Tumor Volume Measurements Research Articles

Using three-dimensional model-based tumour volume change to predict the symptom improvement in patients with renal cell cancer

In our recent study, we explored the efficacy of three-dimensional (3D) measurement of tumor volume in predicting the improvement of quality of life (QoL) in patients suffering from renal cell cancer (RCC), who were treated with axitinib and anti-PD-L1 antibodies. This study encompassed 18 RCC patients, including 10 men and 8 women, with an average age of 56.83 ± 9.94 years. By utilizing 3D Slicer software, we analyzed pre- and post-treatment CT scans to assess changes in tumor volume. Patients' QoL was evaluated through the FKSI–DRS questionnaire. Our findings revealed that 3D models for all patients were successfully created, and there was a moderate agreement between treatment response classifications based on RECIST 1.1 criteria and volumetric analysis (kappa = 0.556, p = 0.001). Notably, nine patients reported a clinically meaningful improvement in QoL following the treatment. Interestingly, the change in tumor volume as indicated by the 3D model showed a higher area under the curve in predicting QoL improvement compared to the change in diameter measured by CT, although this difference was not statistically significant (z = 0.593, p = 0.553). Furthermore, a multivariable analysis identified the change in tumor volume based on the 3D model as an independent predictor of QoL improvement (odds ratio = 1.073, 95% CI 1.002–1.149, p = 0.045).In conclusion, our study suggests that the change in tumor volume measured by a 3D model may be a more effective predictor of symptom improvement in RCC patients than traditional CT-based diameter measurements. This offers a novel approach for assessing treatment response and patient well-being, presenting a significant advancement in the field of RCC treatment.

Prevotella intermedia boosts OSCC progression through ISG15 upregulation: a new target for intervention

PurposePeriodontitis-associated bacteria, such as Porphyromonas gingivalis and Fusobacterium nucleatum, are closely linked to the risk of oral squamous cell carcinoma (OSCC). Emerging studies have indicated that another common periodontal pathogen, Prevotella intermedia (P. intermedia), is enriched in OSCC and could affect the occurrence and progression of OSCC. Our aim is to determine the effects of P. intermedia on the progression of OSCC and the role of antibiotics in reversing these effects.MethodsIn this study, a murine xenograft model of OSCC was established, and the mice were injected intratumorally with PBS (control group), P. intermedia (P.i group), or P. intermedia combined with an antibiotic cocktail administration (P.i + ABX group), respectively. The effects of P. intermedia and ABX administration on xenograft tumor growth, invasion, angiogenesis, and metastasis were investigated by tumor volume measurement and histopathological examination. Enzyme-linked immunosorbent assay (ELISA) was used to investigate the changes in serum cytokine levels. Immunohistochemistry (IHC) was adopted to analyze the alterations in the levels of inflammatory cytokines and infiltrated immune cells in OSCC tissues of xenograft tumors. Transcriptome sequencing and analysis were conducted to determine differential expression genes among various groups.ResultsCompared with the control treatment, P. intermedia treatment significantly promoted tumor growth, invasion, angiogenesis, and metastasis, markedly affected the levels of inflammatory cytokines, and markedly altered M2 macrophages and regulatory T cells (Tregs) infiltration in the tumor microenvironment. However, ABX administration clearly abolished these effects of P. intermedia. Transcriptome and immunohistochemical analyses revealed that P. intermedia infection increased the expression of interferon-stimulated gene 15 (ISG15). Correlation analysis indicated that the expression level of ISG15 was positively correlated with the Ki67 expression level, microvessel density, serum concentrations and tissue expression levels of inflammatory cytokines, and quantities of infiltrated M2 macrophages and Tregs. However, it is negatively correlated with the quantities of infiltrated CD4+ and CD8+ T cells.ConclusionIn conclusion, intratumoral P. intermedia infection aggravated OSCC progression, which may be achieved through upregulation of ISG15. This study sheds new light on the possible pathogenic mechanism of intratumoral P. intermedia in OSCC progression, which could be a prospective target for OSCC prevention and treatment.

Does volumetric measurement of ADC values achieve higher diagnostic performance in bladder cancer MRI?

Apparent diffusion coefficient (ADC) value is an important part of bladder cancer magnetic resonance imaging (MRI) assessment and can predict the aggressive and invasive potentials. There is growing interest in whole tumor volume measurements. To investigate if the volumetric ADC measurement method will significantly exceed the diagnostic performance of the selected region of interest (ROI) method in everyday practice. A prospective evaluation was carried out of 50 patients with bladder cancer by two radiologists. The mean and the minimum ADC values were measured using both methods. The inter-reader agreement was determined by the intraclass correlation coefficient. The ADC values were compared between different grades, states of muscle invasion, and lympho-vascular invasion (LVI); then, validity was evaluated using receiver operating characteristic (ROC) curves. Areas under the curve (AUC) were then compared for the level of statistical significance. The inter-observer agreement was excellent for the ADC values using both methods. The volumetric measurement provides higher mean and lower minimum ADC values with statistically significant differences (P <0.00001). The highest diagnostic accuracy for differentiating tumor grade and predicting muscle invasion was for the minimum ADC by a selected ROI. However, the differences between the achieved AUCs were of no statistical significance. None of the ADC values predicted LVI with statistical significance. The selected ROI and volumetric measurement methods of mean and minimum ADC in bladder cancer yield different values, still having comparable diagnostic performance with accurate ROI sampling. The minimum ADC value by ROI is preferred in everyday clinical practice.

Abstract LB156: Targeting epigenetic activity of beta-catenin/CBP impedes oral cancer progression

Abstract Head and neck cancer is a complex malignancy with its major anatomical subsite, cancer of the oral cavity, ranking among the most deadly and disfiguring cancers. Oral cancer presents primarily as HPV-negative oral squamous cell carcinoma (OSCC) whose etiology is associated with tobacco and alcohol use and for which there are limited treatments. Whereas immunotherapies, such as anti-PD-1 antibodies, have become a promising therapeutic option, only ~20% of head neck cancer patients benefit from anti-PD-1 immunotherapy. We and others have shown that non-mutational epigenetic reprogramming mediated by the β-catenin/CBP complex promotes aggressive cell phenotypes in OSCC by establishing open chromatin at the transcription start sites of genes associated with cancer stemness. Accordingly, pharmacological inhibition of this complex dramatically inhibits OSCC evolution in a syngeneic mouse model of OSCC. Here, we evaluated whether the inhibition of β-catenin/CBP epigenetic activity would enhance the effects of anti-PD-1 immunotherapy. We adapted a syngeneic mouse model of tobacco-associated oral carcinogenesis that utilizes a mouse cell line, 4MOSC1, derived from 4-nitroquinoline-1 oxide- (4NQO)-induced tongue tumors of C57BL/6J mice. After tumors developed for 7 days, mice were blindly separated into treatment cohorts (n=13, each) to receive vehicle control (PBS), monotherapy (either 10 mg/kg anti-PD-1 EOD IP, or 100 mg/kg E7386, a Wnt signaling pathway modulator, QD oral gavage) or combination therapy (anti-PD-1 + E7386). Tumor isografts were harvested 11 days post initiation of treatments and processed for histopathology, immunohistochemistry, and immunofluorescence analyses. Measurements of tumor volumes showed that combination therapy resulted in a statistically significant reduction by ~80% compared to control mice and that it surpassed tumor decrease by either monotherapy. These results were confirmed by histopathology analyses. Evaluation of tumor tissues by immunofluorescence revealed statistically significant decreases in Cbp, H3K4me3, Keratin 14, and Podoplanin expression in response to E7386 alone and in combination with anti PD-1. Collectively our results suggest that a combination therapy comprising anti PD-1 treatment with E7386-targeting β-catenin/CBP epigenetic signaling is likely to impede OSCC evolution to advanced disease. Supported by Eisai, Co Ltd Research Award (MAK), NIH 5R01 DE030350 (MAK, SM, XV) and 5R01 DE031413 (MVB). Citation Format: Emily Fisher, Anthony Spinella, Junji Matsui, Kenichi Nomoto, Xaralabos Varelas, Manish Bais, Maria Kukuruzinska. Targeting epigenetic activity of beta-catenin/CBP impedes oral cancer progression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr LB156.

Abstract 4178: Non-invasive shortwave infrared imaging of cytotoxic T lymphocyte infiltration for monitoring responses to combination immunotherapy and chemotherapy

Abstract Although triple-negative breast cancer (TNBC) can be treated with anti-PD-1 checkpoint immunotherapy in combination with chemotherapy, there remains a challenge in effectively monitoring therapeutic responses. Current non-invasive clinical imaging tools to evaluate response to treatment are reliant upon measurements of tumor volume and may fail to distinguish true progression from increased immune cell infiltration. Invasive biopsy sampling and immunohistochemistry (IHC) can elucidate changes in the immune landscape of treated tumors, but these methods are not conducive to providing real-time information. This study presents shortwave infrared (SWIR) imaging as a potential tool to detect treatment-induced cytotoxic T lymphocyte (CTL) infiltration non-invasively and in real time using rare earth metal-doped nanoparticles encapsulated in human serum albumin nanocomposites (ReANCs). ReANCs were chemically conjugated with anti-CD8α antibodies as targeting ligands to facilitate binding of the nanoprobes to CTLs with high specificity in a syngeneic mouse model of breast cancer. After treating the mice with combination anti-PD-1 and doxorubicin, volumetric analysis of the mammary fat pad tumors did not show any significant impact of treatment compared to single treatment and untreated control mice. However, increased CTL infiltration in the tumors of mice that received combination treatment was detected by in vivo SWIR imaging. CTL infiltration was validated with ex vivo IHC staining, and a monotonic relationship was observed between SWIR fluorescence and CD8 positivity. IHC staining of other immune markers, including CD45, CD3, CD4, and PD-L1, showed that combination treatment may influence in the expression of these markers, presenting additional targets that could be imaged with ReANCs in the future. In conclusion, the increase in SWIR signal from CD8-targeted ReANCs in tumors treated with combination immunotherapy and chemotherapy and the relationship with IHC staining highlight the ability to use SWIR imaging for non-invasive assessment of changes in immune dynamics following treatment. Citation Format: Jay V. Shah, Jake N. Siebert, Xinyu Zhao, Shuqing He, Richard E. Riman, Mei Chee Tan, Mark C. Pierce, Edmund C. Lattime, Vidya Ganapathy, Prabhas V. Moghe. Non-invasive shortwave infrared imaging of cytotoxic T lymphocyte infiltration for monitoring responses to combination immunotherapy and chemotherapy [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 4178.

Abstract 4154: PET imaging to characterize the tumor microenvironment in a breast cancer model of obesity

Abstract Introduction: Obesity is known to reduce efficacy for cancer treatment patients and is thought to modulate the tumor microenvironment and glucose metabolism. In this study, we aim to quantify obesity-induced differences in the breast cancer tumor microenvironment with positron emission tomography (PET) imaging of hypoxia, glucose metabolism, and granzyme B. These experiments are testing the hypothesis that tumors in obese mice have increased glucose metabolism and hypoxia, measured by [18F]F-fluorodeoxyglucose (FDG) and [18F]F-fluoromisonidazole (FMISO) uptake. We also hypothesize that immunotherapy (IMT) increases immune activation, as measured by [68Ga]Ga-Granzyme B peptide (GZP), and that obese mice will respond less to immunotherapy than lean mice. Methods: C57/Bl6 mice were placed on a high-fat diet (HFD) with 60% kcal fat (n=18) or low-fat diet (LFD) composed of 10% kcal fat (n=18) to induce obesity. Blood serum was collected for analysis of cholesterol levels prior to tumor implantation. Body weight and food intake were measured weekly. 14 weeks after initiating each diet, 5x105 E0771 cells were implanted into the 3rd mammary fat pad and allowed to grow to 50-150mm3. Tumor-bearing mice were imaged with [18F]F-FDG and [18F]F-FMISO PET to measure glucose metabolism and hypoxia, respectively prior to treatment. Following imaging, mice began treatment with either saline (n=6/diet) or checkpoint blockade IMT with 200 ug anti-PD-1 and 100 ug anti-CTLA-4 (n=12/diet). After 3 doses of IMT, mice were imaged with [68Ga]Ga-GZP PET to measure immune activation. Tumor volume measurements and treatment administration occurred every 3 days. Metrics of standardized uptake value (SUV) including mean, max, and peak were quantified from imaging data. A one-way independent ANOVA or independent t-test was used to compare differences between groups. Results: HFD-fed mice had significantly increased body weight (p&amp;lt;0.0001) and serum cholesterol (p=0.005) compared to LFD-fed mice. SUVmean for tumor hypoxia (p=0.003) and glucose metabolism (p=0.02) were significantly increased at baseline in HFD-fed mice compared to LFD-fed mice. IMT increases immune activation for both LFD-fed (p=0.009) and HFD-fed mice (p=0.05). IMT treatment significantly reduces tumor burden for LFD mice (p&amp;lt;0.0001), but not HFD mice (p=0.096). Conclusions: Obesity plays a role in the reduction of the effectiveness of immunotherapy. At baseline, tumors of obese mice have increased tumor glucose metabolism and hypoxia. Although immunotherapy increases immune activation, this is not sufficient to reduce tumor burden or improve overall survival. Understanding obesity-induced differences in tumor biology may provide imaging-directed treatment decision making. Citation Format: Shannon E. Lynch, Corinne Crawford, Addison Hunt, Luke Sligh, Benjamin M. Larimer, Suzanne E. Lapi, Anna G. Sorace. PET imaging to characterize the tumor microenvironment in a breast cancer model of obesity [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 4154.

Abstract 2630: Identifying most promising combination therapies for immune suppressive breast cancer using a combined in vitro/in vivo approach

Abstract Combining epigenetic therapy with immunotherapy is a promising strategy to address the complexities of cancer biology. However, it's important to note that the field is still evolving, and more research is needed to understand the optimal combinations, timing, and patient populations that will benefit the most from these approaches. We evaluated a combination of two different checkpoint inhibitor therapies (anti-CTLA4 and anti-PD1) with two different hypomethylating agents (5-azacytidine, AZA and Decitabine, DEC) in vitro and in vivo using a mouse breast cancer cell line 4T1 known to be resistant towards checkpoint inhibition (CPi). Beside tumor cell killing and tumor volume measurement, cytokine expression and immune cell phenotyping was determined. In a co-culture assay with autologous T cells and 4T1 cells, antitumor efficacy weas increased in all combination arms using AZA but not in combination with DEC. The combination of AZA with anti-CTLA4 was significantly better than the respective monotherapies (oneway ANOVA, p&amp;lt; 0.001). This effect was observed as well in the combination with anti-PD1 and AZA, however it was less pronounced (oneway ANOVA, p&amp;lt; 0.01). Of note, AZA restored the CTLA4 expression on CD8+ T cells in vitro, which was reduced by co-culture with tumor cells alone. In the follow-up in vivo experiment we focus on the combination of both CPi with AZA on different treatment schedules in the combination arms. The combination of anti-CTLA4 and AZA in a staggered treatment schedule displayed significant efficacy compared to control (oneway ANOVA, p&amp;lt; 0.05). The implantation of 4T1 reduced the number of T cells in bone marrow (BM), peripheral blood (PB) and spleen of the mice, confirming the immune-suppressive nature of the breast cancer line. This effect was restored under treatment with AZA in monotherapy and combination with CPi. Interestingly AZA reduced the number of immunosuppressive MDSC in BM, spleen and in tumor tissue. Vice versa NK cells were increased in BM, spleen and tumor tissue under treatment with AZA. AZA reduced the number of circulation tumor cells in PB and increased as already shown in vitro the percentage of CD8/CTLA4++ in PB. The PCA analysis of 36 mouse cytokines in vivo displayed two main clusters separated mainly by the presence of absence of AZA in the treatment arms. The combination arms which displayed the highest efficacy showed an increase in CXCL1, G-CSF, IL-6, LIF, M-CSF, MCP-1 (CCL2) and MCP-3 (CCL7) and a decrease of IFN-gamma, CXCL2. This is in line with the more inflammatory pattern of the tumor infiltrating lymphocytes in those groups. In summary, we have strong evidence that AZA influences the immune landscape of breast cancer towards a more inflammatory subtype. The combination with CPi was superior to the monotherapy. In addition, our data indicate that the treatment schedule of the combination might have a crucial influence on efficacy. Citation Format: Hannah Silberzahn, Mattias Bleisch, Anne Löhr, Volker Knauff, Kanstantsin Lashuk, Julia B. Schueler. Identifying most promising combination therapies for immune suppressive breast cancer using a combined in vitro/in vivo approach [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 2630.

Abstract 6907: Micro-implantation of patient tumor samples into the avian embryo, a fast and reliable alternative in vivo technology for preclinical studies on melanoma and follicular lymphoma

Abstract Despite recent efforts to develop reliable and predictive patient-derived cancer models, drug attrition rates in oncology remain high. Moreover, conventional models such as patient-derived xenograft (PDX) mouse models face major cost and time limitations, not supporting real-time clinical decision making. To overcome such limitation, ONCOFACTORY developed a proprietary PDX platform enabling the engraftment of small size tumor biopsy samples within targeted tissue of the avian embryo at early stage of development, to conduct preclinical proof of efficacy studies and provide PDX clinical trial solution helping with patient’s selection prior to clinical phase II/III. On one hand, we performed prospective co-clinical trial aiming to evaluate the utility of the AVI-PDXTM model in predicting the response to standard therapy, consisting of BRAF and MEK inhibitors, for patient with metastatic melanoma harboring BRAF mutations. Skin biopsy samples were implanted into specific tissue driving tumor formation under the skin of avian embryos. On the other hand, we conducted a retrospective cohort study with 20 follicular lymphoma (FL) patient samples divided into “partial” and “complete” responders to the standard immuno-chemotherapy RCHOP regimen to establish FL AVI-PDXTM, and examine sensitivity to RCHOP in ovo. Twenty-four hours post-implantation, avian melanoma and FL replicas were respectively exposed to BRAFi/MEKi or RCHOP and their vehicles, over 24h. Then, embryos were harvested, and tumor response was examined by measuring tumor volume using light sheet microscopy. Alongside, in independent series of avian embryos implanted with FL samples, tumors were harvested for single-cell transcriptomic analyses to explore mechanism of response to RCHOP. For melanoma, we provide the proof of concept that the AVI-PDXTM reliably predict sensitivity or resistance to BRAF and MEK inhibitors within days, matching patient clinical outcome observed in clinic. For FL, we showed that the FL-AVI-PDXTM efficiently captures clinical response to RCHOP in a heterogenous cohort of patients, enabling to discriminate partial and complete responder within short-time frame. Next, we identified a robust genetic signature reflecting exposure of tumoral cells to RCHOP and showed that drug-mediated targeting of one of these genes with a chemotherapy resulted in strong potentiation of RCHOP. Thus, we provide evidence of the high predictive power of the AVI-PDXTM models allowing fast and reproducible generation of tumors replicas from small size patient tumor samples. This places the AVI-PDXTM as a valuable tool for clinical research to rationalize patient inclusion in clinical trials but also for the design of personalized medicine assays. Citation Format: Clelia Costechareyre, Loraine Jarrosson, Marjorie Lacourrege, Romain Teinturier, Julie Caramel, Manon Zala, Stéphane Dalle, Pierre Sujobert, Céline Delloye-Bourgeois, Frédéric Berget, Valérie Castellani. Micro-implantation of patient tumor samples into the avian embryo, a fast and reliable alternative in vivo technology for preclinical studies on melanoma and follicular lymphoma [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 6907.

Abstract 3165: Targeting angiogenesis for improved survival in mantle cell lymphoma

Abstract Mantle cell lymphoma (MCL) is a subtype comprising 6% of all NHL cases and is characterized by overexpression of cyclin D1 due to chromosomal translocation t(11;14) in the nodal MCL subtype. One of the best discriminatory genes between these conventional and indolent MCL tumors is SOX11; in addition, SOX11 has been shown to promote angiogenesis in MCL. Further SOX11 protein expression in MCL patients correlated with increased microvascular density and poor outcomes. Bulk transcriptomics analysis was performed on MCL patients (n=24) and CD19-purified B cells from healthy donors (HD,n=3). To understand the role of the angiogenic process in MCL, we queried 141 genes related to angiogenesis (GO:0001525). Our analysis showed that many genes involved in angiogenesis were predominantly overexpressed in MCL compared to HD, including FLT1 and KDR (p-value;0.05; FC&amp;gt;2). SOX11 has been shown to regulate PDGFA in MCL cell lines. Consistent with this observation, we also see upregulated PDGFA levels in MCL patients. However, PDGFA upregulation was not statistically significant in our analysis. Further expression of VEGFR2 is overexpressed in MCL Patients (n=122) compared to naïve or activated-B cells from HD. We validated that VEGFR2 protein levels were higher in MCL primary patients than in healthy donor PBMC. Further, in two independent cohorts, high VEGFR2 expression shows significant adverse effects on 5-year overall survival (OS). To explore the potential of targeting VEGFR, we utilized lucitanib, which potently and selectively inhibits VEGFRs. Treatment with lucitanib resulted in a dose-dependent decrease in cell viability and cellular death as determined by Annexin PI staining; further, MCL cells treated with lucitanib showed inhibition of autophosphorylation of VEGFR2 and demonstrated PARP cleavage associated with cytotoxicity in-vitro. To assess the role of VEGFR2 inhibitor lucitanib as a single agent in MCL growth in-vivo, we utilized two different murine models of MCLs. First, we used cell-line-derived xenograft (CDX) models of MCL where Jeko-1 and HS5 cells were injected together, followed by treatment (lucitanib;15mg/kg QOD; IP) and measured tumor volume until the ERC of any experimental mice was reached. Kaplan-Meier survival graphs were plotted, demonstrating that lucitanib treatment prolongs survival in-vivo. Further, to confirm if the lucitanib can provide an overall survival benefit in the systemic PDX MCL model, we injected the PDX cells via the tail vein in NSG mice and followed human-B2M levels for disease progression, and overall survival was the endpoint. Lucitanib treatment significantly prolonged median overall survival significantly in the systemic MCL model. Our data demonstrates that targeting angiogenesis in MCL can provide therapeutic benefits, as demonstrated in preclinical MCL models. Citation Format: Satishkumar Singh, Anuvrat sircar, Audrey Odier, Narendranath Epperla, Natarajan Muthusamy, Samir Parekh, Lalit Sehgal. Targeting angiogenesis for improved survival in mantle cell lymphoma [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 3165.

Abstract 1181: Therapeutic efficacy by Streptococcus salivarius as a probiotic in a preclinical model of oropharyngeal carcinoma

Abstract Streptococcus salivarius is a gram-positive, non-pathogenic bacteria found in the oral cavity and upper respiratory tract. This bacterium has been shown to possess antimicrobial properties with the potential to cause activation of natural killer (NK) cells and induction of anti-tumorigenic cytokines such as interferon-gamma and interleukin-12 (IL-12). There is a high abundance of this bacteria in the saliva in oral squamous cell carcinoma patients. Moreover, Streptococcus-reactive cytotoxic T cells were associated with recurrence-free survival. Nevertheless, there is a considerable lack of information regarding the impact of S. salivarius on intratumoral immune responses and its potential as a cancer therapeutic. This study aimed to characterize the immune responses in the tumor microenvironment by S. salivarius in combination with programmed cell death protein 1 (anti-PD-1) therapy and its therapeutic efficacy. We expect that S. salivarius will cooperate with immune checkpoint inhibitors, activating antitumor immune responses. For this project, we used a preclinical murine model where an HPV+ oropharyngeal cancer cell line named mEER was implanted subcutaneously or in the tongue of the mice. We treated with or without S. salivarius and/or anti-PD-1. First, S. salivarius was administered intratumorally on subcutaneous tumors and treated or not with anti-PD-1 therapy administered intraperitoneally. We measured tumor volume and quantified different immune cells by flow cytometry. While anti-PD-1 treated mice showed a continuous increase in tumor volume, the ones treated with anti-PD-1 and S. salivarius reduced the growth rate starting at day 20. Mice treated with anti-PD1 and S. salivarius showed increased CD4+ T cells and myeloid-derived suppressor cells (MDSCs) compared to anti-PD-1 treatment alone. Secondly, we implanted the mice with tongue tumors and applied S. salivarius topically in the oral cavity with or without anti-PD-1. The use of S. salivarius contributed to an increase in CD4+T cells and activation of CD8+T cells and NK cells. The combination of anti-PD-1 with S. salivarius did not further enhance the activation of these cells. Nevertheless, 80% of mice receiving anti-PD-1 with S. salivarius responded to the therapy, whereas 63% responded while receiving only anti-PD-1. In conclusion, Streptococcus salivarius as a probiotic, affected tumor development and immune cell infiltration in oropharyngeal cancer. Future analyses will allow us to explore the effect of the probiotic on the tumor microenvironment and improve colonization in the oral cavity. Citation Format: Jennifer Diaz, Michael Rivera, Kamila A. Del Valle, Edna E. Piñero, Filipa Vitorino, Jorge R. Ortiz, Stephanie M. Estremera. Therapeutic efficacy by Streptococcus salivarius as a probiotic in a preclinical model of oropharyngeal carcinoma [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 1181.

Abstract 3233: EP102: Pharmacological Inhibition of METTL3 causes tumor growth inhibition and prolongs survival in preclinical models of NSCLC, ovarian and squamous cell carcinoma

Abstract METTL3 is the RNA methyltransferase predominantly responsible for the addition of N-6-methyladenosine (m6A), the most abundant epigenetic modification to mRNA. The prevalence of m6A and the activity and expression of METTL3 have been linked to the appearance and progression of numerous hematological and solid tumor cancers. EPICS has discovered and optimized small molecule inhibitors of METTL3 (“M3i”). The aim of the current study is to evaluate the efficacy of M3i in various CDX mouse tumor models. M3i compound potency was evaluated in vitro by measuring enzymatic inhibition of METTL3/14 by scintillation proximity assay (IC50 = 2 nM). The anti-proliferative effects of M3i were measured in cell viability assays following a 72h treatment of A549 (NSCLC, IC50 = 190 nM), SKOV3 (ovarian, IC50 = 9 nM) and FaDu (hypopharyngeal squamous cell carcinoma, IC50 = 24 nM) cells. Complementary data in all three cell lines demonstrates a clear concentration-response for a target engagement biomarker (m6A; IC50 = 2-8 nM, across cell lines) as well as M3i-induced changes in biomarkers of oncogenic drivers. M3i (30 mg/kg, IP, QD) was tested in vivo in mouse models using FaDu (subcutaneous implant) in addition to A549 and SKOV3 (both orthotopic implants); all animal models were performed by LabCorp (MI, USA). Daily M3i treatment significantly prolonged survival in all three disease models consistent with efficacy on tumor growth inhibition as measured by imaging (A549, SKOV3) or direct measurement of tumor volume in the case of subcutaneous implant (FaDu). M3i has previously been shown to be effective in mouse CDX and PDX models of AML. The current results extend the application of METTL3 inhibitors to include the treatment of various types of solid tumors. The efficacy of M3i as a single-agent on tumor growth inhibition and survival advances the validation of METTL3 as a cancer target and provides additional evidence for the applicability of mRNA epigenetic mechanisms to the treatment of solid tumors. Citation Format: Graeme Fraser, Catherine Sorlet, Nicolas Parmentier, Elodie Brunel, Christian Coremans, Sarah Rorive, Anne-France Hartiel, Killian Oukoloff, Guillaume Dutheuil. EP102: Pharmacological Inhibition of METTL3 causes tumor growth inhibition and prolongs survival in preclinical models of NSCLC, ovarian and squamous cell carcinoma [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 3233.

Abstract 4159: Noninvasive measurement of murine glioblastoma in vivo with a benchtop ultrasound instrument

Abstract The purpose of this study was to evaluate a new in vivo approach for rapidly measuring tumor volumes in rodent models for glioblastoma (GBM). GBM is the most common primary brain tumor with &amp;lt;5% of patients surviving &amp;gt;5 years post diagnosis. These poor outcomes underscore the importance of researching new treatment options, and murine models play a vital role in this. Noninvasive measurements of murine GBM tumors are commonly performed using CT and MRI but these tools are costly and time-consuming to use. BLI can quickly detect the presence of GBM cells in vivo, but image data can be challenging to correlate to tumor volume. In this study we demonstrate the feasibility of imaging GBM in vivo through the intact mouse skull using a benchtop robotic ultrasound scanner. This approach could offer researchers a means to quickly size tumors in the murine brain noninvasively. To test feasibility of this approach, a female athymic nude mouse aged 16 weeks was implanted with 2e5 U87 GBM cells in the brain. The tumor was given 25 days to develop prior to ultrasound imaging. After imaging, the brain was harvested for ex vivo validation of tumor presence and volume. Imaging was performed using a Vega ultrasound system (Revvity, Waltham, MA, USA) with the mouse in supine position and fur removed from head with depilatory cream. In vivo imaging consisted of a contrast-enhanced acoustic angiography (AA) scan to assess tumor perfusion. An ex vivo B-mode scan of the brain was collected after sacrificing the animal to validate the location and size of the tumor without interference from the skull. The tumor volumes were measured in each image and compared. 3D segmentations in the ex vivo and in vivo images yielded volumes of 43.1 mm3 and 44.6 mm3, respectively, a 3.5% variance. In the in vivo AA image, the borders of the tumor were adequately well-defined for volume estimation, despite some shadowing from the sagittal suture of the skull. In the B-mode image of the excised brain, the tumor appeared hyperechoic compared to the contralateral hemisphere. Images were acquired in &amp;lt; 2 min. This pilot study demonstrates a potential alternative to CT and MRI for monitoring of GBM volumes in vivo. Citation Format: Thomas M. Kierski, Juan D. Rojas, Morrent Thang, Shawn D. Hingtgen, Phillip G. Durham, Paul A. Dayton, Tomek J. Czernuszewicz, Ryan C. Gessner. Noninvasive measurement of murine glioblastoma in vivo with a benchtop ultrasound instrument [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 4159.

Cumulative cancer locations on prostate biopsy and active surveillance outcomes in the MRI era.

To validate the use of a cumulative cancer locations (CCLO) score, a measurement of tumor volume on biopsy, and to develop a novel magnetic resonance imaging(MRI)-informed CCLO (mCCLO) score to predict clinical outcomes on active surveillance (AS). The CCLO score is a sum of uniquely involved sextants with prostate cancer on diagnostic + confirmatory biopsy. The mCCLO score incorporates MRI findings into the CCLO score. Participants included 1284 individuals enrolled on AS between 1994 and 2022, 343 of whom underwent prostate MRI. The primary outcome was grade reclassification (GR) to grade group ≥2 disease; the secondary outcome was receipt of definitive treatment. Increasing CCLO and mCCLO risk groups were associated with higher risk of GR and undergoing definitive treatment (both p < 0.001). On multivariable analysis, increasing mCCLO score was associated with higher risk of GR and receipt of definitive treatment (hazard ratios [HRs] per 1-unit increase: 1.26 [95% confidence interval [CI]: 1.12-1.41] and 1.21 [95% CI: 1.07-1.36], respectively). The model using mCCLO score to predict GR (c-index: 0.671; 95% CI: 0.621-0.721) performed at least as well as models using the number of cores positive for cancer (0.664 [0.613-0.715]; p = 0.7) and the maximum percentage of cancer in a core (0.641 [0.585-0.696]; p = 0.14). The CCLO score is a valid, objective metric to predict GR and receipt of treatment in a large AS cohort. The ability of the MRI-informed mCCLO to predict GR is on par with traditional metrics of tumor volume but is more descriptive and may benefit from greater reproducibility. The mCCLO score can be implemented as a shorthand, informative tool for counseling patients about whether to remain on AS.

Spot scanning proton therapy for unresectable bulky retroperitoneal dedifferentiated liposarcoma: a case report.

The development of effective treatment strategies for unresectable retroperitoneal sarcoma is desirable. Herein, we suggest that definitive proton therapy (PT) could be a promising treatment option, regardless of the large size of the tumor. A 52-year-old man presented with a discomfort of the lower abdomen. Computed tomography revealed a retroperitoneal tumor, measuring over 20cm in the largest dimensions, which was surrounded by the gastrointestinal (GI) tract. Biopsy revealed dedifferentiated liposarcoma. Neoadjuvant chemotherapy was ineffective, and the tumor was ultimately deemed unresectable. The patient opted to receive PT instead of continuation of chemotherapy. Spot scanning PT (SSPT) at a total dose of 60.8Gy (relative biological effectiveness) in 16 fractions was employed. SSPT administered a dose to the tumor while successfully sparing the surrounding GI tract. He did not receive any maintenance systemic therapy after PT. The tumor gradually shrunk over more than 7 years, with no evidence of recurrence outside the irradiation field. The initial measurable tumor volume of 2925cc decreased to 214cc at the final follow-up, seven and a half years after PT. The patient is alive without any severe complications.

Enhanced Anti-tumor Effect of Flavopiridol in Combination With Gemcitabine in Pancreatic Cancer.

The efficacy of current chemotherapies for pancreatic ductal adenocarcinoma (PDAC) is still unsatisfactory. Flavopiridol inhibits multiple cyclin-dependent kinases, causing cell cycle arrest and inducing cancer cell apoptosis. This study aimed to evaluate the anti-tumor effect of flavopiridol and gemcitabine in PDAC in vitro and in vivo. PANC-1 and MIA PaCa-2 cell lines were treated with gemcitabine and flavopiridol alone, in combination, and sequentially, and cell proliferation, apoptosis, and the cell cycle were evaluated. Proteins related to cell cycle progression (cyclin A, CDK2, E2F-1, and p53) were quantified using western blotting. A xenograft mouse model was generated, and the effects of gemcitabine and flavopiridol, administered alone or in combination, were evaluated by measuring tumor volume and apoptosis degree using the TUNEL assay. Sequential administration of gemcitabine and flavopiridol suppressed PDAC cell proliferation and induced apoptosis. Flavopiridol treatment led to an increase in the number of cells in the S and a decrease in those in the G0/G1 phases. Gemcitabine increased and decreased the number of S- and G2/M-phase cells, respectively. Furthermore, flavopiridol treatment decreased cyclin A and CDK2 expression and increased E2F-1 expression. In a xenograft mouse model, the combined administration of gemcitabine and flavopiridol demonstrated the most significant reduction in tumor volume and induction of apoptosis. Flavopiridol potentiates the anti-tumor activity of gemcitabine by inducing cell cycle arrest and apoptosis. Its synergistic inhibition of PDAC cell proliferation, when combined with gemcitabine, positions flavopiridol as a promising candidate for cancer treatment.

Superior orbital fissure narrowing and tumor-associated pain in spheno-orbital meningiomas.

Spheno-orbital meningiomas (SOMs) represent a distinct subtype of meningioma characterized by their unique multi-compartmental invasion pattern. Previous studies have investigated correlations between SOMs and visual manifestations. However, our comprehension of pain associated with SOMs remains limited. This study aims to provide insight into the pathophysiology underlying SOM-related pain through measurements of tumor volume and superior orbital fissure (SOF) narrowing. This retrospective study included patients who underwent surgical resection of a SOM between 2000 and 2022. Preoperative CT and/or MRI scans were analyzed, and the tumor volume of each segment was measured. Bony 3D reconstructions were used to measure the area of the SOF, and SOF narrowing was calculated. The study cohort included 66 patients diagnosed with SOMs, among which 25.8% (n = 17) presented with pain. Postoperatively, 14/17 (82.4%) of patients reported pain improvement. There was no significant correlation between the total volume or the volume of tumor within each compartment and the presence of pain on presentation (p > 0.05). The median SOF narrowing was significantly different between patients presenting with and without tumor-associated pain with median of 11 mm2 (IQR 2.8-22.3) and 2 mm2 (IQR 0-6), respectively (p = 0.005). Using logistic regression, a significant correlation between the degree of SOF narrowing and the presence of SOM-associated pain on presentation was identified, with an aOR of 1.2 (95% CI 1.12-1.3, p = 0.02). While the exact cause of tumor-associated pain remains unclear, SOF narrowing seems to play a role in pain among SOM patients. Based on the radiological characteristics, SOF neurovascular decompression is recommended in SOM patients.

Autophagy inhibition improves the targeted radionuclide therapy efficacy of 131I-FAP-2286 in pancreatic cancer xenografts

PurposesRadiotherapy can induce tumor cell autophagy, which might impair the antitumoral effect. This study aims to investigate the effect of autophagy inhibition on the targeted radionuclide therapy (TRT) efficacy of 131I-FAP-2286 in pancreatic cancer.MethodsHuman pancreatic cancer PANC-1 cells were exposed to 131I-FAP-2286 radiotherapy alone or with the autophagy inhibitor 3-MA. The autophagy level and proliferative activity of PANC-1 cells were analyzed. The pancreatic cancer xenograft-bearing nude mice were established by the co-injection of PANC-1 cells and pancreatic cancer-associated fibroblasts (CAFs), and then were randomly divided into four groups and treated with saline (control group), 3-MA, 131I-FAP-2286 and 131I-FAP-2286 + 3-MA, respectively. SPECT/CT imaging was performed to evaluate the bio-distribution of 131I-FAP-2286 in pancreatic cancer-bearing mice. The therapeutic effect of tumor was evaluated by 18F-FDG PET/CT imaging, tumor volume measurements, and the hematoxylin and eosin (H&E) staining, and immunohistochemical staining assay of tumor tissues.Results131I-FAP-2286 inhibited proliferation and increased the autophagy level of PANC-1 cells in a dose-dependent manner. 3-MA promoted 131I-FAP-2286-induced apoptosis of PANC-1 cells via suppressing autophagy. SPECT/CT imaging of pancreatic cancer xenograft-bearing nude mice showed that 131I-FAP-2286 can target the tumor effectively. According to 18F-FDG PET/CT imaging, the tumor growth curves and immunohistochemical analysis, 131I-FAP-2286 TRT was capable of suppressing the growth of pancreatic tumor accompanying with autophagy induction, but the addition of 3-MA enabled 131I-FAP-2286 to achieve a better therapeutic effect along with the autophagy inhibition. In addition, 3-MA alone did not inhibit tumor growth.Conclusions131I-FAP-2286 exposure induces the protective autophagy of pancreatic cancer cells, and the application of autophagy inhibitor is capable of enhancing the TRT therapeutic effect.

Contribution of neoadjuvant chemotherapy and radiation therapy (intensity-modulated radiation therapy with concurrent chemotherapy versus stereotactic body radiation therapy alone) on tumor volume regression in patients with borderline resectable or locally advanced pancreatic ductal adenocarcinoma: A single institution experience.

707 Background: Pancreatic ductal adenocarcinoma (PDAC) has a poor prognosis with a minority of patients (pts) eligible for curative resection. Pts with borderline resectable or locally advanced (BR/LA) PDAC frequently receive neoadjuvant chemotherapy (NAC) +/- radiation therapy (RT) to improve resectability. Here, we report the individual contribution of NAC and RT (either intensity modulated RT + concurrent chemotherapy (IMRT+CC) or stereotactic body RT (SBRT) alone) on tumor regression by measuring tumor volumes. Methods: We performed a single institution retrospective review of PDAC pts who underwent resection between 2011-2021 and were part of a tumor biobank registry. Tumor measurements were performed at baseline, post-NAC, and post-RT by five independent, blinded abdominal radiologists. Analyses were performed using paired t-tests, two-proportion z-tests, log-rank tests, and Mann-Whitney U test. Results: We identified 49 BR/LA pts who received NAC followed by RT who had complete pre- and post-treatment imaging. Fifteen pts received IMRT+CC and 28 received SBRT. The effect of NAC on tumor volumes (-29.2% vs -26.3%, p=0.66; mean percent change) and maximum diameter (-9.2% vs -12.0%, p=0.58) was similar within the IMRT+CC and SBRT groups. Both IMRT+CC (-7.12 cm3, p=0.003) and SBRT (-2.70 cm3, p=0.001) resulted in significant tumor regressions. IMRT+CC achieved a significantly greater overall mean percent change in tumor volume (-53.4% vs -28.8%, p=0.024) and maximum diameter (-30.4% vs -16.2%, p=0.020) compared to SBRT. Pts receiving IMRT+CC or SBRT had similar tumor volumes (10.88 vs 11.74 cm3, p=0.87, respectively) and maximum diameter (3.45 vs 3.17 cm, p=0.48) prior to RT. IMRT+CC resulted in improved tumor volume response (&gt;30% regression; 80.0% vs 46.4%; p=0.033) but not an improved response rate by RECIST criteria (46.7% vs 21.4%; p=0.085). Mean resected tumor volumes (by pathological review) for those receiving IMRT+CC (n=9) and SBRT (n=23) were 4.34 vs 13.1 cm3 (p=0.049). The R0 (86.7% vs 85.7%, p=0.93) and N0 (73.3% vs 53.6%, p=0.21) resection rates between the two groups were similar. Compared to SBRT, IMRT+CC resulted in an improved recurrence free survival (RFS; 2.36 vs 1.31 years; p=0.026), but did not meet statistical significance for an overall survival benefit (mOS; 2.85 vs 2.03 years, p=0.19). Conclusions: We found that IMRT+CC yielded superior radiographic volumetric regression and improved RFS but did not significantly impact mOS. Correspondingly, resected tumors from patients treated with IMRT+CC were smaller than those obtained from patients treated with SBRT. The role of IMRT+CC and SBRT in PDAC remains to be clearly defined.

Three-Dimensional Ultrasound Imaging of Retinoblastoma and Its Correlation With Pathology.

Monitoring the response of retinoblastoma to globe-salvaging therapies is based on subjective assessments of changes determined by fundoscopy, ultrasound, and optical coherence tomography. Advances in organ-preserving therapies have increased the need for objective, quantitative estimates of tumor response to treatment. Primary tumor volume is a metric that can be objectively determined as a surrogate measure of treatment response. We evaluated the correlation of objective, quantitative estimates of tumor volume made with two-dimensional (2D) and three-dimensional (3D) ultrasound with gold standard pathological tumor volumes derived by analysis of enucleation specimens. Twelve eyes in 12 patients undergoing primary enucleation were evaluated by 2D and 3D ultrasound during ophthalmic examination under anesthesia prior to enucleation. 2D- and 3D-ultra-sound measurements of tumor volume were both strongly correlated with pathological estimates of tumor volume (r = 0.69, P = 0.018; and r = 0.66, P = 0.027, respectively). 2D- and 3D-ultrasound measurements of retinoblastoma primary tumor volume are highly correlated with pathological estimates. 3D measurements are easy to perform with volumetric probes and consider the irregular morphology of the tumor. Further study should be undertaken to evaluate the performance of these metrics as surrogate markers of tumor response to treatment. [Ophthalmic Surg Lasers Imaging Retina 2024;55:136-140.].

Adoptive immunotherapy with cells from tumor-draining lymph nodes activated and expanded in vitro.

Tumor-draining lymph nodes (tumor-DLNs) provide a rich source of tumor-reactive lymphocytes which can be used in adoptive immunotherapy (AIT) and that circumvent the need to resect autologous tumor, without the challenges and shortcomings associated with using autologous tumor or anti-CD3 monoclonal antibody. Bryostatin/Ionomycin (Bryo/Io) provide a useful method of activating tumor-DLNs such that they can readily be expanded to sufficient numbers to be used in AIT, and growing the tumor-DLN lymphocytes in the gamma chain cytokines IL-7 plus IL-15 is superior to IL-2 in terms of T cell numbers and phenotype. AIT with these cells induces tumor regression and provides protection against metastases and future tumor challenge. Here, we provide a stepwise protocol to sensitize tumor-DLN cells in donor mice, activate tumor-DLN T cells ex vivo using Bryo/Io, expansion of these cells in gamma chain cytokines and adoptive transfer of the expanded cells back into tumor-bearing hosts. Methods relevant to these experiments, such as injecting tumor cells intravenously and monitoring for pulmonary metastases, tumor volume measurement and resection, and use of luciferase-expressing tumor cells to monitor for metastases following resection, are described in detail. The methods outlined herein can be easily adapted to suit similar experiments across multiple tumor cell lines and syngeneic mouse models.