Recurrent Setting Research Articles

Multi-institutional study of reirradiation for recurrent high grade glioma.

2063 Background: Treatment options are limited for recurrent WHO Grade 3-4 glioma (HGG). Reirradiation (ReRT) is an option, but the ideal treatment regimen and the benefit of concurrent and adjuvant systemic therapy in the recurrent setting remains unclear. Methods: A retrospective review of patients with recurrent HGG treated with reRT was conducted at 12 institutions. Eligible patients were treated with two courses of fractionated RT (>3 fractions) for glioma with the second course being for HGG. To estimate overall and progression free survival times, the Kaplan-Meier method was used. To assess the relationship between survival times and study variables, Cox proportional hazard regression models were used to calculate hazard ratios and the corresponding 95% confidence interval along with the p-value. SAS (version 9.4, Cary, NC, USA) was used for all analyses. P values < 0.05 were assumed to be statistically significant. Results: 482 eligible patients were identified from 1997 to 2023. 235 (54%) had histologic confirmation of glioblastoma at reRT. The median age at reRT was 53.1 years and median KPS was 80. 196 patients (51%) were treated with reRT at their initial recurrence and 122 (30%) had an IDH mutation. The most common reRT dose and number of fractions were 35 Gy and 10 fractions. 192 patients (44%) and 95 (24%) received concurrent (conc) and adjuvant (adj) temozolomide (TMZ) respectively and 116 (27%) and 110 (28%) received conc and adj bevacizumab (BEV) respectively with reRT. Median OS and PFS were 9.8 and 5.3 months. OS (16.6 vs 7.8 months, HR 2.44 p < 0.01) and PFS (8.6 vs 4.6 months, HR 1.85 p < 0.01) were longer in patients with IDH mutations. Receipt of conc and adj TMZ with reRT was associated with improved OS (HR 0.67 p < 0.01 and HR 0.49 p < 0.01 respectively) and PFS (HR 0.66 p <0.01 and HR 0.47 p < 0.01 respectively). Receipt of concBEV with reRT was associated with worse OS (HR 1.66 p < 0.01) but not PFS (HR 1.15 p = 0.28). AdjBEV was not associated with OS or PFS. Concurrent and adjTMZ were associated with improved OS ( p = 0.04 and <0.01) and PFS ( p = 0.01 and <0.01) for IDHwt tumors. In IDHmt tumors, concTMZ was associated with improved OS but not PFS ( p = 0.03 and 0.11), while adjTMZ was associated with improved OS and PFS ( p = 0.05 and <0.01). Symptomatic adverse radiation effects and Grade 3 or greater neurologic toxicity were seen in 107 (25%) and 86 (20%) of patients respectively. Neither conc nor adjBEV nor TMZ were associated with symptomatic ARE. ConcBEV was associated with lower (13% vs 23%, p = 0.03) and concTMZ was associated with higher rates (25% vs 15%, p = 0.01) of Grade 3 or greater neurologic toxicity. Conclusions: The use of concurrent and adjuvant TMZ with reRT are associated with improved OS and PFS in recurrent HGG. OS and PFS are improved with conc and adjTMZ for IDHwt tumors, while there was no PFS benefit to concTMZ in IDHmt tumors. The rate of high grade neurologic toxicity was decreased with the use of concurrent BEV and increased with the use of concTMZ.

Identification of a Single-Dose, Low-Flip-Angle-Based CBV Threshold for Fractional Tumor Burden Mapping in Recurrent Glioblastoma.

DSC-MR imaging can be used to generate fractional tumor burden (FTB) maps via application of relative CBV thresholds to spatially differentiate glioblastoma recurrence from posttreatment radiation effects (PTRE). Image-localized histopathology was previously used to validate FTB maps derived from a reference DSC-MR imaging protocol by using preload, a moderate flip angle (MFA, 60°), and postprocessing leakage correction. Recently, a DSC-MR imaging protocol with a low flip angle (LFA, 30°) with no preload was shown to provide leakage-corrected relative CBV (rCBV) equivalent to the reference protocol. This study aimed to identify the rCBV thresholds for the LFA protocol that generate the most accurate FTB maps, concordant with those obtained from the reference MFA protocol. Fifty-two patients with grade-IV glioblastoma who had prior surgical resection and received chemotherapy and radiation therapy were included in the study. Two sets of DSC-MR imaging data were collected sequentially first by using LFA protocol with no preload, which served as the preload for the subsequent MFA protocol. Standardized relative CBV maps (sRCBV) were obtained for each patient and coregistered with the anatomic postcontrast T1-weighted images. The reference MFA-based FTB maps were computed by using previously published sRCBV thresholds (1.0 and 1.56). A receiver operating characteristics (ROC) analysis was conducted to identify the optimal, voxelwise LFA sRCBV thresholds, and the sensitivity, specificity, and accuracy of the LFA-based FTB maps were computed with respect to the MFA-based reference. The mean sRCBV values of tumors across patients exhibited strong agreement (concordance correlation coefficient = 0.99) between the 2 protocols. Using the ROC analysis, the optimal lower LFA threshold that accurately distinguishes PTRE from tumor recurrence was found to be 1.0 (sensitivity: 87.77%; specificity: 90.22%), equivalent to the ground truth. To identify aggressive tumor regions, the ROC analysis identified an upper LFA threshold of 1.37 (sensitivity: 90.87%; specificity: 91.10%) for the reference MFA threshold of 1.56. For LFA-based FTB maps, an sRCBV threshold of 1.0 and 1.37 can differentiate PTRE from recurrent tumors. FTB maps aid in surgical planning, guiding pathologic diagnosis and treatment strategies in the recurrent setting. This study further confirms the reliability of single-dose LFA-based DSC-MR imaging.

On recurrent sets of operators

An operator $T$ acting on a Banach space $X$ is said to be recurrent if for each $U$; a nonempty open subset of $X$, there exists $n\in\mathbb{N}$ such that $T^n(U)\cap U\neq\emptyset.$ In the present work, we generalize this notion from a single operator to a set $\Gamma$ of operators. As application, we study the recurrence of $C$-regularized group of operators.

Periodic Behaviour of General Systems

A continuous function on the product of compact metric spaces to itself and back to the same space is known as a genera system. Where each element's orbit is an infinite sequence and where the first two elements are the same as given and next to it depends on the two elements prior to it form stronger conditions for the orbit. We could define an m-step dynamical system by extending the definition of a compact metric space to its m-times product. Because the system's current state frequently depends directly on the conditions of previous terms, this system appears more realistic. The basic theorems regarding periodic points and their related points, such as fixed point, limit points, recurrent points, will be proved in this paper. We also define the topological transitivity and its properties. In the end we find periodic points with periods one and two for affine maps and periodicity of tent map in dynamical system and generalised dynamical system.

Recurrent sets for endomorphisms of topological groups

This paper studies topological definitions of chain recurrence and shadowing for continuous endomorphisms of topological groups generalizing the relevant concepts for metric spaces. It is proved that in this case the sets of chain recurrent points and chain transitive component of the identity are topological subgroups. Furthermore, we show that some dynamical properties are induced by the original system on quotient spaces. These results link an algebraic property to a dynamical property.

Management Approaches in WHO Grade III Meningioma: A National Oncology Trainees' Collaborative for Healthcare Research (NOTCH) UK Multi-Centre Retrospective Study

AimsWHO Grade 3 (G3) meningiomas are rare tumours with limited data to guide management. This retrospective study documents UK management approaches across 14 centres over 11 years. Materials and methodsPatients with WHO G3 meningioma between 01/01/2008 and 31/12/2018 were identified. Data were collected on demographics, management strategy, adjuvant radiotherapy, approach in recurrence setting and survival. Results84 patients were identified. 21.4% transformed from lower-grade disease. 96.4% underwent primary surgical resection, with 20.8% having evidence of residual disease on their post-op MRI. 59.3% of patients underwent adjuvant radiotherapy (RT) following surgical resection.Overall median PFS and OS were 12.6 months and 28.2 months, respectively. Median OS in the group who underwent complete surgical resection was 34.9 months, compared to 27.5 months for those who had incomplete resection (HR 0.58, 95% CI 0.27–1.23, p = 0.15). Median OS was 33.1 months for those who underwent adjuvant RT and 14.0 months for those who did not (HR 0.48, 95% CI 0.27–0.84, p = 0.004). Median adjuvant RT dose delivered was 60Gy (range 12Gy–60Gy), 45.8% of adjuvant RT was delivered using IMRT.At disease relapse, 31% underwent salvage surgery and 29.3% underwent salvage RT. Of those treated with salvage RT, 64.7% were re-treats and all were treated with hypofractionated RT. ConclusionSurgery continues to be the preferred primary management strategy. Post-operative MRI within 48 hours is indicated to assess presence of residual disease and guide further surgical options. Adjuvant radiotherapy plays an important part of the management paradigm in these patients with the data supporting an attached survival advantage. Further surgery and re-irradiation is an option in the disease recurrence setting with radiosurgery frequently utilised in this context.

Clinical and research follow-up for knee cartilage injuries—an international consensus statement

IntroductionArticular cartilage injuries of the knee are a complex and challenging clinical pathology. ObjectivesThe purpose of this study was to establish consensus statements via a Delphi process on clinical and research follow-up for knee cartilage injuries. MethodsA consensus process on knee cartilage injuries utilizing a modified Delphi technique was conducted. Seventy-seven surgeons across 17 countries were invited to participate in these consensus statements. Nine questions were generated on clinical and research follow-up, with 3 rounds of questionnaires and final voting occurring. Consensus was defined as achieving 80% to 89% agreement, whereas strong consensus was defined as 90% to 99% agreement, and unanimous consensus was defined as 100% agreement with a proposed statement. ResultsOf the 9 total questions and consensus statements on clinical and research follow-up developed from 3 rounds of voting, 1 achieved unanimous consensus, 5 achieved strong consensus, 1 achieved consensus, and 2 did not achieve consensus. ConclusionsThe statement that achieved unanimous consensus was on physical examination findings. The statements that achieved strong consensus were related to defining and monitoring treatment success, patient-reported outcomes, research follow-up, and second-look arthroscopy in the setting of recurrence. The statements that did not achieve consensus were related to routine imaging and length of clinical follow-up after operative intervention.

Abstract PO5-25-09: rs2242652 POLYMORPHISM OF THE hTERT GENE IN WOMEN WITH BREAST CANCER

Abstract Introduction: Breast cancer is the most common neoplasm in women around the world. There are several risk factors for this cancer: sex, age, body mass index (BMI), hormone therapy, family history, genetic mutations, among several others. The vast majority of breast tumors are characterized as carcinomas and may originate from ducts or lobules. Immunohistochemistry is related to the expressions of the estrogen receptor (ER) and progesterone receptor (PR), as well as the expression of the human epidermal growth factor receptor 2 (HER2), cell proliferation or the absence of any expression from receptors on the tumor membrane. The telomeres protect the chromosomes natural endings from suffering DNA loss. Telomerase is a ribonuclear protein complex (RNA and protein) that neutralizes telomeres' shortening. Recurrent point mutations in the TERT telomerase promoter have been identified in several cancers, and the rs2242652 polymorphism is a single nucleotide change, and has been described as associated with breast cancer risk. Objective: The objective of this study is to analyze the TERT rs2242652 polymorphism in breast cancer women and to test the correlation of such data with the prognosis and various clinical variables. Methods: The study was conducted as an observational clinical study of women with breast cancer. A blood sample was collected from the patient and PCR was performed to extract the DNA and to analyze the telomerase polymorphisms in this population. To ensure a more descriptive analysis, the data was used in the construction of tables and graphs, that were then studied in a qualitative manner. The associations were analyzed through direct correlation tests and were followed by comparisons of categorization groups. Results and discussion: Fifty-four women presented polymorphism of the telomerase hTERT gene rs2242652. They were divided into two groups according to the A or G allele that confer the GA/AA and GG gene variants. It was found that the GA/AA group had a trend towards more aggressive tumors, presenting 33% triple negative and 22% of tumors with HER2 overexpression, different from the GG group: 19% triple negative and 10% HER2 overexpression. More aggressive T4 tumors, were more expressive in the GA/AA gene variant group representing 20% of the patients, whereas in the GG group they represented only 8%. Conclusion: The data found in this study on the telomerase TERT gene polymorphism rs2242652 with breast cancer refers to a tendency found in tumors that have a more severe prognosis, to associate with the gene variant linked to the A allele of this gene, however a larger sample number is required for statistical confirmation. Citation Format: Miriam Alvares, Elisa Mascarenhas, Joao Matos. rs2242652 POLYMORPHISM OF THE hTERT GENE IN WOMEN WITH BREAST CANCER [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 PO5-25-09.

Importance of CD8 Tex cell-associated gene signatures in the prognosis and immunology of osteosarcoma

As a highly aggressive bone malignancy, osteosarcoma poses a significant therapeutic challenge, especially in the setting of metastasis or recurrence. This study aimed to investigate the potential of CD8-Tex cell-associated genes as prognostic biomarkers to reveal the immunogenomic profile of osteosarcoma and guide therapeutic decisions. mRNA expression data and clinical details of osteosarcoma patients were obtained from the TCGA database (TARGET-OS dataset). The GSE21257 dataset (from the GEO database) was used as an external validation set to provide additional information on osteosarcoma specimens. 84 samples from the TARGET-OS dataset were used as the training set, and 53 samples from the GSE21257 dataset served as the external validation cohort. Univariate Cox regression analysis was utilized to identify CD8 Tex cell genes associated with prognosis. The LASSO algorithm was performed for 1000 iterations to select the best subset to form the CD8 Tex cell gene signature (TRS). Final genes were identified using the multivariate Cox regression model of the LASSO algorithm. Risk scores were calculated to categorize patients into high- and low-risk groups, and clinical differences were explored by Kaplan–Meier survival analysis to assess model performance. Prediction maps were constructed to estimate 1-, 3-, and 5 year survival rates for osteosarcoma patients, including risk scores for CD8 Texcell gene markers and clinicopathologic factors. The ssGSEA algorithm was used to assess the differences in immune function between TRS-defined high- and low-risk groups. TME and immune cell infiltration were further assessed using the ESTIMATE and CIBERSORT algorithms. To explore the relationship between immune checkpoint gene expression levels and the two risk-defined groups. A CD8 Tex cell-associated gene signature was extracted from the TISCH database and prognostic markers including two genes were developed. The high-risk group showed lower survival, and model performance was validated by ROC curves and C-index. Predictive plots were constructed to demonstrate survival estimates, combining CD8 Tex cell gene markers and clinical factors. This study provides valuable insights into the molecular and immune characteristics of osteosarcoma and offers potential avenues for advances in therapeutic approaches.

A qualitative evaluation of factors influencing Tumor Treating fields (TTFields) therapy decision making among brain tumor patients and physicians

BackgroundTumor Treating Fields (TTFields) Therapy is an FDA-approved therapy in the first line and recurrent setting for glioblastoma. Despite Phase 3 evidence showing improved survival with TTFields, it is not uniformly utilized. We aimed to examine patient and clinician views of TTFields and factors shaping utilization of TTFields through a unique research partnership with medical neuro oncology and medical social sciences.MethodsAdult glioblastoma patients who were offered TTFields at a tertiary care academic hospital were invited to participate in a semi-structured interview about their decision to use or not use TTFields. Clinicians who prescribe TTFields were invited to participate in a semi-structured interview about TTFields.ResultsInterviews were completed with 40 patients with a mean age of 53 years; 92.5% were white and 60% were male. Participants who decided against TTFields stated that head shaving, appearing sick, and inconvenience of wearing/carrying the device most influenced their decision. The most influential factors for use of TTFields were the efficacy of the device and their clinician’s opinion. Clinicians (N = 9) stated that TTFields was a good option for glioblastoma patients, but some noted that their patients should consider the burdens and benefits of TTFields as it may not be the desired choice for all patients.ConclusionsThis is the first study to examine patient decision making for TTFields. Findings suggest that clinician support and efficacy data are among the key decision-making factors. Properly understanding the path to patients’ decision making is crucial in optimizing the use of TTFields and other therapeutic decisions for glioblastoma patients.

Hausdorff dimension of recurrence sets

We consider linear mappings on the 2-dimensional torus, defined by T(x)=Ax (mod 1) , where A is an invertible 2×2 integer matrix, with no eigenvalues on the unit circle. In the case detA=±1 , we give a formula for the Hausdorff dimension of the set {x∈T2:d(Tn(x),x)<e−αn for infinitely many n}.

Uniqueness of Denjoy minimal sets for twist maps with zero entropy *

For monotone twist maps with zero topological entropy, we show that the set of recurrent points with irrational rotation number α can be described by a single orientation preserving circle homeomorphism and hence there is either an invariant circle, or a unique Denjoy minimal set, of rotation number α.

Machine learning approach to detect dynamical states from recurrence measures.

We integrate machine learning approaches with nonlinear time series analysis, specifically utilizing recurrence measures to classify various dynamical states emerging from time series. We implement three machine learning algorithms: Logistic Regression, Random Forest, and Support Vector Machine for this study. The input features are derived from the recurrence quantification of nonlinear time series and characteristic measures of the corresponding recurrence networks. For training and testing, we generate synthetic data from standard nonlinear dynamical systems and evaluate the efficiency and performance of the machine learning algorithms in classifying time series into periodic, chaotic, hyperchaotic, or noisy categories. Additionally, we explore the significance of input features in the classification scheme and find that the features quantifying the density of recurrence points are the most relevant. Furthermore, we illustrate how the trained algorithms can successfully predict the dynamical states of two variable stars, SX Her and AC Her, from the data of their light curves. We also indicate how the algorithms can be trained to classify data from discrete systems.

Abstract 5188: Defining PD-1/PD-L1 receptor-ligand interactions in the head and neck cancer tumor microenvironment identifies unique ‘immune cell rivers’ of cellular interactions

Abstract Head and neck squamous cell carcinoma (HNSCC) is the 7th most common cancer globally with a poor 5-year survival rate of ~50%. With the emerging successes with immune checkpoint blockade (ICB) in the metastatic and recurrent setting, there is a need for predictive biomarkers to identify patients likely to achieve clinical benefit. Whilst PD-L1 expression on tumour cells and PD-1 on immune cells have been investigated, these remain inconclusive biomarkers. To better understand and map the PD-L1/PD-1 receptor-ligand interactions, we evaluated a novel in situ proximity ligation assay (is PLA) across whole tissue sections of pre-treatment HNSCC patients to received ICB therapy. Pre-treatment FFPE whole tissue samples were collected from n=25 advanced stage HNSCC patients across two major Queensland Hospitals (Royal Brisbane and Women’s Hospital and the Princess Alexandra Hospital). Tissues were stained with multiplex immunofluorescence and the Navinci Diagnostics fluorescent is PLA assay for PD-1/PD-L1. Tissues were incubated with the PD1/PD-L1 antibodies and subsequent incubation with oligonucleotide-tagged secondary probes enabled PLA, which highlights PD1 and PD-L1 interactions. Following the application of secondary probes, the sections underwent a ligation step, then a post-blocking, and an amplification process to enhance the detection of protein interactions. Next, the sections were treated with a detection solution to visualize the amplification product. The PLA assay findings were measured against clinical endpoints (PFS/OS criteria). In n=5/25 HNSCC tissues, positive PD-1/PD-L1 interactions were measured across the tumour microenvironment (TME), specifically in the immune rivers on the immediate tumour periphery. These cells showed highly specific binding of the PLA product. These areas positive by the PLA assay were in stark contrast to the tumour bulk/nests which were absent in PD-1/PD-L1 interactions. Notably, the PLA PD-1/PD-L1 do not correlate with tumour PD-L1 expression or tumour proportion scores (TPS). Rather, our study highlighted the difference in spatially mapping PD-1/PD-L1 interactions which may better recapitulate the tumour-immune recognition and activity in the TME. Taken together, these data provide a novel approach for determining clinically relevant receptor/ligand interactions in the HNSCC TME. Citation Format: Habib Sadeghirad, Vahid Yaghoubi Naei, James Monkman, Subham Basu, Agata Wicher, Rahul Ladwa, Brett GM Hughes, Arutha Kulasinghe. Defining PD-1/PD-L1 receptor-ligand interactions in the head and neck cancer tumor microenvironment identifies unique ‘immune cell rivers’ of cellular interactions [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 5188.

Abstract 1760: Mutational landscape of the canine acute myeloid leukemia exome

Abstract Over 21,000 newly diagnosed cases of human acute myeloid leukemia (hAML) and 10,000 hAML-related deaths are reported in the United States every year. hAML is considered a highly diverse aggressive hematopoietic malignancy, with over 16 recurrent gene rearrangements, 60 recurrent point mutations, and hundreds of rarely mutated genes. There are large ongoing multi-institutional studies devoted to advancing medical management for hAML by providing targeted therapeutics to patients based on their molecular characteristics. A preclinical spontaneous large animal model for testing novel therapies could accelerate the development of better treatments in people. Dogs spontaneously develop AML with similar clinical features and outcomes. As such, the dog may be a useful pre-clinical model, but little is known about the molecular landscape and/or drivers of canine AML (cAML). The goal of this work was to identify somatic mutation candidates in cAML and determine the overlapping features with hAML. We utilized whole exome sequencing at 300x coverage to identify candidate mutations in 51 cAML samples. Somatic variant calling was performed per the GATK best practice recommendations using Mutect2 and a reference panel of normals (n=77) and a variant call file of canine germline variants. We focused our analysis on novel variants predicted to have a moderate to high impact and that occurred in genes implicated in cancer. At least one variant was identified in genes involved in the RTK/RAS pathway (e.g. NRAS, KRAS, PTPN11, FLT3, KIT) in over 75% of cAML samples, a trend that is also found in people. Additionally, recurrent point mutations were predicted in NRAS and KRAS, and some of which, such as the codon changes G13R and Q61R/H in NRAS, were noted to be shared between hAML and cAML. Mutations in DNMT3A were uncommon (n=3/44) and NPM1 mutations were not identified in our cohort, both of which are common hAML-associated genes. However, mutations in other epigenetic modifiers, such as KDM5C and KDM6A, occurred at a high frequency. This data provides insight into the candidate mutations potentially driving cAML pathogenesis and highlights the overlapping molecular features with hAML. Citation Format: Robert Harris, Evan Conaway, Anne Avery. Mutational landscape of the canine acute myeloid leukemia exome [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 1760.

Abstract B008: Modeling radiation sensitivity in patient-derived organoid models of endometrial cancer

Abstract Endometrial cancer is the 4th most common cancer in women, with increasing incidence and deaths each year from 2008 to 2017. The typical treatment for high grade and advanced endometrial cancer includes cytoreductive surgery followed by radiation and/or chemotherapy, depending on stage, grade, and other risk factors. Despite advances in molecular classification of endometrial cancer, there is a paucity of data on the mechanisms of sensitivity and resistance to radiation and chemotherapy. One reason for this lack of understanding is because, clinically, surgery is not typically offered in the setting of recurrence; thus, there are no available specimens to assess how the tumor evolves in response to therapy. Preclinical models can in part overcome this roadblock, yet there are very few preclinical models of endometrial cancer that accurately recapitulate the heterogeneity of human disease. Our objective was to define how endometrial tumors respond to radiation and chemotherapy using patient-derived organoid models. First, we have established a living biorepository that includes over 30 patient-derived organoid models of high risk or advanced endometrial cancer, with available clinical response data. Specifically, tumor specimens were obtained at the time of primary surgery and digested to generate single cell suspensions, which were then resuspended in basement membrane extract (BME), plated as three-dimensional domes, and cultured in specialized media. Organoids with a diameter of &amp;gt;50 µm typically formed in 48-96 hours after initial plating. For therapeutic studies, organoids were plated as BME domes in 96-well plates, followed by exposure to increasing levels of radiation (2-16 Gy) and/or chemotherapy (carboplatin+paclitaxel, 10 nM – 10 µM). Drug effects were monitored using an automated kinetic live-cell imaging platform (Cytation5) in which media was supplemented with fluorescent dyes to multiplex interrogation of cell health and induction of apoptosis. To date, we have observed differential sensitivity to radiation and chemotherapy in patient-derived organoid models of high risk and advanced endometrial cancer as determined by changes in organoid number and size and induction of apoptosis. These studies are the first to examine the therapeutic effects of radiation in endometrial cancer patient-derived organoid models. Ongoing studies are correlating response to therapy in patient-derived organoid models with clinical patient outcomes. We are also performing pre- and post-treatment transcriptomic analyses to define gene signatures of response to radiation and cytotoxic chemotherapy in endometrial cancer organoid models. The ultimate goal is to use these heterogeneous preclinical models to identify pretreatment biomarkers of response that can be translated to a clinical diagnostic test. Citation Format: Sofia Gabrilovich, Kaitriana Powell-Smith, Hiruni Sumanasiri, Emily Symons, Emily Hill, Miles Pufall, Donna Santillan, Kristina W. Thiel. Modeling radiation sensitivity in patient-derived organoid models of endometrial cancer [abstract]. In: Proceedings of the AACR Special Conference on Endometrial Cancer: Transforming Care through Science; 2023 Nov 16-18; Boston, Massachusetts. Philadelphia (PA): AACR; Clin Cancer Res 2024;30(5_Suppl):Abstract nr B008.

Abstract B032: Use of patient-derived organoids to model tumor evolution in response to chemotherapy

Abstract Serous endometrial and ovarian cancers represent significant morbidity and mortality for gynecologic cancers due to the high rate of resistance to chemotherapy and recurrence after treatment. Among the many reasons for poor outcomes is a lack of preclinical models that reflect the complex heterogeneity across patients. Our objective was to create patient-derived organoid (PDO) models of serous endometrial and ovarian cancer and examine how genomic profiles evolve in response to standard therapy. This study was performed in four PDO models of serous gynecologic cancer, including serous endometrial, high grade and low grade serous ovarian, and high grade serous fallopian tube. We first compared genomic alterations in the primary tumors and PDOs using a 484-gene NGS panel (NovoPM 2.0, Novogene). A large overlap in single nucleotide variants (SNVs), copy number variations (CNVs) and indels was observed between primary tumor tissue and the corresponding PDO model. For example, there was an average of 175 shared SNVs between each primary tumor and PDO model and &amp;lt;20 unique variants in the PDO that were not present in primary tumor specimen. For the patient with serous fallopian tube cancer, we were further able to generate PDO models from tumor tissue acquired from three different sites: ovary, omentum, and ascites fluid. We found that 217 SNVs were shared among the PDOs from the three sites, with only 2-11 variants unique to each location. Interestingly, eight unique CNVs were detected in the ovary and ascites PDOs but not in the metastatic (omentum) PDO. We next exposed each PDO to a short 3-day pulse of carboplatin+paclitaxel to create chemoexposed models. The rationale for this duration of exposure is that clinical response in patients has been shown to correlate with drug response at 72 hrs in PDO models of ovarian cancer. As expected, all chemoexposed PDOs were more resistant to chemotherapy as compared to treatment-naïve counterparts. Genomic analysis of the treatment-naïve vs. chemoexposed PDOs revealed acquisition of new variants, such as a p53 mutation in the serous endometrial model after the pulse of chemotherapy. Finally, we compared drug sensitivity of the treatment-naïve vs. chemoexposed PDOs to agents used in the adjuvant and recurrent settings. The chemoexposed models yielded different drug profiles, with some showing increased sensitivity and others increased resistance. Taken together, these data substantiate that PDO models retain tumor heterogeneity, exhibited by the different genomic profiles and varying chemosensitivity. In addition, PDO models can be used to model the genomic and drug response profiles that arise in response to chemotherapy. Citation Format: Andreea Newtson, Emily Symons, Paige Malmrose, Eric Devor, Samantha Parks, Craig Rush, Jessica Andrew-Udoh, Haley Losh, Jay Gertz, Kristina Thiel, Kimberly Leslie. Use of patient-derived organoids to model tumor evolution in response to chemotherapy [abstract]. In: Proceedings of the AACR Special Conference on Endometrial Cancer: Transforming Care through Science; 2023 Nov 16-18; Boston, Massachusetts. Philadelphia (PA): AACR; Clin Cancer Res 2024;30(5_Suppl):Abstract nr B032.

Advancements in Endometrial Cancer Research in 2023

Endometrial cancer is one of the most common gynaecological cancers in developed countries, and the incidence is rising significantly. The staging of this disease is evolving from anatomic staging and risk stratification to a more molecular-based stratification. Treatment of endometrial cancer is also evolving. Paclitaxel plus carboplatin is the standard first-line chemotherapy for endometrial cancer; however, there is new evidence that the combination of chemotherapy and immunotherapy has synergistic effects in the treatment of this disease. This article discusses the latest advancements in endometrial cancer research in 2023, including highlights from the Society of Gynecologic Oncology (SGO) Annual Meeting on Women’s Cancers 2023 in March, the 2023 American Society of Clinical Oncology (ASCO) Annual Meeting in June, the 24th European Gynaecological Oncology (ESGO) Congress in September and October, and the European Society for Medical Oncology (ESMO) Congress 2023 in October. The article highlights the unprecedented progression-free survival (PFS) data from two Phase III randomised controlled trials evaluating first-line immunotherapy in combination with chemotherapy in patients with advanced or recurrent endometrial cancer: RUBY with dostarlimab, and NRG-GY018 with pembrolizumab, which created a buzz at SGO 2023 in the spring, and stimulated discussion throughout the remainder of the year. The overall survival (OS) results, the clinically meaningful benefits regardless of mismatch repair status, and health-related quality of life (QOL) in these studies are also discussed. Further topics covered in this year-in-review article include the implications of the results from RUBY and NRG-GY018 on first-line treatment and recurrent settings, and the effect of adding a poly adenosine diphosphate ribose polymerase (PARP) inhibitor to immunotherapy–chemotherapy combinations in the Phase III trial, DUO-E. Disparities in endometrial cancer care, research on fertility-sparing, and the importance of the multidisciplinary team (MDT) in endometrial cancer management are also explored. Following the announcement of practice-changing findings from RUBY and NRG-GY018 in March, data presented and published throughout the remainder of 2023 show that research in endometrial cancer continues at a pace.

Prostate-Specific Membrane Antigen PET/CT Detection of Prostate Cancer Metastasis to Thyroid and Cricoid Cartilages.

Prostate-specific membrane antigen (PSMA) PET/CT has revolutionized the imaging of prostate cancer. Historically, prostate cancer metastasis to thyroid and cricoid cartilages was thought to be exceedingly rare, with only a few reported cases in the literature. Prostate cancer metastasis to the laryngeal cartilages was detected in 4 of 221 patients who underwent imaging with 18 F-PSMA (Pylarify) or 68 Ga-PSMA (Illuccix) PET/CT for initial staging of high-risk prostate cancer or restaging evaluation in the setting of biochemical recurrence from April 2022 through October 2023. The increased sensitivity and specificity of PSMA PET/CT allow for the detection of previously occult metastatic disease.

Operative planning for a functional precision medicine assay of recurrent high-grade glioma: illustrative case.

Functional precision medicine (FPM) represents a personalized and efficacious modality for treating malignant neoplasms. However, acquiring sufficient live tissue to perform FPM analyses is complicated by both difficult identification on imaging and radiation necrosis, particularly in cases of recurrence. The authors describe a case of planning biopsy trajectories for an FPM assay in a patient with recurrent high-grade glioma. A 25-year-old male with a history of recurrent high-grade glioma was scheduled for laser ablation and biopsy with ChemoID assaying after regions of potential recurrence were identified on follow-up imaging. Preoperative magnetic resonance (MR) spectroscopy of the regions showed areas of high choline/creatine ratios within lesions of radiation necrosis, which helped in planning the biopsy trajectories to selectively target malignancies for FPM analysis. ChemoID results showed high tumor susceptibility to lomustine, which was implemented as adjuvant therapy. FPM therapy in the setting of recurrence is complicated by radiation necrosis, which can present as malignancy on imaging and interfere with tissue acquisition during biopsy or resection. Thus, operative approaches should be carefully planned with the assistance of imaging modalities such as MR spectroscopy to better ensure effective tissue acquisition for accurate FPM analysis and to promote more definitive treatment of recurrence.