Emergency Department Visits Before Cancer Diagnosis Among Women at Mayo Clinic

Objective

To determine associations of incident cancer diagnoses in women with recent emergency department (ED) care.

Patients and Methods

A retrospective cohort study analyzing biological females aged 18 years and older, who were diagnosed with an incident primary cancer (12 cancer types studied) from January 1, 2015, to December 31, 2021, from electronic health records. The primary outcome was a cancer diagnosis within 6 months of a preceding ED visit. Secondary outcomes included patient factors associated with a preceding ED visit.

Results

Of 25,736 patients (median age of 62 years, range 18-101) diagnosed with an incident primary cancer, 1938 (7.5%) had an ED visit ≤6 months before a diagnosis. The ED-associated cancer cases were highest in lung cancer (n=514, 14.7%) followed by acute lymphoblastic leukemia (n=22, 13.3%). Patient factors increasing the likelihood of ED evaluation before diagnosis included 18-50 years of age (OR=1.32; 95% CI, 1.09-1.61), Elixhauser score (measure of comorbidities) >4 (OR=17.90; 95% CI, 14.21-22.76), use of Medicaid or other government insurance (OR=2.10; 95% CI, 1.63-2.69), residence within the institutional catchment areas (OR=3.18; 95% CI, 2.78-3.66), non-Hispanic Black race/ethnicity (OR=1.41; 95% CI, 1.04-1.88), and established primary care provider at Mayo Clinic (OR=1.45; 95% CI, 1.28-1.65). The ED visits were more likely in those who died within 6 months of diagnosis (n=327, 37.8%) than those who did not die (n=1611, 6.5%).

Conclusion

Patient characteristics identified in this study offer opportunities to provide cancer risk assessment and health navigation, particularly among individuals with comorbidities and limited health care access.

Benign Breast Disease and Breast Cancer Risk in the Percutaneous Biopsy Era

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.

Leveraging GWAS: Path to Prevention?

Developing novel cancer prevention medication strategies is important for reducing mortality. Identification of common genetic variants associated with cancer risk suggests the potential to leverage these discoveries to define causal targets for cancer interception. Although each risk variant confers small increases in risk, researchers propose that blocking those that produce causal carcinogenic effects might have large impacts on cancer prevention. While a promising concept, we describe potential hurdles that may need to be scaled to reach this goal, including: (i) understanding the complexity of risk; (ii) achieving statistical power in studies with binary outcomes (cancer development: yes or no); (iii) characterization of cancer precursors; (iv) heterogeneity of cancer subtypes and the populations in which these diseases occur; (v) impact of static genetic markers across complex events of the life course; (vi) defining gene-gene and gene-environment interactions and (vii) demonstrating functional effects of markers in human populations. We assess short-term prospects for this research against the backdrop of these challenges and the potential to prevent cancer through other means. See related commentary by Peters and Tomlinson, p. 7.

Concurrent RB1 loss and BRCA-deficiency predicts enhanced immunological response and long-term survival in tubo-ovarian high-grade serous carcinoma

Background

Somatic loss of the tumour suppressor RB1 is a common event in tubo-ovarian high-grade serous carcinoma (HGSC), which frequently co-occurs with alterations in homologous recombination DNA repair genes including BRCA1 and BRCA2 (BRCA). We examined whether tumour expression of RB1 was associated with survival across ovarian cancer histotypes (HGSC, endometrioid (ENOC), clear cell (CCOC), mucinous (MOC), low-grade serous carcinoma (LGSC)), and how co-occurrence of germline BRCA pathogenic variants and RB1 loss influences long-term survival in a large series of HGSC.

Patients and methods

RB1 protein expression patterns were classified by immunohistochemistry in epithelial ovarian carcinomas of 7436 patients from 20 studies participating in the Ovarian Tumor Tissue Analysis consortium and assessed for associations with overall survival (OS), accounting for patient age at diagnosis and FIGO stage. We examined RB1 expression and germline BRCA status in a subset of 1134 HGSC, and related genotype to survival, tumour infiltrating CD8+ lymphocyte counts and transcriptomic subtypes. Using CRISPR-Cas9, we deleted RB1 in HGSC cell lines with and without BRCA1 mutations to model co-loss with treatment response. We also performed genomic analyses on 126 primary HGSC to explore the molecular characteristics of concurrent homologous recombination deficiency and RB1 loss.

Results

RB1 protein loss was most frequent in HGSC (16.4%) and was highly correlated with RB1 mRNA expression. RB1 loss was associated with longer OS in HGSC (hazard ratio [HR] 0.74, 95% confidence interval [CI] 0.66-0.83, P = 6.8 ×10-7), but with poorer prognosis in ENOC (HR 2.17, 95% CI 1.17-4.03, P = 0.0140). Germline BRCA mutations and RB1 loss co-occurred in HGSC (P < 0.0001). Patients with both RB1 loss and germline BRCA mutations had a superior OS (HR 0.38, 95% CI 0.25-0.58, P = 5.2 ×10-6) compared to patients with either alteration alone, and their median OS was three times longer than non-carriers whose tumours retained RB1 expression (9.3 years vs. 3.1 years). Enhanced sensitivity to cisplatin (P < 0.01) and paclitaxel (P < 0.05) was seen in BRCA1 mutated cell lines with RB1 knockout. Among 126 patients with whole-genome and transcriptome sequence data, combined RB1 loss and genomic evidence of homologous recombination deficiency was correlated with transcriptional markers of enhanced interferon response, cell cycle deregulation, and reduced epithelial-mesenchymal transition in primary HGSC. CD8+ lymphocytes were most prevalent in BRCA-deficient HGSC with co-loss of RB1.

Conclusions

Co-occurrence of RB1 loss and BRCA mutation was associated with exceptionally long survival in patients with HGSC, potentially due to better treatment response and immune stimulation.

Intraluminal tumor cells and prognostic accuracy of endometrial cancer stage criteria: A multi-institution study

OBJECTIVE

Endometrial cancer stage is a strong prognostic factor; however, the current stage classification does not incorporate transtubal spread as determined by intraluminal tumor cells (ILTCs). We examined relationships between ILTCs and survival outcomes according to histological subtype and stage and examined whether identification of ILTCs improves prognostic accuracy of endometrial cancer staging.

METHODS

We conducted a retrospective cohort study of women diagnosed with endometrial cancer at five academic hospitals between 2007 and 2012. Pathologists determined ILTC presence (no vs. yes) and location (free in lumen vs. attached to epithelial surface) based on pathology review of hematoxylin and eosin-stained sections of fallopian tubes. Associations between ILTCs with time to recurrence (TTR) and overall survival (OS) were examined with Cox proportional hazards models adjusted for other prognostic factors. Model discrimination metrics were used to assess the addition of ILTCs to stage for prediction of 5-year TTR and OS.

RESULTS

In the overall study population (N = 1303), ILTCs were not independently associated with TTR (HR = 0.95, 95% CI = 0.69-1.32) or OS (HR = 0.97, 95% CI = 0.72-1.31). Among 805 women with stage I disease, ILTCs were independently associated with worse TTR (HR = 2.31, 95% CI = 1.06-5.05) and OS (HR = 2.16, 95% CI = 1.14-4.11). Upstaging early-stage cases with ILTCs present did not increase model discrimination.

CONCLUSION

While our data do not suggest that endometrial cancer staging guidelines should be revised to include ILTCs, associations between ILTCs and reduced survival observed among stage I cases suggest this tumor feature holds clinical relevance for subgroups of endometrial cancer patients.

Methylated DNA Markers for Sporadic Colorectal and Endometrial Cancer Are Strongly Associated with Lynch Syndrome Cancers

Lynch syndrome (LS) markedly increases risks of colorectal and endometrial cancers. Early detection biomarkers for LS cancers could reduce the needs for invasive screening and surgical prophylaxis.To validate a panel of methylated DNA markers (MDM) previously identified in sporadic colorectal cancer and endometrial cancer for discrimination of these cancers in LS.In a case-control design, previously identified MDMs for the detection of colorectal cancer and endometrial cancer were assayed by qMSP on tissue-extracted DNA. Results were normalized to ACTB values within each sample. Least absolute shrinkage and selection operator models to classify colorectal cancer and endometrial cancer were trained on sporadic cases and controls and then applied to classify colorectal cancer and endometrial cancer, in those with LS, and cross-validated.We identified colorectal cancer cases (23 with LS, 48 sporadic), colorectal controls (32 LS, 48 sporadic), endometrial cancer cases (30 LS, 48 sporadic), and endometrial controls (29 LS, 37 sporadic). A 3-MDM panel (LASS4, LRRC4, and PPP2R5C) classified LS-CRC from LS controls with an AUC of 0.92 (0.84-0.99); results were similar for sporadic colorectal cancer. A 6-MDM panel (SFMBT2, MPZ, CYTH2, DIDO1, chr10.4479, and EMX2OS) discriminated LS-EC from LS controls with an AUC of 0.92 (0.83-1.0); the AUC for sporadic endometrial cancer versus sporadic controls was nominally higher, 0.99 (0.96-1.0).MDMs previously identified in sporadic endometrial cancer and colorectal cancer discriminate between endometrial cancer and benign endometrium and colorectal cancer and benign colorectum in LS. This supports the inclusion of patients with LS within future prospective clinical trials evaluating endometrial cancer and colorectal cancer MDMs and may provide a new avenue for cancer screening or surveillance in this high-risk population.

PREVENTION RELEVANCE

Lynch syndrome (LS) markedly increases risks of colorectal and endometrial cancers. Early detection biomarkers for LS cancers could reduce the needs for invasive screening and surgery. Methylated DNA markers previously identified in sporadic endometrial cancer and colorectal cancer discriminate between benign and cancer tissue in LS.

Reproductive Events and Risk of Women's Cancers: From Parturition to Prevention

Reproductive events beginning with pregnancy and ending with remodeling of the breast after cessation of breastfeeding alter breast structure and function and produce dramatic changes in systemic biology. In aggregate, these processes lower overall risk for breast, tubo-ovarian and endometrial cancers, albeit differentially by molecular subtypes of these tumors. Herein, we explore opportunities for research on protective mechanisms operative during this period of the life course, with the goal of encouraging studies to advance cancer prevention. See related article by Getz et al., p. 353.

Detection of endometrial cancer using tampon-based collection and methylated DNA markers

OBJECTIVE

Alterations in DNA methylation are early events in endometrial cancer (EC) development and may have utility in EC detection via tampon-collected vaginal fluid.

METHODS

For discovery, DNA from frozen EC, benign endometrium (BE), and benign cervicovaginal (BCV) tissues underwent reduced representation bisulfite sequencing (RRBS) to identify differentially methylated regions (DMRs). Candidate DMRs were selected based on receiver operating characteristic (ROC) discrimination, methylation level fold-change between cancers and controls, and absence of background CpG methylation. Methylated DNA marker (MDM) validation was performed using qMSP on DNA from independent EC and BE FFPE tissue sets. Women ≥45 years of age with abnormal uterine bleeding (AUB) or postmenopausal bleeding (PMB) or any age with biopsy-proven EC self-collected vaginal fluid using a tampon prior to clinically indicated endometrial sampling or hysterectomy. Vaginal fluid DNA was assayed by qMSP for EC-associated MDMs. Random forest modeling analysis was performed to generate predictive probability of underlying disease; results were 500-fold in-silico cross-validated.

RESULTS

Thirty-three candidate MDMs met performance criteria in tissue. For the tampon pilot, 100 EC cases were frequency matched by menopausal status and tampon collection date to 92 BE controls. A 28-MDM panel highly discriminated between EC and BE (96% (95%CI 89-99%) specificity; 76% (66-84%) sensitivity (AUC 0.88). In PBS/EDTA tampon buffer, the panel yielded 96% (95% CI 87-99%) specificity and 82% (70-91%) sensitivity (AUC 0.91).

CONCLUSION

Next generation methylome sequencing, stringent filtering criteria, and independent validation yielded excellent candidate MDMs for EC. EC-associated MDMs performed with promisingly high sensitivity and specificity in tampon-collected vaginal fluid; PBS-based tampon buffer with added EDTA improved sensitivity. Larger tampon-based EC MDM testing studies are warranted.

Reproducibility and intratumoral heterogeneity of the PAM50 breast cancer assay

BACKGROUND

The PAM50 assay is used routinely in clinical practice to determine breast cancer prognosis and management; however, research assessing how technical variation and intratumoral heterogeneity contribute to misclassification and reproducibility of these tests is limited.

METHODS

We evaluated the impact of intratumoral heterogeneity on the reproducibility of results for the PAM50 assay by testing RNA extracted from formalin-fixed paraffin embedded breast cancer blocks sampled at distinct spatial locations. Samples were classified according to intrinsic subtype (Luminal A, Luminal B, HER2-enriched, Basal-like, or Normal-like) and risk of recurrence with proliferation score (ROR-P, high, medium, or low). Intratumoral heterogeneity and technical reproducibility (replicate assays on the same RNA) were assessed as percent categorical agreement between paired intratumoral and replicate samples. Euclidean distances between samples, calculated across the PAM50 genes and the ROR-P score, were compared for concordant vs. discordant samples.

RESULTS

Technical replicates (N = 144) achieved 93% agreement for ROR-P group and 90% agreement on PAM50 subtype. For spatially distinct biological replicates (N = 40 intratumoral replicates), agreement was lower (81% for ROR-P and 76% for PAM50 subtype). The Euclidean distances between discordant technical replicates were bimodal, with discordant samples showing higher Euclidian distance and biologic heterogeneity.

CONCLUSION

The PAM50 assay achieved very high technical reproducibility for breast cancer subtyping and ROR-P, but intratumoral heterogeneity is revealed by the assay in a small proportion of cases.

p53 and ovarian carcinoma survival: an Ovarian Tumor Tissue Analysis consortium study

Our objective was to test whether p53 expression status is associated with survival for women diagnosed with the most common ovarian carcinoma histotypes (high-grade serous carcinoma [HGSC], endometrioid carcinoma [EC], and clear cell carcinoma [CCC]) using a large multi-institutional cohort from the Ovarian Tumor Tissue Analysis (OTTA) consortium. p53 expression was assessed on 6,678 cases represented on tissue microarrays from 25 participating OTTA study sites using a previously validated immunohistochemical (IHC) assay as a surrogate for the presence and functional effect of TP53 mutations. Three abnormal expression patterns (overexpression, complete absence, and cytoplasmic) and the normal (wild type) pattern were recorded. Survival analyses were performed by histotype. The frequency of abnormal p53 expression was 93.4% (4,630/4,957) in HGSC compared to 11.9% (116/973) in EC and 11.5% (86/748) in CCC. In HGSC, there were no differences in overall survival across the abnormal p53 expression patterns. However, in EC and CCC, abnormal p53 expression was associated with an increased risk of death for women diagnosed with EC in multivariate analysis compared to normal p53 as the reference (hazard ratio [HR] = 2.18, 95% confidence interval [CI] 1.36-3.47, p = 0.0011) and with CCC (HR = 1.57, 95% CI 1.11-2.22, p = 0.012). Abnormal p53 was also associated with shorter overall survival in The International Federation of Gynecology and Obstetrics stage I/II EC and CCC. Our study provides further evidence that functional groups of TP53 mutations assessed by abnormal surrogate p53 IHC patterns are not associated with survival in HGSC. In contrast, we validate that abnormal p53 IHC is a strong independent prognostic marker for EC and demonstrate for the first time an independent prognostic association of abnormal p53 IHC with overall survival in patients with CCC.

Endometrial safety of low-dose vaginal estrogens

ABSTRACT

It is estimated that up to 50% to 90% of postmenopausal women may experience genitourinary syndrome of menopause (GSM), which may have a detrimental impact on quality of life. One of the most effective modes of treatment of GSM is low-dose vaginal estrogens. Numerous studies have addressed the safety of these estrogens using endometrial biopsy and/or endometrial thickness on ultrasound. Based on these studies, the consensus is that low-dose vaginal estrogens do not substantially increase the risk of endometrial hyperplasia or cancer; however, the data are severely limited by short duration of follow-up. Although long-term trials are warranted, they are difficult to carry out, costly, and will not yield data for years. More immediate information regarding endometrial safety may be obtained from studies measuring endometrial tissue and serum concentrations of estradiol, estrone, and relevant equine estrogens after administration of different estrogen formulations and doses. This would allow us to understand better the metabolism of estrogens by the vagina and endometrium, and how much estrogen is reaching the endometrium. Here, we discuss metabolism, receptor binding, and signaling of estrogens in vaginal and endometrial tissue, and summarize the existing studies on the endometrial impact of low-dose vaginal estrogen treatment in postmenopausal women.

Abstract 4213: Comparison of benign breast disease subtypes and breast cancer risk among Hispanic and non-Hispanic white women in New Mexico

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&lt;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.

Methylation Signature Implicated in Immuno-Suppressive Activities in Tubo-Ovarian High-Grade Serous Carcinoma

BACKGROUND

Better understanding of prognostic factors in tubo-ovarian high-grade serous carcinoma (HGSC) is critical, as diagnosis confers an aggressive disease course. Variation in tumor DNA methylation shows promise predicting outcome, yet prior studies were largely platform-specific and unable to evaluate multiple molecular features.

METHODS

We analyzed genome-wide DNA methylation in 1,040 frozen HGSC, including 325 previously reported upon, seeking a multi-platform quantitative methylation signature that we evaluated in relation to clinical features, tumor characteristics, time to recurrence/death, extent of CD8+ tumor-infiltrating lymphocytes (TIL), gene expression molecular subtypes, and gene expression of the ATP-binding cassette transporter TAP1.

RESULTS

Methylation signature was associated with shorter time to recurrence, independent of clinical factors (N = 715 new set, hazard ratio (HR), 1.65; 95% confidence interval (CI), 1.10-2.46; P = 0.015; N = 325 published set HR, 2.87; 95% CI, 2.17-3.81; P = 2.2 × 10-13) and remained prognostic after adjustment for gene expression molecular subtype and TAP1 expression (N = 599; HR, 2.22; 95% CI, 1.66-2.95; P = 4.1 × 10-8). Methylation signature was inversely related to CD8+ TIL levels (P = 2.4 × 10-7) and TAP1 expression (P = 0.0011) and was associated with gene expression molecular subtype (P = 5.9 × 10-4) in covariate-adjusted analysis.

CONCLUSIONS

Multi-center analysis identified a novel quantitative tumor methylation signature of HGSC applicable to numerous commercially available platforms indicative of shorter time to recurrence/death, adjusting for other factors. Along with immune cell composition analysis, these results suggest a role for DNA methylation in the immunosuppressive microenvironment.

IMPACT

This work aids in identification of targetable epigenome processes and stratification of patients for whom tailored treatment may be most beneficial.

Benign Breast Disease, NSAIDs, and Postmenopausal Breast Cancer Risk in the CPS-II Cohort

ABSTRACT

Nonsteroidal anti-inflammatory agents (NSAID) are associated with modest inconsistent reductions in breast cancer risk in population-based cohorts, whereas two focused studies of patients with benign breast disease (BBD) have found lower risk with NSAID use. Given that BBD includes fibroinflammatory lesions linked to elevated breast cancer risk, we assessed whether NSAID use was associated with lower breast cancer risk among patients with BBD.Participants were postmenopausal women in the Cancer Prevention Study-II (CPS-II), a prospective study of cancer incidence and mortality, who completed follow-up surveys in 1997 with follow-up through June 30, 2015. History of BBD, NSAID use, and covariate data were updated biennially. This analysis included 23,615 patients with BBD and 36,751 patients with non-BBD, including 3,896 incident breast cancers over an average of 12.72 years of follow-up among participants. NSAID use, overall and by formulation, recency, duration, and pills per month was analyzed versus breast cancer risk overall and by BBD status using multivariable-adjusted Cox models; BBD status and NSAID use were modeled as time-dependent exposures.Patients with BBD who reported using NSAIDs experienced lower breast cancer risk (HR, 0.87; 95% CI, 0.78-0.97), with similar effects for estrogen receptor (ER)-positive breast cancers [HR, 0.85; 95% confidence interval (CI), 0.74-0.97] and ER-negative breast cancers (HR, 0.87; 95% CI, 0.59-1.29); among women without BBD, NSAID use was unrelated to risk (HR, 1.02; 95% CI, 0.92-1.13; Pinteraction = 0.04). Associations stratified by age, obesity, menopausal hormone use, and cardiovascular disease were similar.Among patients with BBD, NSAID use appears linked to lower breast cancer risk. Further studies to assess the value of NSAID use among patients with BBD are warranted.

PREVENTION RELEVANCE

We examined whether NSAID use, a modifiable exposure, is associated with breast cancer risk in postmenopausal women from the Cancer Prevention Study-II with self-reported benign breast disease, an often inflammatory condition associated with higher rates of breast cancer.

Immune cells are increased in normal breast tissues of BRCA1/2 mutation carriers

PURPOSE

Breast cancer risk is elevated in pathogenic germline BRCA 1/2 mutation carriers due to compromised DNA quality control. We hypothesized that if immunosurveillance promotes tumor suppression, then normal/benign breast lobules from BRCA carriers may demonstrate higher immune cell densities.

METHODS

We assessed immune cell composition in normal/benign breast lobules from age-matched women with progressively increased breast cancer risk, including (1) low risk: 19 women who donated normal breast tissue to the Komen Tissue Bank (KTB) at Indiana University Simon Cancer Center, (2) intermediate risk: 15 women with biopsy-identified benign breast disease (BBD), and (3) high risk: 19 prophylactic mastectomies from women with germline mutations in BRCA1/2 genes. We performed immunohistochemical stains and analysis to quantitate immune cell densities from digital images in up to 10 representative lobules per sample. Median cell counts per mm2 were compared between groups using Wilcoxon rank-sum tests.

RESULTS

Normal/benign breast lobules from BRCA carriers had significantly higher densities of immune cells/mm2 compared to KTB normal donors (all p < 0.001): CD8 + 354.4 vs 150.9; CD4 + 116.3 vs 17.7; CD68 + 237.5 vs 57.8; and CD11c + (3.5% vs 0.4% pixels positive). BBD tissues differed from BRCA carriers only in CD8 + cells but had higher densities of CD4 + , CD11c + , and CD68 + immune cells compared to KTB donors.

CONCLUSIONS

These preliminary analyses show that normal/benign breast lobules of BRCA mutation carriers contain increased immune cells compared with normal donor breast tissues, and BBD tissues appear overall more similar to BRCA carriers.

Reproductive risk factors associated with breast cancer in young women by molecular subtype

BACKGROUND

Few studies have examined detailed features of pregnancy and the postpartum period as potential risk factors for early onset breast cancer (BC) by molecular subtype. These data may have value for improving risk assessment and prevention.

METHODS

We surveyed parous enrollees in the prospective Mayo Clinic Breast Disease Registry (MCBDR) who had been diagnosed with BC at age <55 years between 2015 and 2020. Summary statistics were used to describe survey responses and reproductive risk factors by BC subtype (defined by estrogen/progesterone receptors and human epidermal growth factor receptor expression, nurse-abstracted from the medical record). Associations were assessed with Kruskal-Wallis and Chi-Square tests, followed by age-adjusted linear and logistic regression models. We compared results from this parous cohort to those from a separate cohort of nulliparous MCBDR participants with BC diagnosed at age <55 years.

RESULTS

In 436 parous respondents with subtype data abstracted, we identified a higher frequency of BRCA1 mutation, earlier age at diagnosis, and lower BI in patients with triple negative BC. Comparing parous to nulliparous young women with breast cancer, the proportion with TNBC was larger in the latter (12.2% vs. 15.1%, p = 0.03).

CONCLUSIONS

Early age at diagnosis and deleterious BRCA1 mutation were more frequent among TNBC patients. In addition, parous young women with TNBC had a lower BI than those with other BC subtypes, a hypothesis-generating finding that supports the need for additional research on the cycle of pregnancy-lactation-postpartum involution and BC etiology.

Serum hormone levels and normal breast histology among premenopausal women

PURPOSE

Breast terminal duct lobular units (TDLUs) are the main source of breast cancer (BC) precursors. Higher serum concentrations of hormones and growth factors have been linked to increased TDLU numbers and to elevated BC risk, with variable effects by menopausal status. We assessed associations of circulating factors with breast histology among premenopausal women using artificial intelligence (AI) and preliminarily tested whether parity modifies associations.

METHODS

Pathology AI analysis was performed on 316 digital images of H&E-stained sections of normal breast tissues from Komen Tissue Bank donors ages ≤ 45 years to assess 11 quantitative metrics. Associations of circulating factors with AI metrics were assessed using regression analyses, with inclusion of interaction terms to assess effect modification.

RESULTS

Higher prolactin levels were related to larger TDLU area (p < 0.001) and increased presence of adipose tissue proximate to TDLUs (p < 0.001), with less significant positive associations for acini counts (p = 0.012), dilated acini (p = 0.043), capillary area (p = 0.014), epithelial area (p = 0.007), and mononuclear cell counts (p = 0.017). Testosterone levels were associated with increased TDLU counts (p < 0.001), irrespective of parity, but associations differed by adipose tissue content. AI data for TDLU counts generally agreed with prior visual assessments.

CONCLUSION

Among premenopausal women, serum hormone levels linked to BC risk were also associated with quantitative features of normal breast tissue. These relationships were suggestively modified by parity status and tissue composition. We conclude that the microanatomic features of normal breast tissue may represent a marker of BC risk.

Abstract 2203: Towards prediction of breast cancer risk in benign biopsies with high-plex GeoMx spatial protein profiling

Background: Biopsy diagnoses of benign breast disease (BBD) confer a 1.5- to 4-fold increased risk of developing breast cancer (BC) compared with women without BBD. Previously, we reported that decreased numbers of specific immune cell types in lobules of BBD biopsies predicted increased BC risk, suggesting the promise of future tissue biomarker studies to define BC risk markers among BBD patients. Thus, we applied protein-based GeoMx® Digital Spatial Profiling (DSP) to BBD biopsies preceding BC (cases) and to BBD biopsies from cancer-free patients (controls) to identify possible BC risk markers, which we then evaluated in subsequent BC tissues and in surrounding normal lobules of cases.

Methods: Archived pathology slides of BBD biopsies were reviewed and used to guide preparation of TMAs containing 1.0-mm diameter FFPE cores of lobules from an age- and cohort-period-matched set of 91 cases and 88 controls from the Mayo Clinic BBD Cohort. For patients who later developed BC, we prepared TMAs of BC tissue and surrounding mapped normal lobules. We applied GeoMx® DSP (immune and canonical signaling proteins) to both sets of TMAs. Following QC and data normalization, associations of case status with log-transformed biomarker expression in lobules of BBD biopsies were carried out using linear mixed modeling approaches, accounting for multiple ROIs per individual. Biomarkers significantly associated with case status (p&lt;0.05) were further examined in BCs and adjacent normal lobules, using similar approaches.

Results: The mean age at BBD biopsy was 52 years, and at BC diagnosis of cases, 61.4 years (mean time from BBD to BC was 10.2 years). A family history of BC was more frequent among cases (70% versus 43%; chi-square p=0.002). Of 72 biomarkers tested, 46 (64.4%) were evaluable after QC and normalization and 5 were associated with BC risk after adjustment for family history of BC: BCL2 (p=0.005), STING (p=0.006), CD44 (p=0.02), S100 protein (p=0.03) and pan-AKT (p=0.05); each showed higher levels in lobules of BBD biopsies of controls than cases. Three unique patterns appeared when examining these biomarkers across tissue type within cases: for BCL2 (p=5 x 10-9) and STING (p=2 x 10-19), levels were high in both BC and lobules surrounding BC but low in preceding BBD; for GAPDH (p=4 x 10-53) and pan-AKT (p=2 x 10-33), levels were high in BC, low in preceding BBD, and moderate in lobules surrounding BC; and for CD44 (p=2 x 10-6) and S100B (p=2 x 10-49), levels were low in BC, high in lobules surrounding BC and moderate in preceding BBD.

Conclusions: Using a novel TMA of lobules in combination with DSP, we preliminarily identified immune-based and PI3 kinase-related protein biomarkers in BBD biopsies associated with BC risk. In case-only analyses, these markers demonstrated complex differences between lobules in BBD biopsies, subsequent BCs and adjacent normal lobules.

Citation Format: Robert Alan Vierkant, Jodi M. Carter, Stacey J. Winham, Chen Wang, Jennifer M. Kachergus, Ji Shi, Raymond M. Moore, Bryan M. McCauley, Laura M. Pacheco-Spann, E A. Thompson, Derek C. Radisky, Amy C. Degnim, Mark E. Sherman. Towards prediction of breast cancer risk in benign biopsies with high-plex GeoMx spatial protein profiling [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2203.

Pilot study of women's perspectives when abnormal uterine bleeding occurs during perimenopause

OBJECTIVE

We gained insights into women's experiences and knowledge about the occurrence of vaginal bleeding during perimenopause requiring evaluation.

METHODS

Qualitative inquiry was chosen to explore topics in greater depth to understand individuals' experiences. Interviews with individuals were chosen due to the sensitive nature of gynecologic symptoms and management. Interviews were completed following gynecologic care to explore individuals' experiences with the evaluation and management of vaginal bleeding during perimenopause.

RESULTS

Twelve individuals were interviewed between December 2019 and March 2020. Patient uncertainty about the medical significance of developing vaginal bleeding during perimenopause was associated with self-appraisal and gathering information from multiple sources. This experience of seeking evaluation and treatment resulted in varying degrees of trust concerning information received within or outside the clinic. Regarding new technologies that could replace the current invasive tests performed for diagnosis (i.e. ultrasound, hysteroscopy and biopsy), most women preferred the smartphone app and tampon home collection option.

CONCLUSIONS

The experience of irregular or heavy vaginal bleeding during perimenopause is fraught with ambiguity, feelings of uncertainty about how to make sense of symptoms and inevitably begins with a period of self-appraisal.

Methylated DNA markers discriminate ovarian cancer from benign tissue in BRCA carriers

e17610

Background: Methylated DNA markers (MDMs) associated with sporadic ovarian cancer (OC) are detected in plasma from patients with treatment naïve tumors, but not cancer-free controls. To assess potential benefits to patients at risk for hereditary OC, the aim of this study was to measure the performance of validated sporadic OC MDMs in OC and benign ovarian tissue (BOT), surgically obtained from germline BRCA1 or BRCA2 ( BRCA1/2) mutation carriers. Methods: BRCA1/2 carriers with OC and BRCA1/2 carriers who had undergone risk-reducing salpingo-oophorectomy (SO) were identified at a comprehensive cancer center. BRCA1/2 carriers in both OC and BOT groups were balanced on age and year of surgery with non- BRCA carriers with sporadic OC or benign indications for SO. OC and BOT formalin fixed paraffin embedded (FFPE) tissues were macrodissected following pathologist selection of representative sites; DNA was extracted, and bisulfite converted. 15 OC MDMs ( GDF6, IFFO1, MAX.chr1.147790358, MAX.chr6.10382190, MAX.chr11.14926602, C2CD4D, PDRM14, NCOR2, SKI, DSCR6, SIM2, PALLD, CDO1, GPRIN1, BCAT1) previously identified in sporadic OC were assayed by quantitative methylation specific PCR, normalized by β-actin, by blinded personnel. Areas under the receiver operating characteristic curve (AUC) were generated for each MDM to assess discrimination of OC from benign tissue and compared between BRCA1/2 and sporadic (non- BRCA) patients, using a z-test. Results: Among BRCA1/2 carriers, there were 48 OC ( BRCA-OC) and 48 BOT ( BRCA-BOT); among non- BRCA, we matched 48 OC (Sporadic-OC) and 48 BOT (non- BRCA-BOT). The median AUC for OC MDM discriminated between OC and BOT with AUCs in BRCA1/2 carriers was 0.87, (IQR, 0.83-0.93). Sporadic-OC vs non- BRCA-BOT median AUC was 0.88 (IQR, 0.83-0.92). AUCs were not significantly different for each MDM when stratified by BRCA or sporadic status. MDMs with an AUC of ≥0.9 in either group are shown (Table). Conclusions: OC MDMs identified and validated in sporadic OC are highly discriminant for OC from BOT in DNA extracted from tissues of people who carry a BRCA1/2 mutation. Testing the performance of these OC MDMs in plasma from BRCA1/2 carriers with and without OC may be of clinical value for high-risk patients and inform multi-cancer early detection testing strategies.[Table: see text]

Associations of Genetic Ancestry with Terminal Duct Lobular Unit Involution among Healthy Women

Reduced age-related terminal duct lobular unit (TDLU) involution has been linked to increased breast cancer risk and triple-negative breast cancer (TNBC). Associations of TDLU involution levels with race and ethnicity remain incompletely explored. Herein, we examined associations between genetic ancestry and TDLU involution in normal breast tissue donated by 2,014 healthy women in the US. Women of African ancestry were more likely than European women to have increased TDLU counts (odds ratio [OR]trend=1.36; 95% CI = 1.07-1.74), acini counts/TDLU (OR = 1.47; 95% CI = 1.06-2.03), and median TDLU span (ORtrend=1.44; 95% CI = 1.08-1.91), indicating lower involution; whereas East Asian descendants were associated with decreased TDLU counts (ORtrend=0.52; 95% CI = 0.35-0.78) after controlling for potential confounders. These associations are consistent with the racial variations in incidence rates of TNBC in the US and suggest opportunities for future work examining whether TDLU involution may mediate the racial differences in subtype-specific breast cancer risk.

Lower Exome Sequencing Coverage of Ancestrally African Patients in The Cancer Genome Atlas

BACKGROUND

In the United States, cancer disproportionately impacts Black and African American individuals. Identifying genetic factors underlying cancer disparities has been an important research focus and requires data that are equitable in both quantity and quality across racial groups. It is widely recognized that DNA databases quantitatively underrepresent minorities. However, the differences in data quality between racial groups have not been well studied.

METHODS

We compared the qualities of germline and tumor exomes between ancestrally African and European patients in The Cancer Genome Atlas of 7 cancers with at least 50 self-reported Black patients in the context of sequencing depth, tumor purity, and qualities of germline variants and somatic mutations.

RESULTS

Germline and tumor exomes from ancestrally African patients were sequenced at statistically significantly lower depth in 6 out of the 7 cancers. For 3 cancers, most ancestrally European exomes were sequenced in early sample batches at higher depth, whereas ancestrally African exomes were concentrated in later batches and sequenced at much lower depth. For the other 3 cancers, the reasons of lower sequencing coverage of ancestrally African exomes remain unknown. Furthermore, even when the sequencing depths were comparable, African exomes had disproportionally higher percentages of positions with insufficient coverage, likely because of the known European bias in the human reference genome that impacted exome capture kit design.

CONCLUSIONS

Overall and positional lower sequencing depths of ancestrally African exomes in The Cancer Genome Atlas led to underdetection and lower quality of variants, highlighting the need to consider epidemiological factors for future genomics studies.

Effect of risk-reducing salpingo-oophorectomy on sex steroid hormone serum levels among postmenopausal women: an NRG Oncology/Gynecologic Oncology Group study

BACKGROUND

Risk-reducing salpingo-oophorectomy is an effective ovarian cancer risk reduction strategy. However, bilateral oophorectomy has also been associated with increased long-term nonneoplastic sequelae, effects suggested to be mediated through reductions in systemic sex steroid hormone levels. Currently, it is unclear whether the postmenopausal ovary contributes to the systemic hormonal milieu or whether postmenopausal ovarian volume or other factors, such as body mass index and age, affect systemic hormone levels.

OBJECTIVE

We examined the impact of oophorectomy on sex steroid hormone levels in postmenopausal women. Furthermore, we explored how well ovarian volume measured by transvaginal ultrasound correlated with direct ovarian measures obtained during surgical pathology evaluation and investigated the association between hormone levels and ovarian volumes.

STUDY DESIGN

Postmenopausal women who underwent risk-reducing salpingo-oophorectomy (180 cases) or ovarian cancer screening (38 controls) enrolled in an international, prospective study of risk-reducing salpingo-oophorectomy and risk of ovarian cancer algorithm-based screening among women at increased risk of ovarian cancer (Gynecologic Oncology Group-0199) were included in this analysis. Controls were frequency matched to the cases on age at menopause, age at study entry, and time interval between blood draws. Ovarian volume was calculated using measurements obtained from transvaginal ultrasound in both cases and controls and measurements recorded in surgical pathology reports from cases. Serum hormone levels of testosterone, androstenedione, androstenediol, dihydrotestosterone, androsterone, dehydroepiandrosterone, estrone, estradiol, and sex hormone-binding globulin were measured at baseline and follow-up. Spearman correlation coefficients were used to compare ovarian volumes as measured on transvaginal ultrasound and pathology examinations. Correlations between ovarian volumes by transvaginal ultrasound and measured hormone levels were examined using linear regression models. All models were adjusted for age. Paired t tests were performed to evaluate individual differences in hormone levels before and after risk-reducing salpingo-oophorectomy.

RESULTS

Ovarian volumes measured by transvaginal ultrasound were only moderately correlated with those reported on pathology reports (Spearman rho [ρ]=0.42). The median time interval between risk-reducing salpingo-oophorectomy and follow-up for the cases was 13.3 months (range, 6.0-19.3), and the median time interval between baseline and follow-up for the controls was 12.7 months (range, 8.7-13.4). Sex steroid levels decreased with age but were not correlated with transvaginal ultrasound ovarian volume, body mass index, or time since menopause. Estradiol levels were significantly lower after risk-reducing salpingo-oophorectomy (percentage change, -61.9 post-risk-reducing salpingo-oophorectomy vs +15.2 in controls; P=.02), but no significant differences were seen for the other hormones.

CONCLUSION

Ovarian volumes measured by transvaginal ultrasound were moderately correlated with volumes directly measured on pathology specimens and were not correlated with sex steroid hormone levels in postmenopausal women. Estradiol was the only hormone that declined significantly after risk-reducing salpingo-oophorectomy. Thus, it remains unclear whether the limited post-risk-reducing salpingo-oophorectomy changes in sex steroid hormones among postmenopausal women impact long-term adverse outcomes.

Abstract P2-11-01: Breast cancer (BC) risk among patients with benign breast disease (BBD) by NSAID use

Background: Approximately one million U.S women are diagnosed with benign breast disease (BBD) annually, which increases breast cancer (BC) risk between 1.5- and four-fold, depending on the pathologic characteristics of the lesion and other factors. BBD lesions are associated with inflammation and fibrosis, suggesting that inflammatory pathways may play a role in progression of BBD to BC. Aspirin and other non-steroidal anti-inflammatory drugs (NSAIDs) are well tolerated, widely used drugs that block inflammation by inhibiting cyclooxygenase enzymes, which lowers prostaglandin synthesis, and by exerting numerous additional anti-inflammatory effects. NSAIDs are inversely associated with several types of cancer, including BC in some, but not all studies, and have been linked to lower BC risk among BBD patients in prior publications. We examined the association between NSAID use and BC risk, overall and by self-reported history of BBD, using data from the American Cancer Society Cancer Prevention Study II (CPS-II). Methods: The Cancer Prevention Study-II (CPS-II) Nutrition Cohort is a study of approximately 189,000 U.S. men and women followed prospectively for cancer incidence and mortality. Study participants filled out a detailed questionnaire at baseline in 1992/1993 and follow-up surveys in 1997 and every two years until 2017. On each follow-up survey, participants reported type, quantity, and duration of NSAID use as well as diagnoses of BBD. Incident BCs were either self-reported and validated via medical records or cancer registry linkage, or identified via National Death Index linkage. Women in the analytic cohort were followed from date of 1997 survey until diagnosis of BC, reported use of tamoxifen, report of cancer other than BC, date of death, loss to follow-up or end of follow-up. Hazard ratios (HRs) and 95% confidence intervals (CIs) assessing associations of BBD and NSAID use with BC risk were estimated using Cox proportional hazards regression analysis. Statistical interactions between BBD and NSAID were evaluated by fitting and testing the corresponding cross-product terms, along with the main effects of each. Both NSAID use and BBD were modeled as time-dependent variables, allowing exposure status to change over the course of the multiple surveys returned. Results: Of the 60,517 women included in the study, 3,899 (6.4%) developed BC. Mean follow-up time was 12.7 years. A total of 23,661 women (39%) reported a diagnosis of BBD at some point during the study period, and 54,656 (90%) reported some NSAID use. Women self-reporting BBD were 46% more likely to develop BC than those without self-reported BBD (HR 1.46, 95% CI 1.36-1.57). Overall, BC risk was not increased among NSAID users versus non-users (HR 0.95, 95% CI 0.88-1.02). In contrast, BC risk was reduced among current NSAID users with a history of BBD (HR 0.87, 95% CI 0.78-0.97), but not among NSAID users who did not report a history of BBD (HR 1.02, 95% CI 0.92-1.13, p-interaction=0.04). Risk did not differ across number of pills per month (RR=0.84 for &lt;15 pills/month, 0.89 for 15-29, 0.88 for 30-44, 0.78 for 45-59, 0.88 for 60+). Conclusion: In our study, NSAID use had a statistically-significant protective effect on BC risk among women with BBD, suggesting its potential use as a chemopreventive agent in this high-risk group of women, but not among those who did not report a history of BBD.

Citation Format: Robert A Vierkant, Matthew Masters, Lauren R Teras, Mark E Sherman. Breast cancer (BC) risk among patients with benign breast disease (BBD) by NSAID use [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P2-11-01.

Automated quantification of levels of breast terminal duct lobular (TDLU) involution using deep learning

Convolutional neural networks (CNNs) offer the potential to generate comprehensive quantitative analysis of histologic features. Diagnostic reporting of benign breast disease (BBD) biopsies is usually limited to subjective assessment of the most severe lesion in a sample, while ignoring the vast majority of tissue features, including involution of background terminal duct lobular units (TDLUs), the structures from which breast cancers arise. Studies indicate that increased levels of age-related TDLU involution in BBD biopsies predict lower breast cancer risk, and therefore its assessment may have potential value in risk assessment and management. However, assessment of TDLU involution is time-consuming and difficult to standardize and quantitate. Accordingly, we developed a CNN to enable automated quantitative measurement of TDLU involution and tested its performance in 174 specimens selected from the pathology archives at Mayo Clinic, Rochester, MN. The CNN was trained and tested on a subset of 33 biopsies, delineating important tissue types. Nine quantitative features were extracted from delineated TDLU regions. Our CNN reached an overall dice-score of 0.871 (±0.049) for tissue classes versus reference standard annotation. Consensus of four reviewers scoring 705 images for TDLU involution demonstrated substantial agreement with the CNN method (unweighted κappa = 0.747 ± 0.01). Quantitative involution measures showed anticipated associations with BBD histology, breast cancer risk, breast density, menopausal status, and breast cancer risk prediction scores (p < 0.05). Our work demonstrates the potential to improve risk prediction for women with BBD biopsies by applying CNN approaches to generate automated quantitative evaluation of TDLU involution.

Common variants in breast cancer risk loci predispose to distinct tumor subtypes

BACKGROUND

Genome-wide association studies (GWAS) have identified multiple common breast cancer susceptibility variants. Many of these variants have differential associations by estrogen receptor (ER) status, but how these variants relate with other tumor features and intrinsic molecular subtypes is unclear.

METHODS

Among 106,571 invasive breast cancer cases and 95,762 controls of European ancestry with data on 173 breast cancer variants identified in previous GWAS, we used novel two-stage polytomous logistic regression models to evaluate variants in relation to multiple tumor features (ER, progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2) and grade) adjusting for each other, and to intrinsic-like subtypes.

RESULTS

Eighty-five of 173 variants were associated with at least one tumor feature (false discovery rate < 5%), most commonly ER and grade, followed by PR and HER2. Models for intrinsic-like subtypes found nearly all of these variants (83 of 85) associated at p < 0.05 with risk for at least one luminal-like subtype, and approximately half (41 of 85) of the variants were associated with risk of at least one non-luminal subtype, including 32 variants associated with triple-negative (TN) disease. Ten variants were associated with risk of all subtypes in different magnitude. Five variants were associated with risk of luminal A-like and TN subtypes in opposite directions.

CONCLUSION

This report demonstrates a high level of complexity in the etiology heterogeneity of breast cancer susceptibility variants and can inform investigations of subtype-specific risk prediction.

Protocol for the Detection of Organoid-Initiating Cell Activity in Patient-Derived Single Fallopian Tube Epithelial Cells

Identification of serous tubal intraepithelial carcinomas (STIC) in the fallopian tubes of women who are carriers of germ line pathogenic variants in tubo-ovarian cancer predisposition genes (i.e., BRCA1 and BRCA2) has led to the hypothesis that many high-grade serous carcinomas (HGSC) arise from the fimbria of the fallopian tube. However, the primitive (stem and progenitor) tubal epithelial cells that give rise to STIC and HGSC have not been defined. Further, as putative HGSC precursors are discovered at salpingectomy, the natural history of such lesions is truncated at diagnosis. Thus, living cultures of human fallopian tubes suitable for experimental studies are needed to define and characterize the cellular origin of HGSCs and thereby advance the discovery of improved methods to assess risk, develop effective early detection tests and identify novel prevention approaches. Accordingly, patient-derived tissue-organoids and isolated epithelial stem cell derived-organoids generated from average and high-risk patients are vital resources to understand the developmental biology of aging fallopian tubes and pathogenesis of HGSCs. With a vision to boost HGSC prevention research, we have established state-of-the-art protocols for the collection, processing, storage, distribution, and management of fallopian tube tissues. Here we describe the protocol for preparing these organoids, with emphasis on the key steps that require meticulous attention to achieve success.

The cost of diagnosing endometrial cancer: Quantifying the healthcare cost of an abnormal uterine bleeding workup

OBJECTIVE

The evaluation of women with perimenopausal abnormal uterine bleeding (AUB) and postmenopausal bleeding (PMB) to detect endometrial cancer (EC) and its precursors is not standardized and can vary widely. Consequently, costs associated with the workup and management undoubtedly vary. This study aimed to quantify costs of AUB/PMB evaluation to understand the healthcare burden associated with securing a pathologic diagnosis.

METHODS

Women ≥45 years of age presenting to a single institution gynecology clinic with AUB/PMB for diagnostic workup were prospectively enrolled February 2013-October 2017 for a lower genital tract biospecimen research study. Clinical workup of AUB/PMB was determined by individual provider discretion. Costs of care were collected from administrative billing systems from enrollment to 90 days post enrollment. Costs were standardized and inflation-adjusted to 2017 US Dollars (USD).

RESULTS

In total, there were 1017 women enrolled with 5.6% diagnosed with atypical hyperplasia or endometrial cancer (EC). Within the full cohort, 90-day median cost for AUB/PMB workup and management was $2279 (IQR $512-4828). Among patients with a diagnostic biopsy, median 90-day costs ranged from $2203 (IQR $499-3604) for benign or disordered proliferative endometrium (DPE) diagnosis to $21,039 (IQR $19,084-24,536) for a diagnosis of EC.

CONCLUSIONS

The costs for diagnostic evaluation of perimenopausal AUB and PMB vary greatly according to ultimate tissue-based diagnosis. Even reassuring benign findings that do not require further intervention-the most common in this study's cohort-yield substantial costs. The development of sensitive, specific, and more cost-effective diagnostic strategies is warranted.

Protocol for the Detection of Organoid-Initiating Cell Activity in Patient-Derived Single Fallopian Tube Epithelial Cells

Identification of serous tubal intraepithelial carcinomas (STIC) in the fallopian tubes of women who are carriers of germ line pathogenic variants in tubo-ovarian cancer predisposition genes (i.e., BRCA1 and BRCA2) has led to the hypothesis that many high-grade serous carcinomas (HGSC) arise from the fimbria of the fallopian tube. However, the primitive (stem and progenitor) tubal epithelial cells that give rise to STIC and HGSC have not been defined. Further, as putative HGSC precursors are discovered at salpingectomy, the natural history of such lesions is truncated at diagnosis. Thus, living cultures of human fallopian tubes suitable for experimental studies are needed to define and characterize the cellular origin of HGSCs and thereby advance the discovery of improved methods to assess risk, develop effective early detection tests and identify novel prevention approaches. Accordingly, patient-derived tissue-organoids and isolated epithelial stem cell derived-organoids generated from average and high-risk patients are vital resources to understand the developmental biology of aging fallopian tubes and pathogenesis of HGSCs. With a vision to boost HGSC prevention research, we have established state-of-the-art protocols for the collection, processing, storage, distribution, and management of fallopian tube tissues. Here we describe the protocol for preparing these organoids, with emphasis on the key steps that require meticulous attention to achieve success.

Molecular and clinical characterization of postpartum-associated breast cancer in the Carolina Breast Cancer Study Phase I-III, 1993-2013

BACKGROUND

Breast cancers in recently postpartum women may have worse outcomes, but studies examining tumor molecular features by pregnancy recency have shown conflicting results.

METHODS

This analysis used Carolina Breast Cancer Study data to examine clinical and molecular tumor features among women <50 years of age who were recently ( {less than or equal to} 10 years prior), or remotely (>10 years prior) postpartum, or nulliparous. Prevalence odds ratios (PORs) and 95% confidence intervals (CIs) were estimated using multivariable models.

RESULTS

Recently postpartum women (N=618) were more frequently lymph node positive [POR (95% CI): 1.66 (1.26, 2.19)], ER negative [1.37 (1.02, 1.83)], and IHC-based triple negative [1.57 (1.00, 2.47)] compared to nulliparous (N=360) women. Some differences were identified between recent vs. remotely postpartum; smaller tumor size [0.67 (0.52, 0.86)], p53 wildtype [0.53 (0.36, 0.77)], and non-basal-like phenotype [0.53 (0.33, 0.84)] were more common among recently postpartum. Recently postpartum (vs. nulliparous) had significant enrichment for adaptive immunity, T cells, B cells, CD8 T cells, activated CD8 T cells/NK cells, Tfh cells and higher overall immune cell scores. These differences were attenuated in remotely (compared to recently) postpartum women.

CONCLUSIONS

These results suggest a dominant effect of parity (vs. nulliparity) and a lesser effect of pregnancy recency on tumor molecular features, although tumor immune microenvironments were altered in association with pregnancy recency.

IMPACT

Our study is unique in examining tumor immune microenvironment and RNA-based markers according to time since last childbirth. Future studies should examine the interplay between tumor features, post-diagnostic treatment and outcomes among recently postpartum women.

Mammary collagen architecture and its association with mammographic density and lesion severity among women undergoing image-guided breast biopsy

Background

Elevated mammographic breast density is a strong breast cancer risk factor with poorly understood etiology. Increased deposition of collagen, one of the main fibrous proteins present in breast stroma, has been associated with increased mammographic density. Collagen fiber architecture has been linked to poor outcomes in breast cancer. However, relationships of quantitative collagen fiber features assessed in diagnostic biopsies with mammographic density and lesion severity are not well-established.

Methods

Clinically indicated breast biopsies from 65 in situ or invasive breast cancer cases and 73 frequency matched-controls with a benign biopsy result were used to measure collagen fiber features (length, straightness, width, alignment, orientation and density (fibers/µm²)) using second harmonic generation microscopy in up to three regions of interest (ROIs) per biopsy: normal, benign breast disease, and cancer. Local and global mammographic density volumes were quantified in the ipsilateral breast in pre-biopsy full-field digital mammograms. Associations of fibrillar collagen features with mammographic density and severity of biopsy diagnosis were evaluated using generalized estimating equation models with an independent correlation structure to account for multiple ROIs within each biopsy section.

Results

Collagen fiber density was positively associated with the proportion of stroma on the biopsy slide (p < 0.001) and with local percent mammographic density volume at both the biopsy target (p = 0.035) and within a 2 mm perilesional ring (p = 0.02), but not with global mammographic density measures. As severity of the breast biopsy diagnosis increased at the ROI level, collagen fibers tended to be less dense, shorter, straighter, thinner, and more aligned with one another (p < 0.05).

Conclusions

Collagen fiber density was positively associated with local, but not global, mammographic density, suggesting that collagen microarchitecture may not translate into macroscopic mammographic features. However, collagen fiber features may be markers of cancer risk and/or progression among women referred for biopsy based on abnormal breast imaging.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13058-021-01482-z.

Somatic mutations in benign breast disease tissues and association with breast cancer risk

Background

Benign breast disease (BBD) is a risk factor for breast cancer (BC); however, little is known about the genetic alterations present at the time of BBD diagnosis and how these relate to risk of incident BC.

Methods

A subset of a long-term BBD cohort was selected to examine DNA variation across three BBD groups (42 future estrogen receptor-positive (ER+) BC, 36 future estrogen receptor-negative (ER−) BC, and 42 controls cancer-free for at least 16 years post-BBD). DNA extracted from archival formalin fixed, paraffin-embedded (FFPE) tissue blocks was analyzed for presence of DNA alterations using a targeted panel of 93 BC-associated genes. To address artifacts frequently observed in FFPE tissues (e.g., C>T changes), we applied three filtering strategies based on alternative allele frequencies and nucleotide substitution context. Gene-level associations were performed using two types of burden tests and adjusted for clinical and technical covariates.

Results

After filtering, the variant frequency of SNPs in our sample was highly consistent with population allele frequencies reported in 1 KG/ExAC (0.986, p < 1e−16). The top ten genes found to be nominally associated with later cancer status by four of 12 association methods(p < 0.05) were MED12, MSH2, BRIP1, PMS1, GATA3, MUC16, FAM175A, EXT2, MLH1 and TGFB1, although these were not statistically significant in permutation testing. However, all 10 gene-level associations had OR < 1 with lower mutation burden in controls compared to cases, which was marginally statistically significant in permutation testing (p = 0.04). Comparing between the three case groups, BBD ER+ cases were closer to controls in mutation profile, while BBD ER− cases were distinct. Notably, the variant burden was significantly higher in controls than in either ER+ or ER− cases. CD45 expression was associated with mutational burden (p < 0.001).

Conclusions

Somatic mutations were more frequent in benign breast tissue from women who did not develop cancer, opening questions of clonal diversity or immune-mediated restraint on future cancer development. CD45 expression was positively associated with mutational burden, most strongly in controls. Further studies in both normal and premalignant tissues are needed to better understand the role of somatic gene mutations and their contribution to future cancer development.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12920-021-01032-8.

Abstract 2274: Somatic variant burdenin benign breast disease and association with risk of subsequent breast cancer

Benign breast disease (BBD) is an established risk factor for development of breast cancer (BC). However, little is known about the prevalence of somatic genetic alterations at the time of BBD diagnosis and relationship to subsequent BC. To characterize DNA variants in BBD and investigate association with BC risk, we isolated DNA from formalin-fixed paraffin-embedded (FFPE) BBD biopsies and assessed mutations using a panel of 93 breast cancer predisposition genes (Qiagen GeneRead). The study set consisted of 120 BBD patients from three age-matched groups defined based on 16 years of BC follow-up: BBD-controls (cancer-free after 16 years), BBD-ER+, or BBD-ER- breast cancer (within 16 years). Bioinformatics quality checks included comparisons of paired fresh-frozen and FFPE replicates to reduce false variant calls induced by FFPE artifacts. Gene-level variant burden differences among study groups were assessed using 12 statistical approaches, adjusted for patient age, year of biopsy, and histology. To investigate possible immune implications of increased variant burden, extent of leukocytes in the BBD biopsies was assessed using CD45 immunohistochemistry. To assess variant profile changes during the progression from BBD to BC, we also performed targeted sequencing of 12 BBD-matched subsequent tumor samples (six ER+ and six ER-) developed within 5 years of BBD diagnosis. Gene-level association results showed consistently skewed distributions suggesting a higher variant burden in BBD controls: among the top 10 genes associated with case-status (p&lt;0.05), all had BC-risk odds ratio estimates less than 1.0. Immune infiltrates, assessed by CD45 H-scores, were positively associated with overall variant burden (r=0.42, p=0.0031), and noticeably higher in cancer-free controls (r=0.50, p=0.005). Comparison of mutation variants in 12 BBD cases that developed cancer within 5 years of diagnosis and their subsequent tumors revealed that more than half of the non-SNP variants were shared between the BBD and the subsequent tumor (54.6%), whereas less than one quarter were unique to the tumor (20.6%) or unique to the BBD (24.9%). Through BBD-BC paired variant analysis, three subjects were found with newly emergent clones uniquely appearing in the tumors and four subjects had loss of clones in the tumor that were present in the BBD. These results show that somatic variant burden is lower in patients with BBD that progress to BC, mutation profiles of BC progression are heterogeneous, and BBD tissues with reduced variant burden also show reduced immune infiltrate. This implicates a potential protective role for immune activation in BBD. Future directions will define the characteristics of the potentially protective immune response and its role in variant heterogeneity in a larger sample set, integrated with paired RNA sequencing to better understand the pathways involved and the relationship to immune infiltration.

Citation Format: Stacey J. Winham, Julie M. Cunningham, Yuanhang Liu, Aditya V. Bhagwate, Ethan P. Heinzen, Samantha J. McDonough, Melody L. Stallings-Mann, Robert A. Vierkant, Jodi M. Carter, Mark E. Sherman, Derek C. Radisky, Amy C. Degnim, Chen Wang. Somatic variant burdenin benign breast disease and association with risk of subsequent breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2274.

Protein-based immune profiles of basal-like vs. luminal breast cancers

Tumor-infiltrating lymphocytes play an important, but incompletely understood role in chemotherapy response and prognosis. In breast cancer, there appear to be distinct immune responses by subtype, but most studies have used limited numbers of protein markers or bulk sequencing of RNA to characterize immune response, in which spatial organization cannot be assessed. To identify immune phenotypes of Basal-like vs. Luminal breast cancer we used the GeoMx® (NanoString) platform to perform digital spatial profiling of immune-related proteins in tumor whole sections and tissue microarrays (TMA). Visualization of CD45, CD68, or pan-Cytokeratin by immunofluorescence was used to select regions of interest in formalin-fixed paraffin embedded tissue sections. Forty-four antibodies representing stromal markers and multiple immune cell types were applied to quantify the tumor microenvironment. In whole tumor slides, immune hot spots (CD45+) had increased expression of many immune markers, suggesting a diverse and robust immune response. In epithelium-enriched areas, immune signals were also detectable and varied by subtype, with regulatory T-cell (Treg) markers (CD4, CD25, and FOXP3) being higher in Basal-like vs. Luminal breast cancer. Extending these findings to TMAs with more patients (n = 75), we confirmed subtype-specific immune profiles, including enrichment of Treg markers in Basal-likes. This work demonstrated that immune responses can be detected in epithelium-rich tissue, and that TMAs are a viable approach for obtaining important immunoprofiling data. In addition, we found that immune marker expression is associated with breast cancer subtype, suggesting possible prognostic, or targetable differences.

Discovery and validation of novel methylated DNA markers of cervical cancer

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Background: HR-HPV DNA testing, with or without cervical cytology, provides excellent sensitivity for detection of cervical cancer (CC) and its precursors; negative test results indicate that risk of disease is extremely low and enable women to undergo reduced screening with safety. However, management of women who screen positive remains challenging as many will prove to have self-limited HR-HPV infections. DNA methylation is an early event in carcinogenesis that could enhance CC screening specificity. Methods: For discovery, DNA from 70 FFPE CC (36 squamous, 34 adenocarcinoma) tissues that were reviewed microscopically, 18 fresh frozen benign cervicovaginal (BCV) tissues collected at the time of benign hysterectomy, and 18 buffy coats from cancer-free women underwent reduced representation bisulfite sequencing (RRBS) to identify MDMs associated with CC. Candidate MDM selection was based on area under the receiver operating characteristic curve (AUC) discrimination, methylation fold change, and low background methylation among benign controls. Candidate MDMs were re-tested using methylation-specific PCR (MSP) to confirm performance. Blinded biological validation was performed using MSP on DNA extracted from independent FFPE CC (38 squamous, 43 adenocarcinoma) and BCV (40) tissues. The performance of CC MDMs was also tested in DNA extracted from cervical dysplasia (36 adenocarcinoma in situ (AIS), 32 cervical intraepithelial neoplasia (CIN) 2/3, 11 CIN 1) FFPE tissues. Results: From RRBS discovery and technical validation via MSP, 30 candidate MDMs showed marked methylation fold changes (10 to >1000) across both CC histologies compared to BCV tissue from cancer-free women. Each of the 30 MDMs highly discriminated CC from BCV tissue with 9 MDMs having an AUC >0.90 (Table). CC MDMs also highly discriminated AIS from BCV but did not perform well in CIN 2/3 and CIN 1 (Table). Conclusions: Whole methylome sequencing, stringent filtering criteria, and biological validation have yielded outstanding candidate MDMs for CC that highly discriminate CC from BCV, notably with high specificity. Performance in cervical dysplasias varied with higher positivity rates in AIS than in CIN 2/3 and CIN 1. Translation to testing these novel MDMs in lower genital tract biospecimens and the addition of HR-HPV to the CC panel are warranted.[Table: see text]

Quantifying procedural pain associated with office gynecologic tract sampling methods

OBJECTIVE

Emerging technologies may enable detection of endometrial cancer with methods that are less invasive than standard biopsy methods. This study compares patient pain scores among 3 office gynecologic tract sampling methods and explores their potential determinants.

METHODS

A prospective study including 3 sampling methods (tampon, Tao brush (TB), endometrial biopsy (EB)) was conducted between December 2015 and August 2017 and included women ≥45 years of age presenting with abnormal uterine bleeding, postmenopausal bleeding, or thickened endometrial stripe. Patients rated pain after each sampling procedure using a 100-point visual analog scale (VAS).

RESULTS

Of 428 enrolled, 190 (44.39%) patients underwent all 3 sampling methods and reported a VAS score for each. Nearly half were postmenopausal (n = 93, 48.9%); the majority were parous (172, 90.5%) of which 87.8% had at least one vaginal delivery. Among the 190 patients, the median (IQR) pain score was significantly lower for sampling via tampon (0 [0,2]) compared to TB (28 [12, 52]) or EB (32 [15, 60]) (both p < 0.001, Wilcoxon signed rank test). Among women who underwent tampon sampling, age and pain scores showed a weak positive correlation (Spearman rank correlation, r = 0.14; p = 0.006); EB sampling was associated with a weak inverse correlation between parity and pain scores (r = -0.14; p = 0.016).

CONCLUSION

Gynecologic tract sampling using a tampon had significantly lower pain than both EB and TB. Pain with tampon sampling was positively correlated with age and pain with EB sampling was inversely correlated with parity. Pain scores for TB and EB were not significantly related to age, menopausal status, or BMI.

Disparities and interventions in the timeliness of endometrial cancer diagnosis and treatment in the United States: a scoping review protocol

BACKGROUND

Disparities in the stage at diagnosis of endometrial cancer (EC) account for a significant proportion of the disparities in morbidity and mortality experienced by vulnerable groups in the USA. Evidence suggests that disparities in timeliness of care and treatment play a significant role in stage at diagnosis. Despite an increase in literature on EC disparities, the issue remains largely unchanged. The objectives of this review will be to synthesize the evidence to identify important remaining research questions and inform future interventions to reduce the disparity in stage at diagnosis of EC in the USA.

METHODS

This scoping review protocol will use the five-step framework developed by Arksey and O'Malley. A literature search will be conducted from January 2000 onwards in PubMed, EMBASE, Scopus, and Cochrane CENTRAL databases. Studies on delays in care of EC will be included if they were published in English and reported findings for the US population. Two reviewers will independently screen all citations, full-text articles, and abstract data. The study methodological quality and bias will be appraised using appropriate tools. A narrative summary of findings will be conducted. Data analysis will involve quantitative (e.g., frequencies) and qualitative (e.g., content and thematic analysis) methods. The literature search, data extraction, and evidence synthesis will be informed by the Pathway to Treatment Model, which divides time to cancer care initiation into appraisal, help-seeking, diagnostic, and pre-treatment intervals. Results will be reported in accordance with the PRISMA statement.

DISCUSSION

EC disparities research is currently benefitting form a growing expectation that studies have a real impact on disparities. Patient, healthcare, and disease factors impact the amount of time patients spend in different intervals of the Pathway to Treatment Model, so research and interventions aimed at reducing disparities in EC survival should be designed with cognizance to how these factors impact their target population. Reviews on disparities in stage at diagnosis of EC exist but do not provide a comprehensive picture of the pathway to treatment. This review will seek to provide an expanded bedrock of evidence for future studies to build on as they aim to more actively reduce EC disparities.

TRIAL REGISTRATION

Open Science Framework ( osf.io/v2zxy ).

Sex Hormones, Insulin, and Insulin-like Growth Factors in Recurrence of High-Stage Endometrial Cancer

BACKGROUND

The influence of sex hormone and insulin/insulin-like growth factor (IGF) axis signaling on endometrial cancer recurrence is unknown. We evaluated these pathways in a prospective cohort of Gynecologic Oncology Group (GOG)0210 trial endometrial adenocarcinoma patients.

METHODS

Stage II-IV patients (N = 816) were included in this study. Pretreatment specimens were tested for tumor mRNA and protein expression of IGF1, IGF2, IGF-binding proteins (IGFBP)-1 and -3, insulin (IR) and IGF-I receptors (IGF1R), phosphorylated IR/IGF1R (pIGF1R/pIR), and estrogen (ER) and progesterone receptors (PR) using qPCR and IHC. Serum concentrations of insulin, IGF-I, IGFBP-3, estradiol, estrone, and sex hormone binding globulin were measured. HRs and 95% confidence intervals (CI) for progression-free survival were calculated from Cox models adjusting for age, stage, and grade.

RESULTS

Recurrence occurred in 280 (34%) cases during a median of 4.6 years of follow-up. ER positivity (HR, 0.67; 95% CI, 0.47-0.95), IR positivity (HR, 0.53; 95% CI, 0.29-0.98), and circulating IGF-I (highest vs. lowest quartile: HR, 0.66; 95% CI, 0.47-0.92) were inversely associated with recurrence risk. Circulating estradiol (highest vs. lowest tertile: HR, 1.55; 95% CI, 1.02-2.36) and pIGF1R/pIR positivity (HR, 1.40; 95% CI, 1.02-1.92) were associated with increased recurrence risk.

CONCLUSIONS

Circulating estradiol and tumor tissue phosphorylated (activated) IGR1R/IR were independently associated with higher risk of recurrence in patients with endometrial cancer.

IMPACT

This study may inform future clinical trials of endocrine-targeted adjuvant therapies in patients with endometrial cancer that could include baseline assessment of serum and tissue biomarkers of estradiol and insulin signaling pathways.

Abstract PS7-11: Benign breast disease: Temporal trends from 1967 to 2013

Background: Women with benign breast disease (BBD) are at increased risk of breast cancer (BC). Classic studies based on film-based mammographic screening and pathology diagnosis of surgical biopsies conducted in the 1980s established a hierarchy of increasing BC risk: non-proliferative (NP) BBD, proliferative BBD without atypia (PDWA) and atypical hyperplasia (AH). Given changes in epidemiological BC risk factors and introduction of percutaneous core needle biopsy (CNB) in mid-1990s, and later, digital mammography, we hypothesized that the patient characteristics and relative frequency of BBD diagnoses have changed over time. Accordingly, we performed a longitudinal analysis of the frequency of patient characteristics and BBD diagnoses in the Mayo BBD cohort.

Methods: Utilizing the Mayo Clinic Surgical and Pathology Indices, women ages 18 to 85 who had a BBD biopsy between 1/1/67 and 12/31/13 were identified. Breast pathologists reviewed biopsies masked to diagnoses of incident BC diagnosed in follow-up. Demographic characteristics and BC events were obtained by query of institutional data sources and participant surveys. Trends were evaluated for the following eras: 1: pre-mammogram (1967-1981), 2: pre-CNB (1982-1992), 3: CNB Transition (1993-2001), and 4: CNB (2002-2013). Demographics were formally compared across eras using chi-square tests for categorical variables and analyses of variance (ANOVAs) for continuous variables.

Results: From 1967-2013, the cohort includes 19,582 unique women with BBD. The frequency of CNB increased from eras 1-4: 0.04%, 0.6%, 51.3 %, and 88.9%, respectively. Mean age at BBD diagnosis was younger in era 1 (48.0 years) vs eras 2-4 (53.2, 52.0, and 51.8, respectively, p&lt;0.001). The percentage of biopsies diagnosed as PDWA increased from era 1-4 (25.7%, 34.3%, 35.2%, 46.2%, p&lt;0.001), as did the percentage with AH (2.4%, 5.1%, 8.6%, 12.3%, p&lt;0.001). Over eras 1-4, the percentages of women with a strong family history of BC increased (9.9%, 12.7%, 17.1%, and 29.0%, p&lt;0.001) as did mean BMI (24.8, 26.4, 27.4, and 28.6, p&lt;0.001). With a median follow-up of 10.9 years, 1,719 breast cancers have developed, with increasing proportion of noninvasive (DCIS-only) disease across eras 1-4: 15.0%, 21.1%, 21.2%, and 33.2%, p&lt; 0.001.

Conclusions: Analysis of this large, single institution BBD cohort for the 46 year period 1967-2013 demonstrates that BC risk factors among BBD patients has changed over time, with subjects demonstrating increasing age, BMI, and family history, and that the percentages of BBD classified as PDWA and AH have increased. Impact on BC risk will be further investigated.

Citation Format: Amy Degnim, Karthik Ghosh, Jodi M Carter, Robert A Vierkant, Matthew R Jensen, Stacey J Winham, Tanya L Hoskin, Marlene Frost, Teresa M Allers, Denise L Gehling, Mindy J Kern, Laura M Pacheco-Spann, Celine M Vachon, Derek C Radisky, Daniel W Visscher, Mark E Sherman. Benign breast disease: Temporal trends from 1967 to 2013 [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS7-11.

Abstract PD10-10: Epithelial proliferation score as an independent breast cancer risk predictor in benign breast disease

Background: Women with benign breast disease (BBD) experience an increased risk of breast cancer (BC). Histologic classification of BBD, as non-proliferative disease (NP), proliferative disease without atypia (PDWA) or atypical hyperplasia (AH), stratifies groups of patients into progressively higher categories of BC risk. However, this classification does not comprehensively assess the proliferative state of the epithelium throughout the biopsy. In addition, while AH is considered the most high-risk class of BBD, it is not always a highly proliferative lesion; atypical ductal lesions may reflect focal cytologic and architectural changes. We evaluated the association of an alternative classification of BBD severity and BC risk based on subjective grading of: 1) the maximal degree of epithelial proliferation and 2) multifocality of epithelial proliferation. Methods: Pathologists reviewed biopsies from participants aged 18 to 85 years in the Mayo BBD cohort (2002-2013), masked to BC outcomes, ascertained via questionnaires, tumor registry data and medical record review. Biopsies were classified as NP, PDWA or AH and semi-quantitatively scored for: 1) maximal degree of epithelial proliferation within a focus (DP) (0-3; none to severe) and 2) multifocality of proliferation (MP) (0-3; none to multiple foci). DP and MP scores were also summed to give a DP+MP score (0-6). Associations of DP and MP with BC risk were examined using Cox proportional hazards regression analyses, adjusting for age at BBD biopsy. Women were followed from date of initial biopsy to date of BC, death or last follow-up. Results: Of the 1529 assessable biopsies, 544 (35.6%) were classified as NP, 708 (46.3%) as PDWA and 277 (18.1%) as AH. Both DP and MP scores had significant positive correlation with increasing BBD severity (DP: r=0.51, p&lt; 0.001; MP: r=0.52, p&lt; 0.001). Mean (SD) DP scores were 0.6 (0.6) for NP, 1.6 (0.9) for PDWA, and 1.8 (0.7) for AH (ANOVA p&lt;0.001). Mean (SD) for MP scores were 0.6 (0.6) for NP, 1.4 (0.8) for PDWA, and 1.8 (0.8) for AH (ANOVA p&lt;0.001). Mean (SD) for DP+MP scores were 1.2 (1.2) for NP, 2.9 (1.5) for PDWA, and 3.6 (1.2) for AH (ANOVA p&lt;0.001). With median follow-up of 8.8 years for controls and 5.3 years for cases, 10.6% of the women in the cohort developed BC. Compared to those with DP scores of 0, women with DP scores of 3 had significantly increased BC risk (HR 1.42, 95% CI: 1.16, 1.74, p=0.003). MP was associated with a non-significant increase in BC risk for scores of 3 versus 0 (HR: 1.20, 95% CI: 0.97,1.49, p=0.11). DP+MP scores of 6 conferred the highest BC risk (HR (score 6 vs. 0): 1.62, 95% CI 1.18,2.21, p=0.02). Results did not substantively differ after adjusting for BBD severity as NP, PDWA or AH. Conclusions: In this preliminary analysis within the Mayo BBD cohort, both proliferative degree (DP) and multifocality (MP) scores were correlated with histologic severity of BBD. DP and DP+MP scores were each associated with increased BC risk. We conclude that improved characterization of epithelial proliferation in BBD biopsies may enable refined prediction of individual BC risk.

Citation Format: Jodi M Carter, Matthew R Jensen, Robert A Vierkant, Stacey J Winham, Tanya L Hoskin, Marlene Frost, Karthik Ghosh, Derek C Radisky, Amy C Degnim, Mark E Sherman. Epithelial proliferation score as an independent breast cancer risk predictor in benign breast disease [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PD10-10.

Association of a novel endometrial cancer biomarker panel with prognostic risk, platinum insensitivity, and targetable therapeutic options

During the past decade, the age-adjusted mortality rate for endometrial cancer (EC) increased 1.9% annually with TP53 mutant (TP53-mu) EC disproportionally represented in advanced disease and deaths. Therefore, we aimed to assess pivotal molecular parameters that differentiate clinical outcomes in high- and low-risk EC. Using the Cancer Genome Atlas, we analyzed EC specimens with available DNA sequences and quantitative gene-specific RNA expression data. After polymerase ɛ (POLE)-mutant specimens were excluded, differential gene-specific mutations and mRNA expressions were annotated and integrated. Consequent to TP53-mu failure to induce p21, derepression of multiple oncogenes harboring promoter p21 repressive sites was observed, including CCNA2 and FOXM1 (P < .001 compared with TP53 wild type [TP53-wt]). TP53-wt EC with high CCNA2 expression (CCNA2-H) had a targeted transcriptomic profile similar to that of TP53-mu EC, suggesting CCNA2 is a seminal determinant for both TP53-wt and TP53-mu EC. CCNA2 enhances E2F1 function, upregulating FOXM1 and CIP2A, as observed in TP53-mu and CCNA2-H TP53-wt EC (P < .001). CIP2A inhibits protein phosphatase 2A, leading to AKT inactivation of GSK3β and restricted oncoprotein degradation; PPP2R1A and FBXW7 mutations yield similar results. Upregulation of FOXM1 and failed degradation of FOXM1 is evidenced by marked upregulation of multiple homologous recombination genes (P < .001). Integrating these molecular aberrations generated a molecular biomarker panel with significant prognostic discrimination (P = 5.8×10⁻⁷); adjusting for age, histology, grade, myometrial invasion, TP53 status, and stage, only CCNA2-H/E2F1-H (P = .0003), FBXW7-mu/PPP2R1A-mu (P = .0002), and stage (P = .017) were significant. The generated prognostic molecular classification system identifies dissimilar signaling aberrations potentially amenable to targetable therapeutic options.

Breast cancer risk factors by mode of detection among screened women in the Cancer Prevention Study-II

BACKGROUND

Identifying risk factors for women at high risk of symptom-detected breast cancers that were missed by screening would enable targeting of enhanced screening regimens. To this end, we examined associations of breast cancer risk factors by mode of detection in screened women from the Cancer Prevention Study (CPS)-II Nutrition Cohort.

METHODS

Among 77,206 women followed for a median of 14.8 years, 2711 screen-detected and 1281 symptom-detected breast cancer cases were diagnosed. Multivariable-adjusted associations were estimated using joint Cox proportional hazards regression models with person-time calculated contingent on screening.

RESULTS

Factors associated with higher risks of symptom-detected and screen-detected breast cancer included current combined hormone therapy (HT) use (HR 2.07, 95% CI 1.72-2.48 and 1.45, 1.27-1.65, respectively) and history of benign breast disease (1.85, 1.64-2.08 and 1.43, 1.31-1.55, respectively). Current estrogen-only HT use was associated with symptom-detected (1.40, 1.15-1.71) but not screen-detected (0.95, 0.83-1.09) breast cancer. Higher risk of screen-detected but not symptom-detected breast cancer was observed for obese vs. normal body mass index (1.22, 1.01-1.48 and 0.76, 0.56-1.01, respectively), per 3 h/day sitting time (1.10, 1.04-1.16 and 0.97, 0.89-1.06, respectively), and ≥ 2 drinks per day vs. nondrinker (1.40, 1.16-1.69 and 1.27, 0.97-1.66, respectively).

CONCLUSIONS

Differences in risk factors for symptom-detected vs. screen-detected breast cancer were observed and most notably, use of combined and estrogen-only HT and a history of benign breast disease were associated with increased risk of symptomatic detected breast cancer.

IMPACT

If confirmed, these data suggest that such women may benefit from more intensive screening to facilitate early detection.

Abstract PO-090: Protein-based immune profiles of basal-like vs luminal breast cancers

Background: Tumor infiltrating lymphocytes (TILs) play an important, but incompletely understood role in chemotherapy response and prognosis. In breast cancer, there appear to be distinct immune responses by subtype, but most studies have used limited numbers of protein markers or bulk sequencing of RNA to characterize immune response, in which spatial organization cannot be assessed. Methods: To identify immune phenotypes of Basal-like vs. Luminal breast cancer we used the GeoMx® (NanoString) platform to perform digital spatial profiling (DSP) of immune-related proteins in tumor whole sections and tissue microarrays (TMA). Visualization of CD45, CD68, or pan-Cytokeratin by immunofluorescence was used to select regions of interest (ROIs) in formalin-fixed paraffin embedded tissue sections. 44 antibodies representing stromal markers and multiple immune cell types were applied to quantify the tumor microenvironment. Results: In whole tumor slides, immune hot spots (CD45+) had increased expression of many immune markers, suggesting a diverse and robust immune response. In epithelium-enriched areas, immune signals were also detectable and varied by subtype, with Regulatory T cell (Treg) markers (CD4, CD25, FOXP3) being higher in Basal-like vs. Luminal breast cancer. Extending these findings to TMAs with more patients (n=75), we confirmed subtype-specific immune profiles, including enrichment of Treg markers in Basal-likes. Conclusion: This work demonstrated that immune responses can be detected in epithelium-rich tissue, and that TMAs are a viable approach for obtaining important immunoprofiling data. In addition, we found that immune marker expression is associated with BC subtype, suggesting possible prognostic or targetable differences.

Citation Format: Andrea Walens, Linnea T. Olsson, Xiaohua Gao, Alina M. Hamilton, Erin L. Kirk, Stephanie M. Cohen, Bentley R. Midkiff, Yongjuan Xia, Mark E. Sherman, Nana Nikolaishvili-Feinberg, Katherine A. Hoadley, Melissa A. Troester, Benjamin C. Calhoun. Protein-based immune profiles of basal-like vs luminal breast cancers [abstract]. In: Proceedings of the AACR Virtual Special Conference on Tumor Heterogeneity: From Single Cells to Clinical Impact; 2020 Sep 17-18. Philadelphia (PA): AACR; Cancer Res 2020;80(21 Suppl):Abstract nr PO-090.

Abstract PO-068: Intratumoral heterogeneity of prognostic multigene signatures for breast cancer

Background Multigene assays for breast cancer are becoming more commonly used for research, diagnostic, and treatment-selection purposes. These assays are commonly based on a single tumor sample, so this study assesses whether clinically-relevant multigene scores are subject to misclassification due to technical variation or intratumoral heterogeneity. Methods Using FFPE blocks, tumors from 37 patients were sampled at different pathologist-selected spatial locations, targeting regions with distinct histological appearance. A second pathologist assessed mitotic activity and presence of immune infiltration for each specimen. Gene expression was quantified using the PAM50 assay. Samples were classified with respect to intrinsic subtype (Luminal A, Luminal B, HER2-enriched, or Basal-like) and risk of recurrence with proliferation score (ROR-P, high vs. med/low). Euclidean distances between samples were calculated across the 50 genes, and the distribution of Euclidean distances were compared for samples that were concordant vs. discordant for each multigene classifier for PAM50 or ROR-P. Results Of the 37 tumors, 11 had samples with discordant PAM50 subtype and 7 had samples with discordant ROR-P group (75% and 83% agreement, respectively). The Euclidean distance between paired samples with discordant PAM50 intrinsic subtype or ROR-P score was significantly greater than that among concordant tumors. Samples discordant for ROR-P had more heterogeneity in histological characteristics, while discordance of PAM50 subtype call was generally not predicted by heterogeneity of these histological characteristics. Conclusion The concordance of PAM50 subtype calls and ROR-P, despite oversampling of heterogenous-appearing tumor regions, demonstrates reproducibility of the PAM50 classifier for breast cancer tumor intrinsic subtyping. However, assay sampling strategies for histologically heterogeneous tumors merit further consideration.

Citation Format: Amber N. Hurson, Alina Hamilton, Linnea T. Olsson, Erin L. Kirk, Benjamin C. Calhoun, Joseph Geradts, Mark E. Sherman, Melissa A. Troester. Intratumoral heterogeneity of prognostic multigene signatures for breast cancer [abstract]. In: Proceedings of the AACR Virtual Special Conference on Tumor Heterogeneity: From Single Cells to Clinical Impact; 2020 Sep 17-18. Philadelphia (PA): AACR; Cancer Res 2020;80(21 Suppl):Abstract nr PO-068.