Mammographic densities as a criterion for entry to a clinical trial of breast cancer prevention.
The most convincing evidence that a factor such as dietary fat is causally related to breast cancer would be obtained from a randomised controlled trial in which exposure to dietary fat intake was systematically varied.
A limitation of randomised controlled trials of breast cancer prevention, however, is the large sample size required to detect plausible reductions in risk resulting from the intervention.
We describe here experience over a period of 9 years with the use of one risk factor for breast cancer as a criterion for entry to a clinical trial of breast cancer prevention.
The risk factor used was the presence of extensive densities in the breast tissue on mammography, which has been found by several investigators to be strongly associated with risk of breast cancer.
Using this criterion for selection, 1800 subjects of mean age 46 years were enrolled between 1982 and 1986, and again between 1988 and the present.
Throughout this period, the point estimate of annual invasive cancer incidence was approximately 6 per 1000 per year.
The observed cancer incidence has been consistently 4-5 times the incidence expected from age-specific breast cancer incidence data for women living in Ontario.
These data show that the selection of subjects for a clinical trial of breast cancer prevention using the criterion of extensive breast parenchymal densities does identify a group at substantially increased risk of breast cancer.
Mots-clés Pascal : Tumeur maligne, Glande mammaire, Facteur risque, Epidémiologie, Exploration radiologique, Mammographie, Densité, Prévention, Canada, Amérique du Nord, Amérique, Homme, Glande mammaire pathologie, Radiodiagnostic
Mots-clés Pascal anglais : Malignant tumor, Mammary gland, Risk factor, Epidemiology, Radiologic investigation, Mammography, Density, Prevention, Canada, North America, America, Human, Mammary gland diseases, Radiodiagnosis
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 95-0475839
Code Inist : 002B20E02. Création : 01/03/1996.