Cancer types

Lung cancer

Non-small cell and small cell lung cancer.

- Lung cancer starts in the cells lining the airways or the air sacs of the lungs.
- It can spread to the lymph nodes in the chest, the lining of the lung (pleura, causing fluid), and through the blood to the brain, bones, liver and adrenal glands.
- Smoking is the biggest cause, but many patients in India have never smoked. Air pollution, cooking smoke and other factors play a part. Lung cancer in non-smokers often has a mutation that can be treated with tablets.
- In India, lung cancer is often first treated as tuberculosis (TB), because the symptoms and X-ray can look similar. A cough that does not improve, or does not respond to TB treatment, needs a biopsy.
- The treatment depends on the type, the mutations and the stage.

Lung cancer is divided into two main groups, based on how the cells look under the microscope. Tap a group on the map.

Type	How common
Non-small cell lung cancer (NSCLC)	About 85 out of 100. Includes adenocarcinoma and squamous cell carcinoma.
Small cell lung cancer (SCLC)	About 15 out of 100. Grows fast, almost always linked to smoking.

Why this matters: the two groups are treated very differently. In NSCLC, the gene test results also decide the treatment.

- About 85 out of every 100 lung cancers.
- Includes two main types: adenocarcinoma and squamous cell carcinoma.
- Treatment depends on the stage and on mutations found in the cancer.
Treatment for NSCLC
- - The most common type, especially in non-smokers and women.
  - Most likely to have a treatable mutation such as EGFR or ALK. Gene testing is essential.
  Treatment
- - Usually linked to smoking. Often starts in the large airways near the centre of the chest.
  - Treatable mutations are less common, but gene testing is still advised in non-smokers or light smokers.
  Treatment
- About 15 out of every 100 lung cancers. Almost always linked to smoking.
- Grows and spreads fast, so treatment is started quickly.
- Usually responds well to chemotherapy and radiotherapy at first, but often comes back.
- Staged as limited (one side of the chest) or extensive (spread further).
Treatment for small cell lung cancer

- Confirms the cancer and gives tissue for the type and gene tests.
- Done by CT-guided needle biopsy, bronchoscopy or EBUS (a camera into the airways with an ultrasound probe to sample lymph nodes).
- If there is fluid around the lung, the fluid can be tested, but a tissue biopsy is often still needed.
- Enough tissue is needed for all the tests. Sometimes a second biopsy is needed.
- IHC on the biopsy confirms the type: for example TTF-1 for adenocarcinoma, p40 for squamous cell carcinoma.
- PD-L1 is a protein that tells how likely immunotherapy is to work. Reported as a percentage (TPS). 50% or more = high.

In NSCLC, especially adenocarcinoma, the cancer is tested for mutations that can be treated with specific tablets.

Mutation	Treatment
EGFR	The most common in India (about 1 in 4 adenocarcinomas). Osimertinib, gefitinib, erlotinib, afatinib, amivantamab.
ALK	About 5 out of 100. Alectinib, lorlatinib, brigatinib.
ROS1	Crizotinib, entrectinib, repotrectinib.
KRAS G12C	Sotorasib, adagrasib (usually after first treatment).
BRAF V600E	Dabrafenib with trametinib.
MET exon 14	Capmatinib, tepotinib.
RET	Selpercatinib, pralsetinib.
HER2	Trastuzumab deruxtecan.
NTRK (rare)	Larotrectinib, entrectinib.

NGS (next-generation sequencing) tests all these genes at once, and is preferred over testing one gene at a time.
ALK, ROS1, RET and NTRK are strictly called fusions (two genes joined together), but they are treated the same way and are often grouped with mutations.
A liquid biopsy (blood test for cancer DNA) can be used if the tissue is not enough, or to find out why a tablet has stopped working.
Results take about 2 to 3 weeks. Why it is worth waiting

More about precision and molecular testing

- PET-CT shows whether the cancer has spread to lymph nodes or other organs. This decides the stage.
- MRI of the brain is advised for most patients, because lung cancer can spread to the brain without symptoms.

Before starting chemotherapy, immunotherapy or targeted therapy, these tests check that you are fit for treatment, and give a starting point to compare with later.

Test	Why it is done
CBC (complete blood count)	Haemoglobin, white cells and platelets. Treatment can lower them.
RFT (kidney function)	Many medicines are cleared by the kidneys; the dose may need to change.
LFT (liver function)	Many medicines are processed by the liver.
Viral markers: HBsAg, anti-HCV, HIV	Hepatitis B can flare up during treatment. If positive, a tablet is given to prevent this.
Blood sugar (and HbA1c if diabetic)	Steroids given with chemotherapy can raise blood sugar.
ECG and 2D Echo	Check the heart rhythm and pumping before treatment, as some medicines affect the heart.

Before immunotherapy, also:

Test	Why it is done
Serum TSH (thyroid)	Immunotherapy can affect the thyroid gland.
Serum cortisol (morning sample)	Immunotherapy can affect the adrenal and pituitary glands.

Sometimes needed, depending on your treatment:

Pregnancy test for women who could be pregnant.
Calcium and magnesium: for example before cisplatin or bone-strengthening injections.
Dental check-up before bone-strengthening injections (zoledronic acid or denosumab), as they can rarely affect the jaw bone.
Hearing test before cisplatin, in some patients.
Clotting tests (PT/INR) before a biopsy or chemoport.

Your doctor will choose the tests that apply to you. Some of them are repeated during treatment.

- In stage 4 NSCLC, the gene test decides whether a targeted tablet or immunotherapy / chemotherapy is best.
- If an EGFR or ALK mutation is present, tablets work much better than chemotherapy, with fewer side effects.
- Starting immunotherapy before the gene result is known can be harmful: in patients with an EGFR mutation, immunotherapy followed by targeted tablets increases the risk of serious lung side effects.
- Waiting 2 to 3 weeks for the gene report does not change the outcome for most patients. If you are very unwell, your doctor may start treatment earlier.

The stage tells how far the cancer has spread. It is worked out from the size of the tumour, the lymph nodes and the PET-CT and MRI. Your doctor will write it as a number. Tap your stage on the map.

Small cell lung cancer is also described as limited (stages 1 to 3) or extensive (stage 4).
Treatments used in lung cancer: surgery, radiotherapy, chemotherapy, targeted tablets, and immunotherapy. Many patients need more than one.

The plan depends on the type, the mutations and the stage. On the map, tap your type and stage. Your own plan may differ, depending on your reports, lung function and health.
- 1. Surgery: removing the part of the lung with the cancer (usually a lobectomy), with the lymph nodes. Often done by keyhole surgery (VATS or robotic).
  2. If surgery is not possible (weak lungs, other illnesses): SBRT, a precise high-dose radiotherapy given in 3 to 8 sessions.
  3. For larger tumours (stage 2 and some stage 1B), treatment is added before and/or after surgery:
    - EGFR mutation: chemotherapy, then osimertinib tablets for 3 years after surgery.
    - ALK mutation: alectinib tablets for 2 years after surgery.
    - No EGFR or ALK mutation: chemotherapy with immunotherapy (nivolumab, pembrolizumab or durvalumab) before surgery, often continued after surgery.
  What the research shows
  - ADAURA: osimertinib after surgery lowered the chance of recurrence and helped patients live longer (about 88 out of 100 alive at 5 years, compared with 78 out of 100).
  - ALINA: alectinib after surgery greatly lowered the chance of recurrence compared with chemotherapy.
  - CheckMate 816 and KEYNOTE-671: chemotherapy with immunotherapy before surgery meant more patients had no cancer left at surgery and fewer had it come back.
  Side effects: surgery · radiotherapy · chemotherapy · immunotherapy · targeted tablets
- Stage 3 is treated in one of two ways, decided by the tumour board (surgeon, radiation and medical oncologist together):
  1. If surgery is possible: chemotherapy with immunotherapy before surgery, then surgery, often with immunotherapy after. With an EGFR mutation, osimertinib after surgery.
  2. If surgery is not possible: chemotherapy and radiotherapy together (about 6 weeks), followed by:
    - Durvalumab (immunotherapy) every 2 to 4 weeks for one year, or
    - Osimertinib tablets if there is an EGFR mutation.
  What the research shows
  - PACIFIC: durvalumab after chemoradiotherapy helped patients live longer (about 43 out of 100 alive at 5 years, compared with 33 out of 100).
  - LAURA: osimertinib after chemoradiotherapy controlled EGFR-positive cancer for much longer (about 39 months compared with 6 months).
  Side effects: chemotherapy · radiotherapy · immunotherapy · targeted tablets
- Treatment depends on the gene test result. Tap your result on the map.
  
  Radiotherapy may be added for pain in bones, spread to the brain, or bleeding. A bone-strengthening injection is given if the cancer has spread to bones.
  - 1. First treatment, options:
      
      Osimertinib tablet once a day, or
      
      Osimertinib with chemotherapy (for patients with higher-risk features, such as brain spread), or
      
      Amivantamab (drip) with lazertinib (tablet).
      
      Older, lower-cost tablets (gefitinib, erlotinib, afatinib) also work, though for a shorter time.
    2. Treatment continues as long as it works, often for years.
    3. When it stops working: a repeat biopsy or liquid biopsy to find out why, then chemotherapy, amivantamab with chemotherapy, or other options.
    What the research shows
    
    FLAURA: osimertinib helped patients live longer than older tablets (about 39 months compared with 32 months).
    
    FLAURA2: adding chemotherapy to osimertinib controlled the cancer for longer (about 25 months compared with 17 months).
    
    MARIPOSA: amivantamab with lazertinib controlled the cancer for longer than osimertinib alone, and helped patients live longer.
    Side effects: targeted tablets · chemotherapy
  - 1. First treatment: alectinib or lorlatinib tablets (brigatinib is another option).
    2. These tablets also work well on spread to the brain.
    3. Treatment continues as long as it works, often for many years.
    4. When it stops working: another ALK tablet (such as lorlatinib after alectinib), then chemotherapy.
    What the research shows
    
    ALEX: alectinib controlled the cancer for about 35 months, compared with about 11 months with crizotinib.
    
    CROWN: with lorlatinib, the cancer was still controlled in about 60 out of 100 patients at 5 years.
    Side effects: targeted tablets
  - - ROS1: crizotinib, entrectinib or repotrectinib.
    - BRAF V600E: dabrafenib with trametinib.
    - MET exon 14: capmatinib or tepotinib.
    - RET: selpercatinib or pralsetinib.
    - KRAS G12C: usually immunotherapy with or without chemotherapy first; sotorasib or adagrasib later.
    - HER2: chemotherapy with immunotherapy first; trastuzumab deruxtecan later.
    - NTRK: larotrectinib or entrectinib.
    Some of these medicines may not be easily available or affordable in India. Your doctor will discuss the options.
    
    Side effects: targeted tablets
  - Treatment depends on the PD-L1 result:
    1. PD-L1 50% or more: immunotherapy alone (pembrolizumab, atezolizumab or cemiplimab), or immunotherapy with chemotherapy.
    2. PD-L1 below 50%: chemotherapy with immunotherapy, usually for 4 cycles, then immunotherapy continues (with pemetrexed in adenocarcinoma) for up to 2 years.
    3. If immunotherapy is not affordable or suitable: chemotherapy alone.
    4. When it stops working: docetaxel or other chemotherapy.
    What the research shows
    
    KEYNOTE-024: in PD-L1 50% or more, pembrolizumab alone helped patients live longer than chemotherapy (about 32 out of 100 alive at 5 years, compared with 16 out of 100).
    
    KEYNOTE-189 and KEYNOTE-407: adding pembrolizumab to chemotherapy helped patients live longer, whatever the PD-L1 level.
    Side effects: immunotherapy · chemotherapy
- Choose limited or extensive stage on the map.
  - 1. Chemotherapy (cisplatin or carboplatin with etoposide) with radiotherapy to the chest, at the same time.
    2. Then durvalumab (immunotherapy) for up to 2 years.
    3. Regular MRI brain scans, or radiotherapy to the brain to prevent spread there (PCI).
    4. Very small tumours with no lymph nodes: surgery is sometimes possible.
    What the research shows
    
    ADRIATIC: durvalumab after chemoradiotherapy helped patients live longer (about 56 months compared with 33 months on average).
    Side effects: chemotherapy · radiotherapy · immunotherapy
  - 1. Chemotherapy with immunotherapy (carboplatin and etoposide with atezolizumab or durvalumab) for 4 cycles.
    2. Then immunotherapy continues on its own for as long as it works.
    3. Radiotherapy to the chest or brain may be added.
    4. When it comes back: further chemotherapy (such as lurbinectedin or topotecan) or newer treatments like tarlatamab, which may not be available everywhere.
    What the research shows
    
    IMpower133 and CASPIAN: adding immunotherapy to chemotherapy helped patients live longer, and some patients had long-lasting control.
    Side effects: chemotherapy · immunotherapy
Each treatment has its own side effects. Most can be prevented or managed. Tap a treatment on the map.

Fever of 38°C or more during chemotherapy, or new or worse breathlessness, needs urgent care. When to seek help urgently
- - Nausea and vomiting: well controlled with medicines given before and after chemotherapy.
  - Low blood counts and infection risk: fever of 38°C or more needs urgent care.
  - Tiredness, mouth sores, loose stools or constipation.
  - Hair loss with some drugs (such as docetaxel, paclitaxel, etoposide). Pemetrexed usually does not cause hair loss.
  - Cisplatin: kidney effects and ringing in the ears; plenty of fluids are given with it. Pemetrexed: folic acid tablets and vitamin B12 injections are needed to reduce side effects.
  More about chemotherapy · Side effects of your regimen
- - EGFR tablets (osimertinib, gefitinib, erlotinib, afatinib): acne-like rash, dry skin, painful nail folds, loose stools, mouth sores. Rarely lung inflammation.
  - Amivantamab: reactions during the first drip, rash, nail changes, leg swelling, and a risk of blood clots (a blood thinner is often given).
  - ALK tablets: alectinib can cause constipation, muscle aches and weight gain; lorlatinib can raise cholesterol, cause weight gain, swelling and mood or memory changes.
  - Report any new cough or breathlessness immediately.
  More about targeted therapy · Side effects of your regimen
- - The immune system can affect normal organs: thyroid, skin (rash, itching), bowel (loose stools), lungs (cough, breathlessness) and liver.
  - These can happen months after starting, or even after stopping. Report any new symptom, even if it seems small.
  - Thyroid and liver blood tests are checked regularly.
  More about immunotherapy · Side effects of your regimen
- - Tiredness, and a painful or difficult swallow (the food pipe lies close to the lungs) in the later weeks of treatment. Soft food and medicines help.
  - Cough and breathlessness. A few weeks to months after treatment, some patients get radiation pneumonitis (inflammation of the lung): report new cough, breathlessness or fever.
- - Pain at the operation site, and some breathlessness while the remaining lung adjusts.
  - Breathing exercises and walking soon after surgery help recovery and prevent chest infections.
Looking after yourself during and after treatment. Tap a topic on the map.
- - It is never too late. Stopping smoking makes treatment work better, lowers side effects and complications after surgery, and helps you live longer.
  - Ask us for help: nicotine replacement and medicines double the chance of quitting.
  - Family members should also not smoke around you.
- - Fluid around the lung (pleural effusion) can cause breathlessness. It can be drained with a needle, and if it keeps coming back, a small tube (pleurodesis or a long-term drain) can help.
  - Sitting upright, a fan towards the face, pacing activities and breathing exercises help.
  - Sudden or severe breathlessness, or coughing up blood, needs urgent care.
- - Flu and pneumonia vaccines are advised. About vaccinations
  - Avoid smoke, dust and crowded places when blood counts are low.
  - Nutrition and diet · Work, exercise and daily life · Mind and emotions
- - Check-ups with a CT scan every 3 to 6 months for the first 2 to 3 years, then less often.
  - On long-term tablets or immunotherapy: regular scans (every 2 to 3 months) to check the treatment is working.

This information is general. Your own treatment plan may be different. Please discuss it with your doctor.

Written and medically reviewed by Dr Prathyusha Eaga, MD, DM (Medical Oncology). Last reviewed: 12 October 2026. Based on NCCN and ESMO guidelines.

Have questions?

Book a hospital visit, a video consultation or a second opinion.

Book a hospital visitHospital visit Video consultationVideo consult Second opinion