Current treatment options for locally advanced and metastatic basal cell carcinoma. A narrative review

Although basal cell carcinomas (BCC) are the most common skin cancer and usually considered as 'easy-to-treat,' locally advanced BCC (laBCC) and metastatic BCC (mBCC) are rather exceptional and often more 'difficult-to-treat.' They load a high burden on the quality of life (QoL) of the patients, often elderly and frail individuals. Several management options are possible, varying from supportive therapy without any therapeutic intervention until anti-programmed cell death protein-1 (PD-1) immunotherapy, such as cemiplimab, either administered intravenously or intralesional. In between this spectrum, oral hedgehog inhibitors including vismodegib and sonidegib, electrochemotherapy, different types of radiotherapy, and surgery can be considered. CAR-T cell therapy, anti-LAG therapy, and multiple combination therapies are currently under investigation for laBCC and mBCC. Current and future treatment options for the management of laBCC and mBCC, limitations of different approaches as well as some practical and financial aspects are presented. The management of laBCC and mBCC patients is determined by a multidisciplinary dermato-oncology board, including dermatologists, medical oncologists, radiotherapists, pathologists, and surgeons, as well as the patient's GP. Today, experts recommend keeping as long as possible laBCC and mBCC patients under sequential courses of HHIs, if surgery and/or radiotherapy are not amenable.