Lung Cancer

Types of lung cancer

Mesothelioma, linked to asbestos, affects the lining of the lung rather than the lung itself.

Symptoms

Early lung cancer often causes no symptoms, which is why many cases are found late or by chance on scans. Symptoms include:

• A cough that does not go away or changes
• Coughing up blood or rust-colored sputum (hemoptysis)
• Breathlessness
• Chest, shoulder or back pain
• Hoarseness
• Repeated chest infections that do not clear
• Wheezing
• Tiredness, loss of appetite and unexplained weight loss
• Finger clubbing

Signs of spread

• Bone pain or fractures
• Headaches, seizures, confusion or weakness (brain spread)
• Yellow skin (liver spread)
• Swollen lymph nodes in the neck or above the collarbone

Other syndromes

• Pancoast tumor at the top of the lung: shoulder and arm pain, hand weakness, and Horner syndrome (drooping eyelid, small pupil)
• Superior vena cava syndrome: facial and arm swelling
• Paraneoplastic syndromes: hormone-like substances causing high calcium, low sodium, or neurological problems, especially with small cell cancer

Causes and risk factors

• Smoking: risk rises with the number of years and cigarettes. Quitting at any age reduces it
• Secondhand smoke
• Radon gas: the leading cause in people who never smoked. Test your home
• Asbestos, diesel exhaust, silica and other workplace exposures
• Air pollution
• Family history of lung cancer
• Previous chest radiation
• Lung diseases such as COPD and pulmonary fibrosis
• HIV infection

See also lung cancer in nonsmokers.

Screening

The US Preventive Services Task Force recommends yearly low-dose CT screening for adults aged 50 to 80 who have a smoking history of at least 20 pack-years (for example, 1 pack a day for 20 years) and currently smoke or quit within the past 15 years. Screening reduces lung cancer deaths by finding cancers at an earlier, more curable stage. It also finds harmless nodules that need follow-up scans, so the decision is discussed with a clinician.

Diagnosis

1. Chest X-ray and CT scan of the chest.
2. PET-CT to look for spread.
3. Biopsy to confirm cancer and its type: through bronchoscopy, endobronchial ultrasound (EBUS) of lymph nodes, CT-guided needle biopsy, or surgery.
4. Molecular (biomarker) testing of the tumor for gene changes such as EGFR, ALK, ROS1, KRAS, BRAF, MET, RET, NTRK and HER2, and PD-L1 levels. These guide targeted therapy and immunotherapy.
5. Brain MRI for staging in many cases.
6. Lung function tests to check fitness for surgery or radiation.

Staging

NSCLC is staged from I to IV using the TNM system (tumor size, lymph nodes, metastases):

Small cell lung cancer is often described as limited stage (one side of the chest) or extensive stage (spread further).

Treatment

Treatment is planned by a multidisciplinary team and depends on type, stage, biomarkers, lung function and overall health.

Early stage NSCLC

• Surgery: lobectomy or a smaller resection, often keyhole or robotic
• Stereotactic body radiotherapy (SBRT): precise high-dose radiation for people who cannot have surgery
• Additional treatment before or after surgery: chemotherapy, immunotherapy, or targeted therapy (for example, osimertinib for EGFR-mutated cancer)

Locally advanced NSCLC (stage III)

• Chemotherapy combined with radiation, followed by immunotherapy
• Surgery in selected cases

Advanced NSCLC (stage IV)

• Targeted therapy for tumors with specific gene changes, usually as tablets
• Immunotherapy (checkpoint inhibitors), alone or with chemotherapy
• Chemotherapy
• Radiation to relieve symptoms or treat limited spread

Small cell lung cancer

• Limited stage: chemotherapy with radiation, sometimes followed by immunotherapy and preventive brain radiation
• Extensive stage: chemotherapy with immunotherapy

Supportive and palliative care

Early palliative care improves quality of life and can extend survival. It covers breathlessness, pain, cough, fatigue, nutrition and emotional support.

Outlook

Survival depends heavily on stage at diagnosis. Overall 5-year survival in the US is around 25 to 28%, but it is much higher for cancers found early (over 60% for localized NSCLC) and has improved substantially in advanced disease with targeted therapy and immunotherapy. Stopping smoking improves treatment outcomes at any stage.

Prevention

• Do not smoke, and quit if you do. Support and medicines double or triple the chance of success
• Avoid secondhand smoke
• Test your home for radon and fix high levels
• Follow workplace safety rules for asbestos and other carcinogens
• Get screened if eligible

Frequently asked questions

What are the early signs of lung cancer?

Early lung cancer often has no symptoms. When signs appear, they may include a persistent or changing cough, coughing up blood, breathlessness, chest pain, hoarseness, repeated chest infections, tiredness and unexplained weight loss. Persistent symptoms for 3 weeks need a doctor's check.

Who should get screened for lung cancer?

US guidelines recommend yearly low-dose CT screening for adults aged 50 to 80 with at least a 20 pack-year smoking history who currently smoke or quit within the past 15 years. Talk with a clinician about benefits and risks.

Can you get lung cancer if you never smoked?

Yes. About 10 to 20% of lung cancers occur in people who never smoked. Causes include radon, secondhand smoke, air pollution, workplace exposures and genetic factors. These cancers are often adenocarcinomas with targetable gene changes.

Do swollen lymph nodes mean lung cancer has spread?

Swollen lymph nodes in the neck or above the collarbone can be a sign that lung cancer has spread, but nodes also swell for many harmless reasons. A biopsy or scan is needed to know. Lymph node involvement affects stage and treatment.

Is lung cancer curable?

Early-stage lung cancer can often be cured with surgery or targeted radiation. Advanced lung cancer is usually not curable, but targeted therapy and immunotherapy can control it for years in some people. Outcomes depend on type, stage and biomarkers.