Cancer is on the rise in India: could air pollution be a factor?  Premium

Air pollution in India linked to rising lung cancer cases, emphasizing the urgent need for research and action.

Over the past decade or so, air pollution has been increasingly spoken about in India, particularly in the context of the deterioration of air quality across large parts of the country, especially in the winter months. The air we breathe is known to be linked to respiratory illnesses and even cardiac disease, but now, experts say, there is also a strong association with a disease that is a rising burden in India: cancer.

Cancer numbers are rising, and rising fast in India. The Indian Council of Medical Research-National Cancer Registry Programme has projected that the number of cancer cases in the country will spike from 14.6 lakh in 2022 to 15.7 lakh in 2025. Approximately one in nine people in India is expected to face a cancer diagnosis during their lifetime, the ICMR estimates.

Cancer ranks second when it comes to non-communicable diseases that cause deaths in India. Lung cancer is the second-most common cancer among men in India, and also figures amongst the top five when it comes to women. Globally, it is the leading cause of cancer-related deaths, accounting for the highest mortality rates among both men and women.

Over the past two decades, doctors say there has been a concerning pattern emerging in India: a rise in the number of non-smoking lung cancer cases.

Traditionally, lung cancer has always been associated with smoking (which continues to remain the major risk factor) and its incidence has always been lower in India, compared to the West, says Kumar Prabhash, head, solid unit medical oncology, at Tata Memorial Hospital, Mumbai. “Smoking rates have always been higher in the West and lower in India, and this was reflected in the lung cancer numbers. A large number of cases were associated with smoking, both in the West and India, in the past. Now however, and this is what we have been seeing over the past several years, there is a marked difference: a significant proportion of the lung cancer cases in India are in never smokers,” he says.

Estimates vary, but several doctors agree that up to 30% of lung cancer cases that are now being seen are in those who have never smoked.

At the Cancer Institute, Adyar, Chennai, two separate studies, one from 2012 and one from 2017, reflected this trend. In the first study, says Arvind Krishnamurthy, head of surgical oncology at the institute, researchers analysed patient data from 258 cases between 2003 and 2007, and found nearly 40% of the patients were non-smokers. In the second study, analysing data from 495 patients who came in during 2014-15, the non-smoking cases were over 55%,” he says.