20% of Delhi’s lung cancer patients non-smokers: Doctors
NEW DELHI: In what could be an alarming fallout of air pollution, top cancer doctors say they have noted a significant rise in lung cancer among non-smokers in recent years. Roughly one in every five persons diagnosed with the disease does not smoke, they said.
“Till about a decade ago, less than 10% of all lung cancer patients were non-smokers. This percentage has now gone up to around 20%, which is significantly high. Rising pollution levels may be playing a role,” said Dr P K Julka, professor of oncology at AIIMS, according to Times of India.
Dr Vinod Raina, director of medical oncology at Fortis Memorial, affirmed the trend. “The link between lung cancer and air pollution is a conjecture but it is being seen in studies conducted worldwide. Further research is needed to prove the cause and effect relation between the two,” he said.
Dr Randeep Guleria, professor and head of pulmonology division at AIIMS, recounted a case to underline the trend. “A few years ago, I diagnosed a young woman in her late 30s with lung cancer. She was a non-smoker. Throughout her treatment, she kept saying, ‘Why me?’ Such cases are becoming more common now,” he said.
“The role of air pollution in metros such as Delhi as a risk factor cannot be ruled out,” Guleria added.
According to figures released by the Delhi Cancer Registry, lung cancer cases have shown the highest spurt among all cancers afflicting men, going up from 14 cases per 1,00,000 population in 2008 to 15.5 per 100,000 population in 2010.
Delhi Cancer Registry data shows lung cancer cases have been increasing among women too — from 4.2 cases per 1,00,000 population in 2008 to 4.6 in 2010. DCR, which compiles data from all big hospitals in Delhi, is yet to release data beyond 2010.
While the data is based on cases in Delhi, doctors said it represents a wider trend because a significant number of cancer patients being treated in city hospitals are from outside.
In 2013, the International Agency for Research on Cancer (IARC), the specialised cancer agency of the World Health Organisation (WHO), classified outdoor air pollution as carcinogenic. It issued a statement saying there was sufficient evidence that exposure to outdoor air pollution causes lung cancer and increases risk of bladder cancer.
Delhi’s smog is worse than smoking in causing lung cancer. The other cancer causing element is the wide spread use of pesticides.
Particulate Matter (PM), a major component of outdoor air pollution, was evaluated separately and also classified as carcinogenic by IARC the same year. “The predominant sources of outdoor air pollution are transportation, power generation, industrial and agricultural emissions, and residential heating and cooking,” the IARC stated.