INTRODUCTION

Lung cancer is a type of cancer caused when cells in the lungs grow uncontrollably, forming tumors that affects the normal lung function. It usually begins in the airways (bronchi or bronchioles) or the tiny air sacs (alveoli) of the lungs. Normally cells grow, divide, and replicate as part of their function, but sometimes mutations occurs, causing abnormal cell growth. These cancerous cells, if left untreated, can spread to other parts of the body, making the disease more severe. This uncontrolled cell growth disrupts the normal lung function, making it harder for the body to receive adequate oxygen.

Lung cancer is one of the most common and leading causes of cancer-related deaths worldwide. Smoking is the primary risk factor, as harmful chemicals in tobacco damage lung cells, leading to mutations. the risk of lung cancer increases with the duration and frequency of smoking. However, non-smokers can also develop lung cancer due to exposure to secondhand smoke, air pollution, radiation, or genetic factors. Quitting smoking, for long time it reduces the risk of developing lung cancer.