Rising lung cancers a cause for concern

Doctors call for stricter implementation of tobacco laws and measures to control air pollution to curb incidence of lung cancer. File
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Every year, nearly 3,500 to 4,000 persons are diagnosed with lung cancers in Tamil Nadu, with Chennai accounting for the highest Crude Incidence Rate (CIR/1,00,000 population) of 8.1 and Kanniyakumari not far behind with a CIR of 7.3. While the steady rise in lung cancers is worrying, what is of greater concern is lung cancers in “never smokers” and women.

According to the Tamil Nadu Cancer Registry Project report, 2019, Cancer Institute (WIA), one in 105 persons (0 to 74 years) in Chennai are at risk of lung cancer. Coimbatore (6.5), Tiruvallur (6.4) and Kancheepuram (6.1) are among the top five districts with the highest lung cancer incidence rate after Chennai and Kanniyakumari.

Most common cancer

“Globally, we are finding that lung cancer has overtaken breast cancer. It is now the most common cancer, in terms of incidence in both men and women put together. While smoking is the main risk factor for lung cancer, we are seeing a lot of lung cancers occurring in ‘never smokers’ and women. The reasons could be due to air pollution too; tobacco being a constituent of air pollution,” Arvind Krishnamurthy, professor and head, Surgical Oncology, Cancer Institute, said. Other factors, such as mutations, could also be responsible for this, he added.

Venkatraman Radhakrishnan, professor and head, Medical Oncology, Cancer Institute, added that they are seeing many young persons and non-smokers presenting with lung cancers. “The perception is that non-smokers do not get lung cancers. We do not know the reasons yet but it could be multifactorial. Environment pollution has been shown to be associated with lung cancers. Exposure to chemicals in industries could also be one of the other causes,” he said.

While all forms of smoking – active cigarette smoking and passive smoking – increases the risk of lung cancer, a senior government oncologist explained that asbestos exposure, radon exposure, air pollution and diesel exhaust were the other causes for lung cancer. Occupations associated with asbestos exposure include plumbers, carpenters, welders and motor vehicle mechanics and industries associated with asbestos exposure include construction, ship building/repair, yarn, thread and fabric mills, plastic and rubber manufacturing.

Challenge to diagnose

Diagnosis of lung cancer is challenging. “At least 70% come in advanced stages — 35% locally advanced and 35% in metastatic stages. This is mainly because symptoms occur in advanced stages,” Dr. Radhakrishnan said. Compared to other cancers, lung cancer is very aggressive, Dr. Krishnamurthy added.

There have been a lot of treatment advances. “We have targeted therapy and immunotherapy, which were previously used in advanced lung cancers and are now put to use in early stages itself,” he said.

There are a lot of studies on lung cancer prototypes for precision oncology, Dr. Krishnamurthy, said, adding: “Now, tumours are subjected to molecular testing and we are trying to see the markers expressed. We are personalising the therapy for patients. Targeted treatments and immunotherapies are giving the opportunity to improve survival. We are also performing robotic surgeries for early stage lung cancers.”

In early stages, there are two advances — precision medicine, and the other in terms of minimally invasive approach. “We have video assisted thoracic surgeries and robotic assisted thoracic surgeries. We are finding that minimally invasive approaches are helping patients have good short term outcomes in terms of lesser pain, lesser ICU stay,” he said.

Doctors call for stricter implementation of tobacco laws and measures to control air pollution. Surendran Veeraiah, professor and head, Psycho-oncology and Resource Centre for Tobacco Control, Cancer Institute, expressed concern on the rise in violations under Cigarettes and Other Tobacco Products Act especially smoking in public places. “Smoking in public places is going unchecked, and needs the attention of implementation agencies. With environmental pollution also playing a role, there is a need for effective policies. Vehicle emissions are on the increase, and we need measures to control pollution. We need behavioural change from the people,” he said.