Citations

Abstract Introduction: Incorporation of mammographic density to breast cancer risk models could improve risk stratification to tailor screening and prevention strategies according to risk. However, robust validation of such models in prospective cohort studies is needed to determine their accuracy in identifying women at different risk levels. Methods: We incorporated Breast Imaging and Reporting Data System (BI-RADS) breast density to a literature-based model with questionnaire-based risk factors and a 313-variant polygenic risk score (PRS). The Individualized Coherent Absolute Risk Estimator (iCARE) tool was used to build and validate a 5-year absolute risk model for breast cancer. The model was evaluated for calibration and discrimination in three prospective cohorts of women of European ancestry (1,468 cases, 19,104 controls): US-based Nurses’ Health Study (NHS I and II) and Mayo Mammography Health Study (MMHS); and Sweden-based Karolinska Mammography Project for Risk Prediction of Breast Cancer (KARMA) study. Analyses were done separately for women younger (NHS II, KARMA) and older than 50 years (NHS I, MMHS, KARMA). Improvements in risk stratification were assessed among US non-Hispanic White women aged 50-70 years. Results: For women younger than 50 years, the model with questionnaire-based risk factors, PRS and BI-RADS was well calibrated across risk deciles in NHS II, but overestimated risk at the highest risk decile in KARMA. For women 50 years or older, the model showed good calibration in all studies, with evidence of slight overestimation at the highest risk decile and underestimation at the lowest risk decile. The model with PRS and BI-RADS was well calibrated for women at high-risk in both age groups. Incorporation of BI-RADS to questionnaire-based risk factors and PRS improved risk discrimination: area under the curves (AUC) 67.0% (95% CI: 63.5-70.6%) vs. 65.6% (95% CI: 61.9-69.3%) for models with and without BI-RADS for younger women and 66.1% (95% CI 64.4-67.8%) vs. 65.5% (95% CI: 63.8-67.2%) for older women. The model with BI-RADS identified 18.4% population of non-Hispanic US women 50-70 years old above 3% 5-year risk (used for recommending risk-reducing medication in the US), with 42.4% of future cases expected to occur in this group. Addition of BI-RADS led to the reclassification of ~8.0% of US non-Hispanic White women aged 50-70 years at the high-risk threshold (3% 5-year risk), resulting in identification of 4.2% of additional future cases. Conclusion: Integrating BI-RADS with questionnaire-based risk factors and PRS resulted in improved risk stratification among women of European ancestry, with evidence of slight overestimation of risk for women at elevated risk. Additional validation of the integrated model in diverse populations is needed prior to considering clinical applications. Citation Format: Charlotta V. Mulder, Yon Ho Jee, Xin Yang, Christopher G. Scott, Chi Gao, Amber N. Hurson, Mikael Eriksson, Per Hall, Peter Kraft, Celine M. Vachon, Antonis C. Antoniou, Gretchen Gierach, Montserrat Garcia-Closas, Parichoy Pal Choudhury. Validation of an integrated breast cancer risk model with mammographic density in three prospective cohort studies [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 2256.

Abstract Seven different anti-PD-1 and PD-L1 monoclonal antibodies are now widely used in the US to treat a variety of cancer types, but there have been no clinical trials comparing them directly. Furthermore, because many of these antibodies do not cross react between mouse and human proteins, no preclinical models exist in which to consider these types of questions. Thus, we produced humanized PD-1 and PD-L1 mice in which the extracellular domains of both mouse PD-1 and PD-L1 were replaced with the corresponding human sequences. Using this new model, we sought to compare the strength of the immune response generated by FDA-approved antibodies. To do this, we performed an in vivo T cell priming assay in which anti-PD-1/L1 therapies were given at the time of T cell priming against surrogate tumor antigen (OVA), followed by subsequent B16-OVA tumor challenge. We found that anti-PD-1/L1-treated mice exhibited significantly better tumor rejection than controls, although both the control and antibody-treated mice generated comparable numbers of OVA-specific T cells at the time of priming. To determine what could mediate this strong antitumor immune response, we identified the increased production of CX3CR1+PD-1+CD8+ cytotoxic T cells in the anti-PD-1/L1-treated mice, the same subset of effector T cells known to increase in clinical responders to PD-1/L1 therapy. Thus, our model permits the direct comparison of FDA-approved anti-PD-1/L1 monoclonal antibodies and further correlates successful tumor rejection with the level of CX3CR1+PD-1+CD8 + T cells, making this model a critical tool for future studies to optimize and better utilize anti-PD-1/L1 therapeutics.

AbstractIdentifying biomarkers associated with disease progression and drug resistance are important for personalized care. We investigated the expression of 121 curated genes, related to immunomodulatory drugs (IMiDs) and proteasome inhibitors (PIs) responsiveness. We analyzed 28 human multiple myeloma (MM) cell lines with known drug sensitivities and 130 primary MM patient samples collected at different disease stages, including newly diagnosed (ND), on therapy (OT), and relapsed and refractory (RR, collected within 12 months before the patients’ death) timepoints. Our findings led to the identification of a subset of genes linked to clinical drug resistance, poor survival, and disease progression following combination treatment containing IMIDs and/or PIs. Finally, we built a seven‐gene model (MM‐IMiD and PI sensitivity‐7 genes [IP‐7]) using digital gene expression profiling data that significantly separates ND patients from IMiD‐ and PI‐refractory RR patients. Using this model, we retrospectively analyzed RNA sequcencing (RNAseq) data from the Mulltiple Myeloma Research Foundation (MMRF) CoMMpass (n = 578) and Mayo Clinic MM patient registry (n = 487) to divide patients into probabilities of responder and nonresponder, which subsequently correlated with overall survival, disease stage, and number of prior treatments. Our findings suggest that this model may be useful in predicting acquired resistance to treatments containing IMiDs and/or PIs.

AbstractImmune checkpoint inhibitors (ICIs), as a novel class of anticancer therapy, can be more efficacious and less toxic than chemotherapy, but their clinical success is confined to certain tumor types. Elucidating their targets, mechanisms and scope of action, and potential synergism with chemotherapy and/or targeted therapies are critical to widen their clinical indications. Treatment response to an ICI targeting programmed death‐1 (anti‐PD‐1) is sought to be understood here by conducting a preplanned correlative analysis of a phase II clinical trial in patients with small bowel adenocarcinoma (SBA). The cytolytic capacity of circulating immune cells in cancer patients using a novel ex vivo cytotoxicity assay is evaluated, and the utility of circulating biomarkers is investigated to predict and monitor the treatment effect of anti‐PD‐1. Baseline expression of Bim and NKG7 and upregulation of CX3CR1 in circulating T cells are associated with the clinical benefit of anti‐PD‐1 in patients with SBA. Overall, these findings suggest that the frequency and cytolytic capacity of circulating, effector immune cells may differentiate clinical response to ICIs, providing a strong rationale to support immune monitoring using patient peripheral blood.

Abstract Langerhans cell histiocytosis (LCH) can affect children and adults with a wide variety of clinical manifestations, including unifocal, single-system multifocal, single-system pulmonary (smoking-associated), or multisystem disease. The existing paradigms in the management of LCH in adults are mostly derived from the pediatric literature. Over the last decade, the discovery of clonality and MAPK-ERK pathway mutations in most cases led to the recognition of LCH as a hematopoietic neoplasm, opening the doors for treatment with targeted therapies. These advances have necessitated an update of the existing recommendations for the diagnosis and treatment of LCH in adults. This document presents consensus recommendations that resulted from the discussions at the annual Histiocyte Society meeting in 2019, encompassing clinical features, classification, diagnostic criteria, treatment algorithm, and response assessment for adults with LCH. The recommendations favor the use of 18F-Fluorodeoxyglucose positron emission tomography-based imaging for staging and response assessment in the majority of cases. Most adults with unifocal disease may be cured by local therapies, while the first-line treatment for single-system pulmonary LCH remains smoking cessation. Among patients not amenable or unresponsive to these treatments and/or have multifocal and multisystem disease, systemic treatments are recommended. Preferred systemic treatments in adults with LCH include cladribine or cytarabine, with the emerging role of targeted (BRAF and MEK inhibitor) therapies. Despite documented responses to treatments, many patients struggle with a high symptom burden from pain, fatigue, and mood disorders that should be acknowledged and managed appropriately.

Background: There is a paucity of data regarding the association between radiation exposure of heart substructures and the incidence of major coronary events (MCEs) in patients with esophageal cancer (ESOC) undergoing chemoradiation therapy. We studied radiation dosimetric determinants of MCE risk and measured their impact on patient prognosis using a cohort of ESOC patients treated at a single institution. Methods: Between March 2005 and October 2015, 355 ESOC patients treated with concurrent chemoradiotherapy were identified from a prospectively maintained and institutional-regulatory-board-approved clinical database. Dose-distribution parameters of the whole heart, the atria, the ventricles, the left main coronary artery, and three main coronary arteries were extracted for analysis. Results: Within a median follow-up time of 67 months, 14 patients experienced MCEs at a median of 16 months. The incidence of MCEs was significantly associated with the left anterior descending coronary artery (LAD) receiving ≥30 Gy (V30Gy) (p = 0.048). Patients receiving LAD V30Gy ≥ 10% of volume experienced a higher incidence of MCEs versus the LAD V30Gy < 10% group (p = 0.044). The relative rate of death increased with the left main coronary artery (LMA) mean dose (Gy) (p = 0.002). Furthermore, a mutual promotion effect of hyperlipidemia and RT on MCEs was observed. Conclusion: Radiation dose to coronary substructures is associated with MCEs and overall survival in patients with ESOC. In this study, the doses to these substructures appeared to be better predictors of toxicity outcomes than mean heart dose (MHD) or whole-heart V30Gy. These findings have implications for reducing coronary events through radiation therapy planning.

165 Background: A prior study of patients with advanced cancers treated with immune checkpoint inhibitors (ICI) associated improved overall survival with tissue tumor mutational burden above the 80th percentile in each histology (tTMB-H). TMB can also reliably be calculated via liquid biopsy (bTMB), and trends higher than tTMB in analogous tumors. Here, we generate a plasma-informed benchmark for bTMB-H in advanced prostate cancer and report preliminary data from an ongoing multi-institutional case series of patients treated with ICI. Methods: Circulating tumor DNA (ctDNA) next generation sequencing (NGS) results from 3,504 patients with advanced prostate cancer who received a Guardant360 liquid biopsy within a 12-month period were analyzed. The 80th percentile of TMB was defined as the benchmark for bTMB-H in this cohort, and prevalence of microsatellite instability (MSI-H) was determined. Subsequently, clinical data were collected from patients across five institutions who received pembrolizumab based on bTMB scores or other tumor characteristics (i.e. CDK12 mutation). Results: Overall, mean and median bTMB were calculated as 12.34 mut/Mb and 8.61 mut/Mb, respectively (range: 0 – 1164.75 mut/Mb). The 80th percentile of bTMB was 13.4 mut/Mb and the 90th percentile was 16.6 mut/Mb. 2.6% of patients were both MSI-H and bTMB-H. No patients with bTMB < 13.4 mut/Mb (TMB-L) were found to be MSI-H. Ten patients from five institutions received pembrolizumab (8 monotherapy) after a median of 4.5 lines of prior therapy (Table). Four patients were MSI-H. The 3 patients in the cohort with PSA decreases > 50% had both MSI-H and bTMB ≥ 13.4 mut/Mb. Per RECIST criteria, disease was controlled (CR, PR, SD) in 6 of 7 (86%) patients with bTMB scores ≥ 13.4 mut/Mb. Conclusions: These data continue to affirm that ctDNA NGS is a practical and cost-effective means of assessing potential predictors of ICI activity in patients with advanced prostate cancer. Preliminary data from this growing cohort of patients who have received ICI guided by bTMB scores and other molecular parameters identified via ctDNA NGS, including MSI-H, demonstrate a clinical benefit from therapy. Further studies are warranted for contextualizing individual tumor bTMB scores with established, pathology-specific benchmarks.[Table: see text]

AbstractBackgroundThere is a paucity of data regarding the sex‐related differences in the trends and outcomes of trans‐septal transcatheter mitral valve replacement (TS‐TMVR).MethodsThe Nationwide Readmissions Database (2015–2018) was queried for admissions for TS‐TMVR. Propensity matched analysis was conducted to compare outcomes with hospitalizations for TS‐TMVR among women versus men. The main study outcome was in‐hospital mortality.ResultsOur final analysis included 2063 hospitalizations for TS‐TMVR; of whom, 58.1% were women. The proportion of women among those undergoing TS‐TMVR increased from 50% in 2015 to 60.2% in 2018 (Ptrend = 0.04). Compared with men, women undergoing TS‐TMVR were slightly younger, and had a distinct profile of comorbidities. After matching, there was no significant difference in in‐hospital mortality among women versus men undergoing TS‐TMVR (7.8% vs. 6.1%, OR = 1.30; 95% CI: 0.79–2.13). Subgroup analyzes showed an interaction toward higher mortality with women versus men among patients with CKD (Pinteraction = 0.07). There were no significant differences between women and men in in‐hospital complications or length of stay after TS‐TMVR. Compared with men, women undergoing TS‐TMVR were more likely to be discharged to a nursing facility (17.7% vs. 11.5%, p = 0.01) and had higher rates of 30‐day readmissions (22.4% vs. 13.6%, p = 0.01).ConclusionThis nationwide analysis showed an increase in the proportion of women among patients undergoing TS‐TMVR during the study years. There were no differences in in‐hospital mortality, in‐hospital complications, or length of stay between both sexes following TS‐TMVR. Women were more likely to be discharged to nursing facilities and had higher rates of readmission at 30 days even after propensity matching.