Understanding lung cancer in smokers and non- smokers!

GUEST COLUMN: Dr N Prabhudev

Bengaluru, Nov. 30: We the clinicians have been vexed by a confounding trend: the increase in the number of lung cancer diagnoses in people who never smoked.
15% of lung cancers occur in Non-smokers! Lung cancer in never smokers may be a different disease! It is the seventh leading cause of cancer deaths in the world! It demonstrates a marked gender bias, occurring more frequently among women! Cancers arising in never smokers target the distal airways and favour adenocarcinoma histology. They account for over 300,000 deaths each year! The above-mentioned facts strongly suggest that lung cancer arising in never smokers is a disease distinct from the more common tobacco-associated forms of lung cancer.
Smoking causes cancer in 85% cases! Lung cancer is less common in those who do not smoke, but it can still occur. Two of the main contributors to non-smoking lung cancer are second hand smoke and a naturally occurring radioactive gas called radon. 10–20% of lung cancers each year occur in people who smoked fewer than 100 cigarettes in their lifetime or never smoked at all.
Every person is different, and so is every cancer. Even two lung cancers of the same type and stage may behave quite differently at the molecular level. Six out of ten people with lung cancer survive more than five years with treatment. If the disease is not diagnosed early, this rate drops to less than one in ten. Therefore, periodic health check-ups are very important for lung cancer patients.
Lung cancer is increasingly being recognised as a complex disease with multiple causes. Today, smoking causes nearly 8 – 9 out of 10 lung cancer deaths, while radon gas, pollution, and other things play a smaller role. Newly developed drugs provide new hope for those diagnosed today.
A persistent cough or an unexplained weight loss may seem like minor issues, but when combined with chest pain or shortness of breath, they may signal something far more serious. Many people dismiss these symptoms, attributing them to a simple cold or stress, but they can be early warning signs of lung cancer, especially in non-smokers!
Understanding the nuances of lung cancer in non-smokers has become crucial, and research is uncovering unique genetic, molecular, and environmental factors at play in these cases
Lung cancer can be divided into two primary categories:
• Small cell lung cancer – tend to be more aggressive.
• Non-small cell lung cancer
Nicotine disarms the lungs’ natural defence system! Tobacco smoke prevents the cilia from doing their protective job. This lets the cancer-causing chemicals build up. The risk of lung cancer increases with the length of time and number of cigarettes smoked. People who smoke are 15 to 30 times more likely to get lung cancer than non-smokers.
Quitting has almost-immediate benefits. People who quit smoking reduce their risk of developing lung cancer by 50 percent – 10 years after quitting, compared to people who continue to smoke.
• Inhaling second-hand smoke increases your risk of lung cancer! Long-term exposure to high levels of particulate matter (PM2.5), industrial emissions, and vehicular smoke can lead to severe lung inflammation and oxidative stress, both of which increase the likelihood of cancer development.
• Genetics play a crucial role in lung cancer development, especially among non-smokers.
It accounts for 1.76 million deaths around the world per year. Tobacco smoke exposes you to roughly 7,000 types of chemicals and 70 known cancer-causing chemicals – carcinogens! Link between air pollution and lung cancer is becoming clearer.
Lung cancer begins quietly.
No cough, still cancer! Yes, it’s possible!
Unintentional weight loss – A good rule of thumb is to see your doctor if you’ve lost a significant amount — more than 5% of your weight — within 6 months!
A cough that won’t go away – A cough that gets deeper or more severe, a hoarse or raspy cough! Blood in sputum,
Chest pain, especially during deep breaths
Wheezing or shortness of breath and tightness in the chest
Fatigue, A sudden loss of appetite, A noticeable change in your voice – hoarseness or stridor,
Non-traumatic bone or vertebral fractures indicate cancer that has spread to the bones, known as metastatic lung cancer.
Lung cancer is often diagnosed in advanced stages, which complicates treatment. Early detection is vital, especially in high-risk populations like non-smokers who have been exposed.
Heavy smokers and Non-smokers ages 55-80 should get a CT scan every year. Low-dose CT scans have shown promise in detecting the disease at an early stage, which can drastically improve outcomes. To tackle the rising number of lung cancer cases in non-smokers, a multi-faceted approach is needed, focusing on reducing air pollution, enforcing smoke-free environments, improving workplace safety, and advancing genetic research.
You will get a chest X-ray or other imaging tests. You may also need to cough up phlegm for a sputum test. If either of these tests suggest that you could have cancer, you’ll probably need to get a biopsy.
If you’re diagnosed with lung cancer, you may have other tests to see if the cancer has spread. Cancer staging tests often involve imaging tests – MRI, CT, bone scans and PET scan. Not every test is right for every person.
The stages of lung cancer range from 1 to 4. The lowest number means that the cancer is small and only in the lung. As the cancer grows larger or spreads outside of the lungs, the numbers get higher. A stage 4 lung cancer has spread to other areas of the body.
Surgery may be an option if your cancer is only in the lungs. If you have a larger lung cancer, chemotherapy or radiation therapy may be used before surgery to shrink the cancer. Chemotherapy or radiation therapy also may be used after surgery if there’s a risk that cancer cells were left behind or that your cancer may come back.