Air pollution 'wakes up' dormant cells that cause lung cancer

Air pollution can ‘wake up’ dormant cells which cause lung cancer, scientists warn

  • Inflammation to cells caused by air pollution triggers tumour growth in the lungs
  • It is estimated nearly 6,000 non-smokers die of lung cancer in the UK each year 
  • READ MORE: Polluted cities might harm teenagers’ hearts 

Air pollution can cause lung cancer by ‘waking up’ dormant cells, researchers have found.

Just three years of breathing in toxic air belched out by cars and buses is enough to reactive silenced, mutant cells.

Scientists said their findings, published in the journal Nature, help to explain why so many non-smokers get lung cancer.

And experts claimed their discovery could lead to statin-like pills being developed to ‘stop this from happening inside the body’.

Professor Charles Swanton, of the Francis Crick Institute and UCL and Cancer Research UK chief clinician, who is lead investigator on the study, said: ‘Our study has fundamentally changed how we view lung cancer in people who have never smoked. 

Scientists have discovered how air pollution triggers lung cancer for people who have never smoked

He added: ‘Cells with cancer-causing mutations accumulate naturally as we age, but they are normally inactive.

‘We’ve demonstrated that air pollution wakes these cells up in the lungs, encouraging them to grow and potentially form tumours.

‘The mechanism we’ve identified could ultimately help us to find better ways to prevent and treat lung cancer in never-smokers.

‘If we can stop cells from growing in response to air pollution, we can reduce the risk of lung cancer.’

Read more: Polluted cities might harm teenagers’ hearts: Study warns of dangers of dirty air in cities like London

Lung cancer kills almost 35,000 people each year in the UK and more than 127,000 in the US, figures show.

Smoking is the most common cause of lung cancer, accounting for more than 70 out of 100 cases, according to the NHS.

However, even people who have never smoked can also develop the disease, which mainly affects older people. More than four out of 10 people diagnosed are over 75.

It is estimated that nearly 6,000 people who have never smoked die of lung cancer in the UK each year.

Air pollution causes millions of deaths worldwide each year, including more than 250,000 from a type of lung cancer called adenocarcinoma. 

Air pollution is also understood to increase the risk of other conditions, including heart attack, stroke and diabetes. 

As part of the study, which received £14million in funding from Cancer Research UK, the scientists examined data from more than 400,000 people from the UK, South Korea, and Taiwan.

They focused on a type of lung cancer that is caused by a mutation in the EGFR gene.

Known as epidermal growth factor receptor (EGFR) mutant lung cancer, it is commonly found in people who have never smoked.

Tests on mice showed PM2.5 particles promoted rapid changes in airway cells which had EGFR mutations.

Sarah Woolnough, chief executive of Asthma + Lung UK, said: ‘This important research is further evidence of air pollution having a role in causing lung cancer, the deadliest cancer in the UK, in non-smokers.

‘It also helps us to challenge and change attitudes around lung cancer, that only smokers can get this debilitating disease.

‘The truth is, air pollution affects everyone’s lungs and is responsible for worsening existing lung conditions and creating new ones in healthy people.

‘Up to now the Government has failed to match the ambition that’s needed to tackle this problem.

‘We need to see bold action, including plans to get the most polluting vehicles off our roads, if we are to reduce toxic air and protect people’s health.’

WHAT IS LUNG CANCER?

Lung cancer is one of the most common and serious types of cancer. 

Around 47,000 people are diagnosed with the condition every year in the UK.

There are usually no signs or symptoms in the early stages of lung cancer, but many people with the condition eventually develop symptoms including:

– a persistent cough

– coughing up blood

– persistent breathlessness

– unexplained tiredness and weight loss

– an ache or pain when breathing or coughing

You should see a GP if you have these symptoms.

Types of lung cancer 

There are two main forms of primary lung cancer. 

These are classified by the type of cells in which the cancer starts growing. 

They are:

– Non-small-cell lung cancer. The most common form, accounting for more than 87 per cent of cases. 

– It can be one of three types: squamous cell carcinoma, adenocarcinoma or large-cell carcinoma.

– Small-cell lung cancer – a less common form that usually spreads faster than non-small-cell lung cancer.

– The type of lung cancer you have determines which treatments are recommended.

Who’s affected

Lung cancer mainly affects older people. It’s rare in people younger than 40. 

More than four out of 10 people diagnosed with lung cancer in the UK are aged 75 and older.

Although people who have never smoked can develop lung cancer, smoking is the most common cause (accounting for about 72 per cent of cases). 

This is because smoking involves regularly inhaling a number of different toxic substances.

Treating lung cancer

Treatment depends on the type of mutation the cancer has, how far it’s spread and how good your general health is.

If the condition is diagnosed early and the cancerous cells are confined to a small area, surgery to remove the affected area of lung may be recommended.

If surgery is unsuitable due to your general health, radiotherapy to destroy the cancerous cells may be recommended instead.

If the cancer has spread too far for surgery or radiotherapy to be effective, chemotherapy is usually used.

There are also a number of medicines known as targeted therapies. 

They target a specific change in or around the cancer cells that is helping them to grow. 

Targeted therapies cannot cure lung cancer but they can slow its spread.

Source: NHS 

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