Basal cell carcinoma

Basal cell carcinoma (BCC) is a skin cancer that usually grows locally and rarely spreads to distant organs. It may appear as a shiny bump, a scaly patch, a persistent ulcer or a scar-like area. Brown or black pigmentation is common in some populations and does not by itself make a lesion melanoma or establish its risk.

Biopsy confirms the diagnosis and helps distinguish superficial, nodular and more infiltrative growth patterns, such as morpheaform or micronodular BCC. A small biopsy can sample only part of a mixed tumor. Basosquamous features or an unexpected pathology result may require specialist review because the usual low-risk BCC assumptions may not apply.

Risk assessment considers the site and size together, whether the borders are well defined, the histological pattern, nerve involvement and whether the lesion has recurred. Around the eye, nose, ear or other functionally sensitive sites, obtaining clear margins while preserving tissue can be challenging even for a relatively small tumor.

Most ordinary localized BCCs do not require whole-body staging scans or a sentinel-node biopsy. Deep fixation, neurological symptoms, suspected bone or orbital invasion, or unusual metastatic findings may justify targeted imaging and a specialist review. 'Locally advanced' is a multidisciplinary judgment about feasible curative treatment, not a synonym for every large skin lesion.

Surgery is the main treatment for most BCCs. Standard excision removes the lesion and a planned surrounding margin for pathology assessment. Mohs or another micrographically controlled technique checks the margins systematically while conserving uninvolved tissue, which is particularly valuable for high-risk, recurrent or critically located tumors.

A close margin and a positive margin are different findings. When tumor remains at the edge, further excision is often considered, with the decision shaped by the exact site, subtype, reconstruction and health of the patient. Discuss how clearance will be confirmed before a complex repair and what the expected effect is on eyelid, nasal or ear function.

Selected low-risk superficial BCCs can be treated with topical medicines such as imiquimod or fluorouracil, photodynamic therapy, or other local approaches. These choices depend on depth, site and follow-up reliability. They do not provide the same complete margin assessment as surgery and should not be assumed suitable for an infiltrative, recurrent or deep lesion.

Radiotherapy can be an alternative when surgery is unsuitable or declined after discussion, and can have a role when residual disease cannot reasonably be re-excised. The number of visits, skin changes, healing and longer-term tissue effects matter. In a frail person, treatment burden and the lesion's expected behavior should be weighed explicitly rather than assuming either aggressive treatment or no treatment is always best.

Many BCCs depend on abnormal Hedgehog pathway signaling. Vismodegib and sonidegib inhibit this pathway and can shrink advanced disease when ordinary local treatment is not appropriate. Standard eligibility does not require every patient to have a tumor sequencing panel first.

The drug labels are not identical. In the US, vismodegib includes metastatic BCC and a defined locally advanced setting; sonidegib is indicated for locally advanced BCC with specified prior-treatment or local-treatment limitations. Do not assume a locally advanced indication automatically covers metastatic disease in every country.

Muscle cramps, taste changes, hair loss and weight loss can make prolonged treatment difficult. The team may adjust treatment interruptions and supportive care; resistance also requires reassessment. Sonidegib needs attention to muscle enzymes, kidney function and drug interactions. Both drugs carry serious embryo-fetal risks, with drug-specific contraception and donation precautions extending after treatment.

Cemiplimab is an anti-PD-1 immunotherapy option for advanced BCC after a Hedgehog inhibitor, or when a Hedgehog inhibitor is not appropriate under the applicable indication. This is a different sequence from advanced cutaneous squamous cell carcinoma, where checkpoint therapy commonly has a first-line role.

Single-arm studies found responses in both locally advanced and metastatic BCC previously treated with a Hedgehog inhibitor. A response can last, but it is not guaranteed and is not the same as cure. Cross-trial response rates cannot establish that immunotherapy is superior to targeted therapy for every patient.

The BCC indication does not depend on a positive PD-L1 score. Suitability still requires assessment of autoimmune disease, organ transplantation, previous toxicity and overall health. Immune inflammation may affect the lungs, bowel, liver, endocrine organs or other tissues; early reporting of new symptoms is part of treatment.

For selected difficult facial or function-threatening tumors, a team may use vismodegib before a planned curative procedure. The VISMONEO phase 2 study demonstrated that a less extensive operation could become possible for some patients. Recurrence during follow-up means visible shrinkage cannot be treated as proof that all cancer has gone.

NHS England's updated 2026 policy provides a defined neoadjuvant vismodegib pathway for eligible adults who are suitable, or potentially suitable, for curative treatment and face important functional or cosmetic consequences. This is a regional commissioning policy with specific criteria, not a worldwide approval for routine treatment before every BCC operation.

Before starting, agree on the endpoint, reassessment timing, surgery or radiation plan, and what to do if response stops. New combinations and preoperative immunotherapy remain areas for specialist protocols or trials rather than an automatic replacement for established local care.

Several BCCs do not necessarily mean one tumor has spread. Repeated independent tumors can occur in sun-damaged skin. Numerous lesions at a young age, jaw cysts, characteristic physical findings or a relevant family history can raise concern for Gorlin syndrome or another inherited predisposition.

Genetic counseling may include PTCH1 and SUFU assessment. The result can affect surveillance for the patient and relatives, and should not be confused with an acquired mutation found only in a tumor. Radiotherapy is avoided when suitable alternatives exist in Gorlin syndrome because the treated field can develop further BCCs, particularly after childhood exposure.

Follow-up looks for recurrence at the treated site and new skin cancers elsewhere. Low-risk, completely treated disease and multiple or advanced BCC need different schedules. Continue sun protection and self-checks, and report a new ulcer, bleeding, scar change, numbness or a growing lump rather than waiting for the next routine appointment.

Bring the full pathology report, location photographs, earlier excision and reconstruction details, radiation records and systemic-treatment history. For a difficult lesion, ask whether clear-margin surgery remains feasible, what function is at risk, why an alternative is preferred, and whether a specialist skin-cancer team has reviewed the sequence.