Statistical analysis of chemopreventive efficacy of vitamin A in sun-exposed, normal skin

Anal Quant Cytol Histol. 2002 Aug;24(4):185-97.


Objective: To develop numeric, statistically secured measures of chemopreventive efficacy and to derive procedures with high sensitivity of detection.

Study design: Karyometric features were computed for nuclei from the basal cell layer of biopsies taken from sun-exposed but histologically "normal" skin. Biopsies were collected from placebo-treated subjects and subjects treated for one year with daily, oral doses of 25,000, 50,000 and 75,000 IU of vitamin A. A total of 22,600 nuclei were recorded from 113 cases, at baseline and after one year.

Results: Two numeric measures of chemopreventive efficacy were applied: a measure of nuclear abnormality and a measure based on discriminant function scores. Both showed statistically significant chemopreventive effects of vitamin A. Dose-response curves were derived. A novel procedure, second order discriminant analysis, resulted in very high sensitivity for the detection of change in nuclear chromatin patterns.

Conclusion: Karyometric analysis has increased in sensitivity such that changes on the order of 10%, found in only a low percentage of nuclei in a biopsy specimen, can be reliably documented. The methodology lends itself to cost-efficient screening of compounds for chemopreventive efficacy.

Publication types

  • Clinical Trial
  • Controlled Clinical Trial

MeSH terms

  • Biopsy
  • Cell Nucleus / pathology
  • Data Interpretation, Statistical*
  • Humans
  • Image Processing, Computer-Assisted
  • Keratosis / pathology*
  • Skin / pathology
  • Skin / radiation effects*
  • Sunlight / adverse effects*
  • Vitamin A / administration & dosage*


  • Vitamin A