What Is Immunotherapy and How Does It Treat Cancer?
- ✓Immunotherapy helps your immune system fight cancer. It works very differently from chemotherapy.
- ✓Some patients have remarkable, long-lasting responses to immunotherapy, but it does not work for everyone.
- ✓Immunotherapy is not free of side effects. Because it activates the immune system, it can sometimes cause inflammation in normal organs.
- ✓Biomarker tests such as PD-L1, TMB, and MSI help guide treatment decisions, but they cannot predict with certainty who will benefit.
- ✓Having an autoimmune disease does not automatically rule out immunotherapy, but your oncologist needs to know about it before treatment begins.
- ✓"Immune boosters," herbal remedies, and wellness products are not cancer immunotherapy. Always discuss supplements with your oncologist before taking them.
What Is Immunotherapy, and How Is It Different From Chemotherapy?
Many patients assume immunotherapy is just a "gentler chemotherapy." It isn't. It's a completely different approach.
Chemotherapy vs. immunotherapy — the core difference
Directly kills fast-dividing cells. It also affects some healthy fast-growing cells, causing hair loss, nausea, and low blood counts.
Helps your own immune system recognise and attack cancer cells. It can sometimes make the immune system overactive, causing it to attack normal organs and produce side effects.
Why Your Oncologist Sometimes Orders PD-L1, TMB, and MSI Testing Before Starting
- ✓Immunotherapy does not work equally well for every patient or every type of cancer.
- ✓Biomarker tests are special tests your oncologist may order to understand if immunotherapy will be effective.
Depending on your cancer, immunotherapy may be given alone or together with chemotherapy, targeted therapy, or radiation. It may be used before surgery, after surgery, or for advanced cancers. Your treatment plan depends on your specific cancer and stage.
PD-L1 (IHC)
Higher PD-L1 generally means a higher chance immunotherapy will work — but a low or negative result does not always rule it out, depending on the cancer type.
TMB (Tumour Mutational Burden)
Immunotherapy can be used for any advanced solid cancer with a high TMB level of 10 or more mutations, regardless of where the cancer started in the body.
MSI / dMMR (Microsatellite Instability)
MSI-High / dMMR tumours often respond very well to immunotherapy, regardless of which organ the cancer started in.
If you have an autoimmune condition such as rheumatoid arthritis, lupus, psoriasis, inflammatory bowel disease, or autoimmune thyroid disease, tell your oncologist before starting immunotherapy.
Having an autoimmune disease does not automatically mean you cannot receive immunotherapy. Your oncologist will consider the type of autoimmune condition, how active it is, how well it is controlled, and the expected benefit of immunotherapy before making a recommendation.
Why Has Immunotherapy Changed Cancer Treatment?
As oncologists, we've cared for patients with advanced cancer who had remarkable, long-lasting responses to immunotherapy — some continue to do well for years, far longer than we once thought possible.
Before immunotherapy, we rarely saw responses like this. That's why it has transformed cancer treatment, and why oncologists remain so hopeful about its future.
What Patients in India Commonly Mistake for Immunotherapy
These are widely advertised, and many patients pay for them believing they're getting immunotherapy, or something equivalent.
Many products claim to "boost immunity" or "fight cancer naturally." These are not the same as the immunotherapy prescribed by your oncologist.
- !❌Immune-boosting supplements
- !❌Herbal or "natural" cancer remedies
- !❌Vitamin or immunity IV drips, high-dose vitamin C and antioxidant infusions
- !❌Medicinal mushroom products
- !❌"Immune activation" clinics
- !❌Dendritic cell vaccines
These are NOT cancer immunotherapy. Some may be ineffective, some may interfere with cancer treatment, and some may even be harmful. Always discuss any supplement, herbal medicine, or alternative therapy with your oncologist before taking it.
Frequently Asked Questions
These come up repeatedly in clinic. Answers here intentionally repeat the article above, so each stands on its own.
Related Reads
References
General clinical resources used to support patient education on this site. Your personal treatment plan should always be discussed with your oncologist.
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