Lung Cancer



Lung cancer is abnormal growth of cells in the trachea, bronchus, or the lung tissues. Lung cancer is the most common cancer diagnosed in both male and female in India. According to the Globocan 2018 report, the incidence rate and mortality rate for lung cancer was reported to be 5.9% and 8.1% respectively.

Types of Lung Cancer

Non-small cell lung cancer (NSCLC)

Non-small cell lung cancer account for 80-85% of lung cancers.

Small cell lung cancer (SCLC):

It accounts for 10-15% of lung cancers and they grow and spread faster in comparison to the NSCLC. It is also known as oat cell cancer.

Other types

Other forms of lung cancer carcinoid tumors, adenoid cystic carcinomas, sarcomas.


Smoking tobacco is the leading causes of lung cancer deaths. It accounts for 80% of the lung cancer deaths. Other causes include mutations in inherited genes. In NSCLC, there is formation of EGFR protein which causes lung cancer. Other causes are mutations in RB1and p16 tumor suppressor gene.

Risk Factors

Exposure to radon and asbestos

Increased risk of developing lung cancer is associated with exposure to radon and asbestos because of its accumulation in lungs.

Occupational exposure to certain chemicals:

Increased risk of lung cancer is associated with inhalation of arsenic, mustard gas, coal products, and uranium.

Intake of dietary supplements

Increased risk of lung cancer is associated with beta carotene supplements. The smokers should avoid taking these supplements as it increases the risk.

Family history

The chances of developing lung cancer are higher in people who have their first degree relatives suffering from it or they had a previous history of lung cancer.

Air pollution

The risk increases about 5% worldwide due to air pollution.

Signs & symptoms

Some of the symptoms of lung cancer are:

Breathing problems

Frequent cough

Pain in the chest or shoulder

Loss of appetite

Weight loss


Infections in the chest


Imaging tests

Several imaging tests such as ultrasound CT scan, MRI scan, and PET scan are performed to diagnose lung cancer.

Sputum cytology

The sputum is analyzed to diagnose for the cancer cells. It mostly helps in the diagnosis of squamous cell lung cancers.


A flexible tube is inserted into the lungs and the tissues examined for presence of tumour.


In this, the fluid that has accumulated around the lungs are analysed to diagnose lung cancer.

Needle biopsy

Several biopsy tests such as fine needle aspiration (FNA) biopsy, transrectal FNA, and core biopsy are performed to diagnose lung cancers.