Background
Several studies have demonstrated that mammographic dense breast is related to the risk of breast cancer and is associated with decreased mammographic sensitivity and specificity. In contrast, studies concerning women with dense breast are virtually non-existent. This study was conducted to evaluate the relationship between mammographic dense breast and other risk factors of breast cancer, and to make a plan for individualized strategies in high risk populations. Methods: The study subjects were 565 women, aged 20∼70 years, who had a screening mammogram from April 2005 to August 2005 at a health promotion center. Data of demographic factors, breast caner risk factors and menstrual status were collected by the self-administered questionnaire. Mammographic breast density was classified according to the American College of Radiology Breast Imaging Reporting and Data System (BI-RADS) fours categories, as measured by the proportion of glandular tissues within the total breast tissue. Results: By BI-RADS categories, 'entirely fat' were 46, 'scattered fibroglandular' were 96, 'heterogenous dense' were 332 and 'extremely dense' were 91 (16.1%). Univariate analysis showed that age, occupation, education level, body mass index, age at menarche, parity, breast feeding, menopausal status and triglyceride had significantly related to dense breast (P＜0.05). In the multivariate logistic analysis, only low body mass index (P＜0.001), low parity (P=0.009, 0.038) and premenopausal status (P=0.001) were significantly associated with dense breast. Conclusion: In Korean women, dense breast was significantly associated with low body mass index, low parity and premenopausal status. Therefore, if women with dense breast have these risk factors, they need to be managed more intensively with regular screening, breast sonogram, and lifestyle modification. (J Korean Acad Fam Med 2007;28:937-942)

Background
: Density patterns on mammography have been related to the risk factors for breast cancer in the western countries. High mammographic density appears to confer a 4-fold risk of breast cancer. While the proportion of high-density mammography is higher in Korean women than in Caucasian women, the incidence of breast cancer in Korean women is considerably lower. Therefore, we examined if the mammographic breast density pattern correlates with the risk factors for breast cancer in Korean women.

Methods : In a cross-sectional design, we recruited 1,758 pre- and post-menopause women without prior history of breast cancer and breast surgery who underwent screening mammogram and completed a self-administered questionnaire in 6 general hospitals. On the basis of ACR BI RADS breast composition, four density patterns were classified in caudocranial and mediolateral mammography by a designated radiologist in each hospital. Multiple linear logistic regression was used for statistical analyses.

Results : Inter-rater reliability between the initial report and the report made by another blinded radiologist was high (Pearson's co-efficient=0.81). Overall, the age, body mass index, family history of breast cancer, and duration of hormone replacement therapy correlated with the mammographic density patterns. In pre-menopausal women, the high body mass index and parity (=2) were associated with low mammographic density. In post- menopausal women, older age, high body mass index, negative family history of breast cancer, and duration of hormone replacement therapy were associated with low mammographic density.

Conclusion : Our data showed that the mammographic breast density patterns correlated with risk factors for breast cancer in Korean women. While the proportion of high-density mammography is higher in Korean women, the incidence of breast cancer is lower than in the western population. This maybe dependent on other unknown factors.