The relationship between education level and mammographic density

Abstract

To further understand the factors that contribute to interindividual variation in mammographic density, we evaluated the relationship between education level and each component of the mammographic density measures. Study participants included 535 women between 40 and 65 years of age who received a mammogram for a population-based twin and family study. Mammographic density was measured from digital mammograms using a computer-assisted thresholding method. To avoid negative confounding by obesity level, we calculated BMI-adjusted mammographic measures. Thereafter, each of the mammographic density measures was t-transformed using its mean value and SD for each age strata. The level of education was chosen as a marker representing socioeconomic status at the individual level. A linear mixed model considering familial correlations was used for analyses. In the unadjusted analysis for all women, the BMI-adjusted nondense area gradually decreased with an increase in education level (P for trend=0.017). This association persisted after adjusting for menstrual and reproductive factors. When we repeated the analysis according to menopausal status, an inverse association between education level and nondense area was evident in premenopausal women, whereas the inverse association attenuated to a statistically insignificant level after adjusting for menstrual and reproductive factors in postmenopausal women. Absolute dense area and percentage dense area were not associated with education level. The significant association between nondense area and education level after eliminating the effect of age and BMI suggests that socioeconomic factors may have an influential role in determining the amount of fat tissue in the breast.

Breast cancer risk factors and mammographic density among high-risk women in urban China

“…Consistent with several studies, 61 , 62 we found that higher levels of education were independently associated with higher MD, suggesting that the MD association with education could not be fully accounted for by measured variables such as BMI and reproductive factors. Other unmeasured lifestyle factors including dietary factors, physical activity, and socioeconomic status-related stress may also contribute and further investigation of these relationships is warranted in future studies.…”

Increased breast cancer mortality only in the lower education group: age-period-cohort effect in breast cancer mortality by educational level in South Korea, 1983-2012

“…However, unfortunately, there were few studies that contained evidence to conclude what the main risk factors were. Reproductive factors including age at first birth were still less favorable for the higher education group in Korea [ 38 ], likewise with western countries [ 39 , 40 ], and the study which supported the decreasing gap in reproductive factors between educational groups could not be found. The gap of age at first birth by educational level among the 1960-1964 birth cohort, the 1965-1969 birth cohort, and the 1970-1974 birth cohort was not different [ 41 ], although the gap of the number of live births by educational level decreased between 1980 and 2000 [ 42 ].…”

The epidemiologic factors associated with breast density: A review

“…Some studies evaluated the association between the breast density and other factors, such as residential traffic noise, education level, occupation, metabolic syndrome, socioeconomic status, and diabetes. [ 68 159 160 161 162 163 164 165 166 167 168 ] Roswall et al . [ 159 ] found no association between breast density and traffic noise exposure, either residential road or railway noise in a Danish cohort.…”

“…Another study found that the socioeconomic status played a role in determining the amount of fat in breast. [ 160 ] However, another study found early life socioeconomic status, including education and income was not significantly associated with breast density in adulthood. [ 167 ] Lope et al .…”