What Is Immunotherapy? — How It Differs From Chemotherapy

Immunotherapy is a cancer treatment that removes the brakes stopping your own immune system from recognising and attacking cancer cells, rather than attacking the cancer directly the way chemotherapy, surgery, or radiation do. That single distinction — working with the immune system instead of acting on the tumour — explains almost everything else about how it's used, monitored, and decided on.

It helps to say clearly why this page exists. Immunotherapy carries more hope, and more hype, than almost any other cancer treatment — patients and families searching "what is immunotherapy for cancer" are often holding both real hope and a fear of being given false hope. This page won't tell you immunotherapy is a cure. It explains what it can realistically do, who it tends to work for, and how it's actually decided, so you can ask your oncologist sharper questions rather than second-guess them.

Most cancer patients in India are not automatic candidates for immunotherapy — this needs to be said plainly, before anything else, not buried after the benefits. Eligibility depends on your exact cancer type and stage, prior treatment, biomarker test results, and whether you have an autoimmune condition that immunotherapy could flare.

• Cancer type and stage — only a specific, growing list of cancers has an approved immunotherapy indication; many common cancers and early stages do not.
• Biomarker test results — PD-L1 expression, MSI/dMMR status, and tumour mutation burden are checked first, because they change how likely a response is.
• Prior treatment history — what you've already had, and how you responded, shapes what's tried next.
• Organ function and autoimmune history — immunotherapy activates the immune system broadly, so pre-existing autoimmune conditions or poor organ function need careful review first.
• The overall goal of treatment — curative intent, long-term disease control, and comfort-focused care each point toward different choices.

If your oncologist tells you immunotherapy isn't an option for your specific case, that is a common, normal outcome — not a sign that nothing else can be done. Chemotherapy, surgery, radiation, or a combination often remain the standard, better-evidenced choice, and that's discussed later on this page.

This comparison follows NCCN and ASCO patient-education frameworks and is meant to explain the pattern, not to predict your own outcome. Only your oncologist, reviewing your specific case, can say which column applies to you.

1. 1

   Confirm your exact diagnosis and stage

   The specific cancer type and stage decide which treatments even apply — "cancer" alone isn't specific enough to plan around.

2. 2

   Get biomarker testing done

   PD-L1, MSI/dMMR, or tumour mutation burden results often decide whether immunotherapy is realistic at all for your cancer.

3. 3

   Ask exactly what it would replace, follow, or combine with

   Chemotherapy, surgery, or radiation — and ask your oncologist to explain why that specific combination, for your specific case.

4. 4

   Ask what happens if you wait, or decline

   For some patients, watchful monitoring or an alternative treatment path is genuinely reasonable — it's fine to ask for that option explicitly, and to be told honestly if it isn't.

5. 5

   Get a second opinion before committing

   Especially before starting a newer, longer, or more expensive line of treatment — a second, unhurried set of eyes on your reports rarely hurts.

If you're not eligible for immunotherapy, or you decide against it, that does not mean nothing more can be done. Chemotherapy, surgery, radiation therapy, targeted therapy, and best supportive care remain well-evidenced options, and your tumour board weighs them just as carefully as it would immunotherapy.

For some patients — especially with certain advanced cancers, or when overall health limits the treatments that can be safely given — choosing to focus on comfort and quality of life through best supportive care is a legitimate, respected decision, not a failure or "giving up." Your oncology team's role is to lay out every real option honestly, including that one, and support whichever choice you make.

• Immunotherapy vs Chemotherapy: Which Is Better for You? — a deeper, side-by-side look at the comparison introduced above, specific to individual treatment decisions.
• Does Immunotherapy Actually Work? Honest Response Rates — the honest numbers behind "which cancers respond," sourced and dated.
• Who Is Eligible for Immunotherapy — and Who Is Not — a full breakdown of the eligibility factors introduced in the "who is it actually for" section above.
• Immunotherapy at CION Cancer Clinics — the full picture of how CION supports patients through immunotherapy, from biomarker testing to day-care administration.

This page is for general information and does not replace a consultation. Immunotherapy is administered as day care at CION centres; response-assessment PET-CT is coordinated at partner imaging centres. Only your oncologist, reviewing your complete case, can tell you whether immunotherapy applies to you.

Thousands of families have asked this exact question

Deciding on immunotherapy is rarely simple. Our team walks through the evidence, the eligibility criteria, and the alternatives with you — unhurried, and without pressure to proceed.