Pacheco-Spann, Laura M.

Abstract Objectives: Mammographic microcalcifications (calcs) are a sentinel marker of in-situ and invasive breast cancer (BC) but most calcs reflect benign breast disease (BBD). BBD comprises a diverse set of lesions, variably associated with increased BC risk. While calc frequency data for the modern era are limited, historically, calcs were reported in 11% of BBD biopsies. Some studies suggest that calcs in BBD impact BC risks; however, the frequency and BC risks associated with calcs during the percutaneous biopsy era have not been clearly established. Accordingly, we assessed the association of calcs with specific BBD lesions and BC risk in a large contemporaneous BBD cohort including detailed pathology review. Methods: A cohort of 4,819 patients with percutaneously diagnosed BBD from 2002-2013 at Mayo Clinic, were identified. The cohort was followed from 6 months after biopsy until censoring, BC diagnosis, or December 2021. Mean follow-up was 11.3 (SD=5.1) years for BBD patients who remained cancer-free in follow-up compared with 7.4 (SD=4.3) years for cases. Histology of all biopsies were reviewed microscopically to record pathologic findings. A natural language processing algorithm (NLPA) was developed and utilized to identify the presence of calcs based on pathology reports. NLPA results were compared to 300 matched biopsy reports, taken as ground truth. We performed age-adjusted Cox proportional hazards regression to assess hazard ratios (HRs) with 95% confidence intervals (CIs) for specific BBD lesions, stratified by the presence (calc+) or absence of calcs (calcs-), with estimation of an interaction term to test for differences in risks by calc strata. Standardized incidence ratios (SIRs) estimated risks for calc+ and calc- BBD lesions versus matched strata for Iowa SEER population-based BC incidence rates. Results: The NLPA achieved sensitivity=0.993 and specificity=0.986. Overall, 42.8% of BBD biopsies were calc+, including 49.1% of biopsies preceding BC and 42.4% of biopsies not preceding BC (Chi-square p=0.02). Overall, risks of BC among women with BBD calc+ biopsies did not differ significantly from those of women with calc- BBD: HR=1.13 (95% CI: 0.90,1.41), p=0.290. SIRs were also similar for the two groups; women with BBD calc+ biopsies had an SIR =2.00 (95% CI: 1.72, 2.33) and BBD calc- biopsies yielded an SIR= 1.91 (95% CI: 1.64,2.22) (Table 1). HRs were similar for specific calc+ and calc- BBD lesions, with progressively higher risks for non-proliferative disease (NP), proliferative disease without atypia (PDWA) and atypical hyperplasia (AH) (pinteraction=0.55). Interaction terms were not significant for any specific lesion, apart from a marginally significant result for dilated ducts, wherein risks were marginally higher for calc- lesions (pInteraction =0.048), perhaps representing a chance finding. SIRs for calc+ versus calc- BBD lesions were also similar. Overall, 77.3% of AH was calc+; for AH calc+, SIR=3.76 (95%CI: 2.74-5.17) and for AH calc-, SIR=4.41 (95%CI: 2.56-7.59). Conclusion: In this recent, larger percutaneous BBD cohort, calcs were present in 42.8% of all specimens, representing a marked increase compared with historical BBD data, particularly those dominated by surgical biopsy for diagnosis and preceding implementation of full-field digital mammography. In this study, calcs in percutaneously diagnosed BBD were not associated with increased BC risk. Table 1: Comparison of standard incidence ratio of subsequent breast cancer with and without microcalcifications in benign breast disease by histologic impression (NP = non-proliferative disease, PDWA = proliferative disease without atypia, and AH = atypical hyperplasia). (1) compared to Iowa SEER population Citation Format: Sarah Schrup, Robert Vierkant, Stacey Winham, Celine Vachon, Derek Radisky, Jodi Carter, Laura Pacheco-Spann, Matthew Jensen, Amy Degnim, Mark Sherman. Benign breast disease and microcalcifications in percutaneous biopsies and breast cancer risk [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PS07-02.

Abstract Objectives: Carriers of pathogenic variants in high penetrance mutations, including BRCA 1 or BRCA 2 face higher lifetime risks of developing breast and tubo-ovarian cancers, and possibly endometrial cancers, than non-carriers. In particular, relative risks are higher among carriers than non-carriers at younger ages, suggesting the value of early initiation of breast cancer screening and the use of sensitive imaging methods, such as magnetic resonance imaging (MRI). Further, breastfeeding appears protective for these three cancers in the general population, and potentially among mutation carriers, albeit based on limited evidence. Given that data related to knowledge and perspectives of carriers about these issues are limited, we surveyed mutation carriers regarding breastfeeding, cancer risk, and the deferral of breast cancer screening coinciding with reproductive events. These data may guide future cancer prevention research and developing of targeted communication campaigns. Methods: Researchers at Mayo Clinic, in collaboration with Facing Our Risk of Cancer Empowered (FORCE) – a large, national non-profit organization that addresses the needs of people and families affected by inherited mutations linked to cancer – designed and conducted a survey using the Mayo Clinic’s external RedCap system. The survey covered genetic testing and results, history of live births and breastfeeding history for mothers, history of risk-reducing surgery, personal cancer history, sources of information about cancer screening, breastfeeding knowledge, and breast cancer screening at various times, including during pregnancy, while breastfeeding, and after weaning. The survey was disseminated through FORCE’s electronic newsletter, website, social media pages, and advocacy partners. Survey responses were collected anonymously and analyzed descriptively using standard descriptive statistics, including frequency and percentages for categorical responses and means (SD) or medians (IQR) for continuously scaled responses. The open-ended responses were analyzed qualitatively using standard qualitative methodology. Results: Respondents included 253 women, of whom 88.7% were U.S. residents and 92.9% were white. The mean age + SD was 47(13) years, 61.7% were parous, with a mean age at first birth of 22.58 (13.16) years. Approximately 60% of women were carriers of mutations in BRCA1 or BRCA2 or both genes and all but two of the remaining women reported mutations in other genes linked to increased cancer risk. At the time of the survey, 92% of women had undergone a mammogram, with first screen at a mean age of 35 (6.49) years, and 85.3% had undergone breast MRI, with first screen at a mean age of 43 (12.39) years. Among 34.3% of participants, their 1st postpartum mammogram occurred >3 years after the birth of their last child and 57% had 1st MRI 3 years postpartum. Preliminarily, our analysis shows that nearly 90% of women were unaware of their mutation status prior to pregnancy and approximately 1/3 did not undergo radiologic screening until 3 years postpartum. While 62.6% of respondents believed that breastfeeding lowers breast cancer risk, 74.2% of participants responded that nursing had no effect on tubo-ovarian cancer risk, and 78.2% considered that nursing did not impact endometrial cancer risk. Discussion and Conclusions: Preliminarily, we conclude that most women in the surveyed population were unaware of their mutation status when pregnant years earlier and many had not undergone screening until years after delivery. Many participants did not consider breastfeeding a potentially protective factor for women’s cancers. These data raise issues about the potential value of discussing genetic testing with women when considering family planning and mutation carriers, addressing complex issues about breast cancer screening while pregnant and breastfeeding. Citation Format: Laura Pacheco-Spann, Mark Sherman, Susan Friedman, Diane Rose, Miriam Levi, Alex Hochwald, Jennifer Ridgeway, Sophia Blumenfeld. Breastfeeding and Breast Cancer Screening Among Carriers of Pathogenic Variants in BRCA 1 and BRCA 2 and Other High Penetrance Genes: Knowledge and Perspectives [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO5-08-03.

Abstract Over 1 million women in the U.S. undergo radiologically guided percutaneous biopsies annually. Of these, 75% reveal benign breast disease (BBD), typically surrounded by normal breast lobules, which are proposed to reflect the biology of the breast parenchyma diffusely. With aging, normal lobules undergo involution, and delays in this process are linked to increased breast cancer (BC) risk. Because BBD patients are at increased risk of developing BC, and pathologic classification only stratifies risks among groups of patients, novel methods for individual BC risk prediction are needed to guide precision management. Prior literature has shown that most proliferating epithelial cells in normal lobules do not express estrogen receptor (i.e., ER-/Ki67+), whereas co-expression is frequent in BC precursors and in BCs (i.e., ER+/Ki67+). Thus we developed and applied a novel quantitative dual ER/Ki67 stain to BBD biopsies from the well-characterized contemporary Mayo Clinic BBD cohort (2002-2013) to assess differences by levels of lobular involution and tissue type (BBD vs. normal), as well as associations with BC risk. We identified 100 BBD biopsies preceding BC (cases) and 100 biopsies from cancer-free women (controls), frequency-matched on age and length of follow-up. A multiplex immunofluorescence assay was developed to detect ER/Ki67 coexpression in cytokeratin positive epithelial cells in normal lobules or BBD lesions in FFPE tissue sections. An inverse normal transformation was applied to cell counts and proportions and associations were assessed for levels of lobular involution, tissue type (normal lobule vs. BBD), and case status using t-tests and linear regression models. The final data set included 1152 normal lobules or BBD lesions in biopsies of 177 subjects (88 cases and 89 controls). In univariate analyses, normal lobules showing delayed age related involution included higher counts of ER-/Ki67+, ER+/Ki67- and ER+/Ki67+ cells, and the lowest proportion of ER+/Ki67- cells (p<0.03; all). In separate analyses comparing presence vs. absence, detection of any ER+/Ki67+ cells was suggestively more common in non-involuted vs. involuted lobules. Compared with normal lobules, BBD showed higher counts and proportions of ER+/Ki67- and ER+/Ki67+ cells and lower values for ER-/Ki67+ (all p<0.001). In these preliminary results, marker expression in normal lobules and in BBD did not differ by case-control status. Preliminarily, we find that ER+/Ki67+ cells are increased in normal lobules with delayed age-related involution and in BBD lesions, consistent with their associations with increased BC risk. These findings are consistent with the risk reducing effects of endocrine chemoprevention and may serve as useful biomarkers in prevention therapy. In this analysis, limited to only a few lobules and BBD lesions per biopsy, ER+/Ki67+ cell counts and proportions did not vary significantly by case-control status. Citation Format: Melody L. Stallings-Mann, Robert A. Vierkant, Stacey J. Winham, Bryan McCauley, Matt R. Jensen, Sophie Noel, Laura Pacheco-Spann, Celine M. Vachon, Amy C. Degnim, Derek C. Radisky, Mark E. Sherman. Measurement of ER and Ki67 coexpression in cytokeratin positive epithelial cells in benign breast disease (BBD) percutaneous biopsies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr LB328.

Abstract Triple negative breast cancer (TNBC) represents an aggressive and therapeutically challenging breast cancer subtype with higher incidence and mortality rates in non-Hispanic Black (NHB) women. This disparity persists even after adjusting for socioeconomic factors, tumor biology, and quality of care. The study aims to unravel specific molecular mechanisms underlying this disparity, with a focus on Hedgehog signaling pathways in premenopausal NHB women. Understanding these mechanisms is vital for developing targeted therapies and personalized medicine approaches to address these health disparities. Our research utilized a unique cohort of NHB and non-Hispanic White (NHW) women who underwent breast reduction surgery at the Mayo Clinic and donated breast tissue samples for our study. We isolated RNA from whole tissue sections from a cohort of 12 NHB and 40 NHW women who were parous and premenopausal at time of surgery. We performed gene expression profiling using NanoString BC360 and IO360 assays. This allowed us to identify a distinct gene expression signature characteristic of basal-like/TNBC and indicative of heightened activity in the Hedgehog signaling pathway. We also employed advanced cell culture techniques to generate tissue organoids and subculture human mammary epithelial cells (HMECs) that preserve the intrinsic characteristics of the original tissue samples. We found that significantly differential expression of IL20RA and SOX10, principal factors in the gene expression signature, were preserved in both the derived organoids and the HMECs. These results suggest a potential intrinsic difference in the activation of the Hedgehog pathway in the breast epithelial cells of NHB women. This activation may contribute to increased proliferation and transformation of basal stem cells within the breast, possibly fueling the development and progression of TNBC. The implication of activated Hedgehog signaling in NHB women opens new avenues for understanding TNBC disparities. IL20RA and SOX10 represent potential biomarkers for TNBC risk that may serve as a stratification tool for NHB women. The results of this study have the potential to improve assessment and management of TNBC risk among NHB women, thereby contributing significantly to reducing health disparities in breast cancer outcomes. Citation Format: Jennifer Vanessa Cabezas, Savanna Touré, Matthew Wilson, Melody L. Stallings Mann, Laura M. Pacheco-Spann, Joshua W. Ogony, Mark E. Sherman, Derek C. Radisky. Identifying molecular mechanisms in triple negative breast cancer disparities: Unveiling the role of Hedgehog signaling in non-Hispanic Black women [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2139.

Importance Benign breast disease (BBD) comprises approximately 75% of breast biopsy diagnoses. Surgical biopsy specimens diagnosed as nonproliferative (NP), proliferative disease without atypia (PDWA), or atypical hyperplasia (AH) are associated with increasing breast cancer (BC) risk; however, knowledge is limited on risk associated with percutaneously diagnosed BBD. Objectives To estimate BC risk associated with BBD in the percutaneous biopsy era irrespective of surgical biopsy. Design, Setting, and Participants In this retrospective cohort study, BBD biopsy specimens collected from January 1, 2002, to December 31, 2013, from patients with BBD at Mayo Clinic in Rochester, Minnesota, were reviewed by 2 pathologists masked to outcomes. Women were followed up from 6 months after biopsy until censoring, BC diagnosis, or December 31, 2021. Exposure Benign breast disease classification and multiplicity by pathology panel review. Main Outcomes The main outcome was diagnosis of BC overall and stratified as ductal carcinoma in situ (DCIS) or invasive BC. Risk for presence vs absence of BBD lesions was assessed by Cox proportional hazards regression. Risk in patients with BBD compared with female breast cancer incidence rates from the Iowa Surveillance, Epidemiology, and End Results (SEER) program were estimated. Results Among 4819 female participants, median age was 51 years (IQR, 43-62 years). Median follow-up was 10.9 years (IQR, 7.7-14.2 years) for control individuals without BC vs 6.6 years (IQR, 3.7-10.1 years) for patients with BC. Risk was higher in the cohort with BBD than in SEER data: BC overall (standard incidence ratio [SIR], 1.95; 95% CI, 1.76-2.17), invasive BC (SIR, 1.56; 95% CI, 1.37-1.78), and DCIS (SIR, 3.10; 95% CI, 2.54-3.77). The SIRs increased with increasing BBD severity (1.42 [95% CI, 1.19-1.71] for NP, 2.19 [95% CI, 1.88-2.54] for PDWA, and 3.91 [95% CI, 2.97-5.14] for AH), comparable to surgical cohorts with BBD. Risk also increased with increasing lesion multiplicity (SIR: 2.40 [95% CI, 2.06-2.79] for ≥3 foci of NP, 3.72 [95% CI, 2.31-5.99] for ≥3 foci of PDWA, and 5.29 [95% CI, 3.37-8.29] for ≥3 foci of AH). Ten-year BC cumulative incidence was 4.3% for NP, 6.6% for PDWA, and 14.6% for AH vs an expected population cumulative incidence of 2.9%. Conclusions and Relevance In this contemporary cohort study of women diagnosed with BBD in the percutaneous biopsy era, overall risk of BC was increased vs the general population (DCIS and invasive cancer combined), similar to that in historical BBD cohorts. Development and validation of pathologic classifications including both BBD severity and multiplicity may enable improved BC risk stratification.

(1) Background: Telemetry units allow the continuous monitoring of vital signs and ECG of patients. Such physiological indicators work as the digital signatures and biomarkers of disease that can aid in detecting abnormalities that appear before cardiac arrests (CAs). This review aims to identify the vital sign abnormalities measured by telemetry systems that most accurately predict CAs. (2) Methods: We conducted a systematic review using PubMed, Embase, Web of Science, and MEDLINE to search studies evaluating telemetry-detected vital signs that preceded in-hospital CAs (IHCAs). (3) Results and Discussion: Out of 45 studies, 9 met the eligibility criteria. Seven studies were case series, and 2 were case controls. Four studies evaluated ECG parameters, and 5 evaluated other physiological indicators such as blood pressure, heart rate, respiratory rate, oxygen saturation, and temperature. Vital sign changes were highly frequent among participants and reached statistical significance compared to control subjects. There was no single vital sign change pattern found in all patients. ECG alarm thresholds may be adjustable to reduce alarm fatigue. Our review was limited by the significant dissimilarities of the studies on methodology and objectives. (4) Conclusions: Evidence confirms that changes in vital signs have the potential for predicting IHCAs. There is no consensus on how to best analyze these digital biomarkers. More rigorous and larger-scale prospective studies are needed to determine the predictive value of telemetry-detected vital signs for IHCAs.

Abstract Introduction: We used micro-computed tomography (microCT), a high-resolution imaging option, to detect and characterize microcalcifications (MCs) in three dimensions within pathology blocks of benign and malignant breast tissues. Methods: A set of 44 formalin-fixed, paraffin-embedded breast tissue blocks were assessed from n=22 women at two time points: benign breast biopsy and subsequent DCIS or DCIS with invasive disease breast cancer. Blocks were scanned using the Bruker Skyscan 1276 microCT at a resolution of 10 µm. SkyScan analysis CTAn software was utilized to prepare and analyze morphological parameters and multiple MCs contained within each block were averaged. Paired morphological parameters were compared between the benign and subsequent cancer samples within women using Wilcoxon signed-rank tests. Results: Median age of patients was 53 years (range 37-77 years) at initial benign biopsy and developed breast cancer at median of 5.6 years (range: 2.3-12.8 years) later. The initial benign biopsies were for proliferative disease without atypia in the majority (59%), while 23% had non-proliferative lesions and 18% atypical hyperplasia. The average structural model index was consistent with a near rod-like shape (median 2.99, range: 2.71-3.29). Paired comparisons between benign and cancer blocks showed that the average surface area of MCs was significantly higher in the cancer samples (p=0.0467), as was the average volume of MCs (p=0.0298) (Table 1). Conclusions: Preliminarily, we demonstrate that microCT of routinely prepared pathology blocks of breast tissues may be useful in characterizing the 3-D morphometry of MCs with suggestive differences in benign and cancer tissues. Given that MCs are a sentinel radiologic marker of DCIS but are common in benign breast disease, developing improved approaches for classifying MCs may have value in breast cancer screening and management. Table 1. Comparison of MC parameters in biopsy tissues (IQR = Interquartile Range). Benign sample from women who later developed breast cancer Breast cancer after prior benign sample Paired Differences (Cancer - Benign) Wilcoxon signed-rank p value (N=22) (N=22) (N=22) Number of Objects (Median (IQR)) 43.5 (14, 789) 69.5 (33, 289) -6 (-139, 67) 0.6830 Average Surface Area (mm2)(Median (IQR)) 0.0225 (0.0134, 0.0393) 0.0342 (0.0185, 0.0656) 0.0113 (-0.0027, 0.0322) 0.0467 Average Volume (mm3) (Median (IQR)) 0.0003 (0.0001, 0.0007) 0.0007 (0.0003, 0.0022) 0.0003 (0.000002, 0.0020) 0.0298 Average Surface Area/Volume (mm−1)(Median (IQR)) 214.92 (162.25, 328.39) 199.55 (151.89, 230.52) -20.85 (-86.05, 27.04) 0.1433 Average Structural Thickness (mm)(Median (IQR)) 0.0341(0.0196, 0.0446) 0.0395 (0.0336, 0.0505) 0.0074 (-0.0062, 0.0153) 0.1173 Average Structural Model Index (Median (IQR)) 2.9758 (2.8465, 3.1175) 3.0026 (2.9281, 3.0927) 0.0075 (-0.1073, 0.1381) 0.7656 Citation Format: Sarah E. Schrup, Thomas de Bel, Tanya Hoskin, Teresa Allers, Stacey Winham, Derek Radisky, Laura Pacheco-Spann, Lisa Seymour, Amy Degnim, Mark Sherman. High resolution microCT to analyze the 3D morphology of microcalcifications in benign breast disease and breast cancer biopsy tissues. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3587.

Abstract Background: Human Papillomavirus (HPV) vaccination rates remain low in the U.S., particularly among minorities and low-income patients. In 2014, a Mayo Clinic study of uninsured, low-income, working, Volunteer in Medicine (VIM) Clinic patients in Jacksonville, Florida found a statistically significant lower awareness of HPV (50.3% vs 63.6%) and the HPV vaccine (32.1% vs 62.7%) than the national population. As a result, our team collaborated with Merck to develop a free HPV vaccination program and video education campaign for VIM patients. Methods: We assessed VIM patients HPV vaccination knowledge, awareness, and prevalence of hesitancy towards receiving the vaccine. VIM patients (ages 18-45) with no previous history of HPV vaccination were invited to participate in this study. The Parents Attitudes about Childhood Vaccines (PACV) survey was used to evaluate vaccine hesitancy. Patients who declined the HPV vaccine were shown an educational video to assess effectiveness in persuading patients’ opinion. Each participant received a vaccine hesitancy PACV score, which was compared with their vaccine disposition. Mayo Clinic IRB approval of the study was obtained. Results: Our analysis included 43 patients (34 females, 9 males) with a median age of 40 (age range 27- 45). Patients had overall knowledge of HPV of 88.4%, with 69.8% having heard of the HPV vaccine. 85.7% PACV survey respondents were deemed non-hesitant (PACV scores 0-49), and 80.6% of the non-hesitant subset (29/36) agreed to undergo vaccination. The average PACV score of vaccine-interested participants was lower (25.2) than the average of participants not interested in the vaccine (36.7). Black participants had a statistically significant higher PACV score than White participants. The PACV scores of individuals who were already familiar with the HPV vaccine were significantly lower than those of participants who were unfamiliar with the HPV vaccine. Only 20% (2/10) of individuals, who had previously declined vaccination, agreed to receive the HPV vaccine after viewing the HPV educational video. Of the 33 participants who agreed to receive the free HPV vaccine, only 9 (27.3%) completed all three doses. Conclusions: HPV vaccine awareness and knowledge at VIM increased compared to the 2014 cohort. Vaccine hesitancy was not observed in most patients, yet video education was effective in only a small portion of patients with vaccine hesitancy. Additionally, a minority of patients who agreed to receive the free HPV vaccine series completed all three doses. Our results suggests that free HPV vaccination and video education is not sufficient to achieve adequate vaccination rates among low-income uninsured young adults, nor overcoming vaccine hesitancy. Innovative measures are warranted to improve vaccination rates in this population. Citation Format: Hiram Diaz, Gerardo Colon-Otero, Laura M. Pacheco-Spann, Christopher C. DeStephano, Sandra Casanova-Leyva. Assessing knowledge, vaccine hesitancy, and completion rates of free HPV vaccination in uninsured/underinsured low-income patients. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5539.

Abstract Introduction: Benign breast disease (BBD) is an important breast cancer (BC) risk factor, which may be classified as non-proliferative disease (NPD), proliferative disease without atypia (PDWA), or atypical hyperplasia (AH) for risk stratification. Data related to the frequency of specific types of BBD and their relationship to BC risk in the Hispanic American population are limited. To address this knowledge gap, we compared BBD and associated BC risk among Hispanic white (HW) and non-Hispanic white (NHW) in New Mexico (NM). Methodology: A retrospective IRB-approved study was performed of women 19 years or older residing in six counties in NM (Bernalillo, Sandoval, Sante Fe, Socorro, Torrance, Cibola/Valencia) between 1996 and mid-2007 to compare the frequency of BBD subtypes and BC risk among HW and NHW. We excluded women who had a history of BC prior to BBD diagnosis or who were diagnosed with BC within 6 months after BBD biopsy. Race and ethnicity were self-reported by women at the time of biopsy. BBD was categorized as NPD, PDWA, or AH based on medical records. Incident BC (in-situ or invasive) was ascertained via linkage to the NM Surveillance Epidemiology End Results (SEER) Registry and BC risk was assessed using standardized incidence ratios (SIRs), comparing the observed number of BC events to that expected based on the NM SEER six-county race- and ethnicity-specific incidence rates, accounting for age and calendar period. Results: Our analysis included 3,870 HW and 6,996 NHW women with BBD. The HW were younger (47.1 vs. 51 years) compared to NHW. HW women had slightly more NPD (69.4% vs. 66.6%) but less PDWA (26.2% vs. 29.4%) and similar frequency of AH (4.3% vs. 3.9%) as compared to NHW. Over a median post-BBD follow-up period of 13 years (range 6 months-17 years), 644 BCs were observed (4.81% in HW and 6.55% in NHW). The observed BC risk among women with BBD was higher than population-based expected rates (SIR 1.98, 95% CI 1.82-2.13, p<0.001) and showed expected increases in risk with increasing degrees of BBD abnormality: SIR=1.90 for NPD, 2.00 for PDWA, and 3.01 for AH. Comparing BC risk by ethnic subgroups, HW women had an overall risk of BC after BBD that was statistically indistinguishable from NHW women (SIR=2.17, 95% CI 1.86-2.48 in HW women, and SIR=1.91, 95% CI 1.73-2.08 in NHW women). Within the major subgroups of the BBD findings, there were no significant differences in risk of BC after BBD for HW versus NHW women. Conclusions: In this population-based study, benign breast disease subtypes and their associated breast cancer risk were similar among the Hispanic and non-Hispanic white women. Citation Format: Kush Raj Lohani, Andrea M. Nibbe, Robert A. Vierkant, Laura M. Pacheco-Spann, Lisa R. Seymour, Celine M. Vachon, Mark E. Sherman, Amy C. Degnim, Deirdre Hill. Comparison of benign breast disease subtypes and breast cancer risk among Hispanic and non-Hispanic white women in New Mexico. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4213.

Abstract Purpose: Young women’s breast cancers (YBCs), defined herein as breast cancer (BC) diagnosed at age ≤ 40 years, are etiologically and biologically distinct from postmenopausal BCs, demonstrating a higher proportion of estrogen receptor (ER) negative subtypes and a worse prognosis. Studies have not assessed whether risk factors such as recent parity and body mass index (BMI) are linked to protein expression profiles in YBCs. Accordingly, we examined protein expression assessed with GeoMx® Digital Spatial Profiling (DSP) in 640 YBCs prepared as tissue microarrays (TMAs) in the Young Women’s BC Study (YWBCS). Methods: The YWBCS is a multi-institutional cohort of 1,297 women with incident BC diagnosed at age <40 years identified through medical record review, with risk factor data collected via questionnaires. TMAs including 1,505 cores of 640 YBCs that were collected prior to therapy and were suitable for molecular analysis were evaluated for 72 markers with NanoString GeoMx DSP. Associations of log-transformed biomarker expression with BMI and time from last live birth to BC diagnosis were carried out using linear mixed modeling approaches, accounting for multiple tumor tissue cores per individual. Results: Mean age at BC was 35.5 years (range 17-40). Tumor subtypes based on clinical immunostaining were the following: luminal B 46%; luminal A 36%; triple negative 12% and HER2+ 6%. Of 72 biomarkers tested, 53 (74%) were evaluable after QC and normalization. GeoMx ER and PR protein levels were higher in luminal A and luminal B YBCs than in HER2+ and TNBC (p=2x10-94 and 2x10-52, respectively), supporting the accuracy of the GeoMx assay. Compared to nulliparas or those with most recent birth > 3 years before BC, those who gave birth ≤ 3 years prior to BC had tumors with higher expression of PR (8x10-6) and ER (p=0.006), and lower expression of BCL-2 (p=0.006). In contrast, women with last birth ≥ 6 years prior to BC had higher expression of CD8 (p=0.006) and PD-1 (p=0.001) than nulliparas and those with more recent births. Compared to women with BMI between 18.5 and 29.9, those with higher or lower BMIs had higher expression of CD34 (p=0.0003), CD4 (p=0.0009) and CD14 (p=0.001). BCL-2 expression was higher among women with BMI < 18.5 compared to those with higher values (p=0.005). Women with BMI of 30+ had higher β2-microglobulin levels than those with lower BMIs (p=0.003). Inverse dose-response associations (with higher BMI related to lower levels) were observed for expression of ER (p=0.01), pan cytokeratin (p=0.004) and four proteins in the p13K/AKT signaling pathway (p ≤ 0.01 for each). Conclusions: Preliminarily, we identify differences in hormonal and immune markers in YBCs in relation to timing of births and BMI, suggesting that these factors may contribute to etiologic heterogeneity. Multivariate modeling is ongoing to incorporate molecular subtype and other risk factors. Citation Format: Robert A. Vierkant, Laura M. Pacheco-Spann, Stacey J. Winham, Jennifer M. Kachergus, Ji Shi, Craig Snow, Fergus J. Couch, Janet E. Olson, Chen Wang, Derek C. Radisky, Amy C. Degnim, E. Aubrey Thompson, Laura C. Collins, Kathryn J. Ruddy, Ann H. Partridge, Mark E. Sherman. Associations of parity and body mass index with NanoString digital spatial protein profiling in early onset breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1000.