Diagnosis of skin cancer in the general population: clinical accuracy in the Nambour survey

Abstract

The accuracy and validity of diagnoses of skin cancer that were made by experienced dermatologists in a Queensland community survey have been investigated. Histological examination confirmed 54% of 100 clinical diagnoses of basal-cell carcinoma, squamous-cell carcinoma or intraepidermal carcinoma. Clinical accuracy was higher for basal-cell carcinoma (59%) than for squamous-cell carcinoma (39%) or intraepidermal carcinoma (38%). Such levels of diagnostic accuracy are to be expected when an unselected population is surveyed because of the relatively low prevalence of skin cancer compared with that in the patient population of a specialist practice. This reduction in diagnostic accuracy is unrelated to clinical skills, and should be borne in mind when conducting any skin-cancer screening programme in the general community.