title: Actinic keratosis-related signs predictive of squamous cell carcinoma in renal transplant recipients: a nested case-control study.
abstract: BACKGROUND
  Squamous cell carcinoma (SCC) and intraepidermal carcinoma (IEC) commonly arise in actinically damaged skin.
  
  
  OBJECTIVE
  To identify clinical features of actinic change that correlate with an increased risk of SCC or IEC in the short-to-medium term as guidance for prioritizing field treatment.
  
  
  METHODS
  In a nested case-control study, cases were renal transplant recipients who developed an incident SCC or IEC within 18 months following baseline examination and photography. Controls without SCC or IEC were matched to cases on age, sex and duration of immunosuppression. Predefined skin sites on the head, neck and upper limbs were examined using baseline photographs to assess objectively the following features of actinic damage: presence of actinic keratosis (AK) patch (defined as AK > 1 cm2), number of AK patches, number of AKs and area affected by AK. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using McNemar's test to identify differences in SCC/IEC risk combined and SCC risk alone between case and control skin sites.
  
  
  RESULTS
  Thirty-nine cases were matched to 39 controls. Significant associations with the presence of an AK patch, number of AK patches, number of AKs and area affected by AKs were identified. The presence of an AK patch conferred an 18-fold increased risk of SCC (OR 18·00, 95% CI 2·84-750) and more than a sixfold increased risk of SCC/IEC combined (OR 6·60, 95% CI 2·56-21·66).
  
  
  CONCLUSIONS
  AK patches are predictive of SCC/IEC development within 18 months. This can be used to guide site selection for field treatment in patients with widespread actinic damage.
authors: Cancer and Population Studies Group, QIMR Berghofer Medical Research Institute, Locked Bag 2000, Royal Brisbane Hospital, Brisbane, QLD 4029, Australia.|Institute of Cardiovascular and Cell Sciences (Dermatology Unit), St George's University of London, London, U.K.
authors: Z
authors: Z
authors: Jiyad
authors: Statistics Unit, QIMR Berghofer Medical Research Institute, Locked Bag 2000, Royal Brisbane Hospital, Brisbane, QLD 4029, Australia.
authors: P
authors: P
authors: O'Rourke
authors: Dermatology Research Centre, The University of Queensland, School of Medicine, Translational Research Institute, Brisbane, QLD, Australia.|Department of Dermatology, Princess Alexandra Hospital, Brisbane, QLD, Australia.
authors: H P
authors: HP
authors: Soyer
authors: Cancer and Population Studies Group, QIMR Berghofer Medical Research Institute, Locked Bag 2000, Royal Brisbane Hospital, Brisbane, QLD 4029, Australia.|CRUK Manchester Institute and Institute of Inflammation and Repair, University of Manchester, Manchester Academic Health Sciences Centre, Manchester, U.K.
authors: A C
authors: AC
authors: Green
mesh_terms: D000328:Adult; D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis*; D016022:Case-Control Studies; D055088:Early Detection of Cancer; D005260:Female; D006801:Humans; D055623:Keratosis, Actinic / Q000150:complications*; D016030:Kidney Transplantation; D008297:Male; D008875:Middle Aged; D010328:Patch Tests; D011183:Postoperative Complications / Q000175:diagnosis; D012878:Skin Neoplasms / Q000175:diagnosis*; D066027:Transplant Recipients