Development of the Individualized Health Risk Appraisal Model of Breast Cancer Risk in Korean Women

Jee, Sun Ha; Song, Ji Won; Nam, Chung Mo

Abstract

OBJECTIVES
The objectives of this study were to develop a health risk appraisal (HRA) model of breast cancer and to evaluate the model's ability to accurately predict ndividual breast cancer risk. METHOD: The sample data were from a prospective cohort study in Korea with a follow-up period of 8 years in Korea (1995-2002). The cohort was composed of 108,708 Korean women, aged 30 to 64 years, who received health insurance from the Korea Medical Insurance Corporation and who underwent a medical evaluation in 1994. Between 1995 and 2002 (1,138,349 person-year), there were 772 incident cases of breast cancer (67.8/100,000 person-years). First, we developed the HRA based on the Cox proportional hazard models using a prospective cohort data with half-split data (50% random sample). Second, using Cox proportional hazard models, we compared the probability of breast cancer predicted by the model to the actual number of cases observed in the other 50% of the random sample of the study population.
RESULTS
The HRA Cox proportional hazard model of breast cancer developed in the study included age, age2, age at menarche, and lactation. Multivariate Cox proportional hazards models were used to test the HRA model validation. Compared with women in the lowest 10 percentile of subjects, women in the highest 10 percentile had an increased risk of breast cancer (relative risk, 3.701; 95% confidence interval, 2.554 to 5.364).
CONCLUSION
The model's performance was satisfactory for estimating breast cancer risk for individual women aged 30-64 years.