title: The relationship between UV exposure and incidence of skin cancer.
abstract: BACKGROUND
  The incidence rates of skin cancer increase with decreasing latitude in most western countries. Ultraviolet (UV) radiation is a main risk factor for skin cancer.
  
  
  METHODS
  We have studied the relationship between UV exposure and skin cancer incidence rates of squamous cell carcinoma (SCC), basal cell carcinoma (BCC), and cutaneous melanoma (CM), and tried to fit different mathematical models to the experimental data.
  
  
  RESULTS
  The incidence-UV exposure relationship for all three cancers is best described by the power law: ln(RTD) = Ab ·ln(annual UVEry dose), with relative tumor density (RTD) being age-adjusted incidence rate per unit area of skin, and the power parameter Ab being the biological amplification factor. For SCC, the RTD is a factor of 16-19 times larger on the head than on the trunk. For BCC, this factor is 7 and for CM it is 0.9-1.3. Ab for CM has remained almost unchanged from the 1960s until recently.
  
  
  CONCLUSIONS
  The incidence-sun exposure relationship for all three cancers is well described by the power law. SCC is dependent on total UV exposures, while BCC, and even more CM, is dependent also on exposure patterns, with intermittent exposures being most carcinogenic.
authors.affiliation: Department of Radiation Biology, Institute for Cancer Research, The Norwegian Radium Hospital, Oslo University Hospital, Oslo, Norway; Department of Physics, University of Oslo, Oslo, Norway.
authors.forename: Johan
authors.initials: J
authors.lastname: Moan
authors.forename: Mantas
authors.initials: M
authors.lastname: Grigalavicius
authors.forename: Zivile
authors.initials: Z
authors.lastname: Baturaite
authors.forename: Arne
authors.initials: A
authors.lastname: Dahlback
authors.forename: Asta
authors.initials: A
authors.lastname: Juzeniene
mesh_terms: D002280:Basal Cell Carcinoma / Q000453:epidemiology / Q000209:etiology; D002294:Carcinoma, Squamous Cell / Q000453:epidemiology / Q000209:etiology; D016208:Databases, Factual; D015994:Incidence; D008545:Melanoma / Q000453:epidemiology / Q000209:etiology; D008954:Models, Biological; D009664:Norway / Q000453:epidemiology; D012189:Retrospective Studies; D012878:Skin Neoplasms / Q000453:epidemiology / Q000209:etiology; D014466:Ultraviolet Rays / Q000009:adverse effects*
keywords: basal cell carcinoma; cutaneous melanoma; skin cancer; squamous cell carcinoma; ultraviolet radiation