Primary High Grade Research Articles

Optimal Management for Primary High Grade Ta Bladder Cancer: Role of re-staging TURBT and Intravesical Adjuvant Therapy.

This study aims to investigate the impact of risk group classification, restaging transurethral resection (re-TURBT), and adjuvant treatment intensity on recurrence and progression risks in high-grade Ta tumours in patients with non-muscle invasive bladder cancer (NMIBC). Data from a comprehensive bladder cancer database were utilized for this study. Patients with primary high-grade Ta tumours were included. Risk groups were classified according to AUA/SUO criteria. Tumour characteristics and patient demographics were analysed using descriptive statistics. Cox proportional hazard regression models were used to assess the effect of re-TURBT and other clinical/treatment-related predictors on recurrence- and progression-free survivals. The survivals by selected predictors were estimated using Kaplan-Meier method, and groups were compared by the log-rank test. Among 218 patients with high-grade Ta bladder cancer, those who underwent re-TURBT had significantly better 5-year recurrence-free survival (71.1% vs. 26.8%, p = 0.0009) and progression-free survival (98.6% vs. 73%, p = 0.0018) compared with those with initial TURBT alone. Full BCG treatment (induction and maintenance) showed lower recurrence risk, especially in high-risk patients. However, residual disease at re-TURBT did not significantly affect recurrence risk. This study highlights the significance of risk group classification, the role of re-TURBT, and the intensity of adjuvant treatment in the management of high-grade Ta tumours. A risk-adapted model is crucial to reduce the burden of unnecessary intravesical treatment and endoscopic procedures.

Timing of whole genome duplication is associated with tumor-specific MHC-II depletion in serous ovarian cancer

Whole genome duplication is frequently observed in cancer, and its prevalence in our prior analysis of end-stage, homologous recombination deficient high grade serous ovarian cancer (almost 80% of samples) supports the notion that whole genome duplication provides a fitness advantage under the selection pressure of therapy. Here, we therefore aim to identify potential therapeutic vulnerabilities in primary high grade serous ovarian cancer with whole genome duplication by assessing differentially expressed genes and pathways in 79 samples. We observe that MHC-II expression is lowest in tumors which have acquired whole genome duplication early in tumor evolution, and further demonstrate that reduced MHC-II expression occurs in subsets of tumor cells rather than in canonical antigen-presenting cells. Early whole genome duplication is also associated with worse patient survival outcomes. Our results suggest an association between the timing of whole genome duplication, MHC-II expression and clinical outcome in high grade serous ovarian cancer that warrants further investigation for therapeutic targeting.

Abstract 6835: Profiling of new prostate cancer vulnerabilities through single-nucleus RNAseq implicates the CAF-specific TGF-β pathway in tumor progression

Abstract Background: Transcriptomic profiles of primary high grade prostate cancer (hgPCa) have been extensively studied and prognostic gene expression signatures to classify patients for risk have been identified. However, such studies have employed bulk genomic techniques that blur the contributions of the different cell types. Indeed, tumor microenvironment (TME) cells can significantly contribute to these transcriptomic signatures thereby confounding the lineage of potential therapeutic targets. These challenges underscore the potential of single-nucleus (sn)RNAseq to elucidate new PCa vulnerabilities. We set out to assess whether the TME, particularly cancer-associated fibroblasts (CAFs) drive poor outcome in PCa. Methods: We obtained 15 treatment-naïve frozen primary high risk PCa tissue samples, mostly Gleason >=8. A PCa nuclei dissociation protocol was adapted for single nucleus snRNAseq (10X Genomics). Sample profiling included all cell populations in the tissue including tumor and TME. Output was analyzed using Seurat (v.4.1.1), corrected for ambient RNA expression with CellBender (v.0.3.1) and detected and removed doublets with Scds (v.3.9). Tumor cells were distinguished from normal epithelium cells by a combination of inferCNV (v.1.12.0) and supervised learning with random forests classification. Results: Through snRNAseq, we show that CAFs, and not tumor cells, entirely drive the expression of previously validated poor prognostic signatures (Mortensen, 2015). Our analysis revealed that the TGFβ pathway expression, TGF-β1 in particular, is upregulated in CAFs rather than PCa cells. This pathway, along with poor prognosis signatures are selectively elevated in CAFs from patients with Gleason high compared to low, implicating the TGFb axis as a PCa vulnerability. We also derived a snRNAseq CAF signature that differentiates non-responders to immune checkpoint therapy in mCRPC (Nivolumab+Ipilimumab). Furthermore, cluster profiling of tumor nuclei revealed that hgPCa harbors high heterogeneity with distinct niches of hgPC, mCRPC or neuroendocrine phenotypes for each patient. Conclusions: Through snRNAseq we show that CAFs are the main contributors to prior bulk RNAseq classifiers of poor response, resulting in a refined CAF signature that allows for direct investigation of the contribution of CAFs in other patient segments (mCRPC). Our findings point to a hgPCa patient segment with high CAF representation that may benefit from the addition of a CAF targeting agent (ie.TGFbi) to androgen deprivation therapy. This data has the potential to help refine our prognostic classifiers for patient selection and clinical applicability. Further study of the reported tumor heterogeneity will inform rational combination therapies to tackle resistance mechanisms. Citation Format: Alexandre P. Alloy, Sharmila Chamling Rai, Brendan O'Brien, Anna Lyubetskaya, Arnaud Amzallag, Benjamin Chen, Ana Lako. Profiling of new prostate cancer vulnerabilities through single-nucleus RNAseq implicates the CAF-specific TGF-β pathway in tumor progression [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 6835.

Abstract PR001: Interpretation of patient-specific ex vivo immunotherapy response for ovarian cancer

Abstract Background: Immunotherapies have shown great benefits, including durable clinical responses. However, the overall response rate remains low and it is challenging to select sensitive patients upfront. Patient-derived ex vivo tumor tissues with preserved tumor microenvironment (TME) represent the ideal model for patient-specific testing of immunotherapy sensitivities. This study aims to confirm that patient-specific ex vivo immunotherapy responses are matched by the presence of relevant immune components. Material & Methods: Ascites of 84 patients with predominantly primary high grade ovarian carcinoma was collected between 2019 and 2023 in the Netherlands (IRB P18.032). Fresh tumor clusters with TME were seeded and exposed to six immunotherapies and the superantigen Staphylococcus aureus (SEA) as positive control. Tumor killing and immune cell proliferation were measured using 3D imaging. Ex vivo tumor sensitivity was classified on percentage and statistical significance of tumor killing. Immunohistochemical staining (IHC) for immune cell markers (CD3, CD68) (n=40) and proteomics analyses (n=26) were performed prior to drug exposure. Results: SEA response was observed in 52% (44/84). Differential patient response profiles were observed, with 30% of the patients tissues displaying highly significant sensitivity for at least one of the therapies tested. Clustering the patients based on pathology scores uncovered four distinct groups: 1) CD68-/CD3-, 2) CD3-/CD68+, 3) CD3+/CD68+ and 4) CD3++/CD68++. Clustering and regression analysis demonstrated a significant correlation of increased CD3 and CD68 expression to ex vivo SEA sensitivity (p-value < 0.05). Protein biomarker analysis supported these results, reporting significantly higher levels of chemokines and interleukins in SEA responders. Finally, different immune checkpoint inhibitors demonstrated distinct protein abundance profiles consistent with their mode of action. Conclusion: This study reports classification and characterization of patient-specific sensitivity to 6 immunotherapies in 84 ovarian cancer patients enabled by a robust image-based ex vivo 3D tumor testing platform. The results demonstrate a positive relationship between the ex vivo sensitivity to immune-stimulatory compounds and the presence of functional immune components in the patient's TME. This confirms the interpretability of 3D ex vivo tumor testing for classification of patient-specific immune responses. Discussion: We previously demonstrated the predictive value of the platform by correlation of ex vivo sensitivity to clinical chemotherapy responses of ovarian cancer patients. Assay feasibility was also established for NSCLC, mesothelioma and bladder cancer. The two-week timeline enables its application in clinical practice. Quantifying ex vivo immunotherapy sensitivity will facilitate improved patient stratification for standard of care and novel treatments. Clinical trials are currently ongoing to establish the correlation of the assay with patients' response to immunotherapy. Citation Format: Lieke Ceton, Esmee Koedoot, Timothy Sijsenaar, Marta Montero Garcia, Fanny Grillet, Jurrian van der Valk, Klaus Weber, Roman Schoenauer, Katrin Hufnagel, Ronny Schmidt, Nadine Stroh, Henning Boekhoff, Cor de Kroon, Anne van Altena, Dieudonné van der Meer, Willemijn Vader, Nelleke Ottevanger, Judith Kroep. Interpretation of patient-specific ex vivo immunotherapy response for ovarian cancer [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr PR001.

Immune profile of primary and recurrent epithelial ovarian cancer cases indicates immune suppression, a major cause of progression and relapse of ovarian cancer

BackgroundOvarian cancer is the third most prevalent cancer in Indian women. Relative frequency of High grade serous epithelial ovarian cancer (HGSOC) and its associated deaths are highest in India which suggests the importance of understanding their immune profiles for better treatment modality. Hence, the present study investigated the NK cell receptor expression, their cognate ligands, serum cytokines, and soluble ligands in primary and recurrent HGSOC patients. We have used multicolor flow cytometry for immunophenotyping of tumor infiltrated and circulatory lymphocytes. Procartaplex, and ELISA were used to measure soluble ligands and cytokines of HGSOC patients.ResultsAmong the enrolled 51 EOC patients, 33 were primary high grade serous epithelial ovarian cancer (pEOC) and 18 were recurrent epithelial ovarian cancer (rEOC) patients. Blood samples from 46 age matched healthy controls (HC) were used for comparative analysis. Results revealed, frequency of circulatory CD56Bright NK, CD56Dim NK, NKT-like, and T cells was reduced with activating receptors while alterations in immune subsets with inhibitory receptors were observed in both groups. Study also highlights differential immune profile of primary and recurrent ovarian cancer patients. We have found increased soluble MICA which might have acted as “decoy” molecule and could be a reason of decrease in NKG2D positive subsets in both groups of patients. Furthermore, elevated level of serum cytokines IL-2, IL-5, IL-6, IL-10, and TNF-α in ovarian cancer patients, might be associated with ovarian cancer progression. Profiling of tumor infiltrated immune cells revealed the reduced level of DNAM-1 positive NK and T cells in both groups than their circulatory counterpart, which might have led to decrease in NK cell’s ability of synapse formation.ConclusionsThe study brings out differential receptor expression profile on CD56BrightNK, CD56DimNK, NKT-like, and T cells, cytokines levels and soluble ligands which may be exploited to develop alternate therapeutic approaches for HGSOC patients. Further, few differences in the circulatory immune profiles between pEOC and rEOC cases, indicates the immune signature of pEOC undergoes some changes in circulation that might facilitated the disease relapse. They also maintains some common immune signatures such as reduced expression of NKG2D, high level of MICA as well as IL-6, IL10 and TNF-α, which indicates irreversible immune suppression of ovarian cancer patients. It is also emphasized that a restoration of cytokines level, NKG2D and DNAM-1on tumor infiltrated immune cells may be targeted to develop specific therapeutic approaches for high-grade serous epithelial ovarian cancer.

Abstract B006: Investigating the role of soluble metabolites in primary high grade serous ovarian cancer

Abstract Ovarian cancer is the fifth leading cause of cancer death in women. High grade serous ovarian cancer (HGSOC), the most common and lethal histotype, can originate from fallopian tube epithelial (FTE) cells. Research has not historically focused on the metabolites involved in the migration of transformed FTE cells from the fallopian tube to the ovary. Co-culture of murine FTE and ovaries enabled identification of several significantly upregulated soluble metabolites via imaging mass spectrometry (IMS), including norepinephrine (NE). Therefore, we set out to determine the effect of norepinephrine on FTE and ovarian cancer cell lines. Clinical data analysis revealed that human HGSOC cell lines express the β-adrenergic receptor through which norepinephrine signals, called ADRβ2, and HGSOC patients with increased ADRβ2 expression have worse survival outcomes (p<0.05), suggesting that signaling through ADRβ2 plays a role in HGSOC. When we examined phenotypic changes following NE treatment (10 µM), tumorigenic MOE PTENshRNA p53 cells showed increased invasion in a Boyden chamber (N≥3, p<0.05). Interestingly, in terms of mechanistic pathways, NE enhanced pSRC expression in MOE PTENshRNA p53 cells, which has been linked to invasion in the literature (N≥3, p<0.05). NE treatment also increased N-Cad and C-Myc expression, but did not cause any phenotypic changes, in OVCAR4 cells (N≥3, p<0.05). These data suggest that NE drives alterations in protein expression, which, depending on the cell line, may also induce oncogenic phenotypic changes. Given the above data, we also sought to understand the factors that drive ovarian NE release. Conditioned media from cultured MOE PTENshRNA cells was found to induce ovarian NE release. Further, we determined that only the protein fraction of this conditioned media (3-50kDa) was responsible for NE induction. Therefore, we conducted comparative proteomic analysis using non-tumorigenic tubal cells, MOE SCRshRNA, identifying a uniquely abundant protein potentially responsible for the NE release: SPARC (secreted protein acidic and rich in cysteine). Using our IMS/co-culture paradigm, we have seen that knockdown of SPARC in MOE PTENshRNA cells decreases levels of ovarian-derived NE and that overexpressing SPARC in MOE WT cells increases levels of ovarian-derived NE. To date, this work has identified two key molecules, NE and SPARC, involved in primary metastasis of HGSOC from fallopian tube to ovary. Future studies will focus on effects of blocking NE signaling in vivo and broadening our understanding of the role of SPARC in this signaling pathway. We are also studying effects of the other soluble metabolites identified in the initial IMS studies on ovarian cancer progression, including progesterone and testosterone. Ultimately, we hope that our integration of mass spectrometry techniques with phenotypic and mechanistic readouts will elucidate the signals involved in early ovarian cancer progression to enable more effective therapeutic targets for HGSOC. Citation Format: Tova M. Bergsten, Sarah Levy, Hannah Lusk, Laura Sanchez, Joanna E. Burdette. Investigating the role of soluble metabolites in primary high grade serous ovarian cancer [abstract]. In: Proceedings of the AACR Special Conference: Cancer Metastasis; 2022 Nov 14-17; Portland, OR. Philadelphia (PA): AACR; Cancer Res 2022;83(2 Suppl_2):Abstract nr B006.

Primary High Grade Muscle Invasive Bladder Urothelial Carcinoma with Metastasis to the Penis Sparing the Urethra- A Case Presentation and Review of Literature

Background: Metastatic transitional cell carcinoma in the penis is extremely rare. Symptoms like penile pain, swelling, or priapism should raise the suspicion, when they happen in a known case of invasive bladder cancer. Case presentation: We report an unusual case of penile pain and swelling in a 69-year-old man, known to have invasive bladder cancer that was initially treated with radiotherapy. Although both penile ultrasound and MRI suspected hematoma or scarring rather than malignancy, the penile biopsy confirmed metastatic transitional cell carcinoma. Conclusion: Metastatic urothelial carcinoma in the penis is a rare presentation with poor prognosis, where treatment options are very limited and mainly palliative.

Primary Malignant Peripheral Nerve Sheath Tumor of the Breast: A Rare Case Report

Abstract Introduction/Objective Primary breast sarcomas are uncommon and primary mammary malignant peripheral nerve sheet tumors (MPNST) are exceptionally rare. MPNST’s are malignant variants of peripheral nerve sheath tumors. These neoplasms are often associated neurofibromatosis type I (NF-I) but can also occur sporadically. They tend to occur in the deeper soft tissues, trunk, and extremities. Methods/Case Report A 60-year-old female was referred to our University Hospital for evaluation of an abnormal mammogram. Patient noticed a mass in the left breast 3 months ago and mammogram showed a large solid mass located at the left superior breast. Subsequent biopsy of the left breast lesion showed high grade malignant neoplasm with differential diagnosis of malignant phyllodes tumor, primary sarcoma, and metaplastic carcinoma. The tumor was non-responsive to the initial neoadjuvant therapy. The patient underwent modified radical mastectomy. The excised tumor was well-circumscribed, tan-white, firm, measuring 9.6 x 6.1 x 4.3 cm. The neoplastic cells were positive for CD99, S-100, SOX-10, neuron specific enolase, p53, Vimentin, focally positive for neurofilament, D2-40, p63, and negative for epithelial, melanoma and other sarcoma markers. The tumor was triple negative ER, PR, HER-2, with Ki- 67 at 61%. A diagnosis of primary high grade malignant peripheral nerve sheath tumor of the breast was rendered. The patient does not have a history of NF-1. There was no lympho-vascular or perineural invasion. After the surgery, the patient followed up without complications. Results (if a Case Study enter NA) N/A Conclusion An accurate diagnosis of this rare entity is necessary because it plays a crucial role in the therapeutic options and prognosis. In our case the patient was treated with neo-adjuvant chemotherapy followed by modified radical mastectomy. The purpose of presenting this unique case is to provide awareness of the existence of this entity among pathologists and clinicians for better patient care.

Abstract 2429: Tumor and stromal AXL expression regulate ovarian cancer metastasis

Abstract Objective: Over 75% of patients with ovarian cancer present with widely metastatic disease. We have previously published that AXL is highly expressed in primary ovarian cancer tumors. However, it is unknown whether AXL expression in metastatic tumors correlates with outcome. Additionally, the role of stromally expressed AXL in metastasis has not been fully evaluated. Thus, the objective of this study is to evaluate the role of tumor and stromal AXL in the key steps of tumor metastasis. Methods: Immunohistochemistry was used to measure AXL expression in a tissue microarray with primary and metastatic high grade ovarian tumors. Attachment assays as well as transwell and spheroid invasion assays were performed on established ovarian cancer cell lines. Mesothelial cell clearance assays utilizing human omentum-cultured mesothelial cells (HPMC) and additional invasion assays utilizing normal omental fibroblasts (NOF) were performed. Results: 214 tumor samples were included from 139 patients: 122 primary and 92 metastatic sites, contributing to 85 matched samples. Most had high-grade serous histology (79%) and stage III-IV disease (79%). High AXL expression in metastatic tumors was associated with decreased overall survival (HRadj 1.8, 95% CI 1.03-3.1), but expression in primary tumors was not (1.1, 0.61-2.0). High vs. low AXL expression in metastases was associated with a decreased platinum-free interval (5.92 vs 15.9 months, P=0.03) and decreased progression-free survival (11.6 vs 18.8 months, P=0.02).Tumor AXL expression correlated with stromal AXL expression (R2=0.50, P<0.001). Human ovarian tumor cells depleted of AXL had decreased attachment (OVCAR3-TPMES, 0.55-fold decrease P<0.001) and invasion in transwell (OVCAR5, 173 vs 262 invasive tumor cells/hpf, P<0.01) and spheroid (ES2, 87% vs 31% area invaded, P<0.0001) invasion assays. Human ovarian cancer cells plated on AXL-deficient HPMCs had less cell clearance than those plated on AXL-expressing HPMCs (ES2, 6.0 vs 3.9 normalized area cleared, P<0.001). Further, human ovarian cancer cells plated on AXL-deficient NOFs had less invasion than tumor cells plated on AXL expressing NOFs (OVCAR5, 173 vs 262 invasive tumor cells/hpf, P<0.01). Conclusions: High AXL expression in metastatic ovarian cancer cells correlates with worse survival and worse response to chemotherapy. Further, AXL expression in both tumor and stromal cells contributes to the steps of ovarian cancer metastasis. Citation Format: Mary Margaret Mullen, Lillian N. van Biljon, Jeanne Quinn, Molly Greenwade, Gregory Opara, Hollie Noia, Ian S. Hagemann, Andrea R. Hagemann, Lindsay M. Kuroki, Carolyn K. McCourt, Premal H. Thaker, Matthew A. Powell, David G. Mutch, Dineo Khabele, Katherine C. Fuh. Tumor and stromal AXL expression regulate ovarian cancer metastasis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2429.

High ratio of pCXCR4/CXCR4 tumor infiltrating immune cells in primary high grade ovarian cancer is indicative for response to chemotherapy

BackgroundOvarian cancer (OC) is the fifth most common malignant female cancer with a high mortality, mainly because of aggressive high-grade serous carcinomas (HGSOC), but also due to absence of specific early symptoms and effective detection strategies. The CXCL12-CXCR4 axis is considered to have a prognostic impact and to serve as potential therapeutic target. Therefore we investigated the role of pCXCR4 and CXCR4 expression of the tumor cells and of tumor infiltrating immune cells (TIC) in high-grade serous OC and their association with the recurrence-free (RFS) and overall survival (OS).MethodsA tissue microarray of 47 primary high grade ovarian serous carcinomas and their recurrences was stained with primary antibodies directed against CXCR4 and pCXCR4. Beside the evaluation of the absolute tumor as well as TIC expression in primary and recurrent cancer biopsies the corresponding ratios for pCXCR4 and CXCR4 were generated and analyzed. The clinical endpoints were response to chemotherapy, OS as well as RFS.ResultsPatients with a high pCXCR4/CXCR4 TIC ratio in primary cancer biopsies showed a significant longer RFS during the first two years (p = 0.025). However, this effect was lost in the long-term analysis including a follow-up period of 5 years (p = 0.128). Interestingly, the Multivariate Cox regression analysis showed that a high pCXCR4/CXCR4 TIC ratio in primary cancer independently predicts longer RFS (HR 0.33; 95CI 0.13 - 0.81; p = 0.015). Furthermore a high dichotomized distribution of CXCR4 positive tumor expression in recurrent cancer biopsies showed a significantly longer 6-month RFS rate (p = 0.018) in comparison to patients with low CXCR4 positive tumor expression. However, this effect was not independent of known risk factors in a Multivariate Cox regression (HR 0.57; 95CI 0.24 - 1.33; p = 0.193).ConclusionsTo the best of our knowledge we show for the first time that a high pCXCR4/CXCR4 TIC ratio in primary HGSOC biopsies is indicative for better RFS and response to chemotherapy.Highlights• We observed a significant association between high pCXCR4/CXCR4 TIC ratio and better RFS in primary cancer biopsies, especially during the early postoperative follow-up and independent of known risk factors for recurrence.• High CXCR4 tumor expression in recurrent HGSOC biopsies might be indicative for sensitivity to chemotherapy. We found evidence that at the beginning of the disease (early follow-up) the role of the immune response seems to be the most crucial factor for progression. On the other hand in recurrent/progressive disease the biology of the tumor itself becomes more important for prognosis.• We explored for the first time the predictive and prognostic role of pCXCR4/CXCR4 TIC ratio in high-grade serous ovarian cancer.

Abstract 17074: Primary Cardiac Sarcoma In Elderly Patient And Need For High Index Of Suspicion

Case Presentation: Primary cardiac tumors are rare with an incidence between 0.0017 and 0.2%. Most cardiac tumors are benign such as myxomas, lipomas, and papillary fibroelastomas. Primary malignant cardiac tumors are even more uncommon, with cardiac sarcomas being the most common. We present a case of an 87-year old female who presented initially for progressive shortness of breath and concern for potential endocarditis vs intra-cardiac thrombus noted on outside hospital transthoracic echocardiogram. Blood cultures were negative, no leukocytosis or sequelae of infection were noted. Transesophageal echocardiogram (TEE) noted a large lesion attached to the anterior mitral leaflet, with additional lesions noted on the left atrial free wall just medial to the right sided pulmonary veins. Obstruction of mitral inflow was noted with a mean gradient through the mitral valve of 5mmHg. Cardiac MRI was performed for further delineation of lesions and based on tissue characteristics were felt to be thrombus (Figure 1). Hypercoagulability workup was negative, and there was no improvement in lesion size with systemic anticoagulation. Cardiothoracic surgery was consulted for surgical removal of the mass. Pre-operative cardiac catheterization showed multi-vessel obstructive coronary artery disease. It was also noted that the left circumflex artery appeared to supply blood into a discrete area in the left atrium. The patient was ultimately taken for surgical removal. Surgical pathology demonstrated primary high grade cardiac sarcoma. Discussion: The rarity and heterogeneity of primary cardiac tumors, along with many potential mimickers pose a diagnostic and therapeutic challenge. This, combined with the location and aggressive nature of the tumors, make them difficult to treat and incur a high mortality rate. This highlights the importance of maintaining a high index of suspicion and keeping a broad differential when evaluating intra-cardiac masses.

IMMU-14. REVEALING THE MANY MYELOID STATES IN HUMAN BRAIN TUMORS AND WAYS TO PERTURB THEM

Abstract Recent breakthroughs in immunotherapy have revolutionized treatment for many types of cancer, but unfortunately trials of these therapies have failed to provide meaningful life-prolonging benefit for brain tumor patients, potentially due to abundant immunosuppressive myeloid cells in the tumor. Our ultimate goal is to reprogram immunosuppressive tumor associated myeloid cells to an antitumor state to enable effective immunotherapy. Towards this goal, we have deeply characterized the immune microenvironment of more than 50 primary high and low grade gliomas using high-throughput single-cell RNA-sequencing to reveal recurrent myeloid cell states and immunosuppressive programs across IDH1 wild-type and mutant tumors. We have also established a brain tumor organoid model from primary patient tissue that maintains all of the tumor microenvironment, including myeloid and other immune cells. We utilize the this model to functionally test data-driven reprogramming strategies and understand how they impact the states of tumor and immune cells in the ex vivo human tumor microenvironment.

A combined treatment regimen of MGMT-modified \u03b3\u03b4 T cells and temozolomide chemotherapy is effective against primary high grade gliomas

Chemotherapeutic drugs such as the alkylating agent Temozolomide (TMZ), in addition to reducing tumor mass, can also sensitize tumors to immune recognition by transient upregulation of multiple stress induced NKG2D ligands (NKG2DL). However, the potential for an effective response by innate lymphocyte effectors such as NK and γδ T cells that recognize NKG2DL is limited by the drug’s concomitant lymphodepleting effects. We have previously shown that modification of γδ T cells with a methylguanine DNA methyltransferase (MGMT) transgene confers TMZ resistance via production of O6-alkylguanine DNA alkyltransferase (AGT) thereby enabling γδ T cell function in therapeutic concentrations of TMZ. In this study, we tested this strategy which we have termed Drug Resistant Immunotherapy (DRI) to examine whether combination therapy of TMZ and MGMT-modified γδ T cells could improve survival outcomes in four human/mouse xenograft models of primary and refractory GBM. Our results confirm that DRI leverages the innate response of γδ T cells to chemotherapy-induced stress associated antigen expression and achieves synergies that are significantly greater than either individual approach.

Measurable Absolute Basophil Count is Associated with Progression to Muscle Invasive Disease in Patients with High-Grade Non-Muscle Invasive Bladder Cancer

Intravesical bacillus Calmette-Guérin (BCG) is the standard adjuvant treatment for high-grade non-muscle invasive bladder cancer (NMIBC) after transurethral resection of the bladder tumor (TURBT). Despite this standard of care - 40% of patients experience a recurrence and - 15% progress to muscle invasive disease. Tumors with Th1-polarized lymphocytic infiltrate in the tumor immune microenvironment may have more favorable response to BCG compared to Th2- polarized tumors. Since basophils have a promoting role in Th2-polarization, we explored the association of blood basophils on the outcome of patients with high-grade NMIBC receiving BCG instillations. Clinical data and pre-operative complete blood count (CBC) results from patients with high-grade NMIBC (Ta, CIS and T1) who received BCG instillations at the Vancouver Prostate Centre (VPC) during years 2011 – 2018 were collected. Absolute basophil count (ABC) was correlated with response to BCG, disease recurrence and progression to muscle invasive disease. A total of 174 patients with primary high grade NMIBC treated with BCG at VPC were identified. Pre-operative complete blood count (CBC) data were available from 161 patients. After the initiation of BCG therapy 40% of patients developed recurrent tumors and 13% progressed to muscle invasive disease. ABC was measurable (³ 0.1 × 103 cells /µl) in the blood of 33 (19%) patients of whom 19 (58%) recurred. A total of 95% of recurrent tumors with measurable ABC were considered BCG-unresponsive. In Kaplan-Meier analysis measurable ABC was associated with tumor recurrence (p = 0.024) and progression to muscle invasive disease (p = 0.00015). In multivariate cox-regression analysis measurable ABC was considered an independent prognostic factor for progression to muscle invasive disease (HR 2.9, 95% CI:1.038 – 8.535, p = 0.042). Measurable blood absolute basophil count may have a prognostic impact for patients with high-grade NMIBC. Further studies with larger patient cohorts are needed to confirm these preliminary results.

High expression of Tie-2 predicts poor prognosis in primary high grade serous ovarian cancer.

Antiangiogenic therapy, although part of standard treatment in ovarian cancer, has variable efficacy. Furthermore, little is known about the prognostic biomarkers and factors influencing angiogenesis in cancer tissue. We evaluated the expression of angiopoietin-2 and two endothelial tyrosine kinase receptors, Tie-1 and Tie-2, and assessed their value in the prediction of survival in patients with malignant epithelial ovarian cancer. We also compared the expression of these factors between primary high grade serous tumors and their distant metastasis. We evaluated 86 women with primary epithelial ovarian cancer. Matched distal omental metastasis were investigated in 18.6% cases (N = 16). The expression levels of angiogenic factors were evaluated by immunohistochemistry in 306 specimens and by qRT-PCR in 111 samples. A high epithelial expression level of Tie-2 is a significant prognostic factor in primary high grade serous ovarian cancer. It predicted significantly shorter overall survival both in univariate (p<0.001) and multivariate survival analyses (p = 0.022). Low angiopoietin-2 expression levels in primary ovarian tumors were significantly associated with shorter overall survival (p = 0.015) in the univariate survival analysis. A low expression of angiopoietin-2 was also significantly related to high grade tumors, size of residual tumor after primary surgery and the recurrence of cancer (p = 0.008; p = 0.012; p = 0.018) in the whole study population. The expression of angiopoietin-2 and Tie-2 was stronger in distal omental metastasis than in primary high grade serous tumors in matched-pair analysis (p = 0.001; p = 0.002). The angiogenic factor, angiopoietin-2, and its receptor Tie-2 seem to be significant prognostic factors in primary epithelial ovarian cancer. Their expression levels are also increased in metastatic lesions in comparison with primary tumors.

Primary High Grade Serous Carcinoma of the Fallopian Tube: A Case Report

A 49-year-old, perimenopausal nulliparous woman with lower abdominal pain and abnormal uterine bleeding. Clinical and radiological findings suggested a right adnexal tumor. CA-125 level was moderately elevated. Total abdominal hysterectomy with bilateral salpingo-oophorectomy was done. Peroperative findings revealed a soft to friable growth arising from right fallopian tube with no involvement of ovaries. Histopathologic examination confirmed it to be a high grade serous carcinoma, FIGO stage IA. The histomorphology resembled high grade serous carcinoma of ovary, however ovaries on both sides appeared unremarkable. Surgery was uneventful and the patient was discharged after seven days of hospital stay. She did not receive postoperative chemotherapy or radiotherapy and is under follow-up. The case is reported for its occurrence in an uncommon anatomic site and preoperative dilemma with relevant review of literature.

MiRNA-103/107 in Primary High-Grade Serous Ovarian Cancer and Its Clinical Significance.

Simple SummaryMiRNA-103/107-DICER axis may be one of the key regulators of cancer aggressiveness. Data on miRNA-103/107 in high grade serous ovarian cancer is scarce. We aimed to assess miRNA-103/107 expression levels in high grade serous ovarian cancer tissues and relate them to patients’ clinicopathological data. MiRNA-103/107, DICER expression levels were also evaluated in selected ovarian cancer cell lines. Clinical and prognostic significance of miRNA-103/107 was not confirmed in our study. However, the results of our study support the possible existence of miRNA-103/107- DICER axis in ovarian cancer.High levels of miRNA-103/107 are associated with poor outcomes in the case of breast cancer patients. MiRNA-103/107-DICER axis may be one of the key regulators of cancer aggressiveness. MiRNA-103/107 expression levels have never been related to patients’ clinicopathological data in epithelial ovarian cancer. We aimed to assess miRNA-103/107 expression levels in high grade serous ovarian cancer tissues. Expression levels of both miRNAs were related to the clinicopathological features and survival. We also evaluated expression levels of miRNA-103/107 and DICER in selected ovarian cancer cell lines (A2780, A2780cis, SK-OV-3, OVCAR3). We assessed the relative expression of miRNA-103/107 (quantitative reverse transcription-polymerase chain reaction) in fifty archival formalin-fixed paraffin-embedded tissue samples of primary high grade serous ovarian cancer. Then, miRNA-103/107 and DICER expression levels were evaluated in selected ovarian cancer cell lines. Additionally, DICER, N-/E-cadherin protein levels were assessed with the use of western blot. We identified miRNA-107 up-regulation in ovarian cancer in comparison to healthy tissues (p = 0.0005). In the case of miRNA-103, we did not observe statistically significant differences between cancerous and healthy tissues (p = 0.07). We did not find any correlations between miRNA-103/107 expression levels and clinicopathological features. Kaplan–Meier survival (disease-free and overall survival) analysis revealed that both miRNAs could not be considered as prognostic factors. SK-OV-3 cancer cell lines were characterized by high expression of miRNA-103/107, relatively low expression of DICER (western-blot), and relatively high N-cadherin levels in comparison to other ovarian cancer cell lines. Clinical and prognostic significance of miRNA-103/107 was not confirmed in our study.

NOGGO Ov-42/MAMOC: Rucaparib maintenance after bevacizumab maintenance following carboplatin-based first line-chemotherapy in ovarian cancer patients.

TPS6102 Background: Ovarian cancer (OC) is associated with the highest mortality rates among gynecological malignancies, with most patients being diagnosed in advanced stages. The most common histological subtype is high grade serous OC, which is characterized by deficiency in homologous recombination. Debulking surgery, followed by platinum based chemotherapy and bevacizumab (bev), followed by maintenance therapy with bev, is the standard therapy for advanced BRCA wild type (BRCAwt) OC patients in Germany. BRCA mutant patients will receive maintenance with olaparib, according to SOLO1 data. The anticancer effects of PARP inhibitors (PARPi) seem to be increased by the addition of antiangiogenic drugs. Preclinical data showed increased HRD in tumors pretreated with bev, and clinical trials showed a benefit of the combination of antiangiogenic drugs and PARPi vs. PARPi alone. NOGGO Ov-42/MAMOC trial (NCT04227522) is a phase III, randomized, placebo-controlled study evaluating rucaparib maintenance following bevacizumab maintenance for the treatment of advanced primary high grade BRCAwt OC. Methods: 190 patients with histologically confirmed advanced (FIGO stage IIIA- IV of the 2014 FIGO classification) high grade serous or high grade endometrioid (based on local histopathological findings) OC, fallopian tube cancer, primary peritoneal cancer or clear cell carcinoma of the ovary will be randomized 2:1 to receive either rucaparib 600mg BID or placebo as maintenance therapy following first line chemotherapy with 6 cycles of Carboplatin/Paclitaxel and at least 12 cycles of bev, given together with chemotherapy and as maintenance. Only BRCAwt patients will be included in the trial. Randomization is stratified by surgery planned timepoint (neoadjuvant vs. adjuvant), surgical outcome (no residual tumor mass vs. residual tumor mass), response to chemotherapy followed by bev (CR/NED vs. PR/SD) and study center. Treatment will continue for 24 months or until disease progression, unacceptable toxicity, or withdrawal. Primary endpoint is PFS in BRCAwt patients per RECIST v1.1. Secondary endpoints are PFS2, quality of life (EORTC QLQ-C30/OV28, FSI, SF-12, PROC-CTCAE, every day memory questionnaire), daily activity, time to next medical intervention, time to next subsequent therapy, safety assessments and OS. Clinical trial information: NCT04227522.

Abstract PD6-7: Pathological features and lessons learned from screen detected ductal carcinoma in situ (DCIS) - Results from 11 337 cases in the UK Sloane project

Abstract Background: The UK Sloane project aims to improve knowledge of the pathology, radiology and management of DCIS through a UK national prospective audit of in situ carcinoma and atypias. Methods: Phase one included collection of multidisciplinary data on screen detected DCIS, lobular in situ neoplasia (LISN) and atypical ductal hyperplasia (ADH) between 2003-12 through collation of prospective proformas on imaging, pathology, management and subsequent outcome data. Results: A total of 11337 cases of DCIS from 82 UK screening units have been recorded; 54% of cases &amp;lt;20mm (n=6067), 26% &amp;lt;10mm (n=2881), 28% (10-19.9mm, n=3186). 1979 (18%) were 20 -29.9mm, 1071 (10%) 30 - 39.9mm and 1989 (18%) &amp;gt; 40mm and 131 (1%, unknown). There has been a slight but steady increase in DCIS size, from mean of 21.4mm in 2003/04 to 24.1mm in 2011/12. This was largely due to an increase in lesions measuring 30 mm or more. 7213 DCIS cases (63%) were of high nuclear grade, 27% (3121) intermediate and 9% were of low grade (34 unknown grade). A small gradual increase in the proportion of high grade DCIS was noted from 59% in 2004 to 65% in 2012, coupled with a slight decrease in the proportion of low grade DCIS, from 10% to 6% from 2004 to 2012. Comedo necrosis was reported in 61%, more commonly in high grade DCIS (78%) compared with low/intermediate grade lesions (31%). Solid DCIS was the predominant architectural pattern, seen in 61% of cases; 72% of high grade DCIS was of solid pattern, compared with 42% of non-high grade DCIS. Only 3% (233) of patients with breast conserving surgery had margin clearance described as 0mm, with another 3% having disease &amp;lt;1mm from the margin. The most common margin width was 10mm or over (35%; 2814 patients) with 8% (614), 20% (1559) and 25% (2015) having margin widths of 1-1.9mm, 2-4.9mm and 5-9.9mm, respectively. Atypical ductal hyperplasia (ADH) alone was reported in association with DCIS in 611 patients, of whom 39% had high grade DCIS, 37% intermediate grade DCIS and 24% had low grade disease. In a further 111 patients, ADH and lobular in situ neoplasia were associated with the DCIS, more commonly intermediate (36%) or low grade DCIS (34%) than high grade disease (29%). Lobular neoplasia alone was seen most commonly in patients with high grade DCIS (294 cases, 53%), rather than in patients with low grade DCIS (64, 12%) or intermediate grade disease (190, 34%). ADH and LISN were associated in 6% and 3.6% of cases respectively. Ipsilateral recurrences were almost equally distributed between in situ (n=212) and invasive (n=243) disease (unknown disease in 9 cases). Of the 243 patient who developed ipsilateral invasive disease, 148, 76 and 17 had high, intermediate and low grade disease respectively at presentation (2 original grade unknown). Of the 243 invasive lesions, 148 had a primary diagnosis of high grade DCIS; 66 of these 148 recurrences were also of histological grade 3, 60 were grade 2 and only 10 were of histological grade 1 (12 invasive grade not known). Contralateral lesions were more commonly invasive than DCIS (207 invasive carcinomas and 74 DCIS; 1 unknown). 52 of the invasive carcinomas were of grade 3, 106 grade 2 and 42 grade 1. High grade DCIS was the most common primary disease recorded (174) with 90 intermediate and 18 low grade DCIS. 120 of contralateral invasive cancers had had previous primary high grade DCIS, 72 intermediate and only 15 had had low grade DCIS. Conclusion: The study provides a unique opportunity to understand the histological characteristics and behaviour of screen detected DCIS and the change in the pathological features and management over time. An increase in DCIS size and proportion of high grade lesions is noted. Both ipsilateral and contralateral carcinoma are more common, in the short term, in patients with high grade DCIS but longer follow-up will provide more information. Citation Format: Abeer M Shaaban, Elena Provenzano, Bridget Hilton, Karen Clements, Shan Cheung, Alastair Thompson, Sarah Pinder, on behalf of the Sloane Project Steering Committee. Pathological features and lessons learned from screen detected ductal carcinoma in situ (DCIS) - Results from 11 337 cases in the UK Sloane project [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr PD6-7.

Expression profiles of VEGF-A, VEGF-D and VEGFR1 are higher in distant metastases than in matched primary high grade epithelial ovarian cancer

BackgroundIn many malignancies including ovarian cancer, different angiogenic factors have been related to poor prognosis. However, data on their relations to each other or importance as a prognostic factor in ovarian cancer is missing. Therefore, we investigated the expressions of VEGF-A, VEGF-C, and VEGF-D, and the receptors VEGFR1, VEGFR2, and VEGFR3 in patients with malignant epithelial ovarian neoplasms. We further compared expression levels between primary tumors and related distant omental metastases.MethodsThis study included 86 patients with malignant ovarian epithelial tumors and 16 related distant metastases. Angiogenic factor expression was evaluated using immunohistochemistry (n = 102) and qRT-PCR (n = 29).ResultsCompared to primary high grade serous ovarian tumors, the related omental metastases showed higher expressions of VEGF-A (p = 0.022), VEGF-D (p = 0.010), and VEGFR1 (p = 0.046). In univariate survival analysis, low epithelial expression of VEGF-A in primary tumors was associated with poor prognosis (p = 0.024), and short progression-free survival was associated with high VEGF-C (p = 0.034) and low VEGFR3 (p = 0.002). The relative expressions of VEGF-D, VEGFR1, VEGFR2, and VEGFR3 mRNA determined by qRT-PCR analyses were significantly correlated with the immunohistochemically detected levels of these proteins in primary high grade serous ovarian cancer and metastases (p = 0.004, p = 0.009, p = 0.015, and p = 0.018, respectively).ConclusionsThe expressions of VEGF receptors and their ligands significantly differed between malignant ovarian tumors and paired distant metastases. VEGF-A, VEGF-D, and VEGFR1 protein expressions seem to be higher in distant metastases than in the primary high grade serous ovarian cancer lesions.