title: Reliability and validity of a histologic score as a marker for skin cancer chemoprevention studies.
abstract: OBJECTIVE
  To develop a reliable and valid scoring system for grading skin biopsies from actinic keratosis (AK) and sun-damaged skin for use in evaluating the efficacy of skin cancer chemopreventive agents.
  
  
  METHODS
  A panel of dermatopathologists developed histologic criteria and diagnostic definitions for the progression of lesions from early AK to AK. The criteria were then applied to a sample of 335 histologic slides from an ongoing chemoprevention study. A 10% sample of 35 slides was reread in order to assess intrarater reliability.
  
  
  RESULTS
  Six of the 7 criteria demonstrated high reliability (> 85%). The total histologic score, calculated using the 6 criteria, was found to significantly differentiate between (blinded) biopsy location (normal, pre-AK, AK and adjacent to squamous cell carcinoma) and histologic diagnosis (normal, pre- or early AK, AK and squamous cell carcinoma).
  
  
  CONCLUSIONS
  The total histologic score, having demonstrated reliability on repeated readings and validity in its association with biopsy location and histologic score, is a reliable and valid end point for judging the efficacy of agents in skin cancer chemoprevention studies. Additional interrater reliability tests utilizing larger test sets and a rigorous statistical design should be undertaken to establish its portability.
authors: Arizona Cancer Center, Departments of Pathology and Medicine, University of Arizona, P.O. Box 245024, Tucson, Arizona 85724-5024, USA.
authors: Paul
authors: P
authors: Bozzo
authors: Kathylynn
authors: K
authors: Saboda
authors: Janine G
authors: JG
authors: Einspahr
authors: James
authors: J
authors: Ranger-Moore
authors: Evan R
authors: ER
authors: Farmer
authors: Clay J
authors: CJ
authors: Cockerell
authors: David E
authors: DE
authors: Elder
authors: Jerry L
authors: JL
authors: Bangert
authors: Nancy
authors: N
authors: Hart
authors: Cheryl B
authors: CB
authors: Kramer
authors: David S
authors: DS
authors: Alberts
mesh_terms: D001706:Biopsy; D018890:Chemoprevention; D003094:Collagen / Q000528:radiation effects; D006652:Histological Techniques; D006801:Humans; D015603:Keratinocytes / Q000473:pathology / Q000528:radiation effects; D007642:Keratosis / Q000209:etiology / Q000473:pathology*; D011237:Predictive Value of Tests; D011832:Radiation Injuries / Q000473:pathology; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D012878:Skin Neoplasms / Q000473:pathology / Q000517:prevention & control*; D014466:Ultraviolet Rays / Q000009:adverse effects
chemical_list: D003094:Collagen