OR (95% CI) of breast cancer in pre-menopausal women according to the use of hormonal contraceptive treatment.

<p>(*) Adjusted for: age, socioeconomically status (high/medium/low), BMI (kg/m2), familial history of breast cancer in first degree relatives (yes/no), diabetes(yes/no), number of full term pregnancy, age at first full term pregnancy (years), total duration of breast feeding (months) and age at menarche (years).</p><p>(**) additional adjusted for European ancestry.</p><p>(***) We defined the recent use as the reported use of contraceptive treatment during the year prior to the date of interview.</p

Demographic and risk factor characteristics of the study population, according to the use of hormonal contraceptive and hormone replacement therapy.

<p>P-value (Chi² or Fisher’s exact tests) for the difference between HC non-users and users in premenopausal, and HRT non-users and users in postmenopausal women.</p

OR (95% CI) of breast cancer in post-menopause women according to the use of hormone replacement therapy.

<p>(*) Adjusted for: age, socioeconomic status (high/medium/low), BMI (kg/m2), familial history of breast cancer in first degree relatives (yes/no), diabetes(yes/no), number of full term pregnancy, age at first full term pregnancy (years), total duration of breast feeding (months) and age at menarche (years).</p><p>(**) additional adjusted for European ancestry.</p><p>(***) We defined the recent use as the reported use of menopausal hormone therapy during the year prior to the date of interview.</p

OR (95% CI) of breast cancer in premenopausal women according to ever use of hormone contraceptive, and in postmenopausal women according to ever use of hormone replacement therapy, stratified by BMI.

<p>Adjusted for: age, socioeconomic status (high/medium/low), BMI (kg/m2), familial history of breast cancer in first degree relatives (yes/no), diabetes(yes/no), number of full term pregnancy, age at first full term pregnancy (years), total duration of breast feeding (months) and age at menarche (years)</p

Serum 25–Hydroxyvitamin D₃ and Mammography Density among Mexican Women

<div><p>Low circulating levels of vitamin D and high mammographic density (MD) have been associated with higher risk of breast cancer. Although some evidence suggested an inverse association between circulating vitamin D and MD, no studies have investigated this association among Mexican women. We examined whether serum 25−hydroxyvitamin D3 [25(OH)D3] levels were associated with MD in a cross-sectional study nested within the large Mexican Teacher's Cohort. This study included 491 premenopausal women with a mean age of 42.9 years. Serum 25(OH)D3 levels were measured by liquid chromatography/tandem mass spectrometry. Linear regression and non-linear adjusted models were used to estimate the association of MD with serum 25(OH)D3. Median serum 25(OH)D3 level was 27.3 (23.3–32.8) (ng/ml). Forty one (8%) women had 25(OH)D3 levels in the deficient range (< 20 ng/ml). Body mass index (BMI) and total physical activity were significantly correlated with 25(OH)D3 (r = −0.109, P = 0.019 and r = 0.095, P = 0.003, respectively). In the multivariable linear regression, no significant association was observed between 25(OH)D3 levels and MD overall. However, in stratified analyses, higher serum 25(OH)D3 levels (≥27.3 ng/ml) were significantly inversely associated with percent MD among women with BMI below the median (β = −0.52, P = 0.047). Although no significant association was observed between serum 25(OH)D3 and percent MD in the overall population, specific subgroups of women may benefit from higher serum 25(OH)D3 levels.</p></div

Correlation between serum 25(OH)D3 and other risk factors.

<p>Correlation between serum 25(OH)D3 and other risk factors.</p

Fractional polynomial modelling of the association of serum 25(OH)D3 (ng/ml) with percent mammography density (MD).

<p>A model with 95%CI among women with: A) BMI < median (< 27.4 kgm²), B) BMI ≥ median (≥ 27.4 kgm²).</p

Multivariable linear regression estimates of percent MD (%), dense area (cm²), and non-dense area (cm²).

<p>Multivariable linear regression estimates of percent MD (%), dense area (cm²), and non-dense area (cm²).</p

Characteristics of the study population across predefined cut-points of serum 25(OH)D3.

<p>Characteristics of the study population across predefined cut-points of serum 25(OH)D3.</p

Association between menstrual and reproductive factors and breast cancer risk.

<p>Association between menstrual and reproductive factors and breast cancer risk.</p