Basal and Squamous Cell Carcinoma of the Skin

Abstract

Basal and squamous cell carcinomas of the skin are the most commonly diagnosed malignancies in the USA. Basal cell carcinoma accounts for approximately 80% and squamous cell carcinoma for 20% of all nonmelanoma skin cancers. Exposure to sunlight is the most common cause of skin cancer. Patients with nonmelanoma skin cancer have a 30–50% risk of developing additional skin cancers. Poor prognostic factors in squamous cell carcinoma of the skin are tumor size of at least 4 cm, perineural invasion, and invasion beyond the subcutis. Basal cell carcinoma of the skin rarely metastasizes but has a predilection for local invasion. Squamous and basal cell carcinomas are most commonly treated with surgery, radiation therapy, or a combination of both. Selection of therapy is based on preservation of function and cosmesis, and patient preference. T-classification at diagnosis correlates with local control in irradiated basal and squamous cell carcinoma of the skin. For T1, T2 and T3 tumors, local control rates are 95, 80, and 53%, respectively. Local control rates of irradiated basal and squamous cell carcinomas of the skin smaller than 1 cm are 97 and 91%, respectively. For tumors between 1 and 5 cm, local control rates are 87 and 76%, respectively.