Lung cancer: symptoms, treatment and survival

Lung cancer is a malignant tumour that begins in the lung tissue. The two main types are non-small cell lung cancer (NSCLC), which accounts for about 85% of cases, and small cell lung cancer (SCLC), which accounts for 15%. Lung cancer is the most common cause of cancer death in the UK, with around 49,000 diagnoses and 35,000 deaths per year.

According to the NHS, symptoms to report to your GP include: a cough lasting more than two to three weeks; a worsening long-standing cough; recurring chest infections; coughing up blood; unexplained breathlessness; unexplained fatigue; unexplained weight loss; or persistent chest or shoulder pain. Early lung cancer often causes no symptoms at all.

Lung cancer is the third most common cancer in the UK (after breast and prostate) but by far the most common cause of cancer death. Approximately 49,000 people are diagnosed each year, and around 35,000 die from it — more than from bowel, breast and prostate cancer combined.

Smoking is responsible for approximately 70% of lung cancer cases in the UK. Other causes include exposure to radon gas, asbestos, occupational carcinogens (silica, diesel exhaust), air pollution and, in a minority of cases, inherited genetic susceptibility. Approximately 15% of lung cancer cases occur in people who have never smoked, most commonly adenocarcinoma.

Yes. Around 15% of UK lung cancer cases occur in lifelong non-smokers. The most common type in non-smokers is adenocarcinoma. Risk factors for non-smokers include radon gas exposure, second-hand smoke, air pollution, occupational exposures and, in some cases, inherited genetic mutations (such as EGFR mutations). Non-smokers with lung cancer are more likely to have tumours with targetable mutations that respond to specific therapies.

The two main categories are non-small cell lung cancer (NSCLC, approximately 85% of cases) and small cell lung cancer (SCLC, approximately 15%). NSCLC includes adenocarcinoma (most common in non-smokers, women), squamous cell carcinoma (strongly associated with smoking) and large cell carcinoma. SCLC is almost exclusively seen in smokers, grows very rapidly and tends to respond initially to chemotherapy before frequently recurring.

Diagnosis involves a chest X-ray or CT scan to identify suspicious areas, followed by a biopsy to obtain tissue for pathological analysis. Biopsy may be obtained via bronchoscopy, CT-guided needle biopsy or, in some cases, surgery. Molecular testing of the tumour tissue is performed for NSCLC to detect EGFR mutations, ALK rearrangements and PD-L1 expression, which guide targeted treatment decisions.

NSCLC is staged from I to IV. Stage I means a small tumour confined to the lung. Stage II means the tumour is larger or has spread to nearby lymph nodes. Stage III means the cancer has spread to lymph nodes in the centre of the chest. Stage IV means the cancer has spread to the other lung, the fluid around the lungs, or to distant organs. SCLC is classified as either limited stage (confined to one side of the chest) or extensive stage (spread beyond). Stage determines treatment and prognosis.

Treatment depends on cancer type, stage and the patient's overall health. Options for NSCLC include surgery (lobectomy), stereotactic ablative radiotherapy (SABR), concurrent chemoradiotherapy for locally advanced disease, targeted therapies (osimertinib for EGFR+ tumours, alectinib for ALK-rearranged tumours) and immunotherapy (pembrolizumab, nivolumab). SCLC is treated primarily with chemotherapy (etoposide plus carboplatin or cisplatin) and prophylactic cranial irradiation.

Lung cancer has lower survival rates than most other common cancers. In England, approximately 40% of patients diagnosed with lung cancer survive one year, and around 16% survive five years. For early-stage (Stage I) NSCLC treated surgically, five-year survival can be 60–80%. For Stage IV disease, five-year survival is below 5% for many tumour types, though immunotherapy and targeted therapies are improving outcomes for specific patient groups.

Immunotherapy for lung cancer uses drugs called checkpoint inhibitors — including pembrolizumab (Keytruda), nivolumab (Opdivo) and atezolizumab (Tecentriq) — to help the immune system recognise and attack cancer cells. These drugs work by blocking PD-1 or PD-L1 proteins that cancer cells use to evade immune attack. Immunotherapy is most effective in tumours with high PD-L1 expression and can produce long-lasting responses in a proportion of patients with advanced NSCLC.

The NHS Targeted Lung Health Check (TLHC) is a free low-dose CT scan offered to current and former smokers aged 55–74. It is part of an expanding national programme that can detect lung cancer at an early, treatable stage before symptoms develop. The CT scan takes around 10 minutes and does not require any preparation. Participants may also be assessed for their cardiovascular risk. Contact your GP or local NHS service to find out if TLHCs are available in your area.

The NHS does not yet offer a universal national lung cancer screening programme, but Targeted Lung Health Checks (low-dose CT scans) are being rolled out for current and ex-smokers aged 55–74 across England. Scotland, Wales and Northern Ireland have similar targeted screening initiatives. Evidence shows that low-dose CT screening significantly reduces lung cancer mortality by detecting cancers earlier. The programme is expanding and expected to achieve national coverage.

Lung cancer typically takes many years — often 20–30 years — to develop after the onset of smoking. This long latency period is why lung cancer risk remains elevated even decades after stopping smoking, although ex-smokers' risk does decrease progressively with time. The longer and heavier the smoking history, the greater the risk. Stopping smoking at any age reduces future lung cancer risk.

Early lung cancer frequently causes no warning signs — which is why it is so often diagnosed at an advanced stage. When early symptoms do occur, they are often subtle and attributed to other causes: a new or changing cough, shortness of breath during activity, unexplained fatigue, or a chest infection that takes longer than usual to clear. Any of these persisting for two to three weeks in a current or ex-smoker should prompt a GP visit.

Yes. Brain metastases are a relatively common complication of lung cancer, particularly NSCLC and SCLC. When lung cancer spreads to the brain, symptoms may include persistent headaches, nausea, seizures, changes in personality or speech, or weakness on one side of the body. Brain metastases from lung cancer are treated with stereotactic radiosurgery (for limited metastases), whole-brain radiotherapy, and in some cases targeted therapy drugs that can cross the blood-brain barrier (such as osimertinib for EGFR+ disease).

Radon is a naturally occurring radioactive gas produced by the decay of uranium in rocks and soil. It seeps into buildings through floors and walls and can accumulate to harmful levels indoors. Radon is the second leading cause of lung cancer in the UK, responsible for approximately 1,100 deaths per year. Risk is highest in parts of Cornwall, Devon, Derbyshire, Northamptonshire and Lincolnshire. The UK Health Security Agency provides radon mapping and home testing guidance.

Mesothelioma is not the same as lung cancer. It is a cancer of the mesothelium — the lining of the lungs (pleura), abdomen (peritoneum) or heart — almost always caused by asbestos exposure. It develops in the lining around the lungs, not within the lung tissue itself, and is treated differently from primary lung cancer. Around 2,600 cases of mesothelioma are diagnosed in the UK each year. There is no cure; treatment aims to relieve symptoms and extend life.

Yes. Stopping smoking at any age reduces future lung cancer risk, though risk does not return to that of a never-smoker. After 10 years of not smoking, a former smoker's risk of developing lung cancer falls to approximately half that of a continuing smoker. After 15–20 years, risk approaches (though never fully reaches) that of a lifelong non-smoker. The NHS Stop Smoking Service is available free of charge and significantly increases quit rates.

Lung cancer is a major and growing cause of death in low- and middle-income countries, driven by rising smoking rates and air pollution. Survival rates are lower than in the UK because diagnostic CT scanning, surgical facilities and oncology services are scarce, and chemotherapy and targeted therapies are unaffordable for most poor patients. World Aid Network funds cancer treatment for poor patients through locally-licensed oncologists, helping to address this inequality.