Citations

INTRODUCTION: There are limited data regarding the natural history after ileal pouch-anal anastomosis (IPAA) for ulcerative colitis (UC). The principal objectives of this study were to identify 4 key outcomes in the natural history after IPAA within 1, 3, 5, and 10 years: the incidence of pouchitis, Crohn's-like disease of the pouch, use of advanced therapies after IPAA, and pouch failure requiring excision in a network of electronic health records. METHODS: We performed a retrospective cohort study in TriNetX, a research network of electronic health records. In addition to evaluating incidence rates, we also sought to identify factors associated with pouchitis and advanced therapy use within 5 years of IPAA after 1:1 propensity score matching, expressed as adjusted hazard ratios (aHRs). RESULTS: Among 1,331 patients who underwent colectomy with IPAA for UC, the incidence of pouchitis increased from 58% in the first year after IPAA to 72% at 10 years after IPAA. After propensity score matching, nicotine dependence (aHR 1.61, 95% confidence interval [CI] 1.19–2.18), antitumor necrosis factor therapy (aHR 1.33, 95% CI 1.13–1.56), and vedolizumab prior to colectomy (aHR 1.44, 95% CI 1.06–1.96) were associated with an increased risk of pouchitis in the first 5 years after IPAA. The incidence of Crohn's-like disease of the pouch increased to 10.3% within 10 years of IPAA while pouch failure increased to 4.1%. The incidence of advanced therapy use peaked at 14.4% at 10 years after IPAA. DISCUSSION: The incidence of inflammatory conditions of the pouch remains high in the current era, with 14% of patients requiring advanced therapies after IPAA.

BACKGROUND While increasing evidence supports the safety and effectiveness of immunohistochemistry-assisted Mohs micrographic surgery (MMS) for superficially invasive melanoma, there is a paucity of the literature investigating its effect on final defect size. OBJECTIVE To evaluate the tissue sparing effect of MMS for melanoma. MATERIALS AND METHODS Three hundred and twenty-eight patients with early-stage (T1a/T1b) cutaneous melanomas treated with MMS from January 2008 to December 2018 were evaluated. Measured defect sizes after Mohs tumor extirpation were compared with anticipated defect size that would result from standard-margin wide local excision (WLE). Average actual versus anticipated defect areas were compared using a paired t-test (95% confidence intervals). RESULTS The following groups demonstrated a significantly smaller defect area for MMS-treated tumors when compared with anticipated standard-margin WLE defect: All tumors combined (13.8 cm2 vs 10.4 cm2, p < .001), tumors requiring 1 stage (13.6 cm2 vs 10.1 cm2, p < .001), and tumors requiring 2 stages (13.2 cm2 vs 10.5 cm2, p = .004). The majority of patients (83.5%, n = 274) achieved clear margins with 1 stage. CONCLUSION Immunohistochemistry-assisted MMS for early-stage invasive melanoma is associated with smaller final defect size and overall tissue sparing effect compared with standard WLE margins.

Abstract BACKGROUND ACNS1123 was a Phase 2 study to determine whether irradiation could be safely reduced without impacting survival in a subgroup of NGGCT patients. METHODS Patients with localized disease who achieved a complete (CR) or partial response (PR) to induction chemotherapy were eligible to receive reduced dose/volume of irradiation to 30.6Gy whole ventricular field with 54Gy tumor-bed boost. RESULTS 107 eligible NGGCT patients were accrued. The median age of patients at enrollment was 11 years (3.7-21.6). Eighty patients (75%) were male. Location was pineal in 58 (55%), suprasellar in 37 (35%), ventricles in 6 (6%), and bifocal in 6 patients (6%). Sixty-six (61.7%) patients achieved a CR/PR post-induction and were eligible and evaluable for the primary objective and received reduced dose and volume of irradiation. Eight patients progressed; 6 had a distant spinal relapse (outside the irradiation field) and 2 had a local plus distant relapse. As of December 31, 2023, the median follow-up time for eligible and evaluable patients was 5.6 years (0.9-7.9) from enrollment. Except for an unrelated death due to SARS-CoV-2 at 5.5 years from enrollment, there were no grade 3 or higher adverse events at the 60-month follow-up timepoint and no disease progressions beyond 2 years. The 5-year progression-free and overall survival for all eligible and evaluable patients are 87.9% (95% CI:79%-94.8%) and 92.4% (95% CI:82.8%- 96.8%), respectively. CONCLUSION Although the study was closed prematurely due to the concern of increased spinal relapse, the current data suggest that most patients with localized NGGCT and a CR/PR to chemotherapy will survive long-term, and, in fact, have similar survival (PFS and OS) to patients enrolled on ACNS0122 who received full dose craniospinal irradiation. The key to future biologic studies and clinical trials is identifying at diagnosis those patients at high risk for relapse.

Abstract BACKGROUND Non-germinomatous germ cell tumors (NGGCT) constitute 35%- 45% of intracranial germ cell tumors. Growing teratoma syndrome has been observed in patients with NGGCTs after starting chemotherapy. While growing teratomas are typically benign, this process can rarely involve malignant transformation and result in poor prognosis. We present the case of a patient with pineal NGGCT and growing teratoma syndrome with malignant transformation to embryonal rhabdomyosarcoma. CASE REPORT A 13-year-old male presented with headaches and vision changes. An MRI brain demonstrated a 26 x 25 x 19 mm (AP X TR X CC) mixed solid and cystic pineal mass with no evidence of metastatic disease. Due to elevated alpha fetoprotein levels in the serum and cerebrospinal fluid, he was diagnosed with intracranial NGGCT. Treatment was initiated with alternating cycles of Carboplatin/Etoposide and Ifosfamide/Etoposide. After 2 cycles of chemotherapy, a complete biochemical response was noted but MRI showed increased tumor size (presumed growing teratoma syndrome). The patient underwent complete tumor resection. Histology showed embryonal rhabdomyosarcoma as a somatic malignancy arising in a mature teratoma. Further molecular characterization revealed somatic NF1 and KRAS pathogenic mutations that are consistent with the primary diagnosis. Methylation profiling, however, did not exhibit a match with any known malignancies. Continued complete response was noted following two additional chemotherapy cycles. The patient is planned for six total chemotherapy cycles followed by high-dose craniospinal radiation with boost to the primary tumor. CONCLUSIONS Malignant transformation is a rare phenomenon in NGGCT. There is no standard of care for these patients. Further studies are needed to define ideal therapy for this patient population.

Background: Data on racial/ethnic and sex disparities in the utilization and outcomes of tricuspid valve surgery (TVS) in the United States are scarce. The authors aimed to evaluate the impact of race/ethnicity and sex on the utilization and outcomes of TVS. Methods: The authors analyzed the National Inpatient Sample database from 2016 to 2020 to identify hospitalizations for TVS. Racial/ethnic and sex disparities in TVS outcomes were determined using logistic regression models. Results: Between 2016 and 2020, 19 395 hospitalizations for TVS were identified. The utilization rate (number of surgeries/100,000 hospitalizations) was lower in Black and Hispanic patients compared with White patients for surgical tricuspid valve repair (STVr) (331 versus 493 versus 634, P<0.01) and surgical tricuspid valve replacement (STVR) (312 versus 601 versus 728, P<0.01). Similarly, the utilization rate was lower for women compared with men for STVr (1021 versus 1364, P<0.01) and STVR (930 versus 1,316, P<0.01). Compared to White men undergoing TVS, all women had lower odds of acute kidney injury [adjusted odds ratio (aOR) 0.65, 95% CI 0.55–0.78] and higher odds of blood transfusion (aOR 1.30, 95% CI 1.07–1.59), and Black men had higher odds of blood transfusion (aOR 1.59, 95% CI 1.08–2.35). In-hospital mortality and other surgical complications were similar between all groups (all P>0.05). Conclusions: Significant racial/ethnic and sex disparities exist in the utilization of TVS in the United States. Further studies are needed to understand the reasons for these disparities and to identify effective strategies for their mitigation.

Abstract BACKGROUND Primary intracranial germ cell tumors (GCTs) are rare heterogeneous tumors; germinoma accounts for two-thirds of cases. While neoadjuvant chemotherapy followed by response-based reduced radiotherapy dose and field is the established approach for managing localized CNS germinomas, controversy persists regarding the treatment of primary metastatic disease. Additionally, limited research exists on the utilization of neoadjuvant chemotherapy in primary metastatic germinoma. METHODS A retrospective multi-institutional analysis was conducted to assess overall survival (OS) and event-free survival (EFS) among patients diagnosed with metastatic germinoma who were treated with various modalities. RESULTS We identified 88 patients, including 63 males and 25 females. The median age at presentation was 13.5 years. All patients, who had undergone both brain and spine MRIs, had their diagnoses confirmed through a biopsy, positive CSF cytology, and/or positive CSF tumor markers at presentation. Primary Tumor location was pineal (n=37), suprasellar (n=27), bifocal (n=14) and others (n=9). Eight patients underwent subtotal resection. Craniospinal irradiation (CSI; 21-24 Gy) was administered to 71 patients (81%), while eight patients (9%) received whole ventricular irradiation (WVI; 23.4-30 Gy). Whole brain radiation was given to four patients (5%; 24 Gy), and two patients (2%) had unknown fields. Boosts to primary and/or metastatic sites were administered in all but seven patients. Notably, thirty patients (34%) received CSI without neoadjuvant chemotherapy. At the end of therapy, 69 patients had complete response, 10 partial response and the response was unknown in six. Three patients did not receive irradiation, all died of disease progression. The median follow-up was 64 months (range 6-159 months), yielding an OS of 96.6%. Ongoing multi-institutional data collection and analysis will be presented at the meeting. CONCLUSION Our study is one of the largest studies to date in metastatic germinoma and may provide insight into the role of neoadjuvant chemotherapy with lower CSI doses.

Abstract BACKGROUND Accurate molecular diagnosis of infiltrating brainstem tumors, including diffuse midline gliomas and IDH mutant astrocytomas, is essential for prognostication and optimal therapy. Surgical biopsy of the brainstem carries risk of permanent neurological deficits and may yield insufficient or non-diagnostic tissue. We hypothesized that minimally invasive “liquid biopsy” analyzing circulating tumor cell-free DNA (cfDNA) in cerebrospinal fluid (CSF) could represent an alternative molecular diagnostic modality. METHODS We performed MSK-IMPACT, a New York State Department of Health authorized hybridization capture-based next-generation panel DNA sequencing clinical assay on 44 CSF samples from 37 unique patients with brainstem tumors. Ages at time of CSF collection ranged from 1–47 years (median: 29 years). For samples in which diagnostic alterations could not be detected, we performed a series of secondary analyses for known hotspot mutations such as H3F3A, IDH1/2, and BRAF, including manual review for mutant reads below the official clinical reporting threshold, as well as droplet digital PCR (ddPCR). RESULTS Among 44 samples included in this study, 10/44 (23%) samples had mutations detected by MSK-IMPACT using standard clinical calling criteria and 14 of the remaining 34 samples (41%) had supporting evidence of a diagnostically relevant mutation based on manual review. Testing by ddPCR was performed on 11 samples (based on DNA availability), uncovering 4 additional mutations. Overall positive diagnostic yield was 64% (28/44). In biopsied patients, CSF confirmed disease-defining mutations in 80% (16/20) of CSF samples, including H3F3A K28M (9/10; 90%) and IDH1/2 (5/6; 83%). Among 24 unbiopsied patients, a disease-defining mutation was identified in 60% (15/25) of CSF samples. CONCLUSIONS Analysis of CSF cfDNA in patients with brainstem tumors has a high diagnostic yield and obviates the need for tissue biopsy in a majority of patients. A tiered testing approach using next-generation sequencing and ddPCR assays helps maximize diagnostic information and sensitivity.

Abstract BACKGROUND Medulloblastoma (MB) is a highly malignant childhood cerebellar tumor comprising a collection of molecularly and clinically distinct entities. Group 3 and Group 4-MB subgroups originate from overlapping progenitor pools of the developing rhombic lip when neuronal differentiation hierarchies are subverted through somatic alterations. Mutations suspected to deregulate the activity of chromatin-modifying genes are pervasive in Group 3 and Group 4-MB. However, the molecular consequences of these alterations remain largely undefined. METHODS We characterized the chromatin landscape of fifty-two primary MBs using chromatin immunoprecipitation followed by sequencing (ChIP-seq) for six histone modifications and performed multi-modal integration with sample-matched somatic lesions, genome-wide DNA methylation, and transcriptomic profiles. RESULTS Analysis of differential chromatin states across MB subgroups using a Hidden Markov Model revealed a significant enrichment of the bivalent enhancer state (EnhBiv; marked by coincident H3K4me1 and H3K27me3) in Group 4-MB which localized to promoters of neurodevelopmental genes and transcription factors. To functionally dissect the pathogenetic significance of the enriched EnhBiv state in Group 4-MB, we sought to identify key regulators that confer this state. Integrative bioinformatics coupled with CUT&RUN analysis revealed significant enrichment of KDM2B, a histone lysine demethylase overexpressed in Group 4-MB, in gene promoters marked by the EnhBiv state. CRISPR gene targeting or targeted protein degradation of KDM2B selectively suppressed growth of Group 3 and Group 4-MB models in vitro and in vivo. Mechanistically, inhibition of KDM2B disrupted chromatin bivalency by blocking PRC2 complex recruitment and reducing H3K27me3 deposition, profoundly derepressing PRC2 targets involved in neuronal differentiation. CONCLUSIONS Our comprehensive characterization of the MB chromatin landscape in a large cohort of primary tumors provides unprecedented insights into the epigenetic basis of MB subgroups, implicating novel mechanisms of tumorigenesis, and nominating KDM2B as a selective dependency in Group 3/4-MB that should be prioritized as an attractive therapeutic target.

Abstract BACKGROUND One of the most significant unmet clinical challenges in paediatric oncology is the development of novel therapeutic strategies for recurrent medulloblastoma (R-MB). MYC-driven MBs are defined as classically cold tumours with a low incidence of infiltrating immune cells, resulting in a therapeutic challenge. The identification of cell-cell communications, particularly ligand–receptor pairs, allows for the inference of significant intercellular communications based on the expression of corresponding genes. Consequently, we hypothesised that the most influential cell-cell interactions within the tumour immune microenvironment (TME) of MYC-driven MB could unveil prevalent immune-suppressive interactions and potential vulnerabilities for therapeutic exploration. METHODS/RESULTS Paired primary-recurrent bulk RNA-sequencing data, confirmed myeloid cells as the most infiltrating immune cell type in group3-MB and group4-MB. Comprehensive spatial phenotypic and cell-cell communication analyses corroborated this discovery, validating an increased incidence of macrophages in the matched-recurrent tumours. Subsequently, we used innovative algorithms for MB single-cell data to predict interactions between tumour-cell ligands and immune-cell receptors within the TME; macrophages emerged as the core immune-cells involved in interactions throughout the TMEs, with the most significant ligand-receptor interaction and inflammatory response between MIF and CD74. In-depth immunohistochemistry analyses of primary and recurrent group3 and group4 tumours, and exhaustive tissue microarrays demonstrated expression of both CD74 and MIF, with limited expression of CD74 within the brain. To investigate the therapeutic potential of CD74, we developed recurrent, immune competent MYC-driven medulloblastoma mouse models. Comprehensive deconvolution analysis confirmed the TME integrity of our models to mirror that of the human disease. Locoregional delivery and repeat dosing of a bioactive-CD74 peptide demonstrated complete tumour clearance in our immune-competent mouse models, demonstrating the significant therapeutic potential of targeting the CD74-MIF axis in MYC-driven primary and recurrent MB. CONCLUSIONS Essential cellular interactions and therapeutic vulnerabilities have been identified in the tumour-microenvironment of MYC-driven primary-recurrent MB.

Abstract BACKGROUND Treatment and clinical management decisions for children with NF1-OPGs remain challenging as most existing data are retrospective and have not included standardized visual outcomes. In this study, we prospectively enrolled newly diagnosed NF1-OPGs and performed standardized neuro-oncology and ophthalmology assessments in order to develop evidence-based guidelines for monitoring and treatment. METHODS Children with NF1-OPG on MRI who were evaluated by both a study ophthalmologist and neuro-oncologist/NF1 expert within 1 month of radiologic diagnosis were eligible for enrollment. All subjects attempted quantitative visual acuity using Teller acuity cards (TAC) as well as ATS-HOTV testing. The neuro-oncologist/NF1 expert provided reasons for obtaining the MRI as well as initiating treatment, if applicable. Descriptive statistics calculated the success rate of acquiring TAC and reasons to obtain the MRI. RESULTS Two-hundred fifty subjects from 22 institutions were enrolled and had at least one visit beyond baseline (Median age 3.1 years, range 0.1–16.8; 53% female). TAC was successfully acquired in both eyes (N=195, 78%) and at least one eye in (N=206, 82%). ATS-HOTV was successfully acquired in both eyes (N=97, 39%) and at least one eye in (N=98, 39%). The two most common reasons to obtain an MRI were screening due to a diagnosis of NF1 (N=99, 39%) and ophthalmologic concern (N=81, 32%). At enrollment, continued observation occurred in a majority of subjects (N=221, 88%) while treatment with chemotherapy was initiated in only 11% (N=29). Twenty-nine (11%) subjects initially observed transitioned to treatment after enrollment (range: 2.5–25 months) thus far. DISCUSSION We present a prospective multicenter study of children with newly diagnosed NF1-OPGs. The ability to acquire quantitative visual acuity was higher than anticipated. The frequency of NF1-OPGs requiring treatment is lower than previously reported. Regression models of clinical and MRI features that prompted immediate treatment with chemotherapy versus observation will be discussed.