Now doctors face new cancer crisis - mystery rise of lung tumors in young people who've NEVER smoked

As scientists work to unravel the mysterious rise in early-onset colon cancers, a new worrying trend has emerged.

Lung cancer rates, which have been dropping for decades as the world weans off tobacco, are now rising in young, otherwise healthy people who've never smoked.

One in 10 lung cancer diagnoses in the US are patients under 55, but the rate of early cases has been increasing for the past two decades. And the share of these young patients who have never smoked cigarettes is also growing. 

Researchers believe that the way new homes are built may be exposing residents to a poisonous gas. They also say vaping and cannabis could be factors.

Lung cancer is the deadliest form of the disease, making up one in five US cancer deaths. Along with over 230,000 diagnoses, 125,000 Americans are expected to die of it this year. 

Though most patients are over 70, Dr Laura Mezquita, a medical oncologist in Spain, said during a panel at the world's largest cancer research conference this weekend that there is 'increased incidence' in Americans under 50. 

Beyond smoking, 'we must consider other aspects,' she said. 

Science has long established that smoking definitively causes lung cancer and is the primary risk factor for the disease. 

However, while smokers make up as many as 90 percent of older lung cancer patients, this number drops to 71 percent for younger patients. 

Young patients also have significantly shorter exposures, with an average of 11.5 years compared to 49 years in older patients. 

'The shift away from the perception of smoking as trendy is further diminishing the proportion of smoking in the young population,' the researchers wrote in a report published ahead of ASCO. 

According to recent data from Pew Research, just 10 percent of young adults said they smoked from 2019 to 2023 compared to 35 percent in 2001 to 2003. This, the team suggested, indicates nearly an all-time low. 

'Therefore, new evidence is emerging involving exposure to group 1 carcinogens beyond tobacco, where potency... degree of exposure... may play a more significant role in younger patients.'

Group 1 carcinogens are substances that are proven to cause cancer. Beyond smoking, others include air pollution and ultraviolet radiation.

'Radon gas is a primary cause of lung cancer among nonsmokers and the second leading cause among smokers,' the researchers wrote.

Radon is an invisible, odorless gas produced from the decay or uranium in rocks, soil, and water. The World Health Organization estimates that radon is responsible for three to 14 percent of lung cancers.

‘Radon is the main cause of cancer in non-smokers,' Dr Mezquita said. ‘Radon is a risk factor also in young populations.'

She said this could be due to radon exposure in homes from birth, which could enter the home through contaminated soil. 

Additionally, a 2019 report in Nature found that radon exposure in homes is increasing due to modern construction being more airtight. 

Dr Mezquita also pointed toward vaping, which she noted 'is very prevalent in younger populations.' 

Much of the science is unclear, but some recent reports have suggested that vaping can increase the risk of lung cancer - especially in those who have previously smoked.

A first-of-its-kind study from Seoul, South Korea, analyzed health data from 4.3million ex-smokers and found those who switched to vapes were twice as likely to die from lung cancer, compared to those who went cold turkey. 

Additionally, the ASCO researchers noted that in young people who do smoke, marijuana could exacerbate the risks. 

'Cannabis consumption often occurs in conjunction with tobacco, posing challenges for separate evaluation. Emerging evidence has linked it to more aggressive forms of lung cancer among young patients,' the team wrote.

Dr Mezquita said that while there is evidence pointing toward all of these factors, there is not just one to blame. 'This is not just radon, this is not just air pollution, this is not just smoking. It’s an interaction between all of these risk factors.’ 

During ASCO, lung cancer survivor and scientist Dr Matt Hiznay, 37, of Ohio, took the stage to detail how being diagnosed with lung cancer as a young adult affected him. 

In 2011, Dr Hiznay was diagnosed with stage four adenocarcinoma after several months of persistent cough and pain in his back and chest. He was only 24, and he had never smoked.

‘There were really no warning signs whatsoever,' he said. 'Cancer was nowhere on the radar.' 

‘You're at the start of your life. When you're young and you get diagnosed, it’s very hard to see the future. Thoughts of the future are gone.'

Though he never smoked and had no family history of lung cancer, Dr Hiznay did test positive for a mutation of his EML4-ALK gene. 

Previous reports have shown that EML4-ALK patients are 'significantly' younger than patients with other mutations like the more common EGFR. The median age of these patients was 52 compared to 66 in the control group.

Dr Hiznay relapsed twice but has been cancer-free since 2015. 'As a 12-year survivor, I’ve made many friends in the lung cancer survivor, and I’ve outlived all of them, and that’s something I carry with me,' he said.