Lung cancer is the number one cancer killer in the world. It is the result of uncontrolled growth of abnormal cells. which divide rapidly and form tumors. Primary lung cancer has its origin in the lungs, while secondary lung cancer spreads to the lung from somewhere else in the body. Lung cancer broadly classified into two main types: non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC). NSCLC accounts for 80% of lung cancers and needs further typing and molecular analysis, while SCLC accounts for the remaining 20%. Most lung cancers are the result of inhaling carcinogenic substances lung being the major organ directly exposed to environmental carcinogens.

Risk Factors

Carcinogens- Tobacco smoke both active and passive.
Occupational exposure specially asbestos, radiation.
Genetics- Genetic mutations due to familial inheritance. Genetic predispositions are thought to either directly cause lung cancer or greatly increase one’s chances of developing lung cancer from exposure to certain environmental factors.

Signs and symptoms of lung cancer may include:

  • A new persistent cough
  • Blood on coughing
  • Shortness of breath
  • Chest pain
  • Hoarseness of voice or a recent change in character of voice
  • Weight loss

 Diagnosing lung cancer:

  • Chest X-ray:  May show an abnormal mass or growth
  • CT scan: Done to know the size, location and extent of disease to plan further diagnostic tests.
  • Biopsy: A biopsy involves taking a small sample of tissue  lungs and sending it to the laboratory to check for cancer cells, their type and if present further molecular analysis.
  • Can be done by bronchoscope if lesion in or near airways.
  • From outside under ultrasound or CT guidance.

Further tests like PET scan may be required to know the exact extent of disease.

Adenocarcinoma of lung Diagnosed by bronchoscopy
Osteosarcoma diagnosed by transthoracic needle biopsy
Chondrosarcoma diagnosed by transthoracic needle biopsy
Mesothelioma diagnosed by transthoracic needle biopsy
Thymoma diagnosed by transthoracic needle biopsy and thoracoscopy