Lung Cancer: Welcome back to "The Science Of Health", ABP Live's weekly health column. Last week we explained the role played by genetics in determining which people have a greater risk of cancer, the kinds of mutations and genetic changes that lead to cancer, and the scientific basis behind people developing hereditary cancers. This week, we discuss the current incidence of lung cancer in India, the projected prevalence of the disease by the end of the decade, and which genetic therapies can cure the condition in the future.
Lung cancer affects the tissues of the lungs, usually the cells lining the air passages. It is characterised by symptoms such as chest pain, trouble breathing, blood in sputum, loss of appetite, fatigue, swelling in the face, cough, wheezing, hoarseness, weight loss, and trouble swallowing. Lung cancer is of two types: small cell lung cancer and non-small cell lung cancer.
Small cell lung cancers can be treated through surgery, radiation therapy, endoscopic stent placement, chemotherapy, immunotherapy, and laser therapy. Non-small cell lung cancer can also be treated with the same methods. Some additional methods to treat this type of lung cancer include photodynamic therapy, which uses a medicine and a type of laser light to kill cancer cells, electrocautery, which uses a probe or needle heated by electric current to destroy abnormal tissue, and cryosurgery, which uses an instrument to freeze and destroy abnormal tissue.
Check ABP Live's stories explaining the science behind various health phenomena, and the articles appearing in the weekly health column here.
Current incidence of lung cancer in India, and projected prevalence by decade end
In India, lung cancer is more prevalent among men than women. Lung cancer accounts for 6.9 per cent of all new cancer cases in India, and is responsible for 9.3 per cent of all cancer-related deaths, Dr Vinay Bhatia, Head, Molecular Biology National Reference Lab, Oncquest Laboratories Limited, Gurugram, told ABP Live. "Lung cancer emerges as the prime cause of cancer-related mortality among men".
Citing a report released by the Indian Council of Medical Research (ICMR) and the National Center for Disease Informatics and Research (NCDIR) in 2020, Dr Bhatia said that cancer rates are expected to increase by 12 per cent by 2025. “In 2021, the Indian Thoracic Journal found that 5.9 per cent of all cancer patients in India were diagnosed with lung cancer, which also accounted for 8.1 per cent of all cancer deaths in the country. This may be due to the increasing use of bidi in India, a form of raw tobacco; lack of awareness programs conducted at grass root levels; and the alarming rate of air pollution in the country.”
Lung cancer is the second-most common cancer among males, after lip and oral cancer. It accounts for eight per cent of all cancer cases among males, Dr Shriniwas Kulkarni, Consultant Medical Oncologist, Sahyadri Super speciality Hospital, Hadapsar, Pune, told ABP Live.
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Citing a study published in the journal Cancer, Dr Kulkarni said that the projected prevalence of lung cancer by 2030 is 23.3 per cent. After 2030, the number of new cases of lung cancer per year is expected to be 2,13,000, according to the study. He also said that the increasing incidence of smoking and exposure to air pollution will contribute to the rise in lung cancer prevalence in India by the end of the decade. “Regarding mortality, lung cancer has a significant impact in India. It is the leading cause of cancer-related deaths, responsible for approximately 14% of all cancer deaths in the country.”
According to Dr Kulkarni, lung cancer cases in India can be reduced by prioritising preventive measures, empowering communities with knowledge, and ensuring accessible diagnostic facilities across the country. He said that early detection of lung cancer can be facilitated through routine screenings and awareness campaigns. These will also ensure timely treatment and enhanced survival rates. It is also important to invest in research and advanced diagnostics to improve patient management, and reduce the burden of the disease, he said.
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Genetic therapies to cure lung cancer
Genetic therapies and immunotherapy are some science advances that can completely cure lung cancer in the future. While gene therapy alters the genetic material, immunotherapy enhances one's immune system.
According to Dr Muzammil Shaikh, Director, Medical Oncology, Nanavati Max Super Speciality Hospital, gene therapy rectifies defective genes or uses bioengineered oncolytic viruses to target malignancies.
Gene therapy works by identifying the antigens that cause tumours, and understanding the environment around tumours.
A gene which plays a role in tumour development and progression is p53. This gene regulates cell division and promotes tumour suppression, said Dr Anil Thakwani, Oncologist, Sharda Hospital. “If p53 is defective, it can lead to uncontrolled cell growth. Gene therapy aims to replace or repair these defective genes to restore their normal function and hinder tumour growth.”
Immunotherapy makes the immune system adept at identifying and eradicating cancer cells.
As part of immunotherapy, checkpoint inhibitors are used to block certain proteins that inhibit immune response. This allows the immune system to recognise and attack cancer cells effectively, said Dr Thakwani.
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He also said that both gene mutation therapy and immunotherapy are promising approaches to treat non-small cell lung cancer and have shown significant results in various studies. However, he said that gene mutation therapy and immunotherapy are still evolving, and ongoing research is crucial to improve their efficacy and broaden their application in the treatment of lung cancer.
“The crux of these advancements lies in decoding tumour-specific antigens and comprehending the intricate tumour microenvironment. By pinpointing and neutralising specific genetic aberrations, and simultaneously fortifying our immune response, we are tapping into the body's own profound healing mechanisms. This innovative melding of gene and immune therapies heralds a transformative era in our relentless pursuit against lung cancer,” Dr Shaikh concluded.