Estimates of composite risk factors for death from breast cancer
Davies, D.F.; Torng, A.; Morris, E.B.; Sebes, J.
Journal of the National Cancer Institute 61(1): 41-48
1978
ISSN/ISBN: 0027-8874 PMID: 353294 Document Number: 129957
A method for ranking women according to their weighted composite risks of dying from breast cancer was described. Quantitative reports of relative risks reported in the literature for each of 5 classes of carefully selected prognostic characteristics of breast cancer were recorded. Each class consisted of 2 or more discrete, mutually exclusive categories of risk characteristics. Relative risks were standardized and converted into risk factors (RF) such that an RF of 1.0 represents the average risk of the general population. Estimates were made for women by 5 yr age groups between 40 and 64 yr. For weighted, composite risk factors (CRF), lack of evidence of influence of any prognostic characteristic on another was assumed to indicate their independence. The product of the 5 RF of a woman was expressed as the CRF. The product of the CRF and the average risk of dying from breast cancer in the succeeding 10 yr (for the combined black and white USA female population) gave a 1st approximation of risk/100,000 women. Among 99.7% of women, the estimated CRF ranged between 0.06 and 13.0. Inasmuch as some prognostic characteristics are protective, women with 1 or more high risks (e.g., family history of breast cancer) might still have low composite risks. Because of the assumption made about the weighting of risks to create CRF, these expectations should be compared with previous and subsequent estimates of risk of breast cancer.