Cutaneous squamous cell carcinoma

Cutaneous squamous cell carcinoma (cSCC) begins in skin keratinocytes. A persistent scaly growth, ulcer, bleeding area or enlarging lump needs assessment and usually a biopsy. Its appearance alone cannot reliably distinguish it from another skin cancer or a noncancerous condition.

SCC in situ, also called Bowen disease, is confined to the epidermis. Invasive cSCC extends deeper. Actinic keratosis is a sun-related precancerous change, not another name for invasive cancer. Creams or light-based treatment used for selected superficial lesions should not automatically be used for an invasive tumor.

A skin SCC on the face or scalp is also different from a squamous cancer arising in the mouth or throat. The primary site determines the staging and treatment pathway.

The pathology review should establish invasion, differentiation, depth, margin status and whether cancer tracks along nerves or enters vessels. The clinical assessment adds location, recurrence, immune status and symptoms such as pain, numbness or weakness. A small lesion in a difficult site can require a more complex operation than a larger superficial lesion elsewhere.

The European 2026 guideline separates common low-risk and higher-risk tumors from advanced disease, and also describes difficult-to-treat groups. These practical categories complement formal staging; they are not proof of metastasis. A label such as 'higher risk' alone does not establish eligibility for postoperative immunotherapy.

Skin examination and examination of nearby lymph-node regions are part of assessment. Imaging is selected for risk and symptoms: ultrasound can assess regional nodes, MRI can help evaluate suspected nerve spread, and CT or other scans may define deeper invasion or metastatic disease. A suspicious node usually needs tissue confirmation rather than an assumption based on size alone.

Sentinel-node biopsy is not a routine standard for cSCC in the 2026 European guideline. Recent retrospective studies suggest possible benefit in selected high-risk patients, but selection bias prevents them from establishing that everyone should undergo it. A suspicious node and an elective sentinel-node test are different clinical situations.

For an operable invasive tumor, the aim is complete removal with verified clear margins. Standard excision is appropriate for many lesions. Mohs surgery or another form of complete margin assessment can be especially useful where recurrence risk, indistinct borders or preservation of healthy tissue matters. The method should fit the tumor rather than be chosen purely for the smallest scar.

A positive margin may require further surgery when feasible. Radiotherapy can be definitive when surgery is unsuitable, or postoperative for selected adverse features. The team should discuss wound healing, nerve function, reconstruction and whether a previous radiation course limits another treatment.

Regional nodal disease can still be treated with curative intent in selected patients. Management may combine nodal surgery, radiation and systemic treatment; nodal spread should not automatically be equated with incurable distant disease.

The C-POST randomized trial enrolled patients with defined high-risk features after surgery and postoperative radiation. Cemiplimab reduced recurrence or death compared with placebo. The evidence supports disease-free survival benefit in that selected setting; it does not mean every removed cSCC requires a year of immunotherapy.

The US approval covers adults at high risk of recurrence after both surgery and radiation. Discuss how the actual nodal findings, nerve involvement, bone invasion or recurrence history relate to the study and local indication. Organ-transplant recipients and some other immunosuppressed groups were excluded from the pivotal trial, so benefit and safety cannot simply be assumed to be the same.

This is not a class-wide interchangeable effect: the separate KEYNOTE-630 postoperative pembrolizumab trial did not meet its prespecified primary efficacy threshold. The drug, eligibility criteria and evidence need to match.

A phase 2 neoadjuvant cemiplimab study showed substantial tumor eradication in surgical specimens from selected resectable cSCC. This makes preoperative treatment a relevant specialist discussion when an operation may be extensive. However, a strong response in a study is not an instruction to cancel surgery after a lesion looks smaller.

Ask whether the proposed sequence follows a local guideline, an approved indication or a clinical trial, how response will be checked, and what happens if the tumor progresses. Approval for treatment after surgery and radiation does not automatically approve every use before surgery.

For locally advanced or metastatic disease that cannot be adequately treated with curative surgery or radiation, immune-checkpoint therapy is a central option. US indications include the PD-1 drugs cemiplimab and pembrolizumab, and the PD-L1 drug cosibelimab. Their precise labels differ; availability and funding vary by country.

These cSCC indications do not require a positive PD-L1 score. That differs from some mucosal head-and-neck cancer regimens. Broad tumor sequencing may help identify a trial or an unusual actionable finding, but it is not automatically required before standard checkpoint treatment.

If immunotherapy is unsuitable or the cancer progresses, reassess local options, clinical trials and selected systemic alternatives, including EGFR-directed treatment or chemotherapy. These do not all have equal evidence or approval status. The goal may be symptom relief, durable control, or making a local treatment possible.

Checkpoint treatment may trigger rejection of a transplanted organ. A small prospective kidney-transplant study reported responses without rejection under a tightly managed immunosuppressive protocol, but serious toxicity occurred and one fatal event was attributed to the medication transition. This cannot establish safety for all kidney recipients, other transplanted organs or routine practice.

The cancer and transplant teams must jointly weigh tumor threat, graft function and possible changes to immunosuppression. Do not reduce or stop anti-rejection medicines on your own. A history of autoimmune disease, blood cancer or immune-suppressing treatment also belongs in the first assessment.

During checkpoint therapy, new breathlessness, persistent diarrhea, jaundice, severe weakness or other significant symptoms need prompt contact with the treating team. Immune-related inflammation can affect organs beyond the skin and can occur after treatment ends.

Follow-up checks the treated area, the rest of the skin and, when relevant, regional nodes. Frequency and imaging depend on recurrence risk and treatment rather than a single schedule for everyone. A new lump, persistent wound, pain, numbness or weakness near the treated area should be reported between visits.

Sun protection, avoiding tanning and treatment of extensive sun damage help reduce future skin-cancer burden. New lesions may represent separate primary cancers rather than spread from the original one. Ask a dermatologist which changes to photograph and monitor and which need an examination or biopsy.

Preventive medicines are individualized. Evidence for nicotinamide in some patients with repeated skin cancers should not be assumed to apply to transplant recipients: a randomized transplant study did not demonstrate the same preventive benefit. Supplements do not replace skin surveillance or treatment.

Bring the full biopsy and excision reports, pathology slides or blocks if requested, a timeline and photographs of the lesion, operative and reconstruction notes, node results, imaging, and any previous radiation plan. Include previous skin cancers, medications, transplant details and immune-related illness.

Useful questions are: Can local treatment still cure this cancer? Are margins clear? Is nerve involvement microscopic or clinically apparent? Why is additional treatment recommended? What function may be affected? If systemic treatment is proposed, which exact setting and evidence apply to me?