AIIMS study puts mean age for small cell lung cancer at 57yrs; 13-15% cases result of smoking
New Delhi: The mean age at which Indians are diagnosed with Small Cell Lung Cancer (SCLC), an aggressive form of the disease, is 57 approximately a decade earlier compared to the western countries, says a study that looked at the profile of SCLC cases treated at AIIMS here during 2008-2020.
It also underscores the role of smoking in the development of SCLC which comprises 13-15% of all lung cancer cases globally as well as in India. Between 2008 and 2020, the lung cancer clinic of AIIMS managed 361 SCLC patients. According to the study published in Lung India, 43% of the patients were reformed smokers whereas 35% were current smokers. "More than 60% of the patients were heavy smokers," says the study.
"Our study showed that close to 80% of the patients were former or reformed smokers, making it the single most important factor associated with SCLC. It is also pertinent to note that 65% of the patients in our study were heavy smokers (smoking index more than 300), fur ther reiterating the role of smoking and its intensity in the development of SCLC," it says.According to the study published in Lung India, 43% of the patients were reformed smokers whereas 35% were current smokers. More than 60% of the patients were heavy smokers. The study found that around 20% of the patients diagnosed with SCLC were non-smokers
The study found that around 20% of the patients diagnosed with SCLC were non-smokers. The researchers state that it is difficult to ascertain the exact reasons for the same but point towards the role of air pollution in the development of lung cancer.
"Although it is difficult to ascertain the exact reasons for the same, there is evidence that prolonged exposure to particulate matter 2.5 mm (PM2.5) in ambient air is associated with an increase in the risk of lung cancer, especially in low and middle-income countries," they said.
The most common symptoms of SCLC patients were cough (84%), fatigue/weakness (83%), loss of weight (77%) , shortness of breath (74%), loss of appetite (73%) and chest pain (72%). Also, 4.8% of patients presented with partial block-age in the superior vena cava, a major vein in the upper body that carries blood from head, neck, upper chest and arms to the heart, says the study.
The researchers included for mer AIIMS director Dr Randeep Guleria, head of pulmonology department Dr Anant Mohan and Dr Rambha Pandey from the department of radiation oncology among others. It showed approximately one-third (34%) of the patients had received anti-TB treatment for varying durations before the diagnosis of cancer.
"In our study, the maximum time delays (in the initiation of cancer treatment) occurred between patient referrals from his primary doctor to our referral centre (122 days). One of the primary reasons for this could be the lack of pulmonary medicine specialists involved in the initial management of such patients or simply a lack of clinical suspicion due to the high burden of TB in our population," says the study.