Skin cancers and their etiologies.

Skin cancers are the most common form of malignancy. Early diagnosis and treatment provides the best chance for survival and reduced morbidity. However, some patients have recurrent or resistant lesions. In patients with basal cell carcinoma (BCC), prognosis is relatively good for all four types of lesions (superficial, nodular, infiltrative, and morpheaform), but the highest recurrence rates and greatest morbidity are associated with infiltrative and morpheaform BCC, and prognosis is least favorable when perineural invasion has occurred. Research into the etiology of BCC and other skin cancers has led to the identification of several genetic mutations-those of the Patched and Hedgehog genes. By targeting these pathways, treatments aimed at driver mutations hold promise for new nonsurgical treatments.