For decades, lung cancer has been viewed as a disease of older men who smoked.Now, cases among young women are on the rise and doctors are baffled.Could air pollution be behind it?Towards the end of 2019, Becca Smith’s life was full and hectic.At 28, she had taken on a unit in Chester to convert into a yoga studio, poured in all her savings and hired teachers, while at the same time working as a personal trainer.Her days started at 5am; she was driven, stressed, excited, and had no time for the back pain that just would not subside.

“It kept moving around,” she says.“Every day it would be in a different part of my back.I was strapping on heat packs and ice packs just to get to work.” Smith saw her GP, her physiotherapist and a chiropractor, all of whom suspected a torn muscle.“What really worried me,” she says, “the worst-case scenario, was a slipped disc.

” One day in March 2020, the pain was so intense that Smith took to her bed, fell asleep and woke with a crashing migraine and blurred vision.Her mum took her to the optician who shone a light behind Smith’s eyes, saw haemorrhaging and sent her straight to the hospital.Once there, Smith was admitted, and over the course of a week, had an MRI, a CT scan, and a biopsy taken from the cells in her back.Smith was alone in her bed when two doctors appeared, closed the curtains, and told her that she had cancer in her lungs that had spread down her spine and up into her brain.It was stage four.

“They said there was nothing they could do for me,” says Smith.“All I remember is ringing my mum and screaming down the phone.The doctors told my parents that I probably had about two weeks to live.” This was the early days of Covid, and Smith chose to go home for palliative care.“I think I’ve blocked a lot of it out, as you do when you go through trauma,” says Smith.

“My friends all came to say goodbye,They were sitting at the end of my bed crying their eyes out,I’ve still got a whole book of the letters they wrote me,”For decades, lung cancer has been viewed as a disease of older men, a “smokers’ disease”, heavily stigmatised and until very recently, grossly underfunded,One analysis from 2010 found it received only 6% of cancer research funding, despite being the third most common cancer in the UK.

In recent years though, the patient profile has shifted.Smoking remains the main risk factor, but cases among fit, young, non-smoking women have risen, both as a proportion and in absolute numbers.And while screening is now available in England for those over 55 with a history of smoking – 76% of the lung cancer cases identified by screening are at stage one or two and potentially curable – young, non-smoking women like Smith tend to be diagnosed only after the cancer has spread.Dr Alex Georgiou, a consultant medical oncologist at Guy’s and St Thomas’ hospital, has analysed the data of his lung cancer patients to understand these changes.“Between 2010 and 2021, the number of patients at our clinic who haven’t smoked has increased every year,” he says.

“In 2010, it was 5% of cases.By 2021, it was 14%.”Of these non-smoking lung cancer cases, 68% were women, compared with 43% of those with a history of smoking.There was also a higher proportion of younger patients: 16% of the non-smoking patients were aged below 50 compared with 5% from the smoking group – and more Black and Asian patients too.White people made up 72% of the smoking cases, compared with just 44% of the non-smoking.

“We might expect a high proportion of Asian patients, as non-smoking lung cancer is very prevalent in south-east Asia,” says Georgiou.“But the higher number of black patients is less recognised.They made up 17% of the non-smoking cases versus 5% from the group with a smoking history.” There were also clear differences in stage of presentation and disease progression.Two-thirds of the non-smoking patients presented at stage four, the most advanced stage, and 38% had cancer that had spread to the brain.

“It’s not only that the demographics are different,” says Georgiou.“The biology of the cancer is different too.”These findings reflect worldwide trends but, as yet, none of it is fully understood.According to Cecilia Pompili, a thoracic surgeon and clinical senior lecturer at Hull York Medical School, we are just beginning to ask the questions.“For so long, we didn’t think of lung cancer as a disease of young women and often haven’t even included them in clinical research trials,” she says.

(For example, men have made up 65% of participants in groundbreaking immunotherapy trials for lung cancer,) Pompili is interviewing women with lung cancer about their early symptoms and diagnosis pathway, for a study funded by the Roy Castle Lung Cancer Foundation,Adenocarcinoma is the most common lung cancer diagnosed in non-smokers, and while some women experience the “classic” persistent cough, and also coughing up blood, for others, symptoms are more vague and non-specific, such as weight loss, or back pain,“We want to understand the symptom trajectory and also whether women are treated differently by their health provider,” says Pompili,“We know from some patients that a 40-year-old, fit woman with a persistent cough is more likely to be diagnosed with an allergy, asthma or an infection than an older male smoker who will be sent for a chest X-ray.

”Identifying why lung cancer is rising in women requires much more research, says Pompili.Hormones could play a part.Worldwide, indoor air pollution caused by wood-burning stoves and biomass fuels used for cooking and heating has been identified as a significant risk factor.In the UK, outdoor air pollution is believed to cause around one in 10 lung cancers.“Air pollution has been demonstrated to be significant for both genders, especially in younger patients,” says Pompili.

It’s possible that women’s smaller lungs and narrower airways lead to a higher concentration of pollutants and a greater likelihood of fine particulate matter – 2.5 micrometers or less in diameter – becoming trapped.Rosamund Adoo-Kissi-Debrah, whose nine-year-old daughter Ella was the first person in the world to have air pollution listed as a cause of death on her death certificate, is not surprised.“Ella had asthma but there are 700 diseases impacted by air pollution,” she says.“When I think of younger women with lung cancer, I wonder about the school run, the time sitting in cars or buses in heavy traffic.

When I think about the higher number of black and brown people, I think of economics.Who takes buses, and waits at bus stops, and lives in social housing and cheaper housing close to main roads?“London is the most congested city in Europe.Worldwide, we are number five,” continues Adoo-Kissi-Debrah, who campaigns for cleaner air through the Ella Roberta Foundation.“Yet somehow, officially, Ella is still the only person who has died because of air pollution.We’ve got to the point where the burden of ill health caused by air pollution is so huge, I’m asking myself: ‘What will it take to make the public demand more action?’”Also key here – but again, not fully understood – is the role of genetic mutations, especially in younger non-smoking women.

Mutations in the epidermal growth factor receptor (EGFR) are the most common, believed to cause 10-15% of lung cancers in the UK.Recent research has identified how air pollution might “wake up” dormant cells in the lungs that carry these cancer-causing mutations, promoting their growth.Sarah Li, a 42-year-old freelance film-maker, was diagnosed with EGFR-positive lung cancer last year.A non-smoker and a vegan, Li lives in London and was signed up for her seventh marathon at the time.“I’d had a persistent cough but I wasn’t worried,” she says.

“I’d had a cold first and the cough just seemed to come off the back of it.” Li was also experiencing pain in her right shoulder.“Looking back, that was another symptom but I didn’t know enough to join the dots.” A physio suggested shoulder exercises and a pharmacist sold Li syrup for her cough.After four months though, as the cough worsened, Li saw her GP, expecting antibiotics for a chest infection.

Instead, she was referred for a chest X-ray, then fast-tracked for a CT scan,In April 2024, Li learned she had inoperable lung cancer, with a tumour on her left lung, and cancer also present in nodules in her right lung,“Even now, I find it strange when I say I have lung cancer,” says Li,“I can say I have cancer – so many people get cancer – but the idea of lung cancer still feels quite foreign,How am I the face of lung cancer? When I was first diagnosed, I went through everything, asking: ‘Why? What did I do?’ I think I led a healthy lifestyle, but I lived in India for four years, in Hyderabad, a busy city.

I feel strange blaming any one thing or focusing on what I might have done wrong.Nobody wants this.”Although Li had only been with her partner Robin for 18 months, they had to have difficult conversations about fertility and future children.“Did I want to freeze my eggs before treatment? We decided it was better to keep me alive and start treatment as soon as possible.” In fact, the impact of lung cancer on fertility has only just become an area of research.

The International Pregnancy and Lung Cancer Registry was launched in December 2023.“Understanding how lung cancer and its treatment impacts young women in all ways – their whole lives, their fertility, their young family and caring responsibilities, their career, is only just beginning,” says Pompili.“It’s something we have done for breast cancer – but not lung cancer.”After years of underfunding (widely attributed to lung cancer’s link with smoking), pioneering treatments are developing fast – especially for cancers like Li’s, driven by genetic mutations.In the last decade, the National Institute for Health and Care Excellence has recommended 48 new treatments for lung cancer – six times more than in the previous decade.

Li’s first round of chemotherapy, radiotherapy and immunotherapy led to massive reductions in her tumours.However, in January, a small lesion was found on her brain.She is now having a targeted therapy – a daily pill – and more chemo.“Life is more intense now,” she says.“There’s more vividness to everything.

Like today, I’m just so happy that I’m feeling well enough to be outside, to have a nice lunch.Those little things you take for granted … you’re just way more appreciative of it all.The idea of talking about ‘two years’ time’ or ‘five years’ time’ like my friends do? I can’t.I know that eventually the cancer will outsmart the treatment I’m on.Hopefully, by then, there’ll be another treatment pathway.

”Smith is in the same position,A few weeks into her palliative care, the family were informed by phone that the biopsy taken from Smith’s back showed a genetic mutation, ALK-positive lung cancer, and a treatment was available,She began taking eight tablets a day – targeted cancer drugs, ALK inhibitors – with monthly blood tests and scans every three months,“It went well, there was a big reduction in cancer,” she says,“After two years, I got some progression in my brain, so I’m on the second line of treatment now.

”Explaining her disease to others is exhausting.“You always get the same reaction,” she says.“‘But you don’t smoke?’ ‘You’re so young?’ There’s such a community around breast cancer – more power to it – but with lung cancer, there really isn’t.It feels like it’s just you.” This is despite the fact that the disease kills as many women as breast, ovarian and cervical cancers combined.

Smith is a pilates teacher now – this summer, she went on a yoga retreat in Bali.Her partner, Sammy, flew out to join her in July and, during a walk on the beach, he proposed.“This is my dream.I’m enjoying my life,” she says.“I’ve gone through so much.

I lost the yoga studio, I lost a lot of money, but the things you think matter? They really don’t.All I care about is my family and friends, and being happy and healthy.“I still feel sadness and I’m scared – I’m terrified because I don’t know what’s to come,” she continues.“Scans never get easier, but you get better at dealing with them.It’s a cliche but I genuinely live for today now – and five years on, I’ve finally reached a stage where I can be grateful for that