Mixed Tumor Research Articles

Ameloblastic fibroma of mandible- A case report

Ameloblastic fibromas are uncommon mixed benign odontogenic tumors with an overall prevalence of less than 5%. Asymptomatic uniloular lesions can be effectively managed with curettage, multilocular lesions require meticulous enucleation to avoid the risk of relapse. We report a case successful management of an asymptomatic multilocular ameloblastic fibroma with 2 years of follow up.

Gastric mixed neuroendocrine non-neuroendocrine neoplasms.

The uncommon tumour known as gastric mixed neuroendocrine-non-neuroendocrine neoplasms (G-MiNENs) is made up of parts of neuroendocrine carcinoma and adenocarcinoma. The biological and clinical features are different from those of gastric adenocarcinoma. Their pathophysiology, diagnostic standards, and clinical behaviour have all been the subject of lengthy debates, and their nomenclature has undergone multiple changes. Its emergence has created new challenges in the classification and diagnosis of gastric tumours. This review will update information on the topic, covering molecular aspects, diagnostic criteria, treatment, and prognostic factor discovery. It will also provide a historical context that will aid in understanding the evolution of the idea and nomenclature of mixed gastric tumours. Additionally, it will provide the reader a thorough understanding of this difficult topic of cancer that is applicable to real-world situations.

Abstract CT279: DareonTM-5: An open-label phase 2 trial of BI 764532, a DLL3-targeting T-cell engager, in patients (pts) with relapsed/refractory small cell lung cancer or other neuroendocrine carcinomas

Abstract Background: Small cell lung cancer (SCLC), large cell neuroendocrine carcinoma (LCNEC) of the lung, and extrapulmonary NEC (epNEC) are difficult-to-treat, aggressive tumors with limited treatment options. Purpose: Many pts relapse and have poor outcomes after standard of care platinum-based chemotherapy ± immunotherapy, underscoring the need for better therapies. BI 764532, a humanized IgG-like T-cell engager, binds to delta-like ligand 3 (DLL3) on the cell surface of these tumors and on CD3 on T cells, consequently promoting T-cell-mediated cytotoxicity. In an ongoing first-in-human trial, BI 764532 exhibited efficacy and manageable tolerability in pts with DLL3-positive SCLC, LCNEC of the lung, and epNEC (NCT04429087). We describe a planned phase 2 dose optimization trial to assess safety/efficacy of 2 different doses of BI 764532 monotherapy in pts with progressive/relapsed SCLC, epNEC, or LCNEC of the lung (NCT05882058). Experimental design: The trial will recruit adult pts (n=~120; ~70 sites; ~15 countries) with pathologically confirmed relapsed/refractory SCLC, epNEC, or LCNEC of the lung who have received ≥2 (SCLC) or ≥1 (epNEC/LCNEC) prior lines of therapy, including ≥1 platinum-based regimen. Pts with mixed tumor histology are permitted if the SCLC/NEC component is predominant (≥50% of tumor tissue). Pts will be randomized 1:1 to receive 1 of 2 dose levels of IV BI 764532 (3-week cycles) stratified by tumor type (n=~60/arm). Treatment will continue until disease progression, undue toxicity, withdrawal of consent or any other documented criteria for stopping treatment (maximum treatment duration: 36 months). 2 interim dose-selection analyses are planned after 30 pts per dose have been followed for ≥6 and ≥12 weeks or have stopped treatment. A third interim efficacy analysis will be conducted when 60 pts per dose have been followed for ≥12 weeks or have stopped treatment. Key exclusion criteria: Eastern Cooperative Oncology Group performance status ≥2; untreated/symptomatic brain metastases or leptomeningeal disease; active/history of interstitial lung disease/pneumonitis; previous DLL3-targeting treatment; treatment with other anticancer drugs <4 weeks prior to first administration of BI 764532; unresolved toxicity from prior treatment; immunodeficiency diagnosis; intake of immunosuppressive therapy ≤7 days prior to first administration of BI 764532. Primary endpoints: objective response via Response Evaluation Criteria in Solid Tumors v1.1; occurrence of treatment-emergent adverse events (TEAEs). Secondary endpoints: duration of objective response, progression-free survival, disease control, overall survival, patient-reported outcomes, and TEAEs leading to discontinuation. Further endpoints: pharmacokinetics, and prespecified and exploratory biomarker analysis. Citation Format: Valentina Gambardella, Alastair Greystoke, Martin Reck, Meiruo Liu, Martha Mueller, Ulrich Duenzinger, Emily B. Bergsland, Taofeek Owonikoko. DareonTM-5: An open-label phase 2 trial of BI 764532, a DLL3-targeting T-cell engager, in patients (pts) with relapsed/refractory small cell lung cancer or other neuroendocrine carcinomas [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 CT279.

Chondroid Syringoma of the Upper Eyelid in an Elderly Female

Chondroid syringoma is a rare benign mixed skin tumour. Though head and neck region is commonly involved, we report a rare case of a 55-year-old female who presented with a slow growing, painless swelling over the left upper eyelid and history of surgical excision of 2 such swellings in the arm 3 years back. FNAC and excision biopsy revealed Chondroid syringoma. Considering the chances of malignant transformation and recurrence, chondroid syringoma should always be a differential diagnosis in eyelid masses and total excision with long term follow-up should be done.

Recent Status of Phase I Clinical Trials for Brain Tumors: A Regulatory Science Study of Exploratory Efficacy Endpoints

BackgroundAppropriate exploratory efficacy data from Phase I trials are vital for subsequent phases. Owing to the uniqueness of brain tumors (BTs), use of different strategies to evaluate efficacy is warranted. We studied exploratory efficacy evaluation in Phase I trials involving BTs.MethodsUsing Clarivate’s Cortellis™, 42 Phase I trials of BT interventions conducted from 2020 to 2022 were analyzed for efficacy endpoints, which were set as primary endpoints (PEs) or secondary endpoints (SEs). Additionally, these metrics were compared in two subgroups: trials including only BTs (Group-A) and those including BTs among mixed solid tumors (Group-B).ResultsSelected studies included a median of 1.5 PEs (range, 1–6) and 5 SEs (range, 0–19). Efficacy endpoints were included as PEs and SEs in 2 (5%) and 31 (78%) trials, respectively. Among the latter 31 trials that included 94 efficacy endpoints, 24, 22, 20, 9, and 8 reflected overall response rate (ORR), progression-free survival (PFS), overall survival (OS), duration of response (DOR), and disease control rate (DCR), respectively. ORR for BT was determined using various methods; however, the Response Evaluation Criteria in Solid Tumors (RECIST) was used less frequently in Group-A than in Group-B (p = 0.0039).ConclusionsRecent Phase I trials included efficacy endpoints as SEs, with ORR, PFS, or OS included in ~ 50% trials and DOR or DCR in ~ 25%. No established criteria exist for imaging evaluation of BTs. Phase I trials involving mixed solid tumor cohorts revealed challenges in designing methods to assess the exploratory efficacy of BTs.

A primary cutaneous carcinosarcoma of the retro auricular region, how to treat and literature review.

Carcinosarcomas are malignant biphasic tumours of epithelial and mesenchymal tissue. They are most often found in visceral organs, but also appear on the skin. Older age, male sex and chronic sun exposure are risk factors for its development. In this article we report a case and provide a review of literature regarding primary cutaneous carcinosarcoma (CCS) with special regard to its management. A manual electronic search of the PubMed Medline and Web of Science Core Collection databases was performed encompassing all included reports until 30th November 2022 to identify studies that reported primary CCS. CCS is a rare and aggressive tumour. Diagnosis requires histological examination and immunoreactivity of epithelial and mesenchymal components to specific markers. On its diagnosis, possibility of metastasis of a visceral carcinosarcoma should always be excluded. Surgical excision with clear margins, including the use of Mohs micrographic surgery (MMS), is the primary treatment for CCS. Reconstruction the excision defect should be performed. Regular follow-up for 5 to 10 years after initial treatment is advised. Awareness for CCS is necessary in the diagnostic evaluation of skin tumours. Further research is needed to better understand the underlying mechanisms of CCS and to establish optimal management strategies for this challenging malignancy. We recommend complete surgical excision using MMS as the treatment modality for this type of skin cancer. Dermatological follow-up for at least 5 years should be conducted to monitor for recurrence.

Primary alveolar rhabdomyosarcoma of the brain: a case report

BackgroundPrimary brain rhabdomyosarcoma is a rare primary brain malignancy with few case reports. The vast majority of cases of primary brain rhabdomyosarcoma occur in pediatric patients, and immunohistochemistry can distinguish it from embryonal subtypes; however, few cases of primary brain rhabdomyosarcoma in adults have been reported in the literature.Case presentationWe report the case of a 26-year-old White male patient who was found to have primary brain alveolar rhabdomyosarcoma after developing headaches for several months. A brain MRI revealed a mixed cystic and solid tumor along the vermis of the cerebellum. The patient underwent a gross total surgical resection, which confirmed the diagnosis of alveolar rhabdomyosarcoma. Further staging workup for another primary focus or disseminated disease yielded negative results, confirming the diagnosis of primary alveolar rhabdomyosarcoma of the brain.ConclusionThe standard of care for managing this rare type of brain tumor involves surgery with adjuvant chemoradiotherapy. Further studies should be conducted for a better diagnostic and therapeutic understanding.

Abstract 3050: Evaluating the role of ∆Np63α in driving growth and metastasis of pancreatic ductal adenocarcinoma

Abstract Pancreatic ductal adenocarcinoma (PDAC) is the third leading cause of cancer-related deaths in the US and is rising in incidence. PDAC tumors may be either classical or basal in transcriptomic subtype, and PDAC patients with basal tumors have worse prognosis and may have increased resistance to chemotherapy. Previous studies have shown that ∆Np63α drives basal program expression. The goal of this project is to investigate whether ∆Np63α expression is sufficient to increase pancreatic cancer cell growth, metastasis and chemoresistance and whether these cells can outcompete ∆Np63α non-expressers in mixed tumors. Non-∆Np63α expressing human PDAC cell lines AsPC1 and HPAFII were stably transduced to express either ∆Np63α or mCherry (control). For both AsPC1 and HPAFII, ∆Np63α-expressing and control cells had similar proliferation rates and susceptibility to chemotherapy agents oxaliplatin and SN38 when grown in culture. When control or ∆Np63α-expressing AsPC1 cells were implanted orthotopically into the pancreas of athymic nude mice, there was no significant difference in primary tumor mass and pathological analysis of lungs and livers did not reveal any significant difference in metastatic burden. Bulk RNA sequencing of primary tumors confirmed that tumors in mice inoculated with AsPC1-∆Np63α had significantly upregulated expression of genes associated with the basal subtype. Collectively, these data suggest that while ∆Np63α drives the basal program in PDAC, its expression is insufficient to cause resistance to these chemotherapies or a growth or metastatic advantage in an immunodeficient setting. Further work is needed to elucidate the mechanism by which ∆Np63α contributes to more aggressive PDAC tumors. Citation Format: Daniel H. Ryan, Chin-Hsien (Emily) Tai, Xianyu Zhang, Mayrel Palestino Dominguez, Christine Alewine. Evaluating the role of ∆Np63α in driving growth and metastasis of pancreatic ductal adenocarcinoma [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 3050.

Abstract 4367: PTEN/AKT signal promotes cholangiocyte fate in liver tumorigenesis by inducing SOX9 overexpression and crosstalk with Notch activation

Abstract Cholangiocarcinoma (CCA) is the second most dominant primary liver malignancy next to hepatocellular carcinoma (HCC), and among the most mortal among human cancers. The PI3K/AKT signaling pathway was considered a permissive signal for the development of CCA. To explore how the PI3K/AKT signal contributes to CCA development, we deleted Pten, the lipid phosphatase that negatively regulates the PI3K/AKT signal in the liver. The Lv-PTEN (PtenloxP/loxP; Alb-Cre+) mice developed a mixed HCC and CCA tumor phenotype with all mice developing CCA by 12-month age. Treatment of Lv-PTEN mice with DDC at 3 months to obstruct the bile duct leads to an earlier CCA oncogenesis. Deletion of Akt2 in the Lv-PTEN mice (Lv-DM, Akt2loxP/loxP; PtenloxP/loxP; Alb-Cre+) significantly attenuates tumor development. Compared with the Lv-PTEN mice, loss of AKT2 in Lv-DM mice robustly and significantly reduced the expression of SOX9, a cholangiocyte gene. This data suggests that the AKT signal may permit a cholangiocyte fate by inducing SOX9 expression. Supporting the role of PTEN/AKT in permitting a cholangiocyte fate, SOX9 expression is also induced in the livers of mice where Pten deletion is targeted to the hepatocytes via injection of AAV8-TGB-Cre (Hp-PTEN, PtenloxP/loxP; R26RYFP; AAV8-TBG-Cre). Similar to the Lv-PTEN mice, treatment with DDC induced early onset of CCA development in the Hp-PTEN mice. We next explore Notch signal for its crosstalk with PTEN loss that permits CCA development. Notch signal is robustly induced in the tumors of the Lv-PTEN mice and induced with DDC treatment in both Lv-PTEN and Hp-PTEN livers. We showed that exposure to Jag1 ligand-coated extracellular matrix or expression of NICD also induced the expression of SOX9 while DAPT time-dependently attenuated the expression of SOX9. In the Hp-Pten mice treated with DDC, inhibiting the Notch pathway with DAPT attenuated ductal reaction and led to downregulation of SOX9 in the Lv-PTEN livers, suggesting a positive regulatory role of Notch on SOX9. These data support that Notch activation regulates SOX9 and collaborates with PTEN loss to drive cholangiocyte fate and CCA development. Citation Format: Qi Tang, Jingyu Chen, Ni Zeng, Lina He, Shefali Chopra, Diala Alhousari, Phillip Nguyen, Guo Zhang, Bangyan L. Stiles. PTEN/AKT signal promotes cholangiocyte fate in liver tumorigenesis by inducing SOX9 overexpression and crosstalk with Notch activation [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 4367.

Abstract 4632: Lineage plasticity as a determinant of antibody-drug conjugate target expression in urothelial bladder cancer

Abstract Bladder cancers display a wide spectrum of morphologies that frequently co-exist within individual tumors. Several histologic variants, including plasmacytoid, neuroendocrine, and micropapillary subtypes, are associated with an increased bladder cancer recurrence risk and cancer-specific mortality. The molecular basis and therapeutic implications of this phenotypical plasticity remain poorly understood. Enfortumab vedotin (EV), an antibody-drug conjugate targeting Nectin-4, has also emerged as a new standard-of-care for metastatic bladder cancer patients, but the association between lineage plasticity as manifested by morphologic heterogeneity in bladder cancer, Nectin-4 expression and ADC response remains poorly defined. Previous DNA-based molecular profiling studies of histologic variants revealed that CDH1 mutations were the pathognomonic molecular alteration in plasmacytoid urothelial carcinoma, but no recurrent driver mutations have been found to be unique to the aberrant histology regions of other mixed histology subtypes. Thus, to explore the molecular basis for the lineage plasticity of bladder cancers with aberrant histology and to define the association between lineage plasticity manifested as morphologic heterogeneity and the expression of Nectin-4, HER2 and other potential ADC targets, we performed RNA-seq of pure urothelial carcinomas (n=118, not otherwise specified, UC-NOS) and bladder tumors with divergent differentiation or histologic subtypes (n=199). Our cohort included a subset of tumors in which RNA-seq was performed on microdissected UC-NOS and variant histology regions of the same tumor. Tumors with neuroendocrine, sarcomatoid and squamous histology had the lowest Nectin-4 expression, whereas histologic subtypes that retained a luminal transcriptional profile such as micropapillary, plasmacytoid and nested histology had higher levels of Nectin-4 expression. In mixed histology tumors, Nectin-4 and/or HER2 expression was often restricted to only one of the two histologic components. Gene Set Enrichment Analysis noted enrichment of distinct oncogenic pathway gene sets in different histologic variants. Preliminary investigation into the mechanism(s) of Nectin-4 regulation using bladder cancer cell lines and patient-derived organoids (PDOs) has identified targetable pathways which when inhibited revert lineage plasticity and induce Nectin-4 expression. In sum, lineage plasticity manifested as heterogenous histomorphologies was associated with heterogeneous Nectin-4 expression in some but not all histologic variants of bladder cancer. Ongoing studies using PDOs from bladder cancer patients with mixed histology will seek to identify molecular pathways whose inhibition leads to increased expression of Nectin-4 or other ADC targets such as HER2 and thus increased sensitivity of ADCs targeting these cell surface proteins. Citation Format: Jiaqian Luo, Sizhi P. Gao, Fengshen Kuo, Gamze Gokturk Ozcan, Merve Basar, Florestan Koll, Jacob E. Tallman, Syed M. Alam, Carissa E. Chu, Ziyu Chen, Eugene J. Pietzak, Gopakumar Iyer, Jonathan E. Rosenberg, David B. Solit, Hikmat Al-Ahmadie. Lineage plasticity as a determinant of antibody-drug conjugate target expression in urothelial bladder 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 4632.

Abstract 275: Deciphering biphasic responses to Sonic Hedgehog pathway inhibition in breast cancer: Insights from a tumor-fibroblast spheroid model and PDXs

Abstract A significant subset (30-40%) of triple-negative breast cancer (TNBC) cases exhibit hyperactivation of the sonic hedgehog (SHH) pathway, correlating with poor clinical outcomes. However, the therapeutic efficacy of SHH inhibitors in TNBC has yielded inconsistent results, showcasing biphasic tumor responses going from complete remission in some patients to faster disease progression in others. Such tumor response discrepancies underscore the need for more relevant culture models to elucidate how stromal cells respond to SHH signals and impact tumor cell reprogramming.We have developed a tumor-fibroblast spheroid model of robust paracrine SHH signaling to examine alterations in aggressive tumor cell phenotypes resulting from altered SHH pathway activity levels to understand better how SHH therapy leads to biphasic effects in tumor tissues. Specifically, tumor stemness alterations were examined as a function of SHH signal strength altered by tumor-fibroblast proximity, and findings were confirmed in two PDX models of TNBC of divergent sensitivity to pharmacological SHH pathway inhibition. In vitro, results show that tumor stemness potency is enriched by tumor-fibroblast proximity and inversely correlates with SHH pathway activity levels. Tumor stemness potency was determined via a mammosphere forming assay and resistance to chemotherapy using docetaxel as treatment. CD44+ sorted tumor cells derived from adjacent fibroblast cultures showed higher mammosphere forming efficiency and docetaxel sensitivity than those from mixed cultures. These effects correlated with differences in SHH pathway activity strengths and were reverted by pharmacological inhibition of SHH confirming pathway activity involvement. In two PDX models, both exhibiting high SHH pathway activity and similar tumor vascularization, we observed variable response to pharmacological SHH inhibition. PDX2 displayed favorable responses with minimal alpha-smooth muscle actin-positive (SMA+) fibroblast infiltration, while PDX1 exhibited no benefit from SHH therapy, accompanied by a high level of SMA+ fibroblasts. Spatial transcriptomic analysis confirmed stemness enrichments in the PDX1 model treated with SHH inhibitor- a scenario our mixed co-culture model resembled. Stemness-enriched tumor regions were positive for the Ki67 proliferation marker and confined to areas of high SMA+ cell abundance. Plotting Ki67 vs SMA+ cell levels revealed a positive correlation, suggesting that SMA levels may predict tumor response to SHH pathway inhibition.In summary, our studies demonstrate that pharmacological SHH inhibition can induce altered tumor plasticity by favoring stemness phenotypes. Strategies targeting tumor stemness may mitigate biphasic effects in response to SHH inhibitors, offering insights for optimizing TNBC therapeutic approaches. Citation Format: Heizel M. Rosado-Galindo, Miosotis Acevedo-Esquillin, Wandaliz Torres-García, Ana M. Reyes-Ramos, Gabriela Ortiz-Soto, Michelle M. Martínez-Montemayor, Maribella Domenech. Deciphering biphasic responses to Sonic Hedgehog pathway inhibition in breast cancer: Insights from a tumor-fibroblast spheroid model and PDXs [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 275.

Abstract 4208: In-vitro modeling of Sonic Hedgehog signaling identifies the extracellular matrix as a regulator of tumor invasion outcomes

Abstract Preclinical models of Sonic Hedgehog (SHH)-driven tumors support the therapeutic benefit of pharmacological inhibitors, yet clinical outcomes are conflicted due to biphasic tumor responses that include complete remission or faster disease progression. In such studies, the activity of the SHH pathway in the tumor-adjacent stroma supported or restrained tumor progression. Our prior studies show that altered SHH ligand levels can lead to faster tumor growth during pharmacological inhibition suggesting a role for the SHH pathway strength in the biphasic tumor responses of a triple-negative breast cancer (TNBC) model. In this study, the role of SHH pathway strength altered by tumor-fibroblast proximity was examined on the tumor growth, invasion, and transcriptional activity using in vitro and in vivo models. Tumor spheroid models composed of TNBC cell lines and fibroblasts were used to monitor SHH signal strength as a function of the culture modality and SHH ligand levels. In vitro, SHH signal strength was altered by tumor-fibroblast proximity and ligand concentration. Mixed cultures exhibited significantly higher SHH activity and reduced invasion than adjacent cultures. This effect was reversed by pharmacological inhibition of SMO, confirming the involvement of an SHH-dependent mechanism. In a tumor xenograft model, tumor metastasis outcomes were suppressed by pharmacological inhibition of the SHH pathway, but opposite results were observed in tumor xenografts composed of co-injected with fibroblasts indicating that the biphasic tumor response can be driven by the fibroblasts. Spatial transcriptional analysis identified extracellular matrix (ECM) activities in fibroblasts as the top altered bioprocesses in both in vitro and in vivo. This finding was confirmed in cultures, where fibroblast-derived decellularized matrix stimulated tumor invasion of single TNBC spheroids at levels observed in co-cultures. Further analysis of differentially expressed genes (DEGs) identified a small leucine-rich repeat proteoglycan (SLRP) as the primary ECM target altered by variations in SHH signal strength in fibroblasts. Furthermore, we confirmed the role of SLRP cues in governing tumor invasion potency within spheroid cultures embedded in a collagen hydrogel matrix. While high levels of SLRP in the matrix inhibited spheroid invasion, low SLRP matrix promoted spheroid invasion and increased secondary invasion sites. These findings agreed with the Vimentin expression levels observed in TNBC cells and confirmed the potency of SLRP in regulating tumor invasion outcomes. In summary, our study underscores the significance of ECM remodeling activities in fibroblasts and the role of SLRPs in governing tumor invasion, with implications for understanding the impact of altering SHH signaling activity in TNBC. Citation Format: Emanuel A. Carrasquillo-Dones, Heizel M. Rosado-Galindo, Ana M. Reyes-Ramos, Wandaliz Torres-Garcia, Said Cifuentes, Jan P. Rios-Grant, Gabriela Ortiz-Soto, Natalia A. Ramos-Acevedo, Miosotis Acevedo-Esquilin, Monica Colon-Vargas, Israel Almodovar-Rivera, Camilo Mora, Michelle M. Martinez-Montemayor, Maribella Domenech. In-vitro modeling of Sonic Hedgehog signaling identifies the extracellular matrix as a regulator of tumor invasion outcomes [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 4208.

Abstract 3992: Tandem CAR-T cells against mesothelin and MUC16ectoto overcome tumor-antigen heterogenicity

Abstract Introduction: Antigen heterogeneity is a challenge for CAR-T cell therapy in solid tumors due to antigen escape when targeting a single antigen. In ovarian cancer (OC), mesothelin (meso) and Mucin16 (MUC16) are two of the most overexpressed antigens. Moreover, CA125, which is part of MUC16, is lost in some OC patients, but the ectodomain remains on the cell surface. Targeting both antigens (Meso and MUC16ecto) with a tandem-CAR configuration could overcome antigen heterogeneity to improve CAR-T cell efficacy in OC. Material and Methods: We designed a library of different CARs with tandem Meso and MUC16ecto scFv combinations with varying G4S linker lengths, fused to a CD8 hinge/transmembrane domain and 41BBz intracellular domain. A series of constructs was then tested in an NFAT-GFP reporter system in Jurkat cells to determine which configuration induced maximal T cell activation and antigen-binding capacity via flow cytometry. We identified the top 2 activators and binders, produced primary human tandem CAR-T (TanCAR) cells by LV transduction, and tested their cytotoxicity in vitroagainst dual antigen-expressing or single antigen-expressing tumor cells using luciferase killing assays and Incucyte. We measured the cytokine production with a Luminex® Multiplex Assay and used a z-Movi® Cell Avidity Analyzer to test the tandem scFv avidity towards the antigens. Also, we examined TanCAR activity against a mixed tumor model in NSG mice. Their in vitro and in vivo activity were compared to CAR T cells targeting either single antigen (SS1-anti-Meso or 4H11-anti-MUC16ecto). Results: We found that TanCAR1 and TanCAR3 as the configurations with the best activation and binding capacity in response to cognate antigen. TanCAR1 and TanCAR3 had superior in vitro cytotoxic capacities compared to SS1 or 4H11 in tumor models expressing both antigens and in mixed cultures of tumor cells expressing one, both, or neither target antigen. From this mixed culture, we analyzed the remaining tumor cell populations by flow cytometry and observed an overgrowth of the population not targeted by CAR. In response to tumor cells, tandem CARs also produced INFg, IL6, IL-18, IL-13, and GM-CSF regardless of whether one or two antigens were expressed. For further experiments, we pursued TanCAR1 due to its slightly better functionality compared to TanCAR3. TanCAR1 had the same avidity for cells expressing the single antigens as SS1 or 4H11 CARs, but an intermediate avidity for the double Ag-expressing cell line compared to the single CARs. Finally, we tested TanCAR1-T cells in an in vivo mixed tumor model, showing that they better controlled and reduced tumor growth compared to either SS1 or 4H11. Conclusion: Targeting Meso and MUC16ecto through a tandem CAR design allows for a better anti-tumor response compared to CAR T cells targeting a single antigen. This approach may combat antigen heterogeneity by preventing antigen escape. Citation Format: Diego Salas-Benito, Filippo Birocchi, Alexander Armstrong, Amanda A. Bouffard, Tamina Kienka, Felix Korell, Mark B. Leick, Trisha Berger, Marcela V. Maus. Tandem CAR-T cells against mesothelin and MUC16ectoto overcome tumor-antigen heterogenicity [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 3992.

Component Patterns and Survival Outcomes in Patients with Mixed Malignant Ovarian Germ Cell Tumors: A Retrospective Cohort Study

AimsTo evaluate the component patterns and risk stratification in patients with mixed malignant ovarian germ cell tumors (mMOGCT). MethodsA retrospective study of 70 mMOGCT patients treated in our hospital between 2000 and 2022 was conducted. The recurrence-free survival (RFS), disease-specific survival (DSS), and risk stratification systems based on scoring the identified prognostic factors were assessed. ResultsYolk sac tumor component was the most common type (80%), followed by dysgerminoma (50%), immature teratoma (40%), embryonic carcinoma (27.1%), and chorionic carcinoma (15.7%). The 5-year RFS and DSS rates were 77.9% and 87.9%, respectively. International federation of gynecology and obstetrics (FIGO) stage III-IV (RR 3.253, P = 0.029) and normalization of tumor marker (TM) ≤ 3 cycles of chemotherapy (RR 6.249, P = 0.017) were risk factors for RFS and DSS, respectively. Significant DSS (RR 8.268, P = 0.006) was also noted between patients who had normalized TM ≤ 4 and ≥5 cycles of chemotherapy. FIGO stages I–II and stages III–IV were scored as 0 and 2, respectively. AFP normalization ≤3, 4, and ≥5 cycles of chemotherapy were scored as 0, 1, and 4, respectively. A total score of 0, 1–2, and ≥3 stratified patients into low-risk (43 patients), intermediate-risk (13 patients), and high-risk groups (14 patients), respectively. Patients in three risk stratifications manifested significant differences in DSS (P = 0.010) but not in RFS (P > 0.05). ConclusionDistinct different component patterns existed among mMOGCT patients, and predicting survival outcomes in a universal model was challenging.

Epidemiology and classification for canine and feline mammary gland tumors: a histopathological survey of 437 mammary gland tumor biopsies performed in a secondary care hospital in Chiang Mai, Thailand from 2012 to 2019.

Metastatic disease resulting from mammary gland tumors (MGTs) is a known cause of death among dogs and cats. Keys to successful prevention and management strategies involve the accurate recording of diagnostic data. This retrospective study reviewed the epidemiology and classification of canine mammary gland tumors (CMTs) and feline mammary gland tumors (FMTs), as well as the factors including sex, age, and breed related to the occurrence of these tumors. Accordingly, 1,736 tumor biopsy cases were reported from 2012 to 2019 at Chiang Mai University Small Animal Hospital, Thailand, with 1,639 canine tumor biopsy cases and 97 feline tumor biopsy cases. The proportion of CMTs was reported at 24.5% (401/1,639) for all canine tumor biopsy cases. Benign and malignant tumors were reported at 14.5% (58/401) and 85.5% (343/401) for all CMT cases, respectively. The mean age of dogs affected by benign CMTs was 9.0±3.0 years, which was significantly lower than for malignant CMTs at 9.9±2.8 years (P=0.0239). According to histopathological classification, benign mixed tumors and simple carcinoma types were highest among benign and malignant CMT cases, respectively. Moreover, female dogs were at significantly higher risk of developing mammary gland tumors (OR = 45.8, 95% CI [3.9-86.0], P<0.0001) than male dogs, as well as older dogs (>8 years) (OR = 1.7, 95% CI [1.2-2.2], P=0.0001) compared to young ones (≤8 years). The proportion of FMTs was 37.1% (36/97) for all feline tumor biopsy cases. Benign and malignant tumors for all FMTs were reported at 16.7% (6/36) and 83.3% (30/36), respectively. According to histopathological classifications, adenoma and simple carcinoma were present in the highest proportion among benign and malignant FMTs, respectively. Female cats were at a significantly higher risk of developing mammary gland tumors than male cats (OR=25.7, 95% CI [3.9-272.8], P<0.0001). There was a high proportion of MGT cases compared with other tumor cases reported in a secondary care hospital in Chiang Mai, Thailand from 2012 to 2019, and malignant tumor biopsies have been more frequently observed than benign tumor biopsies in both CMT and FMT cases. The resulting data originating from this study can be an aid for veterinary oncologists in better educating clients and planning treatment and prevention strategies and it can be used as a basis for further experimental studies in the oncology section.

Integral neuro-oncological diagnosis As the basis for personalized treatment Of brain tumors (on the example of gliomas In children)

Brain tumors are the most common group of neoplasms in children, which is in the top-3 causes of infant mortality from oncopathology. The aim of the study is to make a literature review of modern approaches to the personalization of treatment of CNS tumors in children based on the study of molecular genetics, immunohistochemical and imagingт characteristics. The article provides a description of the most common types of neoplasms of the nervous system — low grade gliomas (LGG), high grade gliomas (HGG), mixed glioneural tumors, etc. The molecular genetics, immunohistochemical, visualization characteristics of each type of gliomas are described. Modern information on prognosis and treatment of tumors is also given in the publication. The prognosis of the course of LGG/GNT in children depends more often on the patient’s age, histology, and location of the tumor, as well as its molecular profile. Older patients have a more favorable prognosis than younger children. Well-visualized tumors located superficially have a better outcome than diffuse gliomas, as well as deeply located tumors. Detection of BRAF mutations and FGFR rearrangements may indicate a better prognosis than in the presence of SNV. Local mutations of BRAF with concomitant deletion of CDKN2A, as well as mutations with H3.3 pK27 are the most dangerous.

Clinical analysis of metaplastic breast carcinoma with distant metastases: A multi‑centre experience.

Metaplastic breast cancer (BC-Mp), which includes a range of epithelial and mixed epithelial-mesenchymal tumours, are rare malignancies with an unfavourable prognosis. The limited literature on BC-Mp focuses mainly on retrospective data for radically treated patients. Notably absent are studies dedicated to the palliative treatment of BC-Mp with distant metastases. The present retrospective study investigated treatment modalities and prognosis in a multi-centre cohort of 31 female participants diagnosed with distant metastatic BC-Mp, including 7 patients with de novo metastatic disease. The median age of the patients was 61 years (range, 33-87 years), with 38.7% presenting local lymph node involvement. Lungs were the most common site for the metastatic disease (61.3%). Median Ki-67 index was 50% (range, 35-70%), and 80.7% of cases were classified as grade 3. Human epidermal growth factor receptor 2 (HER2)+ and estrogen receptor+ were detected in 12.9 and 6.5% of cases, respectively. A total of 62.4% of patients received first-line palliative systemic treatment. The 1- and 2-year overall survival (OS) were 38.5 and 19.2%, respectively. Receiving ≥1 line of palliative treatment was significantly associated with improved OS (P<0.001). Factors such as age, Ki-67 index, HER2 or hormonal status, presence of specific epithelial or mesenchymal components, location of metastases or chemotherapy regimen type did not influence OS. The present study provided insights into the clinicopathological profile, systemic treatment experience, prognostic factors and OS data of BC-Mp with distant metastases, emphasizing the imperative for clinical trials in this population.

Intraductal carcinomas of the salivary glands: a clinicopathological and molecular genetic analysis of twenty-seven cases

Objective: To investigate the clinicopathological features, molecular genetic features, and differential diagnosis of intraductal carcinomas (IDC) of the salivary glands. Methods: Twenty-five cases of salivary gland IDC diagnosed at the Department of Oral Pathology, Shanghai Ninth People's Hospital and two cases from Department of Pathology, Henan Provincial People's Hospital, Zhengzhou, China from January 2008 to July 2023 were collected. Their clinical and pathological features were analyzed retrospectively. Fluorescence in situ hybridization and Sanger sequencing were performed. The patients were followed up and related literatures were reviewed. Results: There were 27 patients with IDC, including 15 males and 12 females, ranging in age from 20.0 to 80.0 years (mean 55.9 years). Clinically, the tumor often presented as a painless mass with a tumor diameter of 1.0-3.0 cm (mean 2.0 cm). All patients received surgical treatment. Twenty patients were followed up. One of them (1/20) died of lung cancer, while the rest survived without tumor recurrence. Histologically, IDC were classified as: intercalated (63.0%, 17/27), apocrine (25.9%, 7/27), oncocytic (7.4%, 2/27) and mixed (3.7%, 1/27) types. Intercalated tumors showed positive S-100 and negative androgen receptor (AR) immunoreactivity. Ki-67 proliferation index was low (about 1%-5%). Nine cases had the RET gene disruption, and 2 cases showed the BRAF V600E mutation. Apocrine tumors showed strong AR immunoreactivity but no S-100 immunoreactivity. Ki-67 proliferation index was high (about 10%-60%), and the RET gene rupture was detected in 1 case. Oncocytic tumors were similar to that of intercalated type in 2 cases, and RET gene disruption was detected in the both cases. Mixed tumors showed histologic features of oncocytic and apocrine patterns and harbored the RET gene disruption. Conclusions: IDC is a rare low-grade malignant tumor of the salivary gland and easily confused with other salivary gland tumors with similar morphology. Molecular testing is helpful for its differential diagnosis.

Collagen modifications predictive of lymph node metastasis in dogs with carcinoma in mixed tumours.

Mixed tumours in the canine mammary gland are the most common histological type in routine diagnosis. In general, these neoplasms have a favourable prognosis that does not evolve into metastatic disease. However, some cases develop into lymph node metastases and are associated with worse patient survival rates. Here is a retrospective study of 46 samples of primary mixed tumours of the canine mammary gland: 15 cases of benign mixed tumours (BMT), 16 cases of carcinoma in mixed tumours without lymph node metastasis (CMT), and 15 cases of carcinomas in mixed tumours with lymph node metastasis (CMTM). In addition, we selected 23 cases of normal mammary glands (NMT) for comparison. The samples were collected from biopsies performed during nodulectomy, simple mastectomy, regional mastectomy, or unilateral/bilateral radical mastectomy. We used multiphoton microscopy, second harmonic generation, and two-photon excited fluorescence, to evaluate the characteristics of collagen fibres and cellular components in biopsies stained with haematoxylin and eosin. We performed Ki67, ER, PR, and HER-2 immunostaining to define the immunophenotype and COX-2. We showed that carcinomas that evolved into metastatic disease (CMTM) present shorter and wavier collagen fibres as compared to CMT. When compared to NMT and BMT the carcinomas present a smaller area of fibre coverage, a larger area of cellular coverage, and a larger number of individual fibres. Furthermore, we observed a correlation between the strong expression of COX-2 and a high rate of cell proliferation in carcinomas with a smaller area covered by cell fibres and a larger number of individual fibres. These findings highlight the fundamental role of collagen during tumour progression, especially in invasion and metastatic dissemination.

Spatial insights into immunotherapy response in non-small cell lung cancer (NSCLC) by multiplexed tissue imaging

The spatial localisation of immune cells within tumours are key to understand the intercellular communications that can dictate clinical outcomes. Here, we demonstrate an analysis pipeline for highly multiplexed CODEX data to phenotype and profile spatial features and interactions in NSCLC patients that subsequently received PD1 axis immunotherapy. We found that regulatory T cells (Tregs) are enriched in non-responding patients and this was consistent with their localization within stromal and peripheral tumour-margins. Proximity-based interactions between Tregs and both monocytes (p = 0.009) and CD8+ T cells (p = 0.009) were more frequently found in non-responding patients, while macrophages were more frequently located in proximity to HLADR+ tumour cells (p = 0.01) within responding patients. Cellular neighbourhoods analysis indicated that both macrophages (p = 0.003) and effector CD4+ T cells (p = 0.01) in mixed tumour neighbourhoods, as well as CD8+ T cells (p = 0.03) in HLADR+ tumour neighbourhoods were associated with favorable clinical response. Evaluation of the inferred regulatory functions between immune cells relative to the tumour suggested that macrophages exhibit an immunosuppressive phenotype against both CD4+ and CD8+ T cells, and that this association scores more highly in ICI refractory patients. These spatial patterns are associated with overall survival in addition to ICI response and may thus indicate features for the functional understanding of the tumour microenvironment.