The Relationship Between Breast Density Change During Menopause and the Risk of Breast Cancer in Korean Women

Abstract

Background: The aim of this study was to investigate the relationship between changes in breast density during menopause and breast cancer risk. Methods: This study was a retrospective, longitudinal cohort study for women over 30 years of age who had undergone breast mammography serially at baseline and postmenopause during regular health checkups at Samsung Medical Center. None of the participants had been diagnosed with breast cancer at baseline. Mammographic breast density was measured using the American College of Radiology Breast Imaging Reporting and Data System. Results: During 18,615 person-years of follow-up (median follow-up 4.8 years; interquartile range 2.8–7.5 years), 45 participants were diagnosed with breast cancer. The prevalence of dense breasts was higher in those who were younger, underweight, had low parity or using contraceptives. The cumulative incidence of breast cancer increased 4 years after menopause in participants, and the consistently extremely dense group had a significantly higher cumulative incidence (CI) of breast cancer compared with other groups [CI of extremely dense vs. others (incidence rate per 100,000 person-years): 375 vs. 203, P < 0.01]. Conclusion: Korean women whose breast density was extremely dense before menopause and who maintained this density after menopause were at two-fold greater risk of breast cancer. Prevention Relevance: Extremely dense breast density that is maintained persistently from premenopause to postmenopause increases risk of breast cancer two fold in Korean women. Therefore, women having risk factors should receive mammography frequently and if persistently extremely dense breast had been detected, additional modalities of BC screening could be considered.

Longitudinal Analysis of Change in Mammographic Density in Each Breast and Its Association With Breast Cancer Risk

“…Although density is an accepted intermediate marker of breast cancer risk, studies of change in density are limited. Previous studies have used reader-dependent, subjective measures of density and categorical density data (fatty, scattered, heterogeneously dense, and extremely dense in accordance with BI-RADS) . Previous studies have also been based on analysis of digitized radiographic images, which are of lower image quality than standard digital mammograms .…”

“…Previous studies have used reader-dependent, subjective measures of density and categorical density data (fatty, scattered, heterogeneously dense, and extremely dense in accordance with BI-RADS). 7,[17][18][19][20][21] Previous studies have also been based on analysis of digitized radiographic images, 7,22,23 which are of lower image quality than standard digital mammograms. 24,25 Furthermore, changes in breast density in these studies were often assessed from comparison of only 2 time points.…”

Repeated measures of mammographic density and texture to evaluate prediction and risk of breast cancer: a systematic review of the methods used in the literature

“…Measures of breast density used in these studies are summarized in Table 1 . BI-RADS (six studies) [ 28 – 30 , 32 , 33 , 36 ] and Cumulus (five studies) [ 25 , 26 , 34 , 35 , 42 ] were the most commonly used methods for density assessment. Automated assessments were used on digital mammograms.…”

“…Automated assessments were used on digital mammograms. Studies differed in the view used to forecast the overall breast cancer risk, with some only using the craniocaudal (three studies) [ 26 , 35 , 40 ] or mediolateral oblique (four studies) [ 23 , 25 , 31 , 34 ] while others considered both (seven studies) [ 24 , 27 , 28 , 32 , 36 , 38 , 39 ]. The number of cases included in each study ranged from a low of fourty five cases [ 28 ] to a high of 22,781 in a Korean cohort study as shown in Supplementary Table 1 [ 33 ].…”

“…Other measures of association (relative risk, hazard ratio (HR), odds ratio (OR)) are reported in studies that focus on the association between mammographic features and cancer risk. The statistical methods used to model change and assumptions including the breast imaged (ipsilateral or contralateral to the cancer) and approach to comparing cases and controls for 15 other association studies are summarized in Supplementary Table 4 [ 23 , 25 – 28 , 30 , 32 – 38 , 40 – 42 ]. Some studies used change in BI-RADS category while others had continuous breast density generated from machine-derived measures and then categorized change from the variable.…”