Lung cancer
A cancer that begins in the lungs, most often linked to smoking but also occurring in people who have never smoked. Caught early it can be treated effectively, and screening for people at higher risk, plus prompt assessment of persistent chest symptoms, help find it sooner.
What it is
Lung cancer develops when cells in the lung grow abnormally and form a tumour. It is broadly divided into two types: non-small-cell lung cancer, the more common and generally slower-growing form, and small-cell lung cancer, which is less common and more aggressive. Smoking is by far the largest risk factor, but lung cancer also occurs in people who have never smoked, and other contributors include second-hand smoke, radon gas, air pollution, and certain workplace exposures. It often causes few symptoms early, which is part of why it can be found late; symptoms, when they appear, include a persistent or changing cough, coughing up blood, breathlessness, chest pain, recurrent chest infections, hoarseness, and unexplained weight loss or tiredness. Diagnosis is made by imaging (chest X-ray and CT scan) and a biopsy, not by a blood test. For people at higher risk — typically older adults with a significant smoking history — screening with low-dose CT can find lung cancer earlier, when treatment is more effective. Treatment has advanced greatly and is tailored to the type and stage: surgery, radiotherapy, chemotherapy, and newer targeted and immunotherapy drugs. Blood tumour markers such as CYFRA 21-1, NSE and CEA are used to help monitor known disease, not to screen or diagnose.
Key lab markers
- CYFRA 21-1 — a monitoring marker for non-small-cell lung cancer.
- NSE — a monitoring marker for small-cell lung cancer.
- CEA — sometimes followed alongside these during monitoring.
- SCC antigen — can be followed in squamous-type lung cancer.
- Diagnosis is by imaging and biopsy — chest X-ray, CT and tissue biopsy, not blood tests.
Symptoms
- A persistent cough, or a change in a long-standing cough
- Coughing up blood or blood-streaked phlegm
- Breathlessness or wheezing
- Chest, shoulder or back pain
- Recurrent or persistent chest infections
- Hoarseness
- Unexplained weight loss, tiredness or loss of appetite
- Often no symptoms early — which is why screening matters for those at risk
When to discuss with a doctor
A cough that lasts more than a few weeks or changes in character, coughing up blood, unexplained breathlessness, chest pain, or unexplained weight loss should be assessed by a doctor promptly — coughing up blood in particular always warrants prompt attention, even though most of these symptoms have non-cancer causes. If you have a significant smoking history and are in the eligible age range, ask about low-dose CT lung screening, which can find cancer early when it is most treatable. Stopping smoking lowers risk at any age. Lung cancer is diagnosed by imaging and biopsy, not by a blood test, and markers like CYFRA 21-1, NSE and CEA are used to monitor known disease. Mediora.AI can show these marker trends in context for someone under monitoring, but persistent chest symptoms need specialist assessment; the diagnosis and care belong with your medical team.