THE proportion of people diagnosed with lung cancer who’ve never smoked is increasing, the World Health Organization (WHO) has revealed.
New research highlights air pollution as a growing factor in the increasing number of lung cancer cases worldwide.
Lung cancer in people who’ve never smoked is now the fifth leading cause of cancer deaths worldwide, according to the International Agency for Research on Cancer (IARC), part of the WHO.
Adenocarcinoma makes up as much as 70 per cent of lung cancer cases among never-smokers, according to the IARC.
In 2022, about 200,000 cases of adenocarcinoma were linked to air pollution, according to an IARC study published in the .
The largest burden of adenocarcinoma attributable to air pollution was found in east Asia, particularly China, the research found.
The study’s lead author Dr Freddie Bray said the findings pointed to the need for urgent monitoring of the changing risk of lung cancer.
“With declines in smoking prevalence – as seen in the UK and US – the proportion of lung cancers diagnosed among those who have never smoked tends to increase,” the expert told .
“Whether the global proportion of adenocarcinomas attributable to ambient air pollution will increase depends on the relative success of future strategies to curtail tobacco use and air pollution worldwide.”
The researchers also said that exposure to the burning of fuels in households for heating and cooking could be a factor in rising lung cancer cases among Chinese women who had never smoked.
Lung cancer continues to be the leading cause of cancer cases and deaths worldwide.
In 2022, around 2.5 million people were diagnosed with the disease.
In the UK alone, lung cancer causes around 34,800 deaths annually, making up one in five cancer-related deaths.
That's roughly 95 deaths per day.
However, the patterns of incidence by subtype have shifted dramatically in recent decades.
Among the four main subtypes of lung cancer - adenocarcinoma, squamous cell carcinoma, small-cell carcinoma, and large-cell carcinoma - adenocarcinoma has become the dominant subtype in both men and women, the IARC found.
Adenocarcinoma is a type of cancer that starts in mucus-producing glands that line the insides of the organs.
This is why it can affect different areas of the body, including the lungs, breast, bowel, or stomach.
Lung cancer rates in men have decreased over the past 40 years, while rates in women have risen.
Men still make up most cases (1.6 million in 2022), but the gap between male and female diagnoses is narrowing, with 900,000 women diagnosed in 2022.
At the time, charities urged women to be as alert to potential lung cancer signs as they are to checking their breasts for lumps.
LUNG cancer is the most deadly common cancer in the UK.
It is considered a common cancer alongside prostate, breast and bowel, which together make up more than half of all new cases.
Around 49,000 people are diagnosed with lung cancer every year and 35,000 die from it.
Just one in 10 patients survive for a decade or more after being diagnosed and lung tumours make up 21 per cent of cancer deaths in the UK but only 13 per cent of cases.
The main reason that it is so deadly is that symptoms are not obvious in the early stages, which is why it's sometimes called a 'silent killer'.
When signs do appear they may include:
The NHS does not routinely screen for lung cancer but is rolling out more tests to smokers and ex-smokers at high risk, in a bid to catch it earlier. Testing may involve X-rays and chest CT scans.
Smoking is the number one risk factor for lung cancer and accounts for about 70 per cent of cases.
Risk may also be higher for people who have inhaled other fumes or toxic substances at work, such as asbestos, coal smoke or silica.
