Basal cell carcinoma (BCC), or rodent ulcer, on the cheek of a male patient. This form of skin cancer mostly affects the elderly, although in recent years the average age of onset has steadily decreased. It usually appears on the face and is thought to be caused by the ultraviolet radiation in sunlight. It slowly destroys surrounding tissue, but seldom spreads to other parts of the body. Treatments for basal cell carcinoma include radiotherapy, cryotherapy, cauterisation and surgical excision.