El cáncer de pulmón en no fumadores es más común de lo que piensas

After breast cancer, cáncer de pulmón is the second most common type of cancer for women aged 25-74. It's also still thought of as a smoker's disease.

But a recent estudio estimated last year that around 6,000 people who'd never smoked died from the disease. Although smoking (which doctors call a 'modifiable risk') accounts for 86% of lung cancers, too often we have no control over a diagnosis like this.

Liz Bradley [no relation to Dr Simon Bradley, mentioned below], 42, is a mother of three. When she was younger she competed at the World Championships for rowing, and more recently she sang in a choir. She has never smoked. Her lung cancer diagnosis came out of the blue. Doctors spotted it at stage 3 while screening for a burst abdominal cyst, and she went through treatment last year, followed by another surgery. She finished quimioterapia this year.

Lung cancer stigma

When Liz talks to people about her diagnosis, she often anticipates judgement.

"Every time I talk about my cancer I say 'lung cancer' but I nearly always specifically follow it up with, 'And I've never smoked', because you kind of feel ... Will people think I'm really irresponsible because I smoked and I've got small kids?"

"People have less sympathy, I think, especially [compared to] cancers like breast cancer. People have this idea that you've done it yourself. I've never smoked a cigarette in my life. I used to be a professional sportswoman and I've never done drugs. I look after myself. But it still happens."

Professor Mick Peake, honorary consultant and professor of respiratory medicine in the University Hospitals of Leicester and one of the authors of the paper, believes that lung cancer has not had much coverage thanks to its stigma.

"The fact that it's so heavily linked with cigarette smoke in the public and professional eye means that it hasn't had the attention it deserves."

He points out that funding research into treatment has lagged behind: lung cancer accounts for between a fifth and a quarter of all cancer deaths in England, but an analysis reported in The Lancet in 2016 showed that it got just 6% of research funding.

Cuando The Guardian reported on the paper, rising air pollution was discussed as a possible risk, but Peake says that researchers believe that the biggest risk to never-smokers is other people's smoke.

"Children of parents who smoke are at least twice as likely to get lung cancer, whether they smoke or not. The effect of air pollution is there, but probably with a much smaller effect."

Dr Simon Bradley, a GP in Bristol, said that the difficulty in detecting lung cancer in never-smokers is, mainly, that it's very difficult to anticipate. This also goes some of the way to explaining why so many lung cancer diagnoses in never-smokers are made late, sometimes at stage 4.

In addition, it can be hard to detect. For example, he says, squamous carcinoma is usually discovered when the cancer is about two to three centimetres wide. But because it grows so slowly, it can take eight years to reach that size.

"It's been there a heck of a time and unless you remove most of the lung, nobody could detect it. It is beyond the capacity of science to detect the very earliest disease, so that window of opportunity is small and difficult because symptoms are so vague."

He explains that screening is not as simple as sending a patient off for a test - it carries its own risks and frustrations.

"Often people worried about cancer have an expectation It can be ruled out by test very easily. And that is not the case ... We can do a chest X-ray, say, and that would be normal, but that will miss a certain number of cancers."

Una progressive cough (that is, one getting more intense or frequent over about six weeks) for which there is no 'trigger' (such as a cough or cold that started it), or falta de aliento without a trigger would raise most GPs' suspicions, he says. (A normal postviral cough lasts about three weeks). On top of a cough, he adds, patients might be hoarse, have shoulder pain, feel 'ill' or have a general malaise.

Bradley notes that for a few patients, cooking on open fires or in kitchens with a lot of smoke might have been risk factor, particularly if they have grown up or lived abroad somewhere where that is more common. But for most people, he says, smoking still poses the greatest risk for lung cancer.

"You're more than 20 times likely to get smoking-related lung cancer, than non-smoking-related lung cancer. If you're a smoker, don't worry if you've already tried to quit. Go again to your GP [or pharmacist] and ask for help - this might be the time you'll be successful."

Liz got the all clear quite recently. Fundraising for Macmillan and Race for Life and being open about what happened is helping her recover. She's also a spokesperson for the Roy Castle Foundation's #LikeMe campaign to raise awareness of lung cancer in non-smokers.

"Talking about it is one of the things I've always told myself to try to do to return my luck. Spreading awareness and raising money is my goal - I'm doing hikes and coffee mornings all over the place. I'm hoping I can repay my good fortune."