How much does smoking contribute to Lung Cancer?

Smoking tobacco is the most important

risk factor

associated with lung cancer. It is responsible for 90% of all lung cancers. There are over 7,000

chemicals

in

tobacco smoke

, many of which are carcinogenic and harmful. Smokers are 15 to 30 times more likely to develop and die from

lung cancer

than a non-smoker.
Higher the number of pack years someone is smoking (Number of years smoked x number of packs smoked daily), higher is the risk of developing lung cancer.

The earlier in life you begin smoking, the higher is your risk of developing lung cancer. As per CDC, lung cancer develops in around10 to 20% of all smokers.
When people smoke, they inhale harmful chemicals that cause cell damage inside the lungs. The toxic combination of tobacco smoke chemicals damages mucociliary escalators in airways, causes inflammation and damages the lungs alveoli, Tobacco smoke can weaken the body’s immune system, which can lead to the uncontrolled, ongoing growth of cancer cells. Smoking can block a person’s ability to fight cancer once they have it.

Persons who smoke can lower their risk of lung cancer by quitting this habit, or avoiding second hand smoke, which will also improve their respiratory and overall health. It is never too late to quit smoking, as the prevailing literature indicates that lung cancer risk is reduced when individuals quit smoking. Reducing the number of cigarettes you smoke a day is a good first step.
But, there is no safe level of smoking. The best thing you can do for your health is to stop smoking completely, and it is never too late to stop.

Quitting smoking

, regardless of how long a person has smoked, can reduce the chances of dying from lung cancer by half in 10 years.

Nicotine replacement therapy

and psychological counselling, including mindfulness-based therapies, are effective intervention strategies for smoking cessation.
So it’s never too late to quit. The longer you smoke, the higher your risk of lung cancer. When you stop, your body is able to undo a lot of the damage caused by the chemicals in tobacco smoke.
(Dr (Col) S P Rai, Consultant Pulmonary & Sleep Medicine, Kokilaben Dhirubhai Ambani Hospital, Mumbai)