Mammographic density and the risk of breast cancer in Japanese women

1,856

1,458

Mammographic features are associated with breast cancer risk, but estimates of the strength of the association vary markedly between studies, and it is uncertain whether the association is modified by other risk factors. We conducted a systematic review and meta-analysis of publications on mammographic patterns in relation to breast cancer risk. Random effects models were used to combine study-specific relative risks. Aggregate data for >14,000 cases and 226,000 noncases from 42 studies were included. Associations were consistent in studies conducted in the general population but were highly heterogeneous in symptomatic populations. They were much stronger for percentage density than for Wolfe grade or Breast Imaging Reporting and Data System classification and were 20% to 30% stronger in studies of incident than of prevalent cancer. No differences were observed by age/menopausal status at mammography or by ethnicity. For percentage density measured using prediagnostic mammograms, combined relative risks of incident breast cancer in the general population were 1.79 (95% confidence interval, 1.48-2.16), 2.11 (1.70-2.63), 2.92 (2.49-3.42), and 4.64 (3.64-5.91) for categories 5% to 24%, 25% to 49%, 50% to 74%, and z75% relative to <5%. This association remained strong after excluding cancers diagnosed in the first-year postmammography. This review explains some of the heterogeneity in associations of breast density with breast cancer risk and shows that, in well-conducted studies, this is one of the strongest risk factors for breast cancer. It also refutes the suggestion that the association is an artifact of masking bias or that it is only present in a restricted age range. (Cancer Epidemiol Biomarkers Prev 2006;15(6):1159-69)

Section: Resultssupporting

confidence: 51%

“…2, 3, 10, 27, 29, 30, 32-44), whereas prevalence studies were case-control or crosssectional (Table 2; refs. 1,28,[45][46][47][48][49][50][51][52][53][54][55][56][57][58][59]. Nine studies were conducted using symptomatic populations or controls (Table 3; refs.…”

Section: Resultsmentioning

confidence: 99%

Breast Density and Parenchymal Patterns as Markers of Breast Cancer Risk: A Meta-analysis

McCormack

dos‐Santos‐Silva

2006

1,856

1,458

“…Whether the discrepancy between the two studies is due to unmeasured differences between the Asian populations in Los Angeles and Hawaii, or to other reasons is unknown. In a study of Japanese women (25), where mean breast size was considerably smaller than in the present study, the adjusted increases in risk per 1% mammographic density was 0.7% (P trend = 0.22) and 2.3% (P trend = 0.005) in premenopausal and postmenopausal, respectively. The corresponding value in our study as reported previously was 1.1% for African American, 1.5% for White, and 3.0% for Asian American women (3).…”

Section: Discussionmentioning

confidence: 93%

Does Breast Size Modify the Association between Mammographic Density and Breast Cancer Risk?

Stuedal

Bernstein

et al. 2008

Background: Both the absolute and the percent of mammographic density are strong and independent risk factors for breast cancer. Previously, we showed that the association between mammographic density and breast cancer risk tended to be weaker in African American than in White U.S. women. Because African American women have a larger breast size, we assessed whether the association between mammographic density and breast cancer was less apparent in large than in small breasts. Methods: We assessed mammographic density on mammograms from 348 African American and 507 White women, 479 breast cancer patients and 376 control subjects, from a case-control study conducted in Los Angeles County. We estimated odds ratios (OR) for breast cancer with increasing mammographic density, and the analyses were stratified by mammographic breast area.

“…A high percentage of dense area has been associated with an f3-to 6-fold increased risk of breast cancer in most of the studies, which adopted quantitative assessment methods (1). We have developed an automated method for detecting mammographic density (2) and confirmed a positive association between breast density and breast cancer risk among Japanese women (3).…”

Section: Introductionmentioning

confidence: 85%

Associations of Mammographic Density with Dietary Factors in Japanese Women

Nagata

Matsubara

Fujita

et al. 2005

Background: A high percentage of mammographic dense area has been strongly associated with a risk of beast cancer. The present cross-sectional study evaluated the relations of percent density with dietary factors, such as fats, protein, dietary fiber, and soy isoflavones. Methods: Study subjects were 601 (348 premenopausal and 253 postmenopausal) Japanese women who were recruited from a mammographic screening center. The size of the total breast area and the dense area were measured quantitatively using an automated mammographic mass detection method. Intakes of nutrients were estimated with a validated semiquantitative food-frequency questionnaire. Results: The crude means of the percent density were 39.2% and 18.9% in premenopausal and postmenopausal women, respectively. There were no significant associations of any dietary factors with the percent density in premen-