Lung cancer is a disease where cells in the lungs grow uncontrollably, forming tumours that can impair breathing and spread to other parts of the body. It’s primarily caused by smoking (about 85% of cases), but non-smokers can also develop it due to factors like secondhand smoke, radon exposure, air pollution, or genetic predispositions. Symptoms often appear late, and early detection is challenging. There are two main types: non-small cell lung cancer (NSCLC), which is more common and slower-growing, and small cell lung cancer (SCLC), which is aggressive and spreads quickly. Treatment depends on the type, stage, and patient health. Sometimes, molecular testing is used to identify specific mutations for targeted therapies. Staging (I–IV) determines how far the cancer has spread and guides treatment. Prognosis varies widely.

Person holding a cigarette

Causes and risk factors

  • Smoking is the leading cause of lung cancer
  • Exposure to asbestos, silica and diesel exhausts also increases the risk
  • More common as we age
  • Passive smoking and exposure to other carcinogens can also contribute

Symptoms

  • A persistent cough that worsens or doesn’t go away
  • Shortness of breath
  • Chest pain that gets worse with breathing or coughing
  • Coughing up blood or rust-coloured phlegm
  • Wheezing
  • Hoarseness
  • Fatigue and weight loss

Diagnosis

  • Chest X-Ray
  • A low-dose CT scan for more detailed imaging
  • Other procedures include bronchoscopy, biopsy and blood tests

Treatment

  • Surgery: Removes tumours in early-stage NSCLC
  • Radiation: Targets tumours, often used with chemo or for palliation
  • Chemotherapy: Common for advanced stages or SCLC
  • Targeted therapies: For NSCLC with specific mutations
  • Immunotherapy: Boosts the immune system to fight cancer (e.g., checkpoint inhibitors)
  • Palliative care: Focuses on symptom relief in advanced cases

Prognosis/survival

  • Overall survival rates in the UK are low
  • Early diagnosis and treatment improve the survival rate
  • About 2 in 5 people with lung cancer live at least 1 year after diagnosis, and about 1 in 10 live at least 10 years
  • Early-stage NSCLC has a 5-year survival rate of ~60%, while advanced stages drop to <10%
  • SCLC has a poorer outlook due to its aggressiveness

Prevention

  • Quitting smoking is the most important step in preventing lung cancer
  • Avoiding exposure to carcinogens
  • Regular checkups and early detection