ABSTRACT
Primary keratinocyte carcinoma of the skin is one of the commonest cancers diagnosed worldwide. In patients with an intact immune system, basal cell carcinoma (BCC) is the most common histology followed by squamous cell carcinoma (SCC). SCCs are more common than BCCs in immunocompromised patients. While most skin cancers can be managed with single modality treatment (dermatology, surgery, or radiation), a subset is associated with a higher risk of locoregional recurrence. Adjuvant radiation is used to reduce this risk of recurrence. Distant metastases are rare unless the patient is immunocompromised. Merkel cell carcinoma (MCC) is a rare and aggressive primary skin cancer. Most MCCs will require adjuvant radiation to reduce the risk of locoregional recurrence which is often high with surgery alone. Unlike SCC and BCC, MCC is known to commonly metastasize to regional and distant sites, and this is generally associated with a poor outcome. Radiation therapy forms the cornerstone of adjuvant management. Immunotherapy is being explored in conjunction with radiation to improve outcomes.
