Dominant Tumor Research Articles

211 Deep Phenotyping Reveals Germline Determinants of Disease Severity in Neurofibromatosis Type 2

INTRODUCTION: Neurofibromatosis type 2 (NF2) is an autosomal dominant tumor predisposition syndrome with central and peripheral nervous system tumors and non-neoplastic manifestations including peripheral neuropathy. NF2 presents with a large variation in penetrance and severity. Although germline nonsense and frameshift NF2mutations are hypothesized to confer severe disease, the relationship between mutation type and manifestations of this disease is not completely understood. METHODS: Patients (n = 169) with NF2 (Manchester criteria) were enrolled in a Natural History protocol (NCTNCT00598351). Deep phenotypic profiles were created (serially for 5 years) including clinical evaluations, self-reported functional measures, lifetime interventions (surgical, radiation and drug treatments), and imaging (tumor number, type and volume using volumetric MRI of the neuroaxis). Validated germline mutation data (n = 68) was used to examine relationships between genotype and phenotype with attention to NF2 mutation type (indel/large deletion), genomic effect (missense/nonsense/frameshift), predicted protein effect (truncating/non-truncating) and location (exonic/intronic/splice-site). RESULTS: Tumor burden varied greatly between patients (tumor number range 1-165, median 25). We found that cranial meningiomas were a major determinant of total tumor burden. Total tumor burden (number and volume) was associated with worse KPS and decline in KPS over the study protocol (p < 0.001). We found that truncating mutations in exons 11-12 were associated with more severe disease in terms of tumor number on MRI (p = 0.0439). CONCLUSION: This is the first large scale study to deeply phenotype patients with NF2 including longitudinal analysis and demonstrates several previously unrecognized trends related to germline mutations type, imaging findings, and measures of disease severity.

Proceedings of the North American Society of Head and Neck Pathology, Los Angeles, CA, March 20, 2022: DICER1-Related Thyroid Tumors.

DICER1 syndrome is an autosomal dominant tumor predisposition syndrome caused by germline DICER1 mutations. In the thyroid, DICER1 syndrome is associated with early-onset multinodular goiter and thyroid carcinomas. Subsequent studies have shown that somatic DICER1 mutations, though rare, can occur in follicular-patterned thyroid tumors, such as follicular adenomas and follicular thyroid carcinomas, with a higher rate seen in pediatric follicular thyroid carcinomas and in follicular thyroid carcinomas with a macrofollicular architecture. Somatic DICER1 mutations have also been reported in pediatric papillary thyroid carcinomas lacking other alterations typically associated with thyroid tumorigenesis. Although thyroid carcinomas with underlying DICER1 mutations are usually indolent, recent studies have shown that pediatric poorly differentiated thyroid carcinoma and thyroblastoma, both aggressive tumors, also harbor DICER1 mutations. This review will discuss mechanisms of DICER1 tumorigenesis and describe thyroid tumors associated with germline and somatic DICER1 mutations.

A Paradoxical Effect of Interleukin-32 Isoforms on Cancer.

IL-32 plays a contradictory role such as tumor proliferation or suppressor in cancer development depending on the cancer type. In most cancers, it was found that the high expression of IL-32 was associated with more proliferative and progression of cancer. However, studying the isoforms of IL-32 cytokine has placed its paradoxical role into a wide range of functions based on its dominant isoform and surrounding environment. IL-32β, for example, was found mostly in different types of cancer and associated with cancer expansion. This observation is legitimate since cancer exhibits some hypoxic environment and IL-32β was known to be induced under hypoxic conditions. However, IL-32θ interacts directly with protein kinase C-δ reducing NF-κB and STAT3 levels to inhibit epithelial-mesenchymal transition (EMT). This effect could explain the different functions of IL-32 isoforms in cancer. However, pro- or antitumor activity which is dependant on obesity, gender, and age as it relates to IL-32 has yet to be studied. Obesity-related IL-32 regulation indicated the role of IL-32 in cancer metabolism and inflammation. IL-32-specific direction in cancer therapy is difficult to conclude. In this review, we address that the paradoxical effect of IL-32 on cancer is attributed to the dominant isoform, cancer type, tumor microenvironment, and genetic background. IL-32 seems to have a contradictory role in cancer. However, investigating multiple IL-32 isoforms could explain this doubt and bring us closer to using them in therapy.

Pathologic and radiographic outcomes following prostate cancer diagnosis aided by IsoPSA testing.

276 Background: IsoPSA is a structure-based assay previously demonstrated to outperform prostate specific antigen (PSA) and free-to-total PSA ratio in detecting clinically significant prostate cancer at the time of biopsy (Stovsky, Klein 2019). Herein we report pathologic outcomes in patients treated via radical prostatectomy (RP) whom had undergone IsoPSA testing prior to their diagnostic biopsy. We also explore IsoPSA status in the context of MRI dependent findings, including PIRADS scores and PSA density. Methods: We conducted a retrospective review of patients whom had undergone IsoPSA testing prior to biopsy and RP at our institution between 2019-2021. We also identified subsets of patients with pre-operative prostate MRI’s. Exploratory analyses were performed to determine associations between IsoPSA and adverse histologic (cribiform, intraductal status (CB/ID), grade group status) pathologic (extraprostatic extension, seminal vesicle involvement, surgical margins) and radiographic (PSA density, PIRADS, location) features. We examined these data points in a randomly selected control group of RP patients whom had not had IsoPSA testing. Student’s T-test, Mann Whitney U, Kruskal Wallis, were used where appropriate. Results: A total of 83 patients underwent RP following IsoPSA testing, with 72.2% (60/83) also undergoing pre-operative prostate MRI. The mean total PSA was 10.3 ng/dL, IsoPSA index was 10.2 and prostate size 46.8 cc. IsoPSA was significantly associated with PSA density (median IsoPSA of 9.9 vs 7.8 for PSA density > 0.15, <0.15 respectively, p < 0.001). The median IsoPSA index was higher when the dominant tumor was found in the transitional zone versus peripheral zone (12.7 vs 8.8 p = 0.011). IsoPSA trended towards but was not associated with PIRADS-v2 score (1-2 vs 3 vs 4-5) (p = 0.1). IsoPSA was not selectively associated with adverse pathological or histological features. Conclusions: IsoPSA has been shown to predict clinically significant disease on biopsy, and as such may improve the selection of men for such intervention. In our initial cohort, IsoPSA reliably identified patients with clinically significant disease without selecting for unique adverse pathologic/histologic features when compared to a control group. Radiographically, IsoPSA was significantly associated with elevated PSA density ( > 0.15), tumor location (TZ vs PZ), and trended towards significance with PIRADS v.2 score (p = 0.1. Further work is encouraged to explore its adjunctive benefit in correlation to MRI features.

Epithelial-mesenchymal transition related to bone invasion in oral squamous cell carcinoma

IntroductionBone invasion is an important prognostic factor in oral squamous cell carcinoma, leading to a lower survival rate and the use of aggressive treatment approaches. Epithelial-mesenchymal transition (EMT) is possibly involved in this process, because it is often related to mechanisms of cell motility and invasiveness. This study examined whether a panel of epithelial-mesenchymal markers are present in cases of oral squamous cell carcinoma with bone invasion and whether these proteins have any relationship with patients’ clinical-pathological parameters and prognostic factors. MethodsImmunohistochemical analysis of E-cadherin, twist, vimentin, TGFβ1, and periostin was performed in paraffin-embedded samples of 62 oral squamous cell carcinoma cases. ResultsThe analysis revealed that most cases (66%) presented with a dominant tumor infiltrative pattern in bone tissue, associated with lower survival rates, when compared with cases with a dominant erosive invasion pattern (P = 0.048). Twenty-seven cases (43%) expressed markers that were compatible with total or partial EMT at the tumor-bone interface. There was no association between evidence of total or partial EMT and other demographic or prognostic features. E-cadherin-positive cases were associated with tobacco smoking (P = 0.022); vimentin-positive cases correlated with tumors under 4 cm (P = 0.043). Twistexpression was observed in tumors with a dominant infiltrative pattern (P = 0.041) and was associated with the absence of periostin (P = 0.031). ConclusionWe observed evidence of total or partial EMT in oral squamous cell carcinoma bone invasion. The transcription factor twist appears to be involved in bone invasion and disease progression.

Ascites and serial plasm circulating tumor DNA as a prognostic factor in peritoneal carcinomatosis after hyperthermic intraperitoneal chemotherapy.

661 Background: Hyperthermic intraperitoneal chemotherapy (HIPEC) is the main treatment for peritoneal carcinomatosis (PC). However, It is still a major problem to predict the efficacy of HIPEC. There is currently an urgent need for additional risk stratification for patients with PC to inform treatment decisions. The detection of circulating tumor DNA (ctDNA) represent a promising candidate liquid biopsy that may help to achieve this goal in a minimally invasive fashion. This study aimed to evaluate the predictive value of ctDNA from ascites and serial plasma for HIPEC. Methods: 19 patients with PC were enrolled. Plasma and ascites samples were collected before HIPEC and after the last HIPEC. Ascites and Serial plasma ctDNA were analyzed by next-generation sequencing (NGS). The molecular tumor burden index (mTBI) was used to detect ctDNA, and concurrent changes in the dominant clone variant allele frequency (VAF) and common tumor markers, were used as controls. The correlation between ascites and plasma ctDNA co-mutated genes was expressed by the VAF. Results: Firstly, the mTBI changes of 14 patients whom had plasma samples at two time points (baseline and postHIPEC) were analyzed. Among them, 3 patients had no gene mutation were detected in two time points. There were significant differences in mTBI before and after HIPEC in the remaining 11 patients (p = 0.026). the median Ascites progression free survival (PFS) was 3.35 months (95% CI: 2.34 – 5.13 months), and the median overall survival (OS) was 5.93 months (95% CI: 4.93 – 11.17 months). The mTBI decline was significantly positively correlated with ascites PFS (r = 0.673, p = 0.023) and moderately positively correlated with OS (r = 0.510, p = 0.109). The highest VAF in plasma samples was defined as the main clone mutation. The dominant clone VAF decline was moderately positively correlated with ascites PFS (r = 0.588, p = 0.057) and slightly positively correlated with OS (r = 0.386, p = 0.241). As the controls, We found that the common tumor markers decline was no correlated with ascites PFS(r = 0.091, p = 0.790) and OS (r = 0.287, p = 0.396). We further analyzed the correlation of VAF between ascites and plasma co-mutation genes in 12 patients. The VAF of co-mutated genes in plasma and ascites was positively correlated (r = 0.794, p = 0.001). In addition, ascites PFS (P = 0.003, HR 0.157, 95%CI: 0.046–0.540) and OS (P = 0.017, HR 0.296, 95% CI: 0.109–0.804) in the low mTBI group (mTBI＜0.67) at baseline were significantly better than those in the high mTBI group (mTBI≥0.67). Conclusions: Serial Plasma ctDNA can be used as a biomarker for predicting the efficacy of HIPEC for PC, and its accuracy was significantly higher than that of the dominant clone VAF and concurrent tumor markers. A high baseline mTBI (≥0.67) may be an independent risk factor for prognosis. However, a larger sample size study are needed to validate our results. Clinical trial information: ChiCTR2000035025.

DINs: Deep Interactive Networks for Neurofibroma Segmentation in Neurofibromatosis Type 1 on Whole-Body MRI.

Neurofibromatosis type 1 (NF1) is an autosomal dominant tumor predisposition syndrome that involves the central and peripheral nervous systems. Accurate detection and segmentation of neurofibromas are essential for assessing tumor burden and longitudinal tumor size changes. Automatic convolutional neural networks (CNNs) are sensitive and vulnerable as tumors' variable anatomical location and heterogeneous appearance on MRI. In this study, wepropose deep interactive networks (DINs) to address the above limitations. User interactions guide the model to recognize complicated tumors and quickly adapt to heterogeneous tumors. We introduce a simple but effective Exponential Distance Transform (ExpDT) that converts user interactions into guide maps regarded as the spatial and appearance prior. Comparing with popular Euclidean and geodesic distances, ExpDT is more robust to various image sizes, which reserves the distribution of interactive inputs. Furthermore, to enhance the tumor-related features, we design a deep interactive module to propagate the guides into deeper layers. We train and evaluate DINs on three MRI data sets from NF1 patients. The experiment results yield significant improvements of 44% and 14% in DSC comparing with automated and other interactive methods, respectively. We also experimentally demonstrate the efficiency of DINs in reducing user burden when comparing with conventional interactive methods.

Current Advances in Immune Checkpoint Inhibition and Clinical Genomics in Upper Tract Urothelial Carcinoma: State of the Art.

Upper tract urothelial carcinoma (UTUC) is a rare and challenging-to-treat malignancy. In most patients it is a sporadic tumor entity, less commonly it falls on the spectrum of Lynch syndrome, an autosomal dominant familial tumor syndrome. Localized UTUC with high-risk features as well as the metastatic disease scenario might require systemic therapy. Platinum-based combination chemotherapy is currently the recommended management option. However, the introduction of immune checkpoint inhibitors into the therapeutic armamentarium has led to a paradigm shift in treatment standards. Immunotherapy has been shown to be safe and effective in treating at least metastatic UTUC, although UTUC-specific high-level evidence is still lacking. Recent technological advances and noteworthy research efforts have greatly improved the general understanding of the biological landscape of UTUC. According to the main findings, UTUC represent a particular subtype of urothelial carcinoma frequently associated with activated FGFR3 signaling, a luminal–papillary phenotype and a T-cell-depleted microenvironment. This improved knowledge promises precision oncology approaches that match treatment decision strategies and genomic profile to ultimately result in better clinical outcomes. The aim of this review was to summarize the main currently available evidence on immune checkpoint inhibition and clinical genomics in UTUC.

Ascites and Serial Plasma Circulating Tumor DNA for Predicting the Effectiveness of Hyperthermic Intraperitoneal Chemotherapy in Patients With Peritoneal Carcinomatosis.

PurposeWe investigated the value of ascites and serial plasma circulating tumor DNA (ctDNA) for predicting response to hyperthermic intraperitoneal chemotherapy (HIPEC), monitoring tumor burden, and predicting prognosis in patients with peritoneal carcinomatosis (PC).Experimental DesignIn this observational study, 19 patients with PC were enrolled. Serial plasma ctDNA was analyzed using next-generation sequencing. The molecular tumor burden index (mTBI) was used to detect ctDNA, and concurrent changes in the dominant clone variant allele frequency (VAF) and common tumor markers were used as controls. The correlation between ascites and plasma ctDNA comutated genes was expressed by VAF. The overall response rate (complete response + partial response) after HIPEC was determined. Ascites progression-free survival (PFS) and overall survival (OS) were determined, and potential correlations between these outcomes and change in mTBI (△mTBI), change in sum-VAF (△sum-VAF), dominant close VAF, and tumor markers were assessed.ResultsThe overall response rate at 1 month after HIPEC was 100%. The △mTBI (r = 0.673; P = 0.023) and △sum-VAF (r = 0.945; P <0.001) were significantly positively correlated with ascites PFS; these correlations were stronger than those of the dominant clone VAF (r = 0.588; P = 0.057) and tumor markers in the same period (r =0.091; P = 0.790). Patients with a low baseline mTBI (<0.67) demonstrated significantly longer ascites PFS (P = 0.003; HR = 0.157; 95% CI: 0.046–0.540) and OS (P = 0.017; HR = 0.296; 95% CI: 0.109–0.804) than those with a high baseline mTBI (≥0.67). Consistent mutations were detected in plasma and ascites (r = 0.794; P = 0.001).ConclusionA real-time serial plasma ctDNA assay accurately reflected tumor burden. The △mTBI and △sum-VAF can be used as predictors of HIPEC efficacy in patients with PC. A high baseline mTBI may be a negative risk factor for prognosis.

Medulloblastoma and Cowden syndrome: Further evidence of an association.

Cowden syndrome (CS) is an autosomal dominant hamartoma and tumor predisposition syndrome caused by heterozygous pathogenic germline variants in PTEN in most affected individuals. Major features include macrocrania, multiple facial tricholemmomas, acral and oral keratoses and papillomas, as well as mammary, non-medullary thyroid, renal, and endometrial carcinomas. Lhermitte-Duclos disease (LDD), or dysplastic gangliocytoma of the cerebellum, is the typical brain tumor associated with CS; the lifetime risk for LDD in CS patients has been estimated to be as high as 30%. In contrast, medulloblastoma is much rarer in CS, with only 4 reported cases in the literature. We report a 5th such patient. All 5 patients were diagnosed between 1 and 2 years of age and not all showed the pathognomonic clinical stigmata of CS at the time of their medulloblastoma diagnosis. Where detailed information was available, the medulloblastoma was of the SHH-subtype, in keeping with the observation that in sporadic medulloblastomas, PTEN-alterations are usually encountered in the SHH-subtype. Medulloblastomas can be associated with several tumor-predisposition syndromes and of the 4 medulloblastoma subtypes, SHH-medulloblastomas in children have the highest prevalence of predisposing germline variants (approx. 40%). CS should be added to the list of SHH-medulloblastoma-associated syndromes. Germline analysis of PTEN should be performed in infants with SHH-medulloblastomas, regardless of their clinical phenotype, especially if they do not carry pathogenic germline variants in PTEN or PTEN, the most commonly altered predisposing genes in this age-group. In addition, these cases show that CS has a biphasic brain tumor distribution, both in regards to the age of onset and the tumor type: a small number of CS patients develop a medulloblastoma in infancy while many more develop LDD in adulthood.

Discovering dominant tumor immune archetypes in a pan-cancer census

Cancers display significant heterogeneity with respect to tissue of origin, driver mutations, and other features of the surrounding tissue. It is likely that individual tumors engage common patterns of the immune system-here "archetypes"-creating prototypical non-destructive tumor immune microenvironments (TMEs) and modulating tumor-targeting. To discover the dominant immune system archetypes, the University of California, San Francisco (UCSF) Immunoprofiler Initiative (IPI) processed 364 individual tumors across 12 cancer types using standardized protocols. Computational clustering of flow cytometry and transcriptomic data obtained from cell sub-compartments uncovered dominant patterns of immune composition across cancers. These archetypes were profound insofar as they also differentiated tumors based upon unique immune and tumor gene-expression patterns. They also partitioned well-established classifications of tumor biology. The IPI resource provides a template for understanding cancer immunity as a collection of dominant patterns of immune organization and provides a rational path forward to learn how to modulate these to improve therapy.

Clinical characteristics and risk factors for survival in affected offspring of von Hippel-Lindau disease patients

BackgroundVon Hippel-Lindau (VHL) disease is an autosomal dominant genetic tumour syndrome with poor prognosis. The clinical manifestation was found to be more serious in affected offspring of patients with VHL...

Abstract PO-111: A human single-cell RNA sequencing atlas of pancreatic ductal adenocarcinoma enables harmonized cell type calling and comprehensive analyses of potential intercellular signaling

Abstract Purpose: Pancreatic ductal adenocarcinoma (PDAC) is characterized by a dismal prognosis, low ductal cancer cellularity and a dominant tumor microenvironment (TME) in response to malignant degeneration. Modern single-cell RNA sequencing (scRNA-seq) platforms fundamentally improved the opportunities to analyze PDAC biology through isolation of diverse cell types including ductal, mesenchymal, myeloid and lymphoid populations. Published scRNA-seq data of PDAC patients provide innovative and astounding insights, but are limited by cohort size and intrinsically vulnerable to internal biases. Herein, we present a human single-cell PDAC atlas which links the previous sequencing efforts aiming for increasing depth and robustness with the combined analysis of transcriptomes. Methods: We selected scRNA-seq data of all patients with PDAC from six publicly available datasets (published between 2019-2020). Altogether, 61 different human samples with 142,807 cells were integrated into one dataset leveraging 15,219 genes, which were conclusively identical between all datasets based on the utilized nomenclature in the provided raw data. In addition, we extracted 16 samples with 31,587 cells from control pancreas specimens which were included in three out of the six datasets. The analyses were performed using the R statistics and Python environments utilizing established software including Monocle3 and Seurat. Results: After computational preprocessing of the integrated dataset, cell types were identified based on differentially expressed and canonical markers. The generated PDAC atlas consists of 26% ductal cancer, 2% ductal normal, 12% mesenchymal (stellate cells and cancer-associated fibroblasts), 18% myeloid, 19% lymphoid and 23% other cells (including acinar and endocrine cells). Copy number variation analyses confirmed the discrimination between cancer and normal ductal cells. Certain subpopulations within cell types were mapped based on the expression of supervised gene sets. Within the ductal cancer cell population, the Classical and Basal-like Moffitt signatures coexisted in the majority of patients with distinct ratios and predominance, which were associated with differences in the TME composition. Furthermore, the presence of myofibroblasts and inflammatory fibroblasts could be quantified at the patient-level. The reconstruction of intercellular signaling between ductal cancer cells and several TME components revealed potential ligands, receptors and transcription factors that may functionally define routes and polarity of cross-talk in PDAC. Conclusion: This human scRNA-seq atlas is the largest available dataset of patients with PDAC while harmonizing previously published data. It is engineered to analyze current knowledge gaps with increased rigor and, most importantly, overcomes obstacles related to bulk transcriptome sequencing data. Molecular characteristics of the ductal cancer cells and TME components inferred from the presented framework are promising to identify disease- and patient-specific signaling, key regulators, and therapeutic targets. Citation Format: Benedict Kinny-Köster, Melissa R. Lyman, Dimitrios N. Sidiropoulos, Melanie Loth, Alexandra B. Puscek, Laura D. Wood, Jin He, Jun Yu, Richard A. Burkhart, Elizabeth M. Jaffee, Jacquelyn W. Zimmerman, Elana J. Fertig. A human single-cell RNA sequencing atlas of pancreatic ductal adenocarcinoma enables harmonized cell type calling and comprehensive analyses of potential intercellular signaling [abstract]. In: Proceedings of the AACR Virtual Special Conference on Pancreatic Cancer; 2021 Sep 29-30. Philadelphia (PA): AACR; Cancer Res 2021;81(22 Suppl):Abstract nr PO-111.

CT-based radiomics stratification of tumor grade and TNM stage of clear cell renal cell carcinoma.

To evaluate the utility ofCT-based radiomics signatures in discriminating low-grade (grades 1-2) clear cell renal cell carcinomas (ccRCC) from high-grade (grades 3-4) and low TNM stage (stages I-II) ccRCC from high TNM stage (stages III-IV). A total of 587 subjects (mean age 60.2years ± 12.2; range 22-88.7years) with ccRCC were included. A total of 255 tumors were high grade and 153 were high stage. For each subject, one dominant tumor was delineated as the region of interest (ROI). Our institutional radiomics pipeline was then used to extract2824 radiomics features across 12 texture families from themanually segmented volumes of interest. Separate iterations of the machine learning models using all extracted features (full model) as well as only a subset of previously identified robust metrics (robust model) were developed. Variable of importance (VOI) analysis was performed using the out-of-bag Gini index to identify the top 10 radiomics metrics driving each classifier. Model performance was reported using area under the receiver operating curve (AUC). The highest AUC to distinguish between low- and high-grade ccRCC was 0.70 (95% CI 0.62-0.78) and the highest AUC to distinguish between low- and high-stage ccRCC was 0.80 (95% CI 0.74-0.86). Comparable AUCs of 0.73 (95% CI 0.65-0.8) and 0.77 (95% CI 0.7-0.84) were reported using the robust model for grade and stage classification, respectively. VOI analysis revealed the importance of neighborhood operation-based methods, including GLCM, GLDM, and GLRLM, in driving the performance of the robust models for both grade and stage classification. Post-validation, CT-based radiomics signatures may prove to be useful tools to assess ccRCC grade and stage and could potentially add to current prognostic models. Multiphase CT-based radiomics signatures have potential to serve as a non-invasive stratification schema for distinguishing between low- and high-grade as well as low- and high-stage ccRCC. • Radiomics signatures derived from clinical multiphase CT images were able to stratify low- from high-grade ccRCC, with an AUC of 0.70 (95% CI 0.62-0.78). • Radiomics signatures derived from multiphase CT images yielded discriminative power to stratify low from high TNM stage in ccRCC, with an AUC of 0.80 (95% CI 0.74-0.86). • Models created using only robust radiomics features achieved comparable AUCs of 0.73 (95% CI 0.65-0.80) and 0.77 (95% CI 0.70-0.84) to the model with all radiomics features in classifying ccRCC grade and stage, respectively.

A Prospective Study of Clonal Evolution in Follicular Lymphoma: Circulating Tumor DNA Correlates with Overall Tumor Burden and Fluctuates over Time without Therapy

Background: Follicular lymphoma (FL) shows marked variation in clinical course including spontaneous regression and histologic transformation (HT). Watchful waiting (W&W) is routinely applied to pts with newly diagnosed FL, but monitoring strategies are not standardized. Pts with progression within 1-2y of diagnosis have worse outcomes, but the biologic basis is unclear and biologic-based classifiers are not routinely applied at diagnosis. Circulating tumor DNA (ctDNA) is a highly tumor-specific biomarker that is prognostic in aggressive B-cell lymphomas, but its ability to serially monitor FL remains undefined. We applied a next-generation sequencing assay to identify tumor clonotypes for serial monitoring of peripheral blood in pts with untreated FL as part of an ongoing prospective clinical trial [NCT03190928].Methods: Pts with grade I-II or 3A FL are eligible if evaluable disease on CT or FDG-PET, age ≥18, ECOG ≤2, no evidence of HT, and no prior systemic therapy. Pts undergo W&W until they meet uniform protocol-defined treatment criteria and remain on study until second-line therapy. Baseline testing includes labs, peripheral blood flow cytometry, BM biopsy/aspirate, CT and FDG-PET scans, and research biopsy. Pt have clinic visits every 4m for 2y, every 6m in years 3-5, then annually. CT scans are every 8m for 2y, then annually. FDG-PET scans are at baseline, at 2y, and any time of suspected progression. Peripheral blood samples including Streck tubes (plasma) and PBMCs are drawn at each clinic visit and stored. For ctDNA analysis, tumor DNA was amplified from FFPE using locus-specific primer sets for the Ig heavy-chain and light-chain loci along with BCL1/BCL2 translocations (Adaptive Biotechnologies). Amplified products were sequenced and tumor clonotypes were identified in plasma and PBMCs. Serial tracking of ctDNA was done in plasma and blinded to clinical outcomes.Results: 77 pts enrolled between July 2017 and July 2021. Median age was 57 (range 24-83) including 14 (18%) low-risk, 29 (38%) intermediate-risk, and 34 (44%) high-risk by FLIPI. Fourteen (18%) pts had stage I-II disease. Forty-three (56%) pts had monoclonal B-cells on peripheral blood flow cytometry. Twenty-nine (38%) pts progressed requiring frontline therapy including 7 (9%) pts with HT. Twenty-five (32%) pts were monitored ≥2y with no progression including 10 (13%) pts with evidence of at least some spontaneous regression by CT. Twenty (26%) pts were on study for <2y and 3 (4%) pts were unevaluable. Of 36 pts with FFPE analyzed, 35 (97%) had ≥1 dominant tumor clonotype identified for tracking. Of these, 32 (91%) had ≥1 dominant clonotype identified in plasma suitable for tracking. Three pts without available FFPE had the dominant clonotype identified from plasma that was used for tracking. In 28 pts, plasma was compared to PBMCs, and ≥1 clonotype was identified in both compartments in 21 (75%), plasma only in 5 (18%), and neither in 2 (7%). The median overall levels of baseline plasma ctDNA was 104.7 counts/mL (range 4-2096); progressors had median levels of 136.0 counts/mL (range 4-1493) compared to 40.9 count/mL (32-2096)(p=0.85) for non-progressors (Figure 1A). Baseline ctDNA correlated with the total metabolic tumor volume (TMTV) on FDG-PET scan (r=0.49, p=<0.006)(Figure 1B). Pts who required immediate treatment often had very high baseline levels of ctDNA (black dots, Figure 1C) and serial monitoring prior to progression demonstrated patterns of sharp increases in ctDNA prior to progression or relatively stable levels in others (Figure 1C). Notably, significant fluctuations were noted in ctDNA for non-progressing pts with an overall trend for decreasing values including four pts with evidence of spontaneous regression by CT with corresponding decreases in ctDNA over time (Figure 1D). As a notable examples, FL_14 had baseline ctDNA level of 2096 counts/mL with decreases to 101 counts/mL after 4 months, 14 counts/mL at 16 months, and no detectable ctDNA at 2 years.Conclusions: ctDNA quantified from plasma in FL mirrors TMTV. Serial monitoring of ctDNA in patients without therapy demonstrated various patterns of fluctuation, including some patients in which ctDNA became undetectable coincident with spontaneous clinical regressions. ctDNA thus provides a non-invasive platform to monitor the natural history of FL, enabling future studies of tumor immune surveillance in this disease. [Display omitted] DisclosuresJacob: Adaptive Biotechnologies: Current Employment, Current equity holder in publicly-traded company. Bagaev: BostonGene Corp.: Current Employment, Current holder of stock options in a privately-held company, Patents & Royalties: BostonGene. Meerson: BostonGene: Current Employment, Current holder of stock options in a privately-held company, Patents & Royalties: BostonGene. Postovalova: BostonGene Corp.: Current Employment, Current holder of stock options in a privately-held company, Patents & Royalties: BostonGene. Kudryashova: BostonGene: Current Employment, Current holder of stock options in a privately-held company, Patents & Royalties: BostonGene. Kotlov: BostonGene Corp: Current Employment, Current holder of stock options in a privately-held company, Patents & Royalties. Fowler: BostonGene: Current Employment, Current holder of stock options in a privately-held company.

Combination Therapy Strategy for Lymphoma Based on Cancer Energy Metabolism of OPB-111077, a Novel Antitumor Agent Inhibiting Mitochondrial Oxidative Phosphorylation

Development of antitumor agents targeting energy metabolism pathways of cancer cells has attracted much attention in recent days. In general, most cancer cells are known to display Warburg effect. Recently, it has been reported that cancer cells exist as heterogeneous groups in the microenvironment surrounding cancer cells and that not only glycolysis but also mitochondrial oxidative phosphorylation (OXPHOS) is important for cancer growth. In addition, many research groups have reported that the acquisition of anticancer drug resistance is caused by metabolic reprogramming from glycolysis to OXPHOS. Therefore, OXPHOS inhibitors could be useful antitumor agents. OPB-111077 is an orally active novel antitumor agent and has the inhibitory effect on mitochondrial OXPHOS. OPB-111077 had the inhibitory effect on mitochondrial respiratory chain complex I which led to the inhibition of energy production and activation of AMPK-mTOR energy stress sensor pathway. In in vitro growth inhibition studies, OPB-111077 showed potent inhibitory effects on the growth of various human blood tumor cell lines derived from leukemia, multiple myeloma and lymphoma with IC 50 values between 18.6 and 525.3 nM, and on the growth of human solid tumor cell lines derived from liver cancer, lung cancer, gastric cancer and breast cancer with IC 50 values ranging from 92.6 to 1727.7 nM. In in vivo studies using SCID mice bearing tumors from human tumor cell lines, daily oral administration of OPB-111077 demonstrated significant antitumor effects against leukemia, lymphoma, liver, gastric and breast cancer cell line-derived tumor, dose-dependently.Here, we report the combination therapy strategy based on the cancer energy metabolism of OPB-111077. We found that OPB-111077 combined with alkylating agent, cyclophosphamide or bendamustine, showed the synergistic effect on xenograft mice model using human diffuse large B‐cell lymphoma (DLBCL) cell line. To clarify this mechanism, we examined the effect of alkylating agents on mitochondrial respiration in vitro using flux analyzer and found that alkylating agents induced OXPHOS nature in the DLBCL cell line. Furthermore, the administration of alkylating agents to DLBCL cell line xenograft model mice followed by mRNA expression analysis of their tumor tissue confirmed that expression of OXPHOS-related markers was induced. These results suggest the administration of alkylating agents induced reprogramming to OXPHOS predominant nature in tumor. The tumor environment is actively reprogrammed to OXPHOS by alkylating agents, and it is changed to a state in which the antitumor effect of OPB-111077 can be more exerted. Thus, alkylating agents enhance the effect of OPB-111077 by tilting glycolytically dominant tumors to OXPHOS dominant. The alkylating agents, cyclophosphamide and bendamustine, are used as standard therapies for lymphoma. OPB-111077 could be treated in a wide range of applications as a combination therapy with the alkylating agents for lymphoma.In clinical, we have confirmed that OPB-111077 has tolerable and controllable toxicity profile of single agent in some advanced cancer patients including DLBCL. Bendamustine and rituximab (BR) therapy is indicated for the treatment of patients who are ineligible for transplantation of relapsed / refractory (R/R) DLBCL. However, there is still a high unmet need for patients with R/R DLBCL due to no standard treatment for transplant‐ineligible patients. We are conducting combination therapy of OPB-111077 with bendamustine and rituximab in Phase 1 clinical trial for R/R DLBCL in Japan. DisclosuresOhi: Otsuka Pharmaceutical Co.,Ltd.: Current Employment. Okuno: Otsuka Pharmaceutical Co.,Ltd.: Current Employment. Tanaka: Otsuka Pharmaceutical Co.,Ltd.: Current Employment. Ohtani: Otsuka Pharmaceutical Co.,Ltd.: Current Employment. OffLabel Disclosure:Compound: OPB-111077 Purpose: Development of novel antitumor agent

Hot needles can confirm accurate lesion sampling intraoperatively using [18F]PSMA-1007 PET/CT-guided biopsy in patients with suspected prostate cancer

PurposeProstate-specific membrane antigen (PSMA)-targeted PET is increasingly used for staging prostate cancer (PCa) with high accuracy to detect significant PCa (sigPCa). [68 Ga]PSMA-11 PET/MRI-guided biopsy showed promising results but also persisting limitation of sampling error, due to impaired image fusion. We aimed to assess the possibility of intraoperative quantification of [18F]PSMA-1007 PET/CT uptake in core biopsies as an instant confirmation for accurate lesion sampling.MethodsIn this IRB-approved, prospective, proof-of-concept study, we included five consecutive patients with suspected PCa. All underwent [18F]PSMA-1007 PET/CT scans followed by immediate PET/CT-guided and saturation template biopsy (3.1 ± 0.3 h after PET). The activity in biopsy cores was measured as counts per minute (cpm) in a gamma spectrometer. Pearson’s test was used to correlate counts with histopathology (WHO/ISUP), tumor length, and membranous PSMA expression on immunohistochemistry (IHC).ResultsIn 43 of 113 needles, PCa was present. The mean cpm was overall significantly higher in needles with PCa (263 ± 396 cpm) compared to needles without PCa (73 ± 44 cpm, p < 0.001). In one patient with moderate PSMA uptake (SUVmax 8.7), 13 out of 24 needles had increased counts (100–200 cpm) but only signs of inflammation and PSMA expression in benign glands on IHC. Excluding this case, ROC analysis resulted in an AUC of 0.81, with an optimal cut-off to confirm PCa at 75 cpm (sens/spec of 65.1%/87%). In all 4 patients with PCa, the first or second PSMA PET-guided needle was positive for sigPCa with high counts (156–2079 cpm).Conclusions[18F]PSMA-1007 uptake in PCa can be used to confirm accurate lesion sampling of the dominant tumor intraoperatively. This technique could improve confidence in imaging-based biopsy guidance and reduce the need for saturation biopsy.Trial registration numberNCT03187990, 15/06/2017.

Different Fumarate Hydratase Gene Variants Are Associated With Distinct Cancer Phenotypes.

Whether individuals with monoallelic FH pathogenic variants (PVs) associated with autosomal recessive fumarate hydratase (FH) deficiency are also at risk of autosomal dominant FH-associated tumors is of paramount clinical importance. A retrospective study of individuals with a PV in the FH gene identified via multigene panel testing from 2012 to 2019 through a single testing laboratory was performed. Cancer histories of individuals with PVs in FH (FH PV) were compared to those with PVs associated only with autosomal recessive FH deficiency (FH-d PV) and to FH-negative controls. Cancer histories of individuals with truncating versus nontruncating FH PV were also compared. Individuals with FH PV were more likely to have kidney cancer than those with FH-d PV (odds ratio, 9.0; 95% CI, 4.4 to 20.0; P < .001) or FH-negative controls (odds ratio, 7.6; 95% CI, 5.2 to 11.2; P value < .001). The FH PV cohort had kidney cancer at a significantly younger age (median age: 35.0 years; interquartile range, 26.0-45.0 years) than the FH-d PV cohort (median age: 44.5 years; interquartile range, 43.5-53.5 years; P = .011). Within the FH PV cohort, there were no differences in the frequency or age at kidney cancer between those with truncating versus nontruncating PV. Unlike FH PV, FH-d PV are not associated with kidney cancers at early ages of onset. The FH-d PV cohort had a cancer phenotype that resembled FH-negative controls. These data may inform genetic counseling and risk assessment of individuals with FH-d PV.

Defining MR-Based Parameters of Treatment Response to Immune-Modulatory Therapy for Grade Group 5 Prostate Cancer

<h3>Purpose/Objective(s)</h3> A phase I/II study combining nivolumab with androgen deprivation therapy (ADT) and high dose brachytherapy (HDR) followed by external beam radiotherapy (EBRT) indicated that the regimen is well tolerated and effective with radiographic and pathologic evidence of increased antitumor activity. In the present study we sought to utilize MR-based imaging characteristics to define parameters of antitumor response to HDR+EBRT and nivolumab in patients with Grade Group (GG) 5 prostate cancer. <h3>Materials/Methods</h3> Eligible patients received ADT in combination with nivolumab and HDR followed by EBRT delivered using MR-guided radiotherapy. Data from 12 patients were analyzed using MRI from diagnosis, once-weekly treatment from fractions 5, 10, 15 and 25 and 3-month follow up. Images were fused and analyzed using an image analysis package. At time of enrollment the dominant tumor (ROI) was contoured and tracked at different timepoints. The change in T2 value was assessed using voxel data at diagnosis and follow up. The delta (δ) of average change was estimated between partial and complete responders from diagnosis and follow up. The same analysis was done on the treatment MR using steady-state coherent sequences. All data were normalized against the prostate values. <h3>Results</h3> Median follow up was 17 months. Complete radiographic response (CR) was seen in 6 out of 12 patients. A δ T2 was estimated between baseline and follow up T2 tumor ROI. Partial responders had higher δ of 62.5 as compared to complete responders with δ of 28. When compared longitudinally over 5 fractions, on average change in steady-state coherent sequence over time was higher in partial responders than complete responders. <h3>Conclusion</h3> Our preliminary results show a greater δ in T2 signal in partial responders consistent with continued tumor response on weekly imaging, while complete responders showed minimal change over time. This finding suggests that CR may derive a rapid and early response to nivolumab, ADT and HDR than the partial responders. Furthermore, tracking δ in T2 signal and steady-state coherent sequences may be a reliable tool for defining tumor response in real-time and needs further validation in a larger cohort. This study was registered under NCT03543189.

Clinical and morphological factors that increase the risk of locoregional metastasis of papillary thyroid cancer

Background. The sensitivity of the ultrasound method to determine lymph node metastases of papillary thyroid cancer (PTC) to the central lymphatic collector of the neck at the preoperative stage is low, 49 % only, therefore assessment of the factors leading to the prolongation of the process is of great importance in the development of surgical treatment tactics.Aim — to evaluate factors that increase the risk of locoregional metastases of papillary thyroid cancer and substantiate the advisability of systematic central neck dissection (SCND).Materials and methods. A retro-prospective single center study of the risk of PTC prolongation in the form of locoregional metastases (LRM) was carried out. The data of 514 patients operated for papillary thyroid disease were processed. The main group included 240 patients in whom LRM was found according to the results of histopathological examination (HPE), control group consisted of 274 patients without LRMsigns. The following signs were taken into account: multifocal lesions of the thyroid gland, the patients’age, gender, presence of thyroiditis, the size of the dominant tumor, invasion of adipose tissue. In order to substantiate the expediency of the SCND, retrospective processing of the data of 514 patients, operated from 2018 to 2020, was carried out for PTC, in which the presence of metastases was not cytologically confirmed at the preoperative stage (cN0).Results. The mean age of patients of the main group was lower than in the control group (p &lt; 0.001). The median size of the primary tumor in patients of the main group was significantly higher than in the control group (p &lt; 0.001). The men portion in the main group was significantly higher than in the control group, and the part of women vice versa (p &lt; 0.05). Invasion of the tumor into the adipose tissue in the main group occurred almost twice as often (p &lt; 0.01). The number of patients with multifocal lesions in both groups was practically the same and did not differ statistically (p &gt; 0.05). Ipsilateral and contralateral localization of tumors in both groups did not differ significantly (p &gt; 0.05). The presence of thyroiditis in the control group was higher than in the main group (p &lt; 0.05). The diagnostic efficiency (DE) of accounting for the factor of invasion into adipose tissue was 64.8 %, tumor size over 1.3 cm — 66.7 %, age up to 47 years — 60.0 %. The frequency of detecting metastases with cN0 at the preoperative stage, according to HPE results, was 25.8 %.Conclusions. The reliability of preoperative imaging and diagnostic methods does not allow to ignore the likelihood of LRM and not perform SCND. According to the obtained data, in 25.8 % of casesmetastases were verified based on HPE owing to thesystematic central neck dissection. Male gender (p &lt; 0.01), age of patients (p &lt; 0.001), size of primary tumor (p &lt; 0.001), invasion of adipose tissue (p &lt; 0.01) can serve as predictors of the increased LRMPTC risk. The presence of invasion of adipose tissue (diagnostic efficacy 64.8 %), tumor size more than 1.3 cm (66.7 % DE) and age &lt; 47 (60.0 % DE) increased the risk of LRMPTC. The presence of thyroiditis (the frequency of thyroiditis exposure in control group was higher than in the main group (p &lt; 0.05)), contralateral lesions of the thyroid gland (p &gt; 0.05), multifocal lesions (p &gt; 0.05) cannot serve as reliable prognostic factors for the increased LRMrisk.