Contralateral Tumor Research Articles

Contralateral metachronous pulmonary carcinoid tumor 7 years after lobectomy

Contralateral metachronous pulmonary carcinoid tumor 7 years after lobectomy

Diagnostic and prognostic role of NLR in testicular cancer.

To summarize the results of available studies for investigating the role of neutrophil to lymphocyte ratio (NLR) in testicular cancer (tCa). The search was conducted on PubMed, Scopus, and Web of Science up to November 21, 2021. Finally, a total of 31 studies were included in this review. NLR was higher in tCa patients compared to healthy controls and benign testis pathologies, and decreased significantly after orchiectomy. An elevated NLR predicts poor prognosis, advanced stage, presence of nodal or distant metastases, contralateral tumor development, lower time-to-cancer specific death, worse OS, and poorer response to chemotherapy. However, NLR could not differentiate between seminomas and non-seminomatous tCa. NLR has a significant diagnostic and prognostic value in tCa.

Cryoablation Does Not Significantly Contribute to Systemic Effector Immune Responses in a Poorly Immunogenic B16F10 Melanoma Model.

Cryoablation is a minimally invasive procedure implemented to destroy solid tumors. It also results in the release of tumor antigens into the systemic circulation. Preclinical studies using immunogenic tumor models have shown that cryoablation evokes antitumor immune responses. The mechanisms by which cryoablation impacts immune responses in poorly immunogenic tumors have not been sufficiently explored. We used a bilateral B16F10 melanoma model devoid of strong immunogenic antigens. Cryoablation-induced effector immune responses were investigated, also in combination with a peritumoral STING agonist and systemic anti-PD-1. Selective immune cell depletion, T-cell migration arrest, in vivo T-cell transplantation, and cryoablation versus surgical removal techniques were used to determine the contribution of cryoablation and immunotherapies to systemic antitumor effector immune responses. Treatment of a tumor with cryoablation + STING agonist + anti-PD-1 resulted in the rejection of unablated, contralateral tumors. Depletion studies demonstrated that tumor rejection is essentially dependent on CD8+ T cells. T-cell arrest in the lymph nodes had no effect on the rejection process. Splenic CD8+ T cells isolated from cryoablation-treated mice with B16F10 melanoma, upon transplantation into melanoma-bearing recipients, did not impact the recipient's tumor growth. Finally, comparison of cryoablation + STING agonist + anti-PD-1 versus surgery + STING agonist + anti-PD-1 in the bilateral tumor model showed no difference in the rejection of contralateral tumors. Cryoablation does not significantly contribute to systemic antitumor effector immune responses in a B16F10 melanoma model. Cryoablation primarily performs tumor debulking, and immunotherapy functions independently of cryoablation in eliciting antitumor effector immune responses.

EphA3-targeted chimeric antigen receptor T cells are effective in glioma and generate curative memory T cell responses

BackgroundHigh-grade gliomas including glioblastoma (GBM) and diffuse midline gliomas (DMG) represent the most lethal and aggressive brain cancers where current treatment modalities offer limited efficacy. Chimeric antigen receptor (CAR) T...

Therapeutic activity of retroviral replicating vector-mediated gene therapy in combination with anti-PD-1 antibody in a murine pancreatic cancer model.

Toca 511, a tumor-selective retroviral replicating vector encoding the yeast cytosine deaminase (yCD) gene, exerts direct antitumor effects through intratumoral prodrug 5-fluorocytosine (5-FC) conversion to active drug 5-fluorouracil by yCD, and has demonstrated therapeutic efficacy in preclinical and clinical trials of various cancers. Toca 511/5-FC treatment may also induce antitumor immunity. Here, we first examined antitumor immune responses activated by Toca 511/5-FC treatment in an immunocompetent murine pancreatic cancer model. We then evaluated the therapeutic effects achieved in combination with anti-programmed cell death protein 1 antibody. In the bilateral subcutaneous tumor model, as compared with the control group, enhanced CD8+ T-cell-mediated cytotoxicity and increased T-cell infiltration in Toca 511-untransduced contralateral tumors were observed. Furthermore, the expression levels of T-cell co-inhibitory receptors on CD8+ T-cells increased during treatment. In the bilateral subcutaneous tumor model, combination therapy showed significantly stronger tumor growth inhibition than that achieved with either monotherapy. In an orthotopic tumor and peritoneal dissemination model, the combination therapy resulted in complete regression in both transduced orthotopic tumors and untransduced peritoneal dissemination. Thus, Toca 511/5-FC treatment induced a systemic antitumor immune response, and the combination therapy could be a promising clinical strategy for treating metastatic pancreatic cancer.

Short-term cultured tumor fragments to study immunotherapy combinations based on CD137 (4-1BB) agonism

ABSTRACT Biomarkers for cancer immunotherapy are an unmet medical need. The group of Daniela Thommen at the NKI recently reported on novel methodologies based on short-term cultures of patient-derived tumor fragments whose cytokine concentrations in the supernatants and activation markers on infiltrating T cells were associated with clinical response to PD-1 blockade. We set up a similar culture technology with tumor-derived fragments using mouse tumors transplanted into syngeneic immunocompetent mice to test an agonist anti-CD137 mAb and its combinations with anti-PD-1 and/or anti-TGF-β. Increases in IFNγ concentrations in the tissue culture supernatants were detected upon in-culture activation with the anti-CD137 and anti-PD-1 mAb combinations or concanavalin A as a positive control. No other cytokine from a wide array was informative of stimulation with these mAbs. Interestingly, increases in Ki67 and other activation markers were substantiated in lymphocytes from cell suspensions gathered at the end of 72 h cultures. In mice bearing bilateral tumors in which one was excised prior to in vivo anti-CD137 + anti-PD-1 treatment to perform the fragment culture evaluation, no association was found between IFNγ production from the fragments and the in vivo therapeutic outcome in the non-resected contralateral tumors. The experimental system permitted freezing and thawing of the fragments with similar functional outcomes. Using a series of patient-derived tumor fragments from excised solid malignancies, we showed IFNγ production in a fraction of the studied cases, that was conserved in frozen/thawed fragments. The small tumor fragment culture technique seems suitable to preclinically explore immunotherapy combinations.

Immune Modulation in Untreated, Contralateral Hepatic Metastases after Yttrium-90 Radioembolization of Microsatellite Stable Colorectal Cancer

PurposeTo assess immunogenic effects in unembolized contralateral tumor after single lobar yttrium-90 transarterial radioembolization (90Y-TARE) of colorectal liver metastases (CRLMs). Material and MethodsThe analysis comprised 10 patients with microsatellite stable (MSS) CRLM scheduled for staged treatment in the prospective AROMA trial. Eligibility criteria included bilobar metastatic disease with >5 lesions without any treatment within 3 weeks. Baseline biopsy was followed by initial 90Y-TARE treatment of 1 liver lobe, followed by a second biopsy of yet untreated tumors in the other liver lobe at a median of 13 days (range, 4–49 days) immediately before second treatment. Tumor biopsies and peripheral blood mononuclear cells (PBMCs) were collected before treatments for immune cell analysis. Patients were stratified into responders and nonresponders based on tumor control or progression during follow-up. ResultsAt baseline, responders (n = 4) displayed lower concentrations of FoxP3+ cells and colocation of CD4+FoxP3+ cells than nonresponders (both P = .02) in tumor tissues. At second biopsy, nonresponders showed a higher CD68+ macrophage density (P = .0014) than responders. Responders displayed fewer CD4+FoxP3+ T cells than CD8+ T cells at all time points (P = .02 and P = .0428). Nonresponders demonstrated a trending increase in CD68+ macrophages (P = .062), as well as a higher CD8+PD1+/CD8+ ratio (P = .062). PBMCs of nonresponders displayed lower CD8+PD1+ T cells and CD8+PD1+/CD8+ ratio at both time points. Conclusions90Y-TARE induces local immunogenic effects in nonexposed MSS CRLM, as well as systemic exhaustion of immune cells in nonresponders. Clinical implications such as a prognostic role or synergism of 90Y-TARE and checkpoint inhibition in MSS CRLM warrant further investigation.

Extent of surgery for unilateral papillary thyroid cancer with nonsuspicious contralateral nodules by ultrasound.

The discussion about surgical treatment of patients with papillary thyroid cancer(PTC) has been an ongoing issue, which is mainly focused on characteristics of tumor, but rarely on nonsuspicious contralateral nodules. We aimed to compare recurrence-free survival(RFS)/progression-free survival(PFS) of unilateral PTC patients with nonsuspicious contralateral nodules after different extents of surgery. Unilateral PTC patients with nonsuspicious contralateral nodules underwent surgery from 2015 to 2017 were enrolled. The association between surgical extent and RFS/PFS was analyzed by Kaplan-Meier method and Cox proportional hazards model. A total of 1293 PTC patients (595[46.0%]TT,523[40.4%]lobectomy+nodule enucleation(LNE),175[13.5%]lobectomy) were analyzed. Patients with a greater surgical extent were more likely to be older, have a greater multifocality of the tumor and contralateral nodules, larger contralateral nodules and primary tumors, and more micro extrathyroidal extension (P < 0.05). After a median follow-up of 45 months, significant growth(>3 mm) was identified in 24 (4.6%) and 19 (10.9%) patients in the LNE and lobectomy group, 7 (1.2%), 14 (2.7%) and 11 (6.3%) structural recurrences and 7 (1.2%), 11 (2.1%) and 7 (4.0%) progression in disease were identified in the TT, LNE and lobectomy groups, respectively. Unadjusted and adjusted RFS/PFS were significantly worse for patients treated with lobectomy than for those who underwent LNE or TT(3-year RFS, 95.5%, 98.2% vs. 99.0%; 3-year PFS, 97.9%, 98.9% vs. 99.0%, P < 0.05), but difference in PFS between LNE and TT lost statistical significance (unadjusted P = 0.226, adjusted P = 0.150). Due to subtle changes in nodules and acceptable prognosis, lobectomy is a considerable option for unilateral PTC patients with nonsuspicious nodules, when a similar prognosis to TT is expected, LNE may be an effective alternative to optimize quality of life.

Abstract PO5-22-04: Genomic analysis of local recurrences following risk adapted breast radiotherapy in the IMPORT trials defines 'true recurrences' and 'new primaries'

Abstract Background: Most ipsilateral breast tumor recurrences (IBTR) following breast conserving surgery occur near the tumor bed (Veronisi et al, Ann Oncol 2001) and are considered to represent ‘true recurrence’ (derived from residual malignant cells of the index cancer). A smaller number occur elsewhere in the breast and are thought to be ‘new primaries’ (independently occurring cancer). The IMPORT LOW (Coles et al, The Lancet 2017) and IMPORT HIGH (Coles et al, The Lancet 2023) trials investigated adaptation of radiotherapy dose-volume to this spatially varying risk, testing partial breast irradiation and simultaneous integrated boost in patients with tumors at low and high risk of IBTR respectively. We analysed genomic relationships between index cancers and recurrences in these trials, to ascertain the frequency of true recurrences and unrelated new primaries, and their spatial distribution. Methodology: FFPE blocks were obtained from 137 patients who developed subsequent ipsi- or contralateral breast cancer: 66 from IMPORT HIGH and 71 from IMPORT LOW (4 with bilateral second cancers). DNA extracted from index and subsequent cancers underwent shallow whole genome sequencing (sWGS) using the Illumina NovaSeq 6000 system. Copy number profiles were derived from sWGS data using the R package QDNAseq(Scheinin et al, Genome Res 2014); those that failed QC criteria were removed. Relatedness of tumor pairs was determined using the R package Breakclone (Lips et al, Nat Genet 2022). This approach uses individual copy number aberration breakpoint position rather than events at chromosomal arm level. The p value cutoff for relatedness was 0.01; values between 0.01 and 0.05 were considered ambiguous. Researchers were blinded to clinical information prior to results. Results: In 80/137 tumor pairs both copy number profiles met QC criteria and clonal relationship could be ascertained. In total 26/80 were considered related, 20/80 ambiguous and 34/40 non-related (Table 1). 16/26 ipsilateral subsequent cancers in IMPORT HIGH were clonally related to the primary tumor and could be considered true recurrences. In 5/26 it was impossible to accurately call clonality as pairs shared only common copy number changes such as 1q or 8q gain and 16q loss. 5/26 were considered new primaries. In the lower risk IMPORT LOW cohort, subsequent cancers appear to have similar chances of being related or independent. As expected, most contralateral tumors in IMPORT LOW showed no evidence of a clonal relationship to the index tumors. In both trials an ambiguous subgroup of pairs shared some common copy number changes suggesting similar phenotype.5/14 contralateral tumors in IMPORT HIGH, in which some women were also at high risk of systemic relapse, shared very similar copy number profiles to the index tumor and may be metastases rather than new primaries. Discussion: A considerable number of tumors classed as IBTR appear genomically unrelated to the index cancer particularly in low risk cancer; this biology is relevant to clinical management both initially and at ‘recurrence’. The finding that 5/14 contralateral cancers in the high risk group appear to be clonally related suggests that some may be metastases. Results are being confirmed by targeted sequencing and will be correlated with recorded spatial and clinicopathological data and patient outcome. Future work will analyse spatial relationships more precisely using deformable image registration. *From the 77 patients with baseline circulating tumor DNA samples, 2 patients were excluded because their samples failed during assay quality control. Table. PIK3CA and ESR1 alterations detected in circulating tumor DNA at baseline and post abemaciclib treatment Citation Format: Sara Lightowlers, Maria Roman-Escorza, Elena Provenzano, Judith Bliss, Jason Carroll, H Y Charlie Chan, Clare Griffin, Joanne Haviland, Monica Jefford, Anna Kirby, Navita Somaiah, Mark Sydenham, Jenny Titley, John Yarnold, Charlotte Coles, Elinor Sawyer. Genomic analysis of local recurrences following risk adapted breast radiotherapy in the IMPORT trials defines 'true recurrences' and 'new primaries' [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 PO5-22-04.

Abstract PO1-26-06: The effect of localized radiotherapy in combination with chemoimmunotherapy in a humanized triple-negative breast cancer mouse model

Abstract Background: Metastatic triple-negative breast cancer (TNBC) is an aggressive sub-type of breast cancer that is challenging to treat. While the addition of immunotherapy (IT) with pembrolizumab (pembro) to chemotherapy prolongs overall survival in patients with programmed death-ligand 1 positive (PD-L1+) TNBC, few patients obtain long-term benefit. Radiotherapy (RT) can stimulate cellular damage, release of tumor antigens and promote the T cell anti-tumor response including at distant sites (abscopal response) when used with IT. The purpose of this study was to investigate the combination of RT with pembro and paclitaxel (pac) in a TNBC humanized mouse model. Methods: Human Immune System BRGS (BALB/c, Rag2-/-, IL2RγC-/-, NODSIRPa ) mice were engrafted with TNBC MDA-MB-231 cells in bilateral flanks. Treatments included: vehicle, pac 10 mg/kg intra-peritoneal (IP) weekly, pembro 15 mg/kg IP weekly, and RT 8 Gy x 3 fractions every other day the first week of treatment to one-sided tumors (contralateral tumors received no RT). Mice were treated and analyzed in the following groups: vehicle, pac + pembro, RT + pac, and RT + pac + pembro. Treatments began when tumors reached 100-300 mm3 and tumors were measured twice weekly. At the end of study, sera, lymph nodes (LNs), spleen, and tumor tissue were collected for immunohistochemistry, single cell suspensions, and flow cytometry analysis for immune cell populations. Results: All treatment arms resulted in a decrease in tumor volume when compared to vehicle with the greatest reduction in the RT + pac and RT + pac + pembro arms. Combination therapy with RT + paclitaxel (p=0.0002) and RT + pac + pembro (p=0.008) resulted in a statistically significant decrease in specific growth rate (SGR) when compared to vehicle. An abscopal effect was not observed in the non-RT tumors compared to RT-tumors in either group. RT + pembro was associated with an increase in hCD45 T cells in LNs and spleens but not in tumors. In mice that received RT, a decrease was noted in HLA-ABC class I and Intermediate Class II major histocompatibility complex (MHC). In addition, RT-tumors had reduced expression of PD-L1 and polio virus receptor (PVR) and increased expression of PD-1. The percentage of interferon gamma (IFNg+), tumor necrosis factor alpha (TNFa+) CD8+ T cells increased with radiation. This percentage was the highest in the triplet therapy with RT+ pembro + pac. Conclusion: Combination treatment with RT + immunochemotherapy resulted in a significant increase in anti-tumor activity when compared to immunochemotherapy alone, however, an abscopal effect was not observed in contralateral non-RT tumors. RT resulted in down-regulation of immune inhibitory receptors and tumor MHC. Citation Format: Anna Schreiber, Stacey Bagby, Stephen Smoots, Adrian Dominguez, Christine Fisher, Julie Lang, Todd Pitts, Jennifer Diamond. The effect of localized radiotherapy in combination with chemoimmunotherapy in a humanized triple-negative breast cancer mouse model [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 PO1-26-06.

Irreversible electroporation promotes a pro-inflammatory tumor microenvironment and anti-tumor immunity in a mouse pancreatic cancer model.

Pancreatic cancer is a significant cause of cancer-related mortality and often presents with limited treatment options. Pancreatic tumors are also notorious for their immunosuppressive microenvironment. Irreversible electroporation (IRE) is a non-thermal tumor ablation modality that employs high-voltage microsecond pulses to transiently permeabilize cell membranes, ultimately inducing cell death. However, the understanding of IRE's impact beyond the initiation of focal cell death in tumor tissue remains limited. In this study, we demonstrate that IRE triggers a unique mix of cell death pathways and orchestrates a shift in the local tumor microenvironment driven, in part, by reducing the myeloid-derived suppressor cell (MDSC) and regulatory T cell populations and increasing cytotoxic T lymphocytes and neutrophils. We further show that IRE drives induce cell cycle arrest at the G0/G1 phase in vitro and promote inflammatory cell death pathways consistent with pyroptosis and programmed necrosis in vivo. IRE-treated mice exhibited a substantial extension in progression-free survival. However, within a span of 14 days, the tumor immune cell populations reverted to their pre-treatment composition, which resulted in an attenuation of the systemic immune response targeting contralateral tumors and ultimately resulting in tumor regrowth. Mechanistically, we show that IRE augments IFN-γ signaling, resulting in the up-regulation of the PD-L1 checkpoint in pancreatic cancer cells. Together, these findings shed light on potential mechanisms of tumor regrowth following IRE treatment and offer insights into co-therapeutic targets to improve treatment strategies.

Abstract 3845: High-intensity focused ultrasound ablation increases tumor specific lymphocytes in prostate cancer

Abstract The treatment of localized prostate cancer has been revolutionized by High-Intensity Focused Ultrasound (HIFU), an FDA-approved procedure. Thermal HIFU achieves the destruction of tumor tissue through the noninvasive delivery of ultrasonic energy, causing rapid heating of the targeted area. Given that prostate cancer typically exhibits a low presence of tumor-infiltrating lymphocytes crucial for antitumor immunity, this study aimed to investigate whether HIFU has the potential to activate antitumor immunity and enhance lymphocyte infiltration within the tumor. RM1 tumors were implanted on the flanks of syngeneic C57BL/6J mice, with one tumor subjected to HIFU treatment. The growth of the contralateral tumor was monitored, and at the end of the study, tumors were collected to evaluate immune cell infiltration. Blood samples were obtained from patients both before and after prostatectomy or HIFU treatment. Peripheral blood mononuclear cells (PBMCs) were then isolated to analyze the immune cell population. In murine experiments, the application of HIFU to one tumor resulted in a reduction in the growth of the contralateral (untreated) tumor, specifically when the contralateral tumor was of the same type, but not when it was a different tumor type. Notably, HIFU led to an augmented infiltration of CD4+ and CD8+ lymphocytes into the contralateral (untreated) tumor. Depletion studies further affirmed that the antitumor immune response triggered by HIFU relies on CD4+ and CD8+ lymphocytes. In human subjects, HIFU was observed to elevate the CD4+ and CD8+ lymphocyte populations in PBMCs. HIFU induces a potent antitumor immune response that effectively inhibits the progression of murine prostate tumors. This immune response is contingent upon CD4+ and CD8+ lymphocytes. HIFU demonstrates significant promise in activating antitumor immune responses in patients diagnosed with prostate cancer. Subsequent research endeavors should delve into models of metastatic prostate cancer, exploring the potential synergy of cytoreductive prostate tumor ablation with systemic immunotherapies to elicit a robust and comprehensive antitumor immune response. Citation Format: Shengchen Su, Yanping Wang, Eric M. Lo, Hyung L. Kim. High-intensity focused ultrasound ablation increases tumor specific lymphocytes in prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3845.

Abstract 3728: Treating pancreatic cancer with "armed" oncolytic adenoviruses and adoptive T-cell therapy

Abstract Introduction: Pancreatic ductal adenocarcinoma (PDAC) is the third leading cause of cancer-related mortalities and is projected to become second by 2030. Although major advancements in cancer treatments have improved outcomes for many cancers, the survival rate for PDAC has not improved in nearly four decades. Two primary features make PDAC refractory. First, the highly immunosuppressive tumor microenvironment (TME) plays a crucial role in impeding the innate and effector arms of the immune system to prevent anti-tumor responses. Second, desmoplasia causes formation of fibrotic tissue within and around tumor tissue, which creates a physical barrier for infiltration of anti-tumor immune cells and therapeutics. The goal of this project is to develop viro-immunotherapies against PDAC that target the immunosuppressive TME and desmoplasia by utilizing “armed” oncolytic adenoviruses (OAds) and adoptive T-cell therapy (CAR T-cells). Three transgenes were selected to “arm” the OAd constructs: i.) TGF-beta blocker, ii.) interleukin-7 (IL-7), and iii.) interferon gamma (IFN-gamma). Methods: “Armed” replication-deficient adenovirus (Ad) constructs were first generated to isolate transgene function from oncolytic activity. Each transgene was individually cloned into the E1 region of Ad-5 (WT). Viral particles were amplified in 293 cells and purified via ultracentrifugation using a CsCl gradient. Anti-tumor effects were measured using a syngeneic mouse model. C57BL/6 mice were subcutaneously injected with KPC cells (mouse PDAC cell line), and tumors were treated with Ad constructs via intratumoral injection. Tumors were harvested at various time points and stained for immune cell infiltration and fibrosis. Mesothelin-directed CAR T-cells (meso-CARTs) were injected (tail vein) into NSG mice bearing subcutaneous Panc1 tumors after intratumoral injection of Ad constructs. Results: Tumor growth was significantly inhibited in syngeneic mouse models in the presence of each “armed” Ad construct. Furthermore, significant tumor infiltration of anti-tumor immune cells was induced upon treatment as well as a decrease in fibrosis. Abscopal effects were observed on contralateral tumors after injection of ipsilateral tumors as well as an increase in tumor infiltration of anti-tumor immune cells. Finally, combining meso-CARTs with IFN-gamma-expressing Ad induced the greatest anti-tumor responses. Conclusions: PDAC is very resistant to conventional therapeutics, so utilizing combination strategies seems essential. The findings in this study have broad implications in the field of pancreatic cancer by shedding light on how the TME can be manipulated to enhance anti-tumor effects to aid in the development of more efficient therapeutics against PDAC. Moreover, therapeutics inducing abscopal effects should be highly valued because most PDAC patients die from metastasis. Citation Format: Brett L. Roach, Masato Yamamoto. Treating pancreatic cancer with "armed" oncolytic adenoviruses and adoptive T-cell therapy [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 3728.

Abstract 6319: Characterization of AB-1015 logic-gated CAR induction (ON kinetics), receptor turnover (OFF kinetics), and logic gate sensitivity to ALPG/P and MSLN

Abstract CAR T cell activity in solid tumors is limited, in part, by off-tumor toxicity. To address this obstacle, AB-1015 contains an “AND” logic gate, consisting of a priming receptor (PrimeR) and an inducible chimeric antigen receptor (CAR) that is upregulated by PrimeR activation. The AB-1015 logic gate targets ALPG/P and MSLN, which are coexpressed in ovarian tumors but not normal tissues. AB-1015 CAR induction within the tumor is expected to be a dynamic process influenced by multiple factors, including antigen density, target cell abundance, as well as tumor microenvironmental factors. To characterize CAR induction and receptor turnover, we developed an in vitro assay with plate-bound ALPG to induce CAR. CAR induction occurred quickly in response to ALPG priming, with most ICT cells expressing CAR within 24 hrs, and plateaued by 72 hrs. Once removed from ALPG, CAR expression returned to baseline within 96 hrs. Similar to conventional CAR T cells, the presence of the cytolytic target antigen (MSLN) was expected to increase the rate of CAR turnover on AB-1015. To assess this, we measured the CAR functional half-life of AB-1015 cells once removed from ALPG priming. The cytotoxic activity of AB-1015 cells rapidly decreased in the absence of ALPG, reaching baseline within 24 hrs. Of note, our in vitro assay did not result in 100% CAR induction from all PrimeR+ AB-1015 cells. To understand whether this reflected biology versus a limitation of our in vitro assay, we conducted a CAR induction, sorted the CAR- cells, then performed a second induction. ICT cells that did not express CAR after the first induction were shown to be able to induce CAR during the second induction assay, thereby demonstrating that all PrimeR+ ICT cells have the potential to induce CAR. To assess the sensitivity of AB-1015 for low density ALPG/P and MSLN, isogenic cell lines were engineered to express each antigen at variable levels. In co-culture, AB-1015 was able to prime and kill targets expressing ALPG and MSLN at or below the limit of detection using immunohistochemistry. In light of these observations, the specificity of AB-1015 was verified using a dual flank in vivo model where one tumor expressed both ALPG and MSLN, and the contralateral tumor expressed MSLN alone. While robust anti-tumor activity was observed against the ALPG+/MSLN+ tumor, no activity was detected against the MSLN+ tumor. In summary, AB-1015 CAR induction and receptor turnover kinetics is a dynamic process. A reductionist in vitro model system was developed, enabling analysis of CAR induction and receptor turnover. Importantly, we demonstrated that all PrimeR+ ICT cells have the potential to induce CAR. Finally, the in vivo specificity of AB-1015 for ALPG+/MSLN+ tumors was established using a dual flank specificity model. Together, these data support the continued development of AB-1015 in a phase I clinical trial (NCT05617755). Citation Format: Xinyan Tang, Marvin Chew, Rakesh Sudhakar, Hongruo Yun, Doreen Sakamoto, Vibhavari Sail, Amanda Fearon, Jasper Williams, Jun Feng, Stephen Santoro. Characterization of AB-1015 logic-gated CAR induction (ON kinetics), receptor turnover (OFF kinetics), and logic gate sensitivity to ALPG/P and MSLN [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 6319.

Abstract 6662: Modified oncolytic viruses with immunomodulatory genes enhance anti-tumor efficacy

Abstract While chemotherapy and radiotherapy are considered first-line treatments for most cancers, their significant side effects have prompted ongoing innovation and the discovery of novel cancer treatment strategies. Oncolytic viruses (OV) as one of the most advanced cancer treatments have shown promising results in treating otherwise untreatable types of cancer in last two decades. After selectively targeting tumor cells, OVs could directly kill cancer cells, and induce a powerful anti-cancer immunity. Recently, we evaluated the anti-tumor effect of a modified OV (mOV) in vitro and in vivo. Firstly, the expression of the transgenes were validated on different tumor cells by FCM and ELISA assay. The results showed that a susceptible cell line was identified which has high expression efficiency of transgenes. In order to evaluate the cytotoxicity of mOV, CCK-8 assay was performed on 30+ tumor cell lines. It indicated that mOV has stronger killing effect on susceptible cells through inducing cellular apoptosis. To further evaluate the biological activity of the transgenes on immune cells, mOV-infected tumor cells and supernatant were collected to treat T cell, NK cell or MoDC. The results demonstrated that mOV infection could significantly promote T cell and NK cell activation, and increase the maturation of moDC cells, resulting in the secretion of IFN-γ by CD8+ T cells. In the in vivo efficacy study, MC38 syngeneic model was used to test the anti-tumor effect of mOV. The result showed that mOV could significantly inhibit the growth of the treatment side tumor, and reduce the contralateral tumor to a certain extent. Blood FCM analysis revealed that the percentage of IFN-γ+CD3+, IFN-γ+CD4+ and IFN-γ+CD8+ T cells were markedly increased by mOV treatment compared with vehicle. In addition, IHC analysis of tumor showed that mOV treatment could promote the infiltration of CD4+, CD8+ and CD86+ positive cells. To study the safety or PK of the mOV, viral bio-distribution and shedding assay were performed to detect viral genome at different tissues or excreta. It indicated that mOV was almost undetectable or at very low levels for 14 days after administration. In conclusion, our study revealed that modified OVs with immunomodulatory genes have good anti-tumor efficacy both in vitro and in vivo, which could obviously induce the activation of several immune cells. Moreover, the mOV genome was almost undetectable or at very low levels in mouse tissues and excreta. Keywords: Oncolytic virus, immunotherapy, immunomodulatory genes Citation Format: Zhongbao Song, Guangxu Ding, Anran Xia, Wanqing Ma, Qiuhong Li, Chenhui He, Xu Chen, Zhixiang Zhang, Qingyang Gu. Modified oncolytic viruses with immunomodulatory genes enhance anti-tumor efficacy [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 6662.

Comparison of Clinicopathological Features of Pleomorphic and Invasive Lobular Breast Carcinomas.

Accounting for about 15% of invasive lobular carcinomas and 1% of breast carcinomas, pleomorphic lobular carcinoma is known to be a rare histological subtype of invasive lobular carcinoma. Yet, it is more aggressive and produces a worse prognosis than other breast cancers. Ultimately, the present study compares the clinicopathological features of pleomorphic and invasive lobular breast carcinomas. In the study, we retrospectively evaluated the data of 262 patients with histological subtypes of classical and pleomorphic lobular cancers having been recruited for surgical operations. After resorting to Kolmogorov-Smirnov and Shapiro-Wilk tests to check the normality of distribution, the categorical and continuous variables were compared between the groups using the chi-square test and independent samples t test, respectively. In all analyses, we considered a P-value of <.05 to be statistically significant. Our findings revealed that the groups with lobular and pleomorphic groups significantly differed by Ki-67 value, estrogen receptor negativity, grade, multicentricity, multifocality, surgical margin positivity, completion mastectomy, and metachronous contralateral tumor (P < .05). We discovered that pleomorphic type was associated with higher grades, estrogen receptor negativity, and Ki-67 expression. The incidence of metachronous breast cancer was high in the pleomorphic group, which may be a noteworthy finding to be considered in follow-ups. In addition, the high rates of multicentricity and multifocality of tumors in the pleomorphic group may be associated with increased surgical margin positivity and a higher likelihood of mastectomy. In a nutshell, our findings may guide patients and surgeons regarding the type of intervention and reconstruction options to be adopted in prospective surgeries.

Prediction of bilateral thyroid carcinoma and lateral cervical lymph node metastasis in PTC patients with suspicious thyroid nodules.

This study aimed to evaluate the factors associated with bilateral papillary thyroid carcinoma (PTC) and lateral cervical lymph node metastasis (LLNM) in patients with suspicious unilateral PTC. This study analyzed patients with suspicious unilateral PTC who were enrolled in a university hospital between 2016 and 2019 in Zhejiang, China. Using logistic regression, the study examined the factors associated with bilateral PTC and LLNM in demographic data, anthropometric measurements, lifestyle factors, medical history, preoperative diagnostic tests, and histopathological factors. A total of 256 patients, with a mean age of 49 years, were enrolled. Bilateral PTC was associated with multifocality (aOR: 5.069, 95% CI: 2.440-10.529, P < 0.001), and contralateral nodule in the upper (aOR: 9.073, 95% CI: 2.111-38.985, P = 0.003) and middle (aOR: 9.926, 95% CI: 2.683-36.717, P < 0.001). LLNM was positively associated with bilateral PTC (aOR, 4.283, 95% CI: 1.378-13.308, p = 0.012), male (aOR, 3.377, 95% CI: 1.205-9.461, P = 0.021), upper location of carcinoma (aOR, 3.311, 95% CI: 1.091-10.053, p = 0.035), and punctate echogenic foci (aOR, 3.309, 95% CI: 1.165-9.394, P = 0.025). Contralateral maximal nodule in the upper (aOR: 0.098, 95% CI: 0.015-0.628, p = 0.014), middle (aOR: 0.114, 95% CI: 0.033-0.522, p < 0.001), and lower (aOR, 0.028, 95% CI: 0.003-0.276, P = 0.002) location were inversely associated with LLNM. Upper and middle location of contralateral nodule and tumor multifocality predicted the risk bilateral PTC. Bilateral PTC, male, upper tumor location, punctate echogenic foci and contralateral nodule location in the entire lobes were independent predictors for LLNM.

Abstract B080: AB-1015, an Integrated Circuit T (ICT) cell therapy containing an ALPG/MSLN logic gate and FAS/PTPN2 shRNA-miR, for the treatment of ovarian cancer

Abstract B080: AB-1015, an Integrated Circuit T (ICT) cell therapy containing an ALPG/MSLN logic gate and FAS/PTPN2 shRNA-miR, for the treatment of ovarian cancer

Three Cases of Bilateral Metachronous Testicular Tumors

We present three cases of bilateral metachronous testicular tumors. The patient in case 1 had a history of left orchiectomy for undescended testis at the age of 19. The pathological findings revealed germ cell neoplasia in situ. Twenty-four years later (age＝43), he was diagnosed with right testicular tumor with lymph node and lung metastasis (stage IIIc). Right orchiectomy was performed, and the pathological finding showed nonseminomatous germ cell tumor. He underwent chemotherapy, followed by lymph node dissection and lung metastasectomy. The patient in case 2 had a history of left orchiectomy for testicular tumor at the age of 41. The pathological finding of the left testis revealed seminoma (stage IA). Nineteen years later (age＝60), he was diagnosed with right testicular tumor and underwent right orchiectomy. Herein, the pathological finding showed seminoma (stage IA). The patient in case 3 had a history of right orchiectomy for testicular tumor at the age of 25. The pathological findings revealed seminoma (stage IS), and he underwent adjuvant radiation of the para-aortic field without subsequent recurrence. Fourteen years later (age＝39), he was diagnosed with left testicular tumor and underwent left orchiectomy. The pathological finding revealed seminoma (stage IB). The patient underwent adjuvant carboplatin monotherapy to prevent recurrence. Due to the long interval between the occurrence of bilateral metachronous testicular tumors (mean＝19 years ; three cases), long-term observation is necessary to detect the possible occurrence of contralateral testicular tumors. Contralateral testicular biopsy might be considered at the time of orchiectomy for unilateral testicular tumor if associated with testicular atrophy and/or a history of undescended testis.

Potentiating the radiation-induced type I interferon antitumoral immune response by ATM inhibition in pancreatic cancer.

Radiotherapy induces a type I interferon-mediated (T1IFN-mediated) antitumoral immune response that we hypothesized could be potentiated by a first-in-class ataxia telangiectasia mutated (ATM) inhibitor, leading to enhanced innate immune signaling, T1IFN expression, and sensitization to immunotherapy in pancreatic cancer. We evaluated the effects of AZD1390 or a structurally related compound, AZD0156, on innate immune signaling and found that both inhibitors enhanced radiation-induced T1IFN expression via the POLIII/RIG-I/MAVS pathway. In immunocompetent syngeneic mouse models of pancreatic cancer, ATM inhibitor enhanced radiation-induced antitumoral immune responses and sensitized tumors to anti-PD-L1, producing immunogenic memory and durable tumor control. Therapeutic responses were associated with increased intratumoral CD8+ T cell frequency and effector function. Tumor control was dependent on CD8+ T cells, as therapeutic efficacy was blunted in CD8+ T cell-depleted mice. Adaptive immune responses to combination therapy provided systemic control of contralateral tumors outside of the radiation field. Taken together, we show that a clinical candidate ATM inhibitor enhances radiation-induced T1IFN, leading to both innate and subsequent adaptive antitumoral immune responses and sensitization of otherwise resistant pancreatic cancer to immunotherapy.