lung cancer is no more restricted to smokers as many non-smokers, including young men and women, are also falling prey to it, perhaps due to increase in air pollution, a new study conducted over the last six years has claimed.

Doctors at the Sir Ganga Ram Hospital (SRGH) here, who did the study from March 2012 to June 2018 by analysing 150 in-house patients, dubbed the findings as "disturbing".

"Nearly 50 per cent of these patients were non-smokers. In fact, this figure rose to 70 per cent in the younger age group (less than 50 years). Five patients, all men were in the age group of 20-30 and none of them were smokers," lung surgeon at the SGRH, Arvind Kumar said.

He was speaking at an event held at the hospital premises on the eve of World lung Cancer Day, during which a campaign '#BeatlungCancer' was also launched.

"lung cancer is a dreaded disease with one of the lowest five-year survival rates. We are shocked by the alarming rise in cases, occurrence in younger individuals, non-smokers and women.

"While conventional wisdom says that smoking is the main cause but there is strong evidence now that points to the increasing role of polluted air in increasing incidence of lung cancer," Kumar said.

Out of the 150 patients, 119 were men and 31 women, with nearly half of the female patients from Delhi-NCR. The study was done in various age brackets ranging from 20 to 80 years, and above.

"The patients were from various states such as Uttar Pradesh, Bihar Uttarakhand, Rajasthan, Haryana, Punjab, Himachal Pradesh and Jammu and Kashmir.

"The mean age of these patients was 58. Out of 150, 74 were non-smokers and 76 smokers. Most patients had stage-I or stage-II lung cancer and a few had it in stage-III," he said.

The male to female ratio of the study group was 3.8:1 indicating a "significant rise" in the proportion of female patients compared to studies in the past, which had reported a much lower incidence in females, the study said.

"We referred to a study of 1962, in which the age-group of 20-30 was not even mentioned and the disease was primarily considered a male smokers' disease.

"But, this study suggest that it is no more a smoker's disease only," said Kumar, also chairman of of Center for Chest Surgery at the SGRH.

The study also found that majority of these patients were suffering from adenocarcinoma, which happens more from non-smoking reasons compared to squamous carcinoma that happens from smoking causes.

Siddheshwar Chaudhry, 65, a resident of Begusarai district in Bihar, who got operated in 2013, said he smokes neither cigarette nor any beedi and used to perform yoga, but still got the dreaded disease.

"One fine day, while sleeping, I faced problem in breathing and pain in the chest.       later, I had a chest scan done, and the tumour was found. My right lung has been removed. I never could figure out, how I contracted the disease," Chaudhry said.

Delhi-resident, Hawa Singh (59), is also part of the group which was studied by the SGRH doctors for the study.

After undergoing surgery in 2015, Singh, a businessman who lives in Vikaspuri, now has quit smoking and urges others to do the same, warning them of the consequences. 

"I was a smoker, right from school days. I even used to be scolded by my parents, but I continued to smoke, even in college days and much later in my life.   "Now, after losing my right lung, after it was literally turned into a tar-like object, I don't even think about smoking," he said.      

The study, which the doctors are contemplating, sending for publication, also said that nearly 30 per cent of the patients studied had been "initially misdiagnosed" as tuberculosis cases and were treated for TB for many months, leading to delay in definitive diagnosis and treatment.

Dr Neeraj Jain, chairman, pulmonology department at the SGRH said, "There are always multiple factors at play, smoking, passive smoking, pollution as to the cause of the disease."

"Our study draws attention to the need of more robust data collection system for lung cancer in our country and the need for action to prevent lung cancer deaths by early detection, smoking cessation and strong and immediate measures to control both outdoor as well as indoor air pollution," Kumar said. 

Talking about the '#BeatlungCancer' campaign, he said, it is led by lung Care Foundation, a non-profit organisation in partnership with the SGRH, Mahajan Imaging and YouWeCan, a foundation established by cricketer Yuvraj Singh to spread awareness about cancer.

"The imaging firm will partner for conducting low Dose CT scan for lung cancer screening for people," he said.