A case‐control study to assess the impact of mammographic density on breast cancer risk in women aged 40–49 at intermediate familial risk

Abstract

Mammographic density is a strong risk factor for breast cancer, but its potential application in risk management is not clear, partly due to uncertainties about its interaction with other breast cancer risk factors. We aimed to quantify the impact of mammographic density on breast cancer risk in women aged 40-49 at intermediate familial risk of breast cancer (average lifetime risk of 23%), in particular in premenopausal women, and to investigate its relationship with other breast cancer risk factors in this population. We present the results from a case-control study nested with the FH01 cohort study of 6,710 women mostly aged 40-49 at intermediate familial risk of breast cancer. One hundred and three cases of breast cancer were agematched to one or two controls. Density was measured by semiautomated interactive thresholding. Absolute density, but not percent density, was a significant risk factor for breast cancer in this population after adjusting for area of nondense tissue (OR per 10 cm 2 5 1.07, 95% CI 1.00-1.15, p 5 0.04). The effect was stronger in premenopausal women, who made up the majority of the study population. Absolute density remained a significant predictor of breast cancer risk after adjusting for age at menarche, age at first live birth, parity, past or present hormone replacement therapy, and the Tyrer-Cuzick 10-year relative risk estimate of breast cancer. Absolute density can improve breast cancer risk stratification and delineation of high-risk groups alongside the Tyrer-Cuzick 10-year relative risk estimate.

Mammographic density and breast cancer risk in breast screening assessment cases and women with a family history of breast cancer

“…In conclusion, we found that dense breast tissue volume as measured by automated methods was a significant predictor of breast cancer risk in women with a suspicious screening mammogram or a family history. This is consistent with findings that various measures of density can add predictive power to currently used breast cancer risk assessment tools [46] , [47] . The fully automated methods can be used with little addition to human resource costs.…”

Association between changes in mammographic density category and the risk of breast cancer: A nationwide cohort study in East‐Asian women

“…Regarding the absence/presence of breast cancer family history, despite comparable RRs of changes in density categories, women with a breast cancer family history had higher absolute breast cancer risks, similar to a previous study 18 . Both single measure and changes in breast density are independent risk factors of breast cancer, especially in women with a breast cancer family history 22,27‐29 . In our study, the 5‐year risk of developing breast cancer in women with both family history and rapid density increment or a high initial density category was >1.67%.…”

Mammographic Breast Density and Urbanization: Interactions with BMI, Environmental, Lifestyle, and Other Patient Factors

“…They also contribute to the debate on whether percent or absolute density is more relevant but were not sufficient to draw firm conclusions. A study in young women at intermediate familial risk found that absolute, but not percent, MBD was a significant risk factor for breast cancer after adjusting for the area of non-dense tissue [23] and that absolute density appeared able to improve significantly the risk prediction provided by the Tyrer-Cuzick risk estimate.…”