Gene set enrichment analysis on Hallmark gene sets, comparing 89Zr-trastuzumab classes “high” (positive normalized enrichment score – NES) and “low” (negative NES).

Examples of the four classes of HER2-PET/CT uptake.

BACKGROUND:Current guidelines recommend neoadjuvant systemic therapy (NST) followed by modified radical mastectomy (MRM) for stage T4 breast cancer. In this study, trends in MRM and de-escalated surgery of cT4a-c and cT4d breast cancer were evaluated and the impact of treatment on survival was assessed. METHODS:Patients with cT4NanyM0 breast cancer who received NST between 1989 to 2020 were selected from the Netherlands Cancer Registry. Rates of MRM and de-escalated breast/axillary surgery were analyzed for the periods 1989-1999, 2000-2009, and 2010-2020. Cox proportional hazard regression with inverse probability weighing was used to estimate for confounding-adjusted hazard ratios (HRs) for overall survival. Crude relative survival was calculated using excess mortality ratios from national life tables. RESULTS:This study included 2,541 patients with cT4a-c and 1479 with cT4d breast cancer. The frequency of MRM decreased from 78% in 1989-1999 to 54% in 2010-2020 for cT4a-c and from 82% to 70% for cT4d patients. De-escalated surgery was associated with better overall survival than MRM, for both cT4a-c (HR 0.74, 95% confidence interval [CI] 0.63-0.87) and cT4d breast cancer (HR 0.78, 95% CI 0.63-0.96). Five-year crude relative survival for MRM versus de-escalated treatment was 66% (95% CI 0.64-0.69) versus 83% (95% CI 0.79-0.87) for cT4a-c, and 56% (95% CI 0.53-0.59) versus 70% (95% CI 0.64-0.76) for cT4d. CONCLUSIONS:Modified radical mastectomy rates decreased over time. De-escalated surgery was associated with improved 5-year overall survival compared with MRM. These findings suggest that de-escalated surgery is at least equivalent to MRM in terms of survival and may support consideration of less invasive surgical approaches.

Background: Male breast cancer (MBC) is very rare and has worse outcome compared to BC in women. MBC specific interventions are lacking. Non-adherence to mainstay tamoxifen treatment is common, due to feminizing side effects and reduced quality of life, and related to worse survival. Thus, well-tolerated endocrine treatment is an unmet need in MBC. MBC expresses both estrogen- and androgen receptors (ER and AR) in 97% of cases. As the AR functions as tumor suppressor in ER+ BC, adding testosterone to tamoxifen may improve both tumor response and tolerability in MBC. Therefore, we assessed the safety profile of tamoxifen plus testosterone in patients with metastatic MBC. Methods: In this single-arm pilot study, patients received tamoxifen 20mg plus testosterone 25mg once a day, increased to 50mg after 3 weeks in case of good tolerance. Primary endpoint was safety (assessed as grade 3-4 adverse events (AEs) according to Common Terminology Criteria of Adverse Events (CTCAE) v5.0). Secondary endpoint was tumor response and duration (according to RECIST1.1) assessed after 8 weeks, thereafter every 12 weeks. Results: Five MBC patients were enrolled with median age of 63 years, and mean two (1-3) previous endocrine treatment lines for metastatic MBC. All patients had received prior tamoxifen monotherapy, in either adjuvant or metastatic setting. No grade 3-4 AEs were observed. Two out of 19 grade 1-2 AEs were possibly related to the treatment: grade 1 anxiety and nausea, both spontaneously resolved. Other low grade AEs were probably related to (progressive) disease (n=7) or from another cause not likely related to the treatment (n=10). Regarding responses, 3/5 patients showed clinical benefit with in one patient a partial response duration of 10 months and in two patients ongoing stable disease at the time of analysis (resp. 12 and 15 months), 2/5 patients had progressive disease at 8 weeks. All patients spontaneously reported improved well-being. Conclusions: In this unique MBC intervention trial, tamoxifen plus testosterone showed good safety, tolerability as well as long-term responses in the majority of patients. Therefore, this could be a promising new endocrine approach in this rare MBC population. Citation Format: Jasmine Moustaquim, Jasper van Geel, Michel van Kruchten, Erik de Vries, Marcel Stokkel, Andor Glaudemans, Geke Hospers, Carolien Schröder. Testosterone & Tamoxifen (T&T) trial: adding Testosterone to Tamoxifen in male breast cancer patients [abstract]. In: Proceedings of the San Antonio Breast Cancer Symposium 2024; 2024 Dec 10-13; San Antonio, TX. Philadelphia (PA): AACR; Clin Cancer Res 2025;31(12 Suppl):Abstract nr P4-10-01.

Comparison of abundance scores of immune populations and stromal cell types with MCP-counter according to A, ZrT class (dichotomized into “high” and “low”), and B, metabolic response.

Gene set enrichment analysis on Hallmark gene sets, comparing, within the 89Zr-trastuzumab class “high”, metabolic response (positive normalized enrichment score – NES) and lack of metabolic response (negative NES).

Levels of TILs (%) according to ZrT class (dichotomized into “high” and “low”), and metabolic response.

Levels of stroma (%) according to ZrT class (dichotomized into “high” and “low”), and metabolic response

[89Zr]trastuzumab (ZrT) class and metabolic response signatures

Forest plots for pCR in I-SPY2, HER2-positive population, multivariable analysis controlling for hormone receptor status and treatment arm.

CONSORT diagram showing the patient selection for the present analysis in the ZEPHIR trial

PURPOSE:The ZEPHIR clinical trial evaluated the role of [89Zr]trastuzumab-PET/CT (HER2-PET/CT) and 2-[18F]fluoro-2-deoxy-D-glucose PET/CT ([18F]FDG-PET/CT) in predicting outcomes in patients with advanced HER2-positive breast cancer treated with trastuzumab emtansine (T-DM1). In this study, we combined molecular/metabolic imaging and transcriptomic data to investigate the biological processes associated with [89Zr]trastuzumab and [18F]FDG uptake and to dissect the mechanisms involved in T-DM1 resistance. EXPERIMENTAL DESIGN:RNA was extracted from metastasis biopsies obtained in the ZEPHIR trial. HER2-PET/CT and [18F]FDG-PET/CT imaging data of biopsied lesions were integrated with transcriptomic data. Lesions were compared based on the level of [89Zr]trastuzumab uptake as well as on the presence/absence of metabolic response, defined comparing baseline and on-treatment [18F]FDG-PET/CT. RESULTS:We analyzed matched transcriptomic and molecular/metabolic imaging data for 24 metastases. Genes and pathways involved in extracellular matrix (ECM) organization and glycosylphosphatidylinositol synthesis were enriched in lesions presenting low [89Zr]trastuzumab uptake. [18F]FDG uptake at baseline correlated with proliferation and immune-related processes. Hypoxia and ECM-related processes were enriched in lesions showing no metabolic response to T-DM1, whereas immune-related processes were associated with high [89Zr]trastuzumab uptake and metabolic response. Gene signatures including differentially expressed genes according to [89Zr]trastuzumab uptake and metabolic response showed predictive value in an external cohort. CONCLUSIONS:To the best of our knowledge, this study represents the first correlative analysis between [89Zr]trastuzumab tumor uptake and gene expression profiling in humans. Our findings suggest a role for ECM in impairing [89Zr]trastuzumab tumor uptake and T-DM1 metabolic response in advanced HER2-positive breast cancer, highlighting the potential of molecular imaging to depict tumor microenvironment features.

Gene set enrichment analysis on Hallmark gene sets, comparing metabolic response (positive normalized enrichment score – NES) and lack of metabolic response (negative NES).

BACKGROUND:Cyclin E1 overexpression drives oncogenesis in several cancers through deregulation of DNA replication and induction of genomic instability, which may potentially trigger immune signaling via cytoplasmic DNA. However, the effects of cyclin E1 overexpression on tumor immunity and its effects on the response to immune checkpoint inhibitors remain largely unclear. METHODS:Tissue microarrays and clinical outcomes of 398 patients with breast cancer were analyzed to explore the correlation between cyclin E1 expression, patient survival, and immune cell infiltration using immunohistochemistry. Genomic data from publicly available data sets and three clinical trials evaluating immunotherapy were assessed to measure the impact of cyclin E1 expression on the immune cells in the tumor microenvironment and response to immunotherapy in patients with breast cancer. In addition, breast cancer cell lines with inducible cyclin E1 overexpression were employed to analyze the effects of cyclin E1 on inflammatory signaling. RESULTS:Increased cyclin E1 expression in breast cancer was positively correlated with immune cell infiltration, including T cells, B cells, and natural killer cells, and activation of interferon-related pathways. Importantly, higher cyclin E1 expression or CCNE1 amplification was associated with better response to immunotherapy in three clinical trials. Mechanistically, cyclin E1 overexpression resulted in micronuclei formation and activation of innate immune signaling, resulting in increased immune cell migration. CONCLUSIONS:Our data show that cyclin E1 overexpression associate with antitumor immunity through activation of innate inflammatory signaling and warrants investigation into amplification or overexpression of cyclin E1 in identifying patients with breast cancer eligible for immunotherapy.

Gene set enrichment analysis on Hallmark gene sets, on genes ranked based on the correlation between gene expression and FDG-PET uptake described by SUVmax (positive normalized enrichment score – NES – for positive correlation, negative NES for negative correlation).

Gene set enrichment analysis on Reactome gene sets, on genes ranked based on the correlation between gene expression and FDG-PET uptake described by SUVmax (positive normalized enrichment score – NES – for positive correlation, negative NES for negative correlation).