Skin cancer is a type of cancer that grows on the skin. It develops from abnormal cells and may even invade and spread to different parts of the body, and is one of the common malignant tumors. The incidence of skin cancer is very low in China, accounting for about 1.5% of all malignant tumors. Skin cancer is one of the common malignant tumors among the white race. In the United States, there were 600,000 new cases of skin cancer other than malignant melanoma in 1991. The incidence of skin cancer in southern Australia is at least 650 per 100,000, which is 100 times the incidence rate in China. It is estimated that 40% to 50% of all white Americans who live to age 65 have had at least one skin cancer, which may be related to the geographic location and lifestyle of the people. The three most common types of skin cancers are basal cell carcinoma (BCC), squamous cell carcinoma (SCC) and melanoma, the most common of which is basal cell carcinoma which, if not treated early, will cause local tissue erosion but will not spread to other parts of the body, and squamous cell carcinoma which, without proper treatment, will spread. Fortunately, these two types of skin cancer are slow growing and almost all cases can be cured. Squamous cell carcinoma can occasionally be seen in the vulva of postmenopausal women, and that is more difficult to manage. Malignant melanoma is the least common of the three and usually results from the malignant transformation of existing moles on the body, which are cancers of melanocytes. It is the most serious type of skin cancer and spreads rapidly after its onset. If detected and treated early, the cure rate is about 75 percent. The triggering factors of skin cancer include daily exposure to sunlight and ultraviolet radiation, chemical carcinogens, ionizing radiation, chronic irritation and inflammation, etc. Treatment of skin cancer: Drug treatment: including local treatment: mainly local topical application, local dressing and local injection; systemic treatment: systemic chemotherapy is needed for squamous cell carcinoma that occurs on the basis of original scar, squamous carcinoma at the junction of skin and mucous membrane, patients with low immune function and those with regional lymph nodes and distant metastasis. Surgery: Up to the beginning of the 21st century, surgery is still one of the main methods to treat skin cancer. The most classic and reliable surgical method is Mohs microsurgery, which can achieve a cure rate of 99% for primary basal cell carcinoma and 95% for recurrent basal cell carcinoma. Other treatments: such as scraping treatment, cryotherapy, radiotherapy and laser treatment, herbal medicine treatment, etc.