Malignant transformation of solar keratoses to squamous cell carcinoma

Lancet. 1988 Apr 9;1(8589):795-7. doi: 10.1016/s0140-6736(88)91658-3.


1689 people aged 40 years and over were examined over a 5-year period to determine the incidence of malignant transformation of solar keratoses. They were seen on 2 consecutive years on 4267 occasions; a total of 21,905 solar keratoses were present on the first visit. A squamous cell carcinoma (SCC) developed within 12 months on 28 of the 4267 occasions. Where accurate mapping of both SCCs and pre-existing solar keratoses was available, it was found that 10/17 (60%) SCCs arose from a lesion diagnosed clinically as a solar keratosis in the previous year and the other 7 (40%) SCCs on what had been clinically normal skin 12 months previously. The risk of malignant transformation of a solar keratosis to SCC within 1 year was less than 1/1000. The cost-effectiveness of treating all solar keratoses to prevent the development of SCC is questionable.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Carcinoma, Squamous Cell / epidemiology
  • Carcinoma, Squamous Cell / pathology*
  • Cell Transformation, Neoplastic / epidemiology
  • Cell Transformation, Neoplastic / pathology*
  • Female
  • Humans
  • Keratosis / diagnosis
  • Keratosis / etiology
  • Keratosis / pathology*
  • Male
  • Middle Aged
  • Occupations
  • Prospective Studies
  • Risk
  • Skin Neoplasms / epidemiology
  • Skin Neoplasms / pathology*
  • Sunlight / adverse effects*
  • Time Factors
  • Victoria