Immunotherapy for Squamous and Basal Cell Skin Cancers — When Surgery Is No Longer an Option

Most patients are not. The large majority of squamous and basal cell skin cancers are removed completely by a small operation, and no drug treatment follows. Immunotherapy is considered only when the cancer cannot be removed or irradiated safely, or when it has spread beyond the skin.

That leaves two groups. The first is locally advanced disease: a tumour on the scalp, ear, nose, eyelid or lip that has grown into cartilage, bone or nerve, where removing it would mean losing an eye or an ear, or would need reconstruction the patient cannot safely undergo. The second is disease that has travelled to lymph nodes or further.

Medical history decides the rest, and one item matters more than any other here. People who have had an organ transplant are usually not candidates. Anti-rejection medicines make squamous cell skin cancer far more common, so transplant recipients turn up in this clinic often. Checkpoint inhibitor immunotherapy loosens restraints on the immune system, and in a transplant recipient that can provoke rejection of the transplanted organ. Losing a kidney graft means going back to dialysis. Active autoimmune disease and ongoing high-dose steroids raise the same kind of problem.

Age is not a bar in itself. What is assessed is fitness: how independent the person is, what other illnesses they live with, what tablets they already take, and whether travelling to a centre every few weeks is realistic. A frail 78-year-old and an active 88-year-old are not the same patient.

Basal cell cancer follows a different sequence from squamous cell cancer. For advanced basal cell disease, targeted tablets that block the hedgehog pathway are usually tried first. Immunotherapy is discussed after those tablets stop working, or when their side effects make them impossible to continue.

Nothing on this page decides eligibility. That rests on the biopsy report, the extent of disease on imaging, previous treatment and overall fitness, read together by a medical oncologist.

When surgery and radiotherapy can no longer do the job. NCCN and ESMO guidance, as of August 2026, places checkpoint inhibitor immunotherapy as a first systemic option for locally advanced or spread squamous cell skin cancer. For basal cell skin cancer it sits later, after targeted tablets have failed or become intolerable.

“Locally advanced” is a phrase families are handed without explanation, so here is what it usually means in the clinic. A sore on the ear or scalp that has been there for a year. A lesion on the nose that has eaten into cartilage. A tumour near the eye where clear removal would cost the eye. In each case the cancer is still in one region, but the operation needed to clear it has become bigger than the patient can safely take, or bigger than they are willing to accept.

This is why the group who reach immunotherapy for these cancers skews elderly. Older patients present later, often after months of treating a non-healing sore as an infection. They are also the patients most likely to have a heart or lung condition that rules out a long operation under general anaesthetic. A treatment that is given through a drip in a few hours, with no anaesthetic and no admission, changes what is possible for them.

There is an Indian pattern worth naming as well. Squamous cell skin cancer here arises not only on sun-exposed skin but in long-standing burn scars, chronic ulcers and sinuses that have been draining for years, and in people with xeroderma pigmentosum or albinism. Scar-related cancers are often thick and neglected by the time they are shown to a doctor, which is exactly how a removable cancer becomes a locally advanced one.

At CION, immunotherapy is administered as day care at our centres. Staging and response-assessment CT and PET-CT imaging is coordinated at partner imaging centres.

Surgery first, radiotherapy second, for almost everyone. Immunotherapy is not competing with either. It is what gets discussed once both have been ruled out, already used, or have failed. For advanced basal cell cancer, targeted tablets usually come before it. Doing nothing active is also a real option for a very frail patient.

Ask which of these were considered and why they were set aside. If nobody has mentioned radiotherapy for an elderly patient who cannot have surgery, that is a question worth asking before any drug is started.

Because they carry more genetic mutations than almost any other cancer. Decades of ultraviolet exposure leave squamous and basal cell skin cancers riddled with DNA errors. Each error can produce an abnormal protein that immune cells read as foreign. That makes these tumours unusually visible to the immune system once checkpoint inhibition releases the brakes.

The practical consequence is that reported response rates in advanced squamous cell skin cancer sit among the highest published for this class of treatment in any cancer. NCCN and ESMO guidance, as of August 2026, describes measurable tumour shrinkage in roughly four to five in ten patients treated. Reported figures for advanced basal cell cancer treated after targeted tablets are lower.

Those numbers deserve two honest qualifications. They come from selected trial populations, generally patients well enough to enrol, and they describe groups rather than individuals. And a response rate says what a scan showed, not how long it lasted.

On duration, the truthful answer is that some responses hold for a long time and oncologists still call them durable responses rather than anything stronger. Late relapse is documented. So is a separate problem that patients rarely have explained to them: immunotherapy treats the tumour, not the sun-damaged skin around it. A patient whose scalp has taken sixty years of ultraviolet damage can respond well and still grow a new, unrelated skin cancer later. Regular skin examination continues regardless of how well the drug worked.

One more thing to expect before the first assessment scan. A deposit can look slightly larger early on because immune cells have flooded into it rather than because the cancer has grown. This is called pseudoprogression. It is uncommon, but it is the reason a single early scan rarely ends treatment on its own.

• Is surgery genuinely off the table, or just difficult? There is a difference between an operation that would be disfiguring and one that is medically unsafe. Ask which of the two applies, and ask whether a surgical oncologist has actually seen the patient rather than only the report.
• Has radiotherapy been considered and set aside for a reason? For an elderly patient who cannot have an operation, radiotherapy is often the option that gets skipped over in the rush to discuss a newer treatment. It should be on the table and explicitly ruled in or out.
• Does anyone know the full transplant, autoimmune and steroid history? A kidney transplant thirty years ago, rheumatoid arthritis on treatment, or a long-running steroid prescription changes the safety of this treatment completely. Bring the old records, not a summary from memory.
• What are we aiming for — shrinking the tumour, or comfort? Both are legitimate goals and they lead to different plans. Saying it out loud early prevents a family from drifting into treatment nobody actually chose.
• Who do we call, at what number, and for which symptoms? Immune-related side effects can appear weeks after a dose. Before the first infusion, get in writing which symptoms mean call today, and keep the CION helpline on 1800 202 8726 saved on the phone of whoever is at home.

• Anal cancer is also a squamous cell carcinoma, but it is driven by a virus rather than by sunlight, so it carries far fewer mutations and reported response is much lower — Immunotherapy for Anal Cancer shows the same cell type behaving very differently.
• Thyroid and salivary gland cancers sit at the other end again, where this class of treatment has a narrow and largely trial-based role — see Immunotherapy for Thyroid and Salivary Gland Cancers.
• Testicular cancer is the clearest reminder that responsive cancers and immunotherapy-responsive cancers are not the same list — Immunotherapy for Testicular Cancer explains why a highly treatable cancer is not treated this way.
• For how immunotherapy is delivered, monitored and paid for across our centres, see Immunotherapy at CION Cancer Clinics.

Still unsure how any of this applies to a specific diagnosis? Book a free consultation and a medical oncologist will go through the reports with you.