Mammographic density changes in surgical weight loss-an indication for personalized screening

Effects of bariatric surgery on breast density in adult obese women: systematic review and meta-analysis

Introduction

Bariatric surgery is one of the most effective methods for treating obesity. It can effectively reduce body weight and reduce the incidence of obesity-related breast cancer. However, there are different conclusions about how bariatric surgery changes breast density. The purpose of this study was to clarify the changes in breast density from before to after bariatric surgery.

Methods

The relevant literature was searched through PubMed and Embase to screen for studies. Meta-analysis was used to clarify the changes in breast density from before to after bariatric surgery.

Results

A total of seven studies were included in this systematic review and meta-analysis, including a total of 535 people. The average body mass index decreased from 45.3 kg/m2 before surgery to 34.4 kg/m2 after surgery. By the Breast Imaging Reporting and Data System score, the proportion of grade A breast density from before to after bariatric surgery decreased by 3.83% (183 vs. 176), grade B (248 vs. 263) increased by 6.05%, grade C (94 vs. 89) decreased by 5.32%, and grade D (1 vs. 4) increased by 300%. There was no significant change in breast density from before to after bariatric surgery (OR=1.27, 95% confidence interval (CI) [0.74, 2.20], P=0.38). By the Volpara density grade score, postoperative volumetric breast density increased (standardized mean difference = -0.68, 95% CI [-1.08, -0.27], P = 0.001).

Discussions

Breast density increased significantly after bariatric surgery, but this depended on the method of detecting breast density. Further randomized controlled studies are needed to validate our conclusions.

OUP accepted manuscript

In screening for breast cancer (BC), mammographic breast density (MBD) is a powerful risk factor that increases breast carcinogenesis and synergistically reduces the sensitivity of mammography. It also reduces specificity of lesion identification, leading to recalls, additional testing, and delayed and later-stage diagnoses, which result in increased health care costs. These findings provide the foundation for dense breast notification laws and lead to the increase in patient and provider interest in MBD. However, unlike other risk factors for BC, MBD is dynamic through a woman’s lifetime and is modifiable. Although MBD is known to change as a result of factors such as reproductive history and hormonal status, few conclusions have been reached for lifestyle factors such as alcohol, diet, physical activity, smoking, body mass index (BMI), and some commonly used medications. Our review examines the emerging evidence for the association of modifiable factors on MBD and the influence of MBD on BC risk. There are clear associations between alcohol use and menopausal hormone therapy and increased MBD. Physical activity and the Mediterranean diet lower the risk of BC without significant effect on MBD. Although high BMI and smoking are known risk factors for BC, they have been found to decrease MBD. The influence of several other factors, including caffeine intake, nonhormonal medications, and vitamins, on MBD is unclear. We recommend counseling patients on these modifiable risk factors and using this knowledge to help with informed decision making for tailored BC prevention strategies.

Weight-lowering Effects of Glucagon-like Peptide-1 Receptor Agonists and Detection of Breast Cancer Among Obese Women with Diabetes

BACKGROUND

It has been proposed that the weight loss associated with glucagon-like peptide-1 receptor agonists (GLP-1 RAs) may improve detection of breast cancer in patients undergoing this treatment. We aimed to determine whether the weight-lowering effects of GLP-1 RAs are associated with an increased detection of breast cancer among obese women with type 2 diabetes.

METHODS

Using the UK Clinical Practice Research Datalink, we conducted a propensity score-matched cohort study among female obese patients with type 2 diabetes newly treated with antidiabetic drugs between 1 January 2007 and 31 January 2018. New users of GLP-1 RAs (n = 5,510) were matched to new users of second- to third-line noninsulin antidiabetic drugs (n = 5,510). We used time-dependent Cox proportional hazards models to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) of breast cancer associated with different GLP-1 RA maximal weight loss categories (<5%, 5%-10%, >10%).

RESULTS

Breast cancer incidence gradually increased with GLP-1 RA maximal weight loss categories, with the highest HR observed for patients achieving at least 10% weight loss (HR = 1.8, 95% CI = 1.1, 2.8). In secondary analyses, the HR for >10% weight loss was highest in the 2-3 years since treatment initiation (HR = 2.9, 95% CI = 1.2, 6.9).

CONCLUSIONS

In this population-based study, the detection of breast cancer gradually increased with GLP-1 RA weight loss categories, particularly among those achieving >10% weight loss. These results are consistent with the hypothesis that substantial weight loss with GLP-1 RAs may improve detection of breast cancer among obese patients with type 2 diabetes.

Adiposity Change Over the Life Course and Mammographic Breast Density in Postmenopausal Women

Mammographic breast density is a strong risk factor for breast cancer. We comprehensively investigated the associations of body mass index (BMI) change from ages 10, 18, and 30 to age at mammogram with mammographic breast density in postmenopausal women. We used multivariable linear regression models, adjusted for confounders, to investigate the associations of BMI change with volumetric percent density, dense volume, and nondense volume, assessed using Volpara in 367 women. At the time of mammogram, the mean age was 57.9 years. Compared with women who had a BMI gain of 0.1-5 kg/m2 from age 10, women who had a BMI gain of 5.1-10 kg/m2 had a 24.4% decrease [95% confidence interval (CI), 6.0%-39.2%] in volumetric percent density; women who had a BMI gain of 10.1-15 kg/m2 had a 46.1% decrease (95% CI, 33.0%-56.7%) in volumetric percent density; and women who had a BMI gain of >15 kg/m2 had a 56.5% decrease (95% CI, 46.0%-65.0%) in volumetric percent density. Similar, but slightly attenuated associations were observed for BMI gain from ages 18 and 30 to age at mammogram and volumetric percent density. BMI gain over the life course was positively associated with nondense volume, but not dense volume. We observed strong associations between BMI change over the life course and mammographic breast density. The inverse associations between early-life adiposity change and volumetric percent density suggest that childhood adiposity may confer long-term protection against postmenopausal breast cancer via its effect of mammographic breast density.

The impact of bariatric surgery on qualitative and quantitative breast density

BACKGROUND

Obesity and breast density are associated with breast cancer in postmenopausal women. Bariatric surgery effectively treats morbid obesity, with sustainable weight loss and reductions in cancer incidence. We evaluated changes in qualitative and quantitative density; hypothesizing breast density would increase following bariatric surgery.

METHODS

Women undergoing bariatric surgery from 1990 to 2015 were identified, excluding patients without a mammogram performed both before and after surgery. Changes in body mass index (BMI), time between mammograms and surgery, and American College of Radiology Breast Imaging Reporting and Data System (BI-RADS) scores were assessed. VolparaDensity™ automated software calculated volumetric breast density (VBD), fibroglandular volume (FGV), and total breast volume for the 82 women with digital data available. Differences between pre- and postsurgery values were assessed.

RESULTS

One hundred eighty women were included. Median age at surgery was 50.0 years, with 8.8 months between presurgery mammogram and surgery and 62.3 months between surgery and postsurgery mammogram. Median BMI significantly decreased over the study period (46.0 vs 35.4 kg/m² ; P < 0.001). No change in BI-RADS scores was seen between the pre- and postsurgery mammograms. Eighty-two women had VolparaDensity™ data available. While VBD increased in these patients, FGV and total breast volume both decreased following bariatric surgery.

CONCLUSIONS

Increased VBD, decreased FGV, and decreased total breast volume were seen following bariatric surgery-induced weight loss. There was no difference in qualitative breast density, highlighting the discrepancy between BI-RADS and VolparaDensity™ measurements. Further investigation will be required to determine how differential changes in components of breast density may affect breast cancer risk.

Changes in mammographic density following bariatric surgery

BACKGROUND

Obesity and high breast density both increase breast cancer risk but paradoxically are inversely related. Bariatric surgery decreases breast cancer risk, but its impact on mammographic breast density is not well understood.

OBJECTIVES

We investigated how mammographic density changes after bariatric surgery and whether this change is related to weight loss.

SETTING

University of California, San Francisco Medical Center.

METHODS

We reviewed records from 349 prospectively collected patients who underwent bariatric surgery between 2013 and 2015 and identified 42 women with pre- and postoperative screening mammograms within 1.5 years of surgery. We recorded body mass index (BMI), height and Breast Imaging Reporting and Data System density and calculated BMI loss and total weight loss. Data were analyzed in Stata 14.2.

RESULTS

Average age was 54.2 years, mean preoperative BMI was 43.8 kg/m², mean BMI lost was 30.9%, and total weight loss was 31.1% at 1.3 years. Over one-third had a change in mammographic breast density, which increased 93.3% of the time (P < .001). Amount of weight loss was not associated with a density change. Patients with the lowest mammographic density preoperatively were most likely to have a density change (P = .02).

CONCLUSIONS

Most women with a mammographic change had an increase in breast density, despite bariatric surgery being associated with reduced breast cancer risk. Baseline breast density was associated with a density change, but amount of weight loss was not. These findings suggest the metabolic effects of bariatric surgery have an effect on breast parenchyma independent of absolute BMI reduction or weight loss.