Immunotherapy for Cancer — What to Expect, Honestly Explained

Immunotherapy is a group of cancer treatments that work by helping your own immune system recognise and attack cancer cells, rather than killing cells directly the way chemotherapy does. The most widely used type — checkpoint inhibitor therapy — blocks proteins such as PD-1, PD-L1 or CTLA-4 that cancer cells use to hide from immune attack.

Other forms include monoclonal antibodies that mark cancer cells for destruction, and, for a small number of blood cancers, CAR-T cell therapy — a highly specialised, hospital-based treatment that CION does not administer (see below). Immunotherapy is used alone or alongside chemotherapy, radiation or surgery depending on the cancer type, and its role in standard care is set out in NCCN and ASCO treatment guidelines, updated as evidence evolves.

It is not a replacement for every existing treatment, and it does not work the same way — or at all — for every cancer. The sections below explain how CION decides who is a candidate.

Immunotherapy is not appropriate for every patient or every cancer — eligibility depends on biomarker tests such as PD-L1 expression, MSI/MMR status or tumour mutational burden (TMB), alongside your cancer type, stage and overall health. Many patients who ask about immunotherapy are not candidates until these tests are done, and that is a normal, expected part of the process — not a delay.

At CION, biomarker results are reviewed by a tumour board — a team of oncologists, not a single opinion — before immunotherapy is recommended, combined with another treatment, or ruled out in favour of a different plan. If a biomarker result doesn't support immunotherapy, your oncologist will explain what the result means and what the alternatives are.

At CION, immunotherapy is administered as day care at our centres, so most patients go home the same day rather than staying overnight. Response to treatment is assessed with PET-CT scans, which are coordinated at partner imaging centres — CION does not own PET-CT equipment, and your care team arranges these scans and reviews the results as part of your ongoing plan.

CION does not administer CAR-T or other cell therapy. CAR-T is a separate, highly specialised treatment available at a small number of accredited centres in India for certain blood cancers. If CAR-T may be relevant to your diagnosis, our oncology team can help you understand whether you're a potential candidate and refer or orient you toward a centre that provides it — we do not stock or infuse CAR-T product ourselves.

We're organising everything CION publishes on immunotherapy into eight areas patients and caregivers ask about most — from the first decision about whether to consider it, through to living with treatment over time. Each area will grow into its own set of pages, and this overview will keep linking to them as they go live.

Every page in this cluster cites the guideline body behind a clinical fact or figure — NCCN, ASCO, ESMO, ICMR, CDSCO or WHO — and is medically reviewed and dated by one of our medical oncologists before it's published. We avoid response-rate or survival figures unless they're sourced, dated, and common citable patient-education knowledge; we never attach a specific percentage to a treatment decision.

If you already have a diagnosis and want an independent read on your reports before deciding on immunotherapy, you can request a free second opinion — it doesn't commit you to treatment at CION.