title: The majority of cutaneous squamous cell carcinomas arise in actinic keratoses.
abstract: BACKGROUND
  Retrospective studies have given conflicting results with respect to how many cutaneous squamous cell carcinomas (SCCs) arise in actinic keratoses (AK).
  
  
  OBJECTIVE
  This study was conducted to determine what percentage of SCCs arise in AKs and to obtain more information about two histological features of SCCs, namely, thickness and ulceration.
  
  
  METHODS
  A prospective study was done of all SCCs treated by the authors during one calendar year.
  
  
  RESULTS
  Two hundred eight patients with SCC were entered into the study. An AK was contiguous with an SCC in 72% of the cases. This was taken as evidence that the SCC arose in the AK. Men presented with thicker and more ulcerated SCCs than women, but these were not statistically significant: p = 0.06 for thickness and p = 0.07 for ulceration. Ulcerated SCCs were more likely to arise on the head and neck (p = 0.02), on patients who had multiple skin cancers (p = 0.005), and on patients who had a family history of skin cancer (p = 0.03).
  
  
  CONCLUSIONS
  Actinic keratoses need to be removed before they turn into SCCs. The prognostic significance of ulceration of cutaneous SCCs needs to be determined.
authors.affiliation: The Austin and Repatriation Medical Centre, Heidelberg, Australia. knoxsurgi@bigpond.com
authors.forename: D
authors.initials: D
authors.lastname: Czarnecki
authors.forename: C J
authors.initials: CJ
authors.lastname: Meehan
authors.forename: F
authors.initials: F
authors.lastname: Bruce
authors.forename: G
authors.initials: G
authors.lastname: Culjak
mesh_terms: D000328:Adult; D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000209:etiology* / Q000473:pathology; D005260:Female; D006801:Humans; D007642:Keratosis / Q000150:complications* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012189:Retrospective Studies; D012878:Skin Neoplasms / Q000209:etiology* / Q000473:pathology; D012883:Skin Ulcer / Q000209:etiology / Q000473:pathology