Citations

Abstract BACKGROUND H3K27-altered diffuse midline glioma (DMG) is a devastating pediatric brainstem tumor that affects 200-300 individuals in the US per year. Median survival is 9-11 months, and there are virtually no long-term survivors. Despite decades of clinical trials, radiation therapy remains standard of care, extending survival by 2-3 months. Elucidating the mechanisms that drive H3K27-altered DMG pathogenesis in order to uncover therapeutic vulnerabilities is of critical importance. Recent studies implicate MALT1 as a potential therapeutic target in gliomas. MALT1 is the effector molecule of the CARMA-BCL10-MALT1 (CBM) signalosome, a cytoplasmic protein complex that drives downstream pro-survival transcriptional activity. MALT1, which possesses scaffolding and protease functions, promotes cell viability, proliferation, and migration/invasion in multiple cancer types. We aim to evaluate the hypotheses that MALT1 promotes DMG cancer cell proliferation and migration and that MALT1 inhibition will abrogate tumor progression. METHODS/RESULTS We screened a panel of cells including astrocytes, neural stem cells, and DMG cell lines by Western blot and found that CBM complex members BCL10 and MALT1 are present in all cells tested. We next demonstrated that MALT1 is proteolytically active in DMG cell lines SF8628 and HSJD-DIPG-007. Specifically, we showed cleavage of the MALT1 protease substrate HOIL, which was abrogated by treatment with the MALT1 protease inhibitor MLT-748. We next generated multiple dox-inducible MALT1 shRNA DMG cell lines to assess the impact of MALT1 deficiency on DMG biology. Thus far, we find that shRNA knockdown of MALT1 does not impact SF8628 cell proliferation. CONCLUSIONS MALT1 is expressed and proteolytically active in DMG cells. Initial studies show that MALT1 knockdown does not affect proliferation of SF8628 cells. We will next evaluate the effect of MALT1 knockdown on proliferation of additional DMG cell lines, as well as the impact on other malignant features of DMG cells including migration/invasion.

Abstract Background Radiation‐associated soft tissue sarcomas (RA‐STS) are rare complications of patients receiving radiation therapy (RT) and are generally associated with a poor prognosis. Most of the literature surrounding RA‐STS of the chest is centered on angiosarcoma. Therefore, we aim to document the management and outcome of patients with non‐angiosarcoma RA‐STS of the chest. Methods We reviewed 17 patients (all female, median age 65 years) diagnosed with RA‐STS. The most common primary malignancy was breast carcinoma ( n = 15), with a median RT dose of 57.9 Gy. All patients underwent surgical resection; five patients (29%) received radiotherapy; and five patients (29%) received peri‐operative chemotherapy. Results The 5‐year local recurrence and metastatic‐free survival were 61% and 60%, while the 5‐year disease‐specific survival was 53%. Local recurrence was associated with death due to disease (HR 9.06, p = 0.01). Complications occurred in nine of patients, most commonly due to a wound complication ( n = 7). At the most recent follow‐up, the median Musculoskeletal Tumor Society Score was 63%. Conclusion RA‐STS involving the chest wall are aggressive tumors with a high risk of local relapse and death due to disease. Local recurrence was associated with death due to disease; as such, we recommend aggressive surgical management with evaluation for adjuvant therapies.

AbstractINTRODUCTIONWhile Latin America (LatAm) is facing an increasing burden of dementia due to the rapid aging of the population, it remains underrepresented in dementia research, diagnostics, and care.METHODSIn 2023, the Alzheimer's Association hosted its eighth satellite symposium in Mexico, highlighting emerging dementia research, priorities, and challenges within LatAm.RESULTSSignificant initiatives in the region, including intracountry support, showcased their efforts in fostering national and international collaborations; genetic studies unveiled the unique genetic admixture in LatAm; researchers conducting emerging clinical trials discussed ongoing culturally specific interventions; and the urgent need to harmonize practices and studies, improve diagnosis and care, and use affordable biomarkers in the region was highlighted.DISCUSSIONThe myriad of topics discussed at the 2023 AAIC satellite symposium highlighted the growing research efforts in LatAm, providing valuable insights into dementia biology, genetics, epidemiology, treatment, and care.

Introduction Empowering people living with multimorbidity (multiple chronic conditions) to gain greater confidence in managing their health can enhance their quality of life. Education focused on self-management is a key tool for fostering patient empowerment and is mostly provided on an individual basis. Virtual communities of practice (VCoP) present a unique opportunity for online education in chronic condition self-management within a social context. This research aims to evaluate the effectiveness/cost-effectiveness of individualised, online self-management education compared with VCoP among middle-aged individuals living with multiple chronic conditions. Methods and analysis People aged 30–60, living with ≥2 chronic conditions and receiving care in primary care (PC) centres and outpatient hospital-based clinics in Madrid and Canary Islands will enrol in an 18-month parallel-design, blinded (intervention assessment and data analysts), pragmatic (adhering to the intention-to-treat principle), individually randomised trial. The trial will compare two 12-month web-based educational offers of identical content; one delivered individually (control) and the other with online social interaction (VCoP, intervention). Using repeated measures mixed linear models, with the patient as random effect and allocation groups and time per group as fixed effects, we will estimate between-arm differences in the change in Patient Activation Measure from baseline to 12 months (primary endpoint), including measurements at 6-month and 18-month follow-up. Other outcomes will include measures of depression and anxiety, treatment burden, quality of life. In addition to a process evaluation of the VCoP, we will conduct an economic evaluation estimating the relative cost-effectiveness of the VCoP from the perspectives of both the National Health System and the Community. Ethics and dissemination The trial was approved by Clinical Research Ethics Committees of Gregorio Marañón University Hospital in Madrid/Nuestra Señora Candelaria University Hospital in Santa Cruz de Tenerife. The results will be disseminated through workshops, policy briefs, peer-reviewed publications and local/international conferences. Trial registration number NCT06046326 .

Abstract Rearrangements that place the oncogenes MYC, BCL2, or BCL6 adjacent to superenhancers are common in mature B-cell lymphomas. Lymphomas with diffuse large B-cell lymphoma (DLBCL) or high-grade morphology with both MYC and BCL2 rearrangements are classified as high-grade B-cell lymphoma with MYC and BCL2 rearrangements (“double hit”; HGBCL-DH-BCL2) and are associated with aggressive disease and poor outcomes. Although it is established that MYC rearrangements involving immunoglobulin (IG) loci are associated with inferior outcomes relative to those involving other non-IG superenhancers, the frequency of and mechanisms driving IG vs non-IG MYC rearrangements have not been elucidated. Here, we used custom targeted capture and/or whole-genome sequencing to characterize oncogene rearrangements across 883 mature B-cell lymphomas including Burkitt lymphoma, follicular lymphoma, DLBCL, and HGBCL-DH-BCL2 tumors. We demonstrate that, although BCL2 rearrangement topology is consistent across entities, HGBCL-DH-BCL2 have distinct MYC rearrangement architecture relative to tumors with single MYC rearrangements or with both MYC and BCL6 rearrangements (HGBCL-DH-BCL6), including both a higher frequency of non-IG rearrangements and different architecture of MYC::IGH rearrangements. The distinct MYC rearrangement patterns in HGBCL-DH-BCL2 occur on the background of high levels of somatic hypermutation across MYC partner loci in HGBCL-DH-BCL2, creating more opportunity to form these rearrangements. Furthermore, because 1 IGH allele is already disrupted by the existing BCL2 rearrangement, the MYC rearrangement architecture in HGBCL-DH-BCL2 likely reflects selective pressure to preserve both BCL2 and B-cell receptor expression. These data provide new mechanistic explanations for the distinct patterns of MYC rearrangements observed across different lymphoma entities.

Abstract Importance Menopausal hormone therapy (HT) includes a wide variety of hormonal compounds, and its effect on blood pressure is still uncertain. Objective The aim of this study was to assess evidence regarding the effect of HT on blood pressure in postmenopausal women and its association with arterial hypertension. Evidence Review This systematic review and meta-analysis included randomized clinical trials and prospective observational studies. Systolic blood pressure (SBP), diastolic blood pressure (DBP), and the incidence of hypertension were assessed. All stages were independently performed by two reviewers. For blood pressure outcome, standardized mean differences (SMD) and 95% confidence intervals (95% CI) were calculated as effect measures. Heterogeneity was assessed using the I 2 statistic. The results are presented based on the HT type. The incidence of hypertension was compared using descriptive analyses. Findings Eleven studies were included with 81,041 women evaluated, of which 29,812 used HT. The meta-analysis, conducted with 8 studies and 1,718 women, showed an increase in SBP with the use of oral conjugated equine estrogens plus progestogen (SMD = 0.60 mm Hg, 95% CI = 0.19 to 1.01). However, oral or transdermal use of estradiol plus progestogen (SMD = −2.00 mm Hg, 95% CI = −7.26 to 3.27), estradiol alone, and tibolone did not show any significant effect. No significant effect on DBP was observed for any formulation. Women who used oral estrogen plus progestogen had a higher risk of incident hypertension than those who never used it. Conclusions and Relevance The effect of HT on blood pressure is influenced by the formulation used, especially the type of estrogen. The combined formulations of conjugated equine estrogens plus progestogen increased SBP and the risk of hypertension, which was not observed among estradiol plus progestogen, estradiol alone, and tibolone users.

Abstract Adagrasib, an irreversible, selective KRASG12C inhibitor, may be an effective treatment in KRASG12C-mutated colorectal cancer, particularly when combined with an anti-EGFR antibody. In this analysis of the KRYSTAL-1 trial, patients with previously treated KRASG12C-mutated unresectable or metastatic colorectal cancer received adagrasib (600 mg twice daily) plus cetuximab. The primary endpoint was objective response rate (ORR) by blinded independent central review. Ninety-four patients received adagrasib plus cetuximab. With a median follow-up of 11.9 months, ORR was 34.0%, disease control rate was 85.1%, and median duration of response was 5.8 months (95% confidence interval [CI], 4.2–7.6). Median progression-free survival was 6.9 months (95% CI, 5.7–7.4) and median overall survival was 15.9 months (95% CI, 11.8–18.8). Treatment-related adverse events (TRAEs) occurred in all patients; grade 3–4 in 27.7% and no grade 5. No TRAEs led to adagrasib discontinuation. Exploratory analyses suggest circulating tumor DNA may identify features of response and acquired resistance. Significance: Adagrasib plus cetuximab demonstrates promising clinical activity and tolerable safety in heavily pretreated patients with unresectable or metastatic KRASG12C-mutated colorectal cancer. These data support a potential new standard of care and highlight the significance of testing and identification of KRASG12C mutations in patients with colorectal cancer. This article is featured in Selected Articles from This Issue, p. 897 See co-corresponding author Rona Yaeger discuss this research article, published simultaneously at the AACR Annual Meeting 2024: https://vimeo.com/932606282/f27a6e46f4

Abstract Background Hereditary transthyretin amyloidosis (ATTRv) is an inherited, progressive, and fatal disease still largely underdiagnosed. Mutations in the transthyretin (TTR) gene cause the TTR protein to destabilize, misfold, aggregate, and deposit in body tissues, which makes ATTRv a disease with heterogeneous clinical phenotype. Objective To describe the long-term efficacy and safety of inotersen therapy in patients with ATTRv peripheral neuropathy (ATTRv-PN). Methods Patients who completed the NEURO-TTR pivotal study and the NEURO-TTR OLE open-label extension study migrated to the present study and were followed-up for at least 18 more months to an average of 67 months and up to 76 months since day 1 of the inotersen therapy (D1–first dose of inotersen). Disease progression was evaluated by standard measures. Results Ten ATTRv-PN patients with Val30Met mutation were included. The mean disease duration on D1 was of 3 years, and the mean age of the patients was of 46.8 years. During an additional 18-month follow up, neurological function, based on the Neuropathy Impairment Score and the Polyneuropathy Disability Score, functionality aspects (Karnofsky Performance Status), and nutritional and cardiac aspects were maintained. No new safety signs have been noted. Conclusion The treatment with inotersen was effective and well tolerated for the average of 67 months and up to 76 months. Our results are consistent with those of larger phase-III trials.

Abstract Breast cancer (BC) remains a leading health concern worldwide and is often undetected until the cancer metastasizes. Early detection can limit the need for aggressive treatments and improve prognosis. We analyzed early immune and molecular markers in benign breast disease (BBD) biopsies prior to BC development to identify women at elevated risk of developing node-positive invasive BC, which might direct surveillance and prevention efforts aimed at reducing incidence of this disease. Utilizing the Mayo Clinic BBD cohort, we compared women who developed node-positive BC following their BBD biopsy (cases; n=42) with those who remained cancer-free (controls; n=37), matched on patient age and biopsy date. We used NanoString nCounter system to identify differentially expressed genes (DEGs) between cases and controls. We also developed a multiplex immunofluorescence (mIF) approach using Opal system by Akoya Biosciences for comprehensive marker detection in FFPE tissue, enabling correlation of cells expressing DEGs with innate and adaptive immune cells. Digitized images were segmented, and cell phenotyping, and spatial relationships were compared between cases and controls. Our findings revealed significantly increased expression levels of IRF8 (interferon regulatory factor 8, a factor involved in immune cell differentiation) in controls as compared to cases and found that increased IRF8 expression in cases is correlated with delayed cancer onset. Additionally, controls exhibited higher frequencies of CD4+, CD8+, CD68+, CD20+ and CD11c+ immune cells, and lower frequency of Ki67+ staining, with a notable increase of CD11c+/CD68+ cells, a marker for M1 type macrophages, indicating a pro-inflammatory, antitumorigenic immune microenvironment polarization. Furthermore, our mIF analyses offer new insights into spatial biomarker localization, enhancing prognostic accuracy. Our findings suggest that decreased numbers of immune cells in BBD biopsies may be associated with increased risk of developing axillary node-positive BC. This research underscores the importance of dissecting molecular and immune interactions in BBD for assessing the risk of this disease. Our results have the potential to improve individualized risk assessment, leading to more targeted surveillance and informed screening, potentially reducing BC incidence and mortality through early intervention. This study not only contributes to our understanding of BC pathogenesis but also opens avenues for developing novel preventive strategies. Citation Format: Matilde Rossi, Nicole Cruz-Reyes, Melody L. Stallings Mann, Bryan M. McCauley, Tanya L. Hoskin, Robert A. Vierkant, Stacey J. Winham, Amy C. Degnim, Mark E. Sherman, Derek C. Radisky. Interferon regulatory factor 8 (IRF8) as a biomarker for early detection and prevention of axillary lymph node-positive breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4773.