Grimm, Lars J.

Abstract Background: Metformin may impact tumorigenesis directly, through effects on AMP kinase, and indirectly, through reduction in circulating growth factors such as insulin. To examine the potential preventive effects of metformin, we analyzed MD, a known risk factor for breast cancer, in participants enrolled in the NCIC MA.32 trial, a randomized, placebo-controlled trial investigating the effects of 5 years of metformin on invasive disease-free survival in women with early breast cancer. The primary aim of this companion to MA.32 (Alliance A211201) was to examine the effects of 1 year of metformin vs placebo on MD in women treated for estrogen receptor negative (ER-) breast cancer. Methods: Eligible women were enrolled on MA.32, had ER- breast cancer, had >25% MD at baseline, and had an unaffected contralateral breast. MD was calculated on the contralateral breast using Cumulus software and analyzed at baseline, 1 and 2 years. The aim was to achieve a sample size of 274 (137 per arm), which would have at least 85% power to detect a 4% difference between study arms, i.e., 5% change from baseline to one year of treatment for metformin vs. 1% for placebo, using a two-sided two-sample t-test at a significance level of 5%. The current study was activated in the United States on 8/22/2012. Enrollment was halted on 10/13/2017 with 177 participants enrolled. Results: 146 women were evaluable (66 on metformin and 80 on placebo). The mean age of evaluable women was 53.6 years (standard deviation [SD] 9.4), 88.4% were white, 31.5% had a body mass index greater than or equal to 30 kg/m2, 99.3% of participants received chemotherapy. The proportions of white women and HER2+ participants in the metformin group were higher compared to placebo ([white 92.4% vs. 85.0%] and [HER2+ 21.2% vs. 11.3%], respectively). The mean MD at baseline was 22.7% (SD 14.1%) for the group as a whole (24.5% (SD 14.5%) for the metformin group and 21.2% (SD 13.6%) for the placebo group. This is lower than the eligibility criteria (>25%MD), due to difference in methods of calculation of MD (BIRADs for eligibility and Cumulus for study analysis). At 1 year, MD decreased by 0.7% (SD 7.6%) in the metformin group and 0.2% (SD 7.3%) in the placebo group (p = 0.58). At 2 years, MD decreased by 0.7% (SD 8.0%) in the metformin group and 0.8% (SD 7.1%) in the placebo group (p=0.60). Conclusions: In a cohort of women with early ER- breast cancer, there was no significant difference in the change in MD in women treated with metformin vs. placebo. There was a non-significant trend toward decreased MD while on metformin after 1 year of treatment. The arms were well balanced, though with more white and HER2+ participants in the metformin arm. The sample size for this study was about half of what was intended thus limiting power to detect a significant difference. Additional limitations include low mean MD, which may have limited our ability to detect the benefit in those at the highest risk, and further, the Cumulus method of MD determination can be imprecise. Interestingly, trends toward decreased MD with metformin were seen in Alliance A211102, and it might be reasonable to consider further study of metformin in a select population (highest MD or atypical hyperplasia). Support: UG1CA189823, U10CA180863, CCS 707213; https://acknowledgments.alliancefound.org.Clinicaltrials.gov ID: NCT01666171. Citation Format: M. Wood, M. I. Elsaid, L. J. Grimm, H. Liu, C. Oswold, C. S. Kuzma, I. Bedrosian, J. Ligibel, P. J. Goodwin. Change in mammographic density (MD) with metformin use: Alliance A211201, A companion study to NCIC study MA.32 [abstract]. In: Proceedings of the San Antonio Breast Cancer Symposium 2025; 2025 Dec 9-12; San Antonio, TX. Philadelphia (PA): AACR; Clin Cancer Res 2026;32(4 Suppl):Abstract nr PS3-01-30.

Abstract Breast image-guided procedures play a critical role in the diagnosis and management of breast cancer, serving as the gold standard for tissue sampling and preoperative localization. These minimally invasive procedures carry a very low risk of complications, with postprocedural infections occurring in fewer than 0.2% of cases. However, given the high volume of breast interventions performed annually, the potential impact of infections remains significant. Despite this, published guidelines addressing procedural cleanliness techniques in breast imaging are sparse and often provide conflicting recommendations, leading to variability in clinical practice and resource utilization. The lack of clear and specific guidance creates challenges for radiologists navigating institutional policies and best practice implementation. This review synthesizes existing standards and guidelines, evaluating the supporting evidence to propose an evidence-based best practice approach for maintaining clean techniques in breast image-guided procedures. By standardizing cleanliness protocols, we aim to enhance patient care, optimize procedural success, and promote consistency across breast imaging practices.

Abstract Objectives Implicit bias is common and is thought to drive discriminatory behaviour. Having previously demonstrated discrimination against specific applicant demographics by academic radiology departments in a simulated resident selection process, the authors sought to better understand the relationship between implicit bias and discrimination, as well as the potential and mechanisms for their mitigation. Methods A total of 51 faculty reviewers at three academic radiology departments, who had participated in a 2017 audit study in which they were shown to treat applicants differently based on race or ethnicity and physical appearance, were invited to complete testing for implicit racial and weight bias using the Implicit Association Test in 2019. Respondents were also surveyed regarding awareness of their own personal racial and weight biases, as well as any prior participation in formal diversity training. Comparisons were made between implicit bias scores and applicant ratings, as well as between diversity training and self‐awareness of bias. Results A total of 31 out of 51 faculty reviewers (61%) completed and submitted results of race and weight Implicit Association Tests. A total of 74% (23/31) reported implicit anti‐obese bias, concordant with discrimination demonstrated in the resident selection simulation, in which obese applicants were rated 0.40 standard deviations (SDs) lower than non‐obese applicants ( P < .001). A total of 71% (22/31) reported implicit anti‐Black bias, discordant with application ratings, which were 0.47 SDs higher for Black than for White applicants ( P < .001). A total of 84% (26/31) of participants reported feeling self‐aware of potential racial bias at the time of application review, significantly higher than the 23% (7/31) reporting self‐awareness of potential anti‐obese bias ( P < .001). Participation in formal diversity training was not associated with implicit anti‐Black or anti‐fat bias, nor with self‐reported awareness of potential racial or weight‐based bias (all P > .2). Conclusions These findings suggest that implicit bias, as measured by the Implicit Association Test, does not inevitably lead to discrimination, and that personal awareness of implicit biases may allow their mitigation.

Purpose To evaluate for appearance-based discrimination in the selection of radiology residents. Method A deception study simulating the resident selection process examined the impact of attractiveness and obesity on resident selection. Seventy-four core faculty from 5 academic radiology departments reviewed mock residency applications in September and October 2017. Each application included demographic information and a photograph, representing a prespecified distribution of facial attractiveness and obesity, combined with randomized academic and supporting variables. Reviewers independently scored applications for interview desirability. Reviewer scores and application variables were compared using linear mixed fixed- and random-effects models. Results Reviewers evaluated 5,447 applications (mean: 74 applications per reviewer). United States Medical Licensing Examination Step 1 scores were the strongest predictor of reviewer rating (B = 0.35 [standard error (SE) = 0.029]). Applicant facial attractiveness strongly predicted rating (attractive vs unattractive, B = 0.30 [SE = 0.056]; neutral vs unattractive, B = 0.13 [SE = 0.028]). Less influential but still significant predictors included race/ethnicity (B = 0.25 [SE = 0.059]), preclinical class rank (B = 0.25 [SE = 0.040]), clinical clerkship grades (B = 0.23 [SE = 0.034]), Alpha Omega Alpha membership (B = 0.21 [SE = 0.032]), and obesity (vs not obese) (B = −0.14 [SE = 0.024]). Conclusions Findings provide preliminary evidence of discrimination against facially unattractive and obese applicants in radiology resident selection. Obesity and attractiveness were as influential in applicant selection for interview as traditional medical school performance metrics. Selection committees should invoke strategies to detect and manage appearance-based bias.