Lung cancer rates among non-smokers doubles – ? pollution

It rather fits in with ex-Vice-President and environmental campaigner Al Gore’s description of the skies above us as “vast outdoor open sewers”.

“Lung cancer rates among non-smokers have doubled over the past decade amid concerns that high levels of air pollution lie behind the rise, a study shows.

The number of lung cancer deaths among people who have never smoked will overtake deaths from smoking- related cancer within a decade if the trend continues, according to the UK’s largest cancer surgery centre.

Researchers worry that this shift would make the condition, which is the deadliest form of cancer, even harder to diagnose and treat in time. There are 46,400 new cases and 36,000 associated deaths in Britain each year, and only one in 20 patients survives for more than ten years.

Lung cancer has overwhelmingly been linked to cigarettes, which caused about nine out of ten cases. As smoking rates have fallen to a record low, however, specialists at the Royal Brompton Hospital and Harefield NHS Trust in London have seen a substantial increase in the number of operations they are performing on non-smokers.

Other researchers said they had yet to see any sign of the trend, and there is little rigorous national data on whether lung cancer patients ever smoked. However, a similar rise was recently identified by three big hospitals in America. Eric Lim, a consultant thoracic surgeon, said he was confident that his team had identified a new and troubling phenomenon.

Between 2008 and 2014 the number of lung cancer patients treated at the centre remained constant at about 310 a year, but the proportion of people who had never smoked climbed steadily from 13 to 28 per cent, rising from fewer than 50 never-smokers to nearly 100 a year, 67 per cent of whom were women.

Mr Lim said that the reasons for this change were unclear but air pollution was a strong candidate. The International Agency for Research on Cancer has classified fine particles such as soot as a carcinogen, and Cancer Research UK estimates that pollution accounts for 3,500 cases of lung cancer each year. Another possible explanation is better detection of tumours through scans for other diseases.

Mr Lim said the rise of lung cancer in people who had never smoked could lead to a higher death rate because it was harder for doctors to spot the disease early without the red flag of a cigarette habit. Even now only 21 per cent of cases are diagnosed by GPs, compared with the 35 per cent that are discovered at accident and emergency wards.

The Royal Brompton group plans to launch the first clinical trials of a “liquid biopsy” blood test next year that could catch fragments of DNA shed by lung cancer months or years before the most serious symptoms appeared.

Some experts argue that the study, which involved 2,170 patients and is published in the European Journal of Cancer, is too small to be truly reliable.

Stephen Spiro, a former head of respiratory medicine at University College Hospital and an honorary adviser to the British Lung Foundation, said: “There is no good evidence that lung cancer is becoming commoner in never-smokers.” He added: “Lung cancer will become more frequent in never-smokers as a proportion, as smoking cancers begin to decline.”

Mr Lim stood by his findings, saying that Britain was not good enough at monitoring lung cancer rates to have spotted the trend.”

Source: The Times, pay wall

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