Molecular Profiling of Basal Cell Carcinoma
Basal cell carcinoma (BCC) is the most common type of cancer in the United States. BCC and squamous cell carcinoma are grouped together as non-melanoma skin cancers; BCC makes up about 80% of non-melanoma skin cancers (Kim and Armstrong 2012). Approximately 2.2 million individuals are diagnosed with non-melanoma skin cancer in the United States each year (Kim and Armstrong 2012).
The main subtypes of BCC include nodular, superficial, morpheaform, infiltrative, and pigmented; individual lesions can have several BCC subtypes (Marghoob 2011). The most common cause of BCC is exposure to UV radiation such as sunlight. BCC is slow-growing. It may spread locally, but it is rarely metastatic. As a result, BCC is usually curable. Surgical resection is the treatment of choice for basal cell carcinoma, and it is curative in most cases. Radiation therapy may be used to treat BCCs with a high risk for recurrence or to treat patients who are not candidates for surgery. When locally advanced or metastatic basal cell carcinoma is inoperable, chemotherapy or a targeted therapeutic may be used.
The genes most frequently mutated in BCC are TP53 (39% of BCC), PTCH1 (39% of BCC), and SMO (12% of BCC). PTCH1 encodes a negative regulator of SMO, and loss of function mutations and/or gene deletion of PTCH1 lead to constitutive activation of SMO. Development of targeted therapeutics has focused on SMO at the present time. SMO inhibitors may be effective both in the context of loss of PTCH1 and activating mutations in SMO.
Last Updated: February 20, 2013