Lung cancer: Full guide

What is lung cancer?

Lung cancer starts when cells in the lung grow out of control. These cells can form a lump called a tumor. Over time, they can spread to lymph nodes or other parts of the body.

Smoking causes most lung cancers. But people who never smoked can get it too. Radon gas, asbestos, and some workplace chemicals also raise the risk.

There are two main kinds: non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC). They grow differently and are treated differently. Knowing which kind you have is one of the first steps.

Treatment has improved a great deal. New pills, immune treatments, and better surgery and radiation help many people. Your care team will explain what this means for you.

Types

Non-small cell lung cancer (NSCLC)

The most common kind. About 8 or 9 out of 10 lung cancers are NSCLC. It usually grows more slowly than small cell lung cancer.

Adenocarcinoma

The most common type of NSCLC. It often starts in the outer parts of the lung. It is the type most often seen in people who never smoked. It is also the type most likely to have gene changes that pills can target.

Squamous cell carcinoma

A type of NSCLC that often starts in the larger airways near the middle of the chest. It is closely linked to smoking. Some medicines work differently for this type.

Large cell carcinoma

A less common type of NSCLC. It is usually treated like adenocarcinoma.

Small cell lung cancer (SCLC)

About 1 in 8 lung cancers. It grows and spreads quickly, and it is almost always linked to heavy smoking. It often responds well to treatment at first, but it tends to come back.

Carcinoid tumors

Rare, often slow-growing tumors that start in hormone-making cells of the lung. They are treated differently from other lung cancers.

Tests you may have

CT scan

A detailed X-ray that makes pictures of the inside of your chest. It shows the size and place of the tumor. It may also check your belly and pelvis.

PET-CT scan

A scan that uses a small amount of a sugar tracer. Cancer cells take up more of it and light up. It helps show if cancer has spread.

Brain MRI

Lung cancer can spread to the brain. An MRI (a scan that uses magnets) is the best way to check. Many people need one even without symptoms.

Biopsy

Taking a small piece of tissue to look at under a microscope. This is the only way to know for sure it is cancer, and which type.

Bronchoscopy and EBUS

A thin tube with a camera goes through your mouth into your airways. With EBUS (endobronchial ultrasound), the doctor can also take samples from lymph nodes in the chest. You are usually asleep or sedated.

Needle biopsy

A thin needle goes through the skin into the tumor, often guided by a CT scan. It takes a small tissue sample.

Gene (biomarker) testing

Tests on the tumor tissue or blood that look for gene changes and proteins. The results help choose the best treatment for advanced NSCLC.

Breathing tests

Also called pulmonary function tests. They measure how well your lungs work. They help your team decide if surgery or radiation is safe for you.

Blood tests

These check your blood counts, kidneys, liver, and salt levels. They help plan treatment and watch for side effects.

What the stage means

The stage tells how big the cancer is and how far it has spread. It helps your care team plan treatment.

NSCLC uses stages 1 to 4. Lower numbers mean the cancer is smaller and has not spread far.

Small cell lung cancer is often described as limited stage or extensive stage.

Stage 1

The tumor is small and only in the lung. It has not spread to lymph nodes. Surgery or focused radiation is often used, with the goal of cure.

Stage 2

The tumor is larger, or it has spread to lymph nodes near the lung. Surgery is common, often with medicine before or after.

Stage 3

The cancer has spread to lymph nodes in the middle of the chest, or has grown into nearby parts. Treatment often combines chemotherapy, radiation, surgery, and immunotherapy.

Stage 4

The cancer has spread to the other lung or the fluid around the lungs or heart. Or it has reached distant organs like the brain, bones, liver, or adrenal glands. Treatment uses medicines that travel through the whole body. Some people live for years, especially with targeted pills or immunotherapy.

Limited-stage SCLC

Small cell cancer that is only on one side of the chest. It can be treated with chemotherapy and radiation at the same time, often followed by immunotherapy.

Extensive-stage SCLC

Small cell cancer that has spread more widely. It is usually treated with chemotherapy plus immunotherapy.

Tumor markers and gene tests

In NSCLC, especially adenocarcinoma, some tumors have a gene change that drives their growth. These are called driver mutations.

If your tumor has one, a targeted pill may work better than other treatments. For advanced NSCLC, these results should be back before treatment starts when possible.

Testing can be done on tumor tissue or a blood sample (liquid biopsy). A negative blood test does not always rule out a gene change.

EGFR

One of the most common gene changes, especially in people who never smoked. Targeted pills called EGFR inhibitors can work very well.

ALK

A gene change often found in younger people who never smoked. ALK-targeted pills can control the cancer for a long time and also work in the brain.

KRAS G12C

A gene change more common in people who smoked. Targeted pills are available, usually after other treatment first.

ROS1, RET, and NTRK

Less common gene changes called fusions. Each has its own targeted pills.

BRAF, MET, and HER2

Other less common gene changes. Targeted treatments are available for each.

PD-L1

A protein on cancer cells. The level helps predict how well immunotherapy may work. It is measured as a percentage.

DLL3

A protein found on most small cell lung cancers. A newer treatment called tarlatamab targets it.

Main treatments

Surgery

Removing part of the lung that has the tumor, plus nearby lymph nodes. It is used for many stage 1 to 3 NSCLCs, and rarely for early small cell cancer. It is often done through small cuts with a camera.

Radiation therapy

High-energy beams that kill cancer cells. It can be used instead of surgery, with chemotherapy, or to ease symptoms like pain.

SBRT

Stereotactic body radiation therapy. It gives very focused, high doses of radiation in a few visits. It is often used for small tumors when surgery is not a good choice.

Chemotherapy

Medicines that kill fast-growing cells. They are usually given by IV. They are often combined with surgery, radiation, or immunotherapy.

Immunotherapy

Medicines that help your immune system find and attack cancer. They are used in many stages of both NSCLC and SCLC, sometimes before or after surgery.

Targeted therapy

Medicines, often pills, that block a specific gene change in the cancer. They are used when a tumor has a driver mutation like EGFR or ALK.

Antibody-drug conjugates

A newer type of medicine. An antibody carries chemotherapy straight to cancer cells. Some are used for certain lung cancers after other treatments.

Prophylactic cranial irradiation (PCI)

Low-dose radiation to the brain to lower the chance small cell cancer spreads there. Some people have regular brain MRIs instead. Ask your team which fits you.

Clinical trials

Research studies that test new treatments. They can give access to promising options. Ask if a trial is right for you.

Supportive (palliative) care

Care focused on comfort, symptoms, and quality of life. It can be given at any stage, along with cancer treatment.

Common side effects and what helps

Fatigue

Feeling very tired is common. Light activity like short walks can help. Rest when you need to, and ask others for help with chores.

Nausea

Anti-nausea medicines work well. Take them as directed, even before you feel sick. Eat small meals and sip fluids.

Low blood counts and infection

Chemotherapy can lower your white blood cells. Wash your hands often and avoid sick people. Call right away if you have a fever.

Immune side effects

Immunotherapy can cause swelling in healthy organs like the lungs, bowels, liver, skin, or hormone glands. Tell your team about new cough, diarrhea, rash, or feeling unwell. Early treatment helps.

Skin rash and nail changes

Common with EGFR pills. Use gentle soap and moisturizer and wear sunscreen. Your team can give creams or other medicines.

Diarrhea

Can happen with targeted pills, chemotherapy, or immunotherapy. Drink plenty of fluids. Call if it is severe or does not stop.

Sore throat or trouble swallowing

Radiation to the chest can irritate the esophagus (food pipe). Soft, cool foods help. Ask about numbing mouthwash or pain medicine.

Shortness of breath and cough

Can come from the cancer or treatment. Breathing exercises, rest, and medicines can help. New or worse breathing needs a call to your team.

Nerve and mood changes

Some medicines can cause numbness or tingling. Some ALK pills can affect mood or thinking. Tell your team about any changes.

Low appetite and weight loss

Eat small, frequent meals with protein. A dietitian can help. Nutrition drinks may also help.

Living with and after lung cancer

If you smoke, quitting is one of the best things you can do. It helps treatment work and lowers the chance of other health problems. Ask your team for help. Medicines and counseling make quitting more likely to work.

You will have regular checkups and scans after treatment. These look for any return of cancer and for new lung problems.

More people with advanced lung cancer now live with it for years, like a long-term illness. Targeted pills or immunotherapy may continue for a long time.

Stay as active as you can. Pulmonary rehab (a guided exercise and breathing program) can help your lungs and energy.

It is normal to feel worried, sad, or alone. Support groups, counselors, and social workers can help you and your family. Some people feel judged because lung cancer is linked to smoking. No one deserves cancer.

Family members who smoke or have smoked may qualify for lung cancer screening. Encourage them to ask their doctor.