Advanced basal cell carcinoma: What dermatologists need to know about diagnosis.

Basal cell carcinoma (BCC) is the most common human cancer, with approximately 3.6 million cases diagnosed each year. About 2000 deaths annually in the United States are attributed to basal and squamous cell skin cancers. There is a direct link between ultraviolet exposure and the development of BCC, as UV exposure damages DNA and induces mutations in tumor suppressor genes. Aberrations in the hedgehog pathway can also result in BCC, highlighted by the fact that most cases of sporadic BCCs have been found to have mutations in different genes involved in the hedgehog pathway. There are several genetic syndromes that are associated with BCCs, including basal cell nevus syndrome, xeroderma pigmentosum, Bazex-Dupré-Christol syndrome, Rombo syndrome, and Oley syndrome. Other risk factors include age, male gender, occupational hazards, radiation, and immunosuppression. BCCs are not typically staged but are instead stratified by their risk of recurring or metastasizing. Locally advanced BCCs are those tumors that are not amenable to surgery or radiation therapy.