Gallagher, Kristalyn K.

Abstract Background Current American Joint Committee on Cancer (AJCC) breast cancer staging considers contralateral axillary metastasis (CAM) stage IV disease (M1). Retrospective studies suggest that women with CAM have improved overall survival (OS) compared to those with distant metastasis (M1) and/or comparable OS to locally advanced breast cancer (LABC). These studies support consideration of curative intent treatment; however, they contain heterogeneous cohorts with highly variable treatment strategies. We sought to evaluate treatment and outcomes in a well-defined CAM cohort treated with contemporary systemic and locoregional therapy. Methods We performed a retrospective multi-institution cohort study to compare OS of patients with CAM matched 1:3 on age +/- 5 years to LABC (defined as cN2-3 and/or pN2-3), and to non-CAM M1. CAM patients classified as type 1) de novo CAM, synchronous with the contralateral primary, 2) metachronous isolated CAM in the setting of prior surgical and/or radiation treatment to primary index cancer, 3) synchronous with, or 4) metachronous after an in-breast or axillary nodal recurrence of the primary index cancer. The M1 cohort included de novo and recurrent metastasis with varied sites and number of metastasis. OS was defined as time from CAM diagnosis to death or last follow-up for CAM patients; time from primary diagnosis to death or last follow-up for LABC; and time from metastatic diagnosis to death or last follow-up for M1. Unadjusted OS was estimated with the Kaplan-Meier method, and Cox proportional hazards models were used to estimate the association of group with OS after adjustment for covariates Results We identified 57 CAM and 155 LABC from 8 institutions (2016-2022), and 632 M1 from a single institution. The median age was similar between groups (CAM=59 years, LABC=58, M1=57, p=0.44), and there were no statistically significant differences in hormone receptor status (p=0.25). There were more Non-Hispanic Black patients in the M1 cohort compared to CAM or LABC (p< 0.001). The majority of CAM cases were delayed metachronous from the index cancer (type 2, 35.1%), or synchronous with a recurrence (type 3, 33.3%). Type 1 (de novo, 14%) and type 4 (delayed metachronous after breast cancer recurrence, 17.5%) were less frequent. Among CAM patients, 49.1% were hormone receptor positive (HR+)/HER2-negative (HER2-), 22.8% HR-/HER2-, 10.5% HR+/HER2+, and 5.3% HR-/HER2+. Comparing CAM versus LABC, invasive ductal carcinoma (IDC) was more commonly seen in CAM (82.5% vs 66.5%), as was grade 3 (45.6% vs 35.5%), and triple negative (22.8% vs 13.5%). Conversely, in LABC, treatment of the primary index cancer more frequently included chemotherapy (CAM=71.9%, LABC=92.3%), mastectomy (CAM=54.4%, LABC 74.2%), and adjuvant radiation (CAM=73.7%, LABC=90.3%). On multivariable analysis adjusting for age, race/ethnicity, and hormone receptor status, both CAM and M1 had inferior survival to LABC (Table 1), but with a 2.4-fold difference for CAM (95% CI 1.42-4.07, p=0.001) versus a 6.3-fold difference for M1 (95% CI 4.29-9.23, p=< 0.001). Discussion In this contemporary, multi-institution study, we demonstrated that CAM patients selected for presumed curative intent treatment experienced improved OS when compared to stage IV (M1) patients. Our data adds additional support for re-evaluating the current stage IV designation, in favor of N3, and consideration of curative intent treatment in this disease. Table. Adjusted* Overall Survival Comparing Patients with Breast Cancer Contralateral Axillary Metastasis (CAM) to those with Locally Advanced Breast Cancer (LABC) and Metastatic Disease (M1) *Adjusted for age, race/ethnicity, hormone receptors. Citation Format: Meghan R. Flanagan, Stephanie Downs-Canner, Samantha Thomas, Astrid Botty van de bruele, Margaret Lillie, Kristalyn Gallagher, Tammeza Gibson, James Jakub, Alexandra Verosky, Sarah Tevis, Malia Brennan, Francys Verdial, Jennifer Q. Zhang, Leisha Elmore, Jennifer Plichta, Laura Rosenberger. A Multi-Institutional Review of Contralateral Axillary Metastases: Time for Reclassification as Local-Regional Event? [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO3-05-13.

Abstract PURPOSE To examine incremental values of estrogen receptor (ER) status, body mass index (BMI), menopausal status, and a previously reported multi-gene classifier over commonly used clinical factors (i.e. age, tumor grade, comedonecrosis, surgical margins, and treatment) in predicting risk of any ipsilateral recurrence (IR) event within five years after DCIS diagnosis. METHODS A derivation cohort consisted of participants in the Translational Breast Cancer Research Consortium (TBCRC) 038, a retrospective multicenter cohort study in women undergoing surgical resection for DCIS between 01/01/1998 and 02/29/2016 (n=216). The validation cohort, the Repository of Archival Human Breast Tissue (RAHBT) at Washington University School of Medicine, provided cases meeting the same eligibility criteria as TBCRC038 (n=97). Participants in both cohorts had RNA-seq data and either developed IR 1-5y after initial DCIS diagnosis or were free from subsequent breast events for at least five years. The previously reported 812-gene classifier had been developed from a subset of the TBCRC038 samples using a negative-binomial regression model to identify differentially expressed genes in the primary tumor associated with subsequent recurrence events. This classifier has been shown to be highly correlated with 5-year invasive, DCIS, and all breast cancer events, and validated in the RAHBT cohort. Cox proportional hazards regression was used to estimate hazard ratios (HRs) of IR in the TBCRC038 cohort (76 with IR). The clinical score was developed using clinical predictors (aforementioned clinical factors and ER) and their regression coefficients from the model with the maximum predictive accuracy (e.g. c-index) and the minimum number of predictors; the summary score integrated the clinical score and multi-gene classifier. Predictive performance of both clinical and summary scores was validated in the RAHBT cohort (20 with IR). RESULTS In the TBCRC cohort derivation set, we used a multivariable model based on clinical factors alone (clinical score) and found that ER status, but not BMI or menopausal status, was independently associated with a higher IR risk (HR=2.06, 95% CI 1.18-3.58). Adding the multi-gene classifier to the clinical factors-based model (summary score) in the TBCRC038 test set increased predictive accuracy (c-index 0.68 to 0.70), with the genomic classifier-adjusted HR of 14.96 (95% CI 8.64-25.91). The summary score had higher predictive performance for IR risk than clinical score alone (c-index 0.82 vs. 0.70). In the RAHBT validation samples, model performance was similarly improved using summary scores clinical factors-based model plus multigene classifier as compared to clinical scores along (c-index 0.74 vs. 0.58). CONCLUSION Combining clinical factors and a multigene classifier provided more accurate risk estimates of IR within five years after excision of DCIS than clinical factors alone. Figure 1. Observed and predicted recurrence-free survival in the first five years after initial DCIS diagnosis in the RAHBT validation cohort, by risk groups defined by clinical scores (left) and clinical score plus multigene classifier (right). Citation Format: Ying Liu, Siri H. Strand, Lorraine King, Bryan Harmon, Fergus J. Couch, Kristalyn Gallagher, Mark Kilgore, Shi Wei, Angela DeMichele, Tari King, Priscilla F. McAuliffe, Jeffrey Marks, Carlo Maley, Robert West, E Shelley Hwang, Graham A. Colditz. Using clinical characteristics and molecular markers to predict the risk of subsequent ipsilateral breast events after excision of DCIS [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P1-07-02.

AbstractBackground and objectivesPrevious studies have identified racial‐ethnic differences in the diagnostic patterns and recurrence outcomes of women with phyllodes tumors (PT). However, these studies are generally limited in size and generalizability. We therefore sought to explore racial‐ethnic differences in age, tumor size, subtype, and recurrence in a large US cohort of women with PT.MethodsWe performed an 11‐institution retrospective review of women with PT from 2007 to 2017. Differences in age at diagnosis, tumor size and subtype, and recurrence‐free survival according to race‐ethnicity.ResultsWomen of non‐White race or Hispanic ethnicity were younger at the time of diagnosis with phyllodes tumor. Non‐Hispanic Other women had a larger proportion of malignant PT. There were no differences in recurrence‐free survival in our cohort.ConclusionsDifferences in age, tumor size, and subtype were small. Therefore, the workup of young women with breast masses and the treatment of women with PT should not differ according to race‐ethnicity. These conclusions are supported by our finding that there were no differences in recurrence‐free survival.

Abstract Background. DCIS consists of a molecularly heterogeneous group of premalignant lesions, with variable risk of invasive progression. Understanding biomarkers for invasive progression could help individualize treatment recommendations based upon tumor biology. As part of the NCI Human Tumor Atlas Network (HTAN), we conducted comprehensive genomic analyses on two large DCIS case-control cohorts. Methods. We performed smart3-seq and low-pass whole genome sequencing on two independent, retrospective, longitudinally sampled DCIS case-control cohorts. TBCRC 038 was a multicenter cohort diagnosed with DCIS between 1998 and 2016 at one of the Translational Breast Cancer Research sites; the RAHBT (Resource of Archival Human Breast Tissue) cohort included women identified through the St. Louis Breast Tissue Repository, and the Women’s Health Repository diagnosed between 1997 and 2001. We studied the spectrum of molecular changes present and sought genomic predictors of subsequent ipsilateral breast events (iBEs: DCIS recurrence or invasive progression) in both DCIS epithelium and stroma in formalin fixed paraffin embedded tissue. We generated de novo tumor and stroma-centric subtypes for DCIS that represents fundamental transcriptomic organization. Copy number analysis was performed using low-pass DNA sequencing. Non-negative matrix factorization (NMF) was applied to the RNA expression of all coding genes to identify clusters. A negative-binomial regression model was used to identify differentially expressed genes. Results. We analyzed 677 DCIS samples from 481 patients with 7.1 years median follow-up. In TBCRC samples, we identified three clusters via NMF in TBCRC referred to as ER low, quiescent, and ER high. The ER-low cluster had significantly higher levels of ERBB2 and lower levels of ESR1 compared to quiescent and ER-high clusters. Quiescent cluster lesions were less proliferative and less metabolically active than ER high and ER low subtypes. These findings were replicated in the RAHBT cohort. Focusing on the stromal component of DCIS from laser capture microdissection in RAHBT samples, we identified four distinct DCIS-associated stromal clusters. A “normal-like” stromal cluster with ECM organization and PI3K-AKT signaling; a “collagen-rich” stromal cluster; a “desmoplastic” stromal cluster with high fibroblast and total myeloid abundance, mostly associated with macrophages and myeloid dendritic cells (mDC); and an “immune-dense” stromal cluster. Further, we compared differentially expressed genes in patients with or without subsequent iBEs within 5 years of diagnosis. Hypothesizing that the resulting 812 DE genes (DESeq2) represent multiple routes to subsequent iBEs, we leveraged NMF to identify paths to progression. In both TBCRC and RAHBT cohorts, poor outcome groups exhibited increased ER, MYC signaling, and oxidative phosphorylation, supporting that these pathways are important for DCIS recurrence and progression. Conclusion. Comprehensive genomic profiling in two independent DCIS cohorts with longitudinal outcomes shows distinct DCIS stromal expression patterns and immune cell composition. RNA expression profiles reveal underlying tumor biology that is associated with later iBEs in both cohorts. These studies provide new insight into DCIS biology and will guide the design of diagnostic strategies to prevent invasive progression. Citation Format: Siri H Strand, Belén Rivero-Gutiérrez, Kathleen E Houlahan, Jose A Seoane, Lorraine M King, Tyler Risom, Lunden Simpson, Sujay Vennam, Aziz Khan, Timothy Hardman, Bryan E Harmon, Fergus J Couch, Kristalyn Gallagher, Mark Kilgore, Shi Wei, Angela DeMichele, Tari King, Priscilla F McAuliffe, Julie Nangia, Joanna Lee, Jennifer Tseng, Anna Maria Storniolo, Alastair Thompson, Gaorav Gupta, Robyn Burns, Deborah J Veis, Katherine DeSchryver, Chunfang Zhu, Magdalena Matusiak, Jason Wang, Shirley X Zhu, Jen Tappenden, Daisy Yi Ding, Dadong Zhang, Jingqin Luo, Shu Jiang, Sushama Varma, Cody Straub, Sucheta Srivastava, Christina Curtis, Rob Tibshirani, Robert Michael Angelo, Allison Hall, Kouros Owzar, Kornelia Polyak, Carlo Maley, Jeffrey R Marks, Graham A Colditz, E Shelley Hwang, Robert B West. The Breast PreCancer Atlas DCIS genomic signatures define biology and correlate with clinical outcomes: An analysis of TBCRC 038 and RAHBT cohorts [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 GS4-07.

PURPOSE Phyllodes tumors (PTs) are rare breast neoplasms, which have little granular data on margins. Current guidelines recommend ≥ 1 cm margins; however, recent data suggest narrower margins are sufficient, and for benign PT, a negative margin may not be necessary. METHODS We performed an 11-institution contemporary (2007-2017) review of PT practices. Demographics, surgical, and histopathologic data were captured. Logistic regression was used to estimate the association of select covariates with local recurrence (LR). RESULTS Of 550 PT patients, the majority underwent excisional biopsy (55.3%, n = 302/546) or lumpectomy (wide excision) (38.5%, n = 210/546). Median tumor size was 30 mm, 68.9% (n = 379) were benign, 19.6% (n = 108) borderline, and 10.5% (n = 58) malignant. Surgical margins were positive in 42% (n = 231) and negative in 57.3% (n = 311). A second operation was performed in 38.0% (n = 209) of the total cohort, including 51 patients with an initial negative margin (82.4% with < 2 mm), and 157 with an initial positive margin, with residual disease only found in six (2.9%). Notably, 32.0% (n = 74) of those with an initial positive margin did not undergo a second operation, among whom only 2.7% (n = 2) recurred. Recurrence occurred in 3.3% (n = 18) of the total cohort (n = 15 LR, n = 3 distant), at median follow-up of 36.7 months. LR (all PT grades) was not reduced with wider negative margin width (≥ 2 mm v < 2 mm: odds ratio [OR] = 0.39; 95% CI, 0.07 to 2.10; P = .27) or final margin status (positive v negative: OR = 0.96; 95% CI, 0.26 to 3.52; P = .96). CONCLUSION In current practice, many patients are managed outside of current guidelines. For the entire cohort, a wider margin width was not associated with a reduced risk of LR. We do not recommend re-excision of a negative margin for benign PT, regardless of margin width, as a progressively wider surgical margin is unlikely to reduce LR.