title: Basal cell carcinomas on sun-protected vs. sun-exposed body sites: a comparison of phenotypic and environmental risk factors.
abstract: BACKGROUND
  Basal cell carcinoma (BCC) is the most commonly diagnosed cancer in White populations. There are indications that risk factors for BCC may differ according to the anatomic site of the tumour but this is not well understood.
  
  
  OBJECTIVE
  To compare phenotypic and environmental risk factors for BCCs arising on sun-protected sites with that of those on sun-exposed sites.
  
  
  METHODS
  We conducted a case-case study in which people who had been diagnosed with incident BCC were recruited between February 2012 and September 2013 in Brisbane, Australia.
  
  
  RESULTS
  Fair skin (OR: 4.50; 95% CI: 1.22, 16.59), having more than 15 lesions frozen/burnt off compared to less than 5 (OR: 5.68; 95% CI: 1.78, 18.08) and severe acne (OR: 5.25; 95% CI: 1.34, 20.56) were associated with increased risk of BCC on sun-protected sites. The presence of more than 5 nevi on the body was associated with decreased risk (OR: 0.28; 95% CI: 0.11, 0.71).
  
  
  CONCLUSIONS
  BCCs on sun-protected sites arise as a result of excessive sun exposure, most likely combined with phenotypic susceptibility. The strong negative association with nevi also suggests that there are constitutional factors that underlie the propensity for BCCs to arise on these body sites.
authors: Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, QLD, Australia.|Department of Population Health, QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia.|NHMRC Centre for Research Excellence in Sun and Health, Queensland University of Technology, Brisbane, QLD, Australia.
authors: Mohammad
authors: M
authors: Khalesi
authors: Department of Population Health, QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia.|NHMRC Centre for Research Excellence in Sun and Health, Queensland University of Technology, Brisbane, QLD, Australia.
authors: David C
authors: DC
authors: Whiteman
authors: Skin Cancer College Australasia, Brisbane, QLD, Australia.|School of Medicine, The University of Queensland, Brisbane, QLD, Australia.
authors: Cliff
authors: C
authors: Rosendahl
authors: Skin Cancer College Australasia, Brisbane, QLD, Australia.
authors: Richard
authors: R
authors: Johns
authors: Skin Cancer College Australasia, Brisbane, QLD, Australia.|School of Medicine, The University of Queensland, Brisbane, QLD, Australia.
authors: Timothy
authors: T
authors: Hackett
authors: Skin Cancer College Australasia, Brisbane, QLD, Australia.|School of Medicine, The University of Queensland, Brisbane, QLD, Australia.
authors: Alan
authors: A
authors: Cameron
authors: Department of Population Health, QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia.
authors: Mary
authors: M
authors: Waterhouse
authors: National Centre for Epidemiology and Population Health, The Australian National University, Canberra, ACT, Australia.|Telethon Kids Institute, University of Western Australia, Perth, WA, Australia.
authors: Robyn M
authors: RM
authors: Lucas
authors: Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, QLD, Australia.|NHMRC Centre for Research Excellence in Sun and Health, Queensland University of Technology, Brisbane, QLD, Australia.
authors: Michael G
authors: MG
authors: Kimlin
authors: Department of Population Health, QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia.|NHMRC Centre for Research Excellence in Sun and Health, Queensland University of Technology, Brisbane, QLD, Australia.
authors: Rachel E
authors: RE
authors: Neale
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002280:Basal Cell Carcinoma / Q000453:epidemiology / Q000473:pathology; D016022:Case-Control Studies; D004781:Environmental Exposure / Q000009:adverse effects*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D012878:Skin Neoplasms / Q000453:epidemiology / Q000473:pathology; D013472:Sunlight / Q000009:adverse effects*
keywords: acne; basal cell carcinoma; nevi; risk factors; sun-exposed; sun-protected