The time relationship between carcinogenic stimulus and neoplastic response is of major importance to the understanding of the pathogenesis of cancer. Actinic keratoses (AK) are dysplastic epidermal lesions that commonly affect sun-exposed skin of elderly, fair-skinned individuals. In bald men it is possible to be relatively precise as to the levels and duration of sun exposure to the scalp. The aim of our study was to determine the time taken for men to develop AK on the scalp and to assess the prevalence of risk factors for AK and nonmelanoma skin cancer (NMSC) for these individuals.
Patients attending the Dermatology Clinic at the University Hospital of Wales in Cardiff with AK on the scalp were recruited. They were asked details of their tanning history (skin type), age of complete scalp hair loss, and age of development of scalp AK. The presence of risk factors for NMSC was recorded. The patients were