after several months, it didn’t improve, she finally went to her GP.

‘It was more of an irritation than a chesty cough and it was getting on my nerves,’ says the 52-year-old nurse from Stafford.

A chest X-ray in June 2010 — seven months after she had started coughing — showed her lungs were clear.

However, the cough got worse — Lyn could get out only three or four words before coughing — and in November 2010 she collapsed with chest pain, unable to breathe, and took herself to A&E.

An X-ray again found nothing, but her blood tests were abnormal and, following scans, doctors diagnosed pneumonia. Lyn was admitted to hospital, put on intravenous antibiotics and pain- killers and had a week off work.

But the cough still didn’t clear and Lyn was starting to become worried — she could feel a ‘grating’ sensation in her chest as she breathed and didn’t feel at all well.

Finally, in February 2011 — 15 months after the cough started — she saw a lung specialist, who told her the only way to find out what was going on was to carry out a thoracotomy, a major operation involving an incision to the back allowing doctors to investigate the lungs.

‘I came round in the high-dependency unit and the surgeon told me they’d found an 11cm tumour at the base of my lungs below my diaphragm. The cancer was stage four — the worst kind.’

Lyn — married to Paul, a former aerial installer, and with a grown-up daughter — is one of an increasing number of people with lung cancer who have never smoked.

Among them was Sian Busby, author and wife of BBC business editor Robert Peston, who died from the disease in September, aged 51.

Last week, Mr Peston revealed Sian, diagnosed five years earlier, was ‘probably the only person I know who has never smoked a cigarette’.

In Lyn’s case, she says: ‘The cancer had spread throughout my lungs. It was inoperable and untreatable. I was on a lot of morphine because of the surgery and it was as if they were talking about someone else.

‘The nurse was crying and Paul and my mum and dad couldn’t understand what was happening.

‘I was just 49, had never smoked and was fit and healthy. I remember saying to the surgeon “I’ve so much I want to do with my life,” to which he replied: “I suggest you get on and do it then.” ’

While the chance of non-smokers developing lung cancer is much lower than smokers, latest figures show that of the 41,500 new lung cancer cases each year in Britain, 14 per cent — around 6,000 — are unrelated to smoking.

And it seems women are more likely to develop this non-smoking form. As Dr Michael Beckles, a consultant respiratory physician at the Royal Free Hospital and the private Physicians’ Clinic, London, says: ‘Anecdotally, we are seeing more female patients who have never smoked being diagnosed with lung cancer compared with ten years ago.’

What causes the disease in non-smokers isn’t fully known, but researchers suspect a genetic susceptibility combined with exposure to cancer-causing substances such as asbestos, the gas radon (found naturally in the environment), solvents, diesel exhaust fumes — and other people’s tobacco smoke.

One study estimated that non-smokers who live with a smoker have a 31 per cent increase in risk for developing lung cancer.

Other risk factors are radiation treatment to the chest for diseases such as breast cancer or lymphoma or a scarring of the lungs from previous medical condition. Asian women also seem to be at higher risk.

While lung cancer is usually associated with smoking, before people started to smoke widely in the early 20th century, it was a disease of the non-smoking and women, says Stephen Spiro, a retired professor of respiratory medicine and deputy chairman of the British Lung Foundation.

Non-smokers are more likely to develop adenocarcinoma or non-small cell lung cancer, which is what Lyn has (she has a family history of cancer that may explain why she developed it). This develops in mucus-producing glands lining the airways.

Many with this form of cancer also have a genetic fault on a protein on the surface of cells, which helps regulate cell growth.

The good news is that patients who test positive for this defect can benefit from new lung cancer drugs — such as gefitinib — which slow down the progression of the disease without the side-effects of standard chemotherapy.

Meanwhile, several studies are under way to find what causes lung cancer in non-smokers, but it’s not easy securing funding for lung cancer research, partly because the disease is perceived as self-inflicted by smoking.

So though investment in lung cancer research has doubled over the past decade, it still receives only a third of funds allocated to breast cancer, around half of those to bowel cancer, and less than half that for leukaemia — yet it kills 35,000 a year, more people than all the other three diseases put together.

And with the high number of women who continue to smoke, experts are predicting an ‘epidemic’ of female lung cancer cases, with cases quadrupling by 2040 because women are refusing to kick the habit.

While we are getting better at detecting and treating the condition, more needs to be done to improve these, says Professor Spiro.

Screening high-risk individuals such as smokers would help pick up the disease earlier, but he warns the condition is hard to diagnose.

‘The problem is that the lungs have no pain fibres, so they can’t tell you something is wrong. There are no obvious symptoms and it is difficult to identify a cough or wheeze caused by lung cancer.

‘Sadly by the time you get an irritating cough that won’t go away, the disease has often advanced.
‘In 70 per cent of people, the symptom that takes them to their doctor is one linked to advanced disease.’

And as Lyn’s case showed, even then the tools are inadequate. Chest x-rays, the first step for diagnosing lung cancer, can fail to identify a problem, says Dr Beckles.

‘Chest x-rays are limited as they are two-dimensional, and there will be areas of uncertainty such as behind the heart.’

But he adds: ‘More detailed investigations such as CT scans are almost routine.’

Lyn is campaigning for more detailed X-rays, which look at the lateral (side view) of the lungs as well as the front, to try to ensure patients are diagnosed as early as possible.

The NHS advises anyone who has a cough for more than three weeks to see a doctor.

Claire Knight, from Cancer Research UK, says lung cancer can affect anyone.

‘Many people think if you live a healthy lifestyle, you won’t get cancer but that is not always the case,’ she says.

Since her diagnosis in March 2011, Lyn has been taking gefitinib. Based on the statistics, her life expectancy should have been between six and 12 months.

But it’s over two years since she was diagnosed. ‘I have been on the drug longer than anyone else in the country,’ she says.

Lyn looks well, but gets breathless at times and her voice is croaky.

Sadly, a scan in November showed the cancer has spread to her lymph nodes, small glands in the body’s immune system.

This suggests gefitinib is no longer working as well and she may need to begin conventional intravenous chemotherapy.

‘People need to realise that lung cancer can affect everyone, not just smokers. I went to the doctor and underwent several X-rays and none picked up the disease.

‘With better scans the disease might have been picked up earlier when it was treatable.’