Type 2 diabetes and mammographic breast density among underserved women

The association of metformin and aspirin intake with mammographic breast density: A cross-sectional study

Background

Our purpose was to investigate the association between Mammographic breast density (MBD), a known strong marker for breast cancer and metformin and aspirin use and duration of use alone or simultaneously, in a sample of Iranian women considering other confounding factors.

Methods

In a cross-sectional study, 712 individuals were selected out of women referred to two university hospitals for screening mammography. Participants' information was collected with a questionnaire. Four-category density scale (a = almost entirely fatty, b = scattered fibroglandular densities, c= heterogeneously dense, and d = extremely dense) was categorized as low (a&b) and high (c&d) density.

Results

The mean age of the participants was 49.80 ± 7.26 years. Sixty-five percent of women belonged to the high and 35% to the low MBD category. Both aspirin and metformin had a significantly negative association with MBD, however, when confounding factors were entered into the models, only aspirin after adjustment for age and BMI had an inverse association with MBD (OR = 0.53, 95% CI: 0.35-0.94). Simultaneous use of metformin and aspirin (OR = 0.44, 95 %CI: 0.17-1.12) was associated with lower MBD. Furthermore, in women who used metformin (OR = 0.23, 95% CI: 0.09-0.62) and aspirin (OR= 0.35, 95% CI: 0.17-0.72) for 2 to 5 years, MBD was significantly lower. However, after the adjustment of confounding factors, these associations were not statistically significant.

Conclusion

It seems metformin and aspirin intakes are associated with MBD. However, further studies with more sample size are needed.

Independent and joint cross-sectional associations of statin and metformin use with mammographic breast density

BACKGROUND

Well-tolerated and commonly used medications are increasingly assessed for reducing breast cancer risk. These include metformin and statins, both linked to reduced hormone availability and cell proliferation or growth and sometimes prescribed concurrently. We investigated independent and joint associations of these medications with mammographic breast density (MBD), a useful biomarker for the effect of chemopreventive agents on breast cancer risk.

METHODS

Using data from a cross-sectional study of 770 women (78% Hispanic, aged 40-61 years, in a mammography cohort with high cardiometabolic burden), we examined the association of self-reported "ever" use of statins and metformin with MBD measured via clinical Breast Imaging Reporting and Data System (BI-RADS) density classifications (relative risk regression) and continuous semi-automated percent and size of dense area (Cumulus) (linear regression), adjusted for age, body mass index, education, race, menopausal status, age at first birth, and insulin use.

RESULTS

We observed high statin (27%), metformin (13%), and combination (9%) use, and most participants were overweight/obese (83%) and parous (87%). Statin use was associated with a lower likelihood of high density BI-RADS (RR = 0.60, 95% CI = 0.45 to 0.80), percent dense area (PD) (β = - 6.56, 95% CI = - 9.05 to - 4.06), and dense area (DA) (β = - 9.05, 95% CI = - 14.89 to - 3.22). Metformin use was associated with lower PD and higher non-dense area (NDA), but associations were attenuated by co-medication with statins. Compared to non-use of either medication, statin use alone or with metformin were associated with lower PD and DA (e.g., β = - 6.86, 95% CI: - 9.67, - 4.05 and β = - 7.07, 95% CI: - 10.97, - 3.17, respectively, for PD) and higher NDA (β = 25.05, 95% CI: 14.06, 36.03; β = 29.76, 95% CI: 14.55, 44.96, respectively).

CONCLUSIONS

Statin use was consistently associated with lower MBD, measured both through clinical radiologist assessment and continuous relative and absolute measures, including dense area. Metformin use was associated with lower PD and higher NDA, but this may be driven by co-medication with statins. These results support that statins may lower MBD but need confirmation with prospective and clinical data to distinguish the results of medication use from that of disease.

Gestational diabetes, type II diabetes, and mammographic breast density in a U.S. racially diverse population screened for breast cancer

PURPOSE

Type II diabetes mellitus (T2DM) has consistently been associated with an increased risk of breast cancer, but the association of gestational diabetes mellitus (GDM) with breast cancer is less clear. T2DM and GDM may influence breast cancer risk through mammographic breast density, a strong risk factor for breast cancer. We examined whether T2DM and GDM are associated with higher mammographic breast density in a largely racial/ethnic minority sample.

METHODS

We collected digital mammograms, anthropometric measures, and interview data from 511 racially diverse women recruited during screening mammography appointments between 2012 and 2016 (mean age 51 years; 70% Hispanic). We examined the associations of self-reported GDM, T2DM, and medication use (metformin and insulin) with mammographic breast density, measured as percent and area of dense tissue using Cumulus software.

RESULTS

In multivariable linear regression models, history of T2DM and/or GDM and length of time since diagnosis were not associated with percent density or dense breast area, either before or after adjustment for current BMI. Use of metformin in diabetic women was associated with lower percent density (β = - 5.73, 95% CI - 10.27, - 1.19), only before adjusting for BMI. These associations were not modified by menopausal status.

CONCLUSIONS

Our results do not support associations between T2DM and/or GDM and higher amount of mammographically dense breast tissue, suggesting that the mechanism linking diabetes with breast cancer risk may not include mammographic breast density in midlife.

Diabetes, diabetes treatment, and mammographic density in Danish Diet, Cancer, and Health cohort

Purpose

We examined whether diabetes and diabetes treatment are associated with MD in a cohort study of Danish women above age of 50 years.

Methods

Study cohort consisted of 5,644 women (4,500 postmenopausal) who participated in the Danish Diet, Cancer, and Health cohort (1993–1997) and subsequently attended mammographic screening in Copenhagen (1993–2001). We used MD assessed at the first screening after the cohort entry, defined as mixed/dense or fatty. Diabetes diagnoses and diabetes treatments (diet, insulin, or oral antidiabetic agents) were self-reported at the time of recruitment (1993–1997). The association between MD and diabetes was analyzed by logistic regression adjusted for potential confounders. Effect modification by menopausal status and body mass index (BMI) was performed by introducing an interaction term into the model and tested by Wald test.

Results

Of 5,644 women with mean age of 56 years, 137 (2.4%) had diabetes and 3,180 (56.3%) had mixed/dense breasts. Having diabetes was significantly inversely associated with having mixed/dense breasts, in both, the crude model (odds ratio; 95% confidence interval: 0.33; 0.23–0.48), and after adjustment for adiposity and other risk factors (0.61; 0.40–0.92). Similar inverse associations were observed for 44 women who controlled diabetes by diet only and did not receive any medication (0.56; 0.27–1.14), and 62 who took oral antidiabetic agents only for diabetes (0.59; 0.32–1.09), while women taking insulin had increased odds of mixed/dense breasts (2.08; 0.68–6.35). There was no effect modification of these associations by menopausal status or BMI.

Conclusions

Having diabetes controlled by diet or oral antidiabetic agents is associated with a decrease in MD, whereas taking insulin is associated with an increase in MD.