Aetiology

The development of a basal cell carcinoma appears to be mainly related to sunlight exposure.

Lesions occur in exposed areas of the skin (75% occur in the head and neck), and the incidence is increased in parts of the world with increased sunlight. Similarly there is an increased incidence in Caucasians, whose skin is perhaps least protected against the harmful affects of the sun.

Basal cell carcinomas may also arise in association with Gorlin's syndrome. Patients with this condition appear to have a great tendency to develop basal cell epitheliomata.

• an autosomal (non-sex determining chromosome) dominantly inherited condition characterised by developmental abnormalities and the occurrence of multiple BCCs
  • mutations in people with Gorlin syndrome have been found on the PTCH1 gene located on chromosome nine, which appears to
    be crucial for proper embryonic development and for tumour suppression (1)

Reference:

• Johnson RL et al. Human homolog of patched, a candidate gene for the basal cell nevus syndrome. Science 1996;272(5268):1668-71