Citations

AbstractThe goal of the National Institutes of Health–funded American Society for Parenteral and Enteral Nutrition 2017 research workshop (RW) “Gastric Bypass: Role of the Gut” was to focus on the exciting research evaluating gut‐derived signals in modulating outcomes after bariatric surgery. Although gastric bypass surgery has undoubted positive effects, the mechanistic basis of improved outcomes cannot be solely explained by caloric restriction. Emerging data suggest that bile acid metabolic pathways, luminal contents, energy balance, gut mucosal integrity, as well as the gut microbiota are significantly modulated after bariatric surgery and may be responsible for the variable outcomes, each of which was rigorously evaluated. The RW served as a timely and novel academic meeting that brought together clinicians and researchers across the scientific spectrum, fostering a unique venue for interdisciplinary collaboration among investigators. It promoted engaging discussion and evolution of new research hypotheses and ideas, driving the development of novel ameliorative, therapeutic, and nonsurgical interventions targeting obesity and its comorbidities. Importantly, a critical evaluation of the current knowledge regarding gut‐modulated signaling after bariatric surgery, potential pitfalls, and lacunae were thoroughly addressed.

Purpose FGFR genetic aberrations (GAs) occur in an estimated 10% to 16% of intrahepatic cholangiocarcinomas (CCAs). The natural history of CCA with FGFR GAs, the prognostic role of coexisting GAs, and the outcome with FGFR-targeted inhibitors are unknown. Patients and Methods Patients with CCA with FGFR GAs were identified using next-generation sequencing or fluorescence in situ hybridization from four tertiary cancer centers and compared with FGFR wild-type counterparts. Data reviewed included demographic, treatment, overall survival (OS), and GA data. Fisher’s exact test, Kaplan-Meier plots, and log-rank tests were used for statistical analysis. Results Three hundred seventy-seven patients with CCA were identified, and 95 had FGFR GAs. FGFR2 GA was most common (n = 74, with 63 fusions) and seen in intrahepatic CCA. In patients with CCA, FGFR GAs occurred more frequently in younger patients (≤ 40 years; 20%) compared with older patients (> 40 years; 6.7%; P < .001), presented at an earlier stage (TNM stage I/II v III/IV: 35.8% v 22%, respectively; P = .001), and were associated with a longer OS compared with patients without FGFR GAs (37 v 20 months, respectively; P < .001). This difference remained significant after excluding 36 patients treated with FGFR inhibitors. There was no OS difference ( P = .60) between CCA with FGFR2 fusions (n = 63) versus other FGFR GAs (n = 29). Patients with FGFR GAs had a better OS with FGFR-targeted therapy compared with standard treatment ( P = .01). BAP1 mutation was the most common coexisting mutation without prognostic impact, whereas TP53 ( P = .04) and CDKN2A/B ( P = .04) were correlated with a shorter OS. Conclusion CCA with FGFR GAs represents a unique subtype occurring in younger patients with an indolent disease course. FGFR-targeted therapy may have a positive impact on OS in this subgroup.

OBJECTIVE Intensive treatment (INT) of type 1 diabetes reduces the incidence of cardiovascular disease (CVD) events compared with conventional treatment (CONV), but it also results in more weight gain. Our objective was to examine whether excessive weight gain from INT of type 1 diabetes is independently associated with subsequent CVD events. RESEARCH DESIGN AND METHODS Quartiles (Q) of weight gain in 1,213 participants aged 18 years and older at enrollment in the Diabetes Control and Complications Trial (DCCT) were determined within randomized treatment groups (INT vs. CONV) using change in BMI from baseline to the closeout DCCT visits. Effects of this weight gain on CVD risk factors and outcomes during an additional 20 years of observational follow-up were then determined. RESULTS The Q4 INT group experienced greater proportional weight gain (median change in BMI, 6.08 kg/m2), increases in CVD risk factors, and need for medications for hypertension and lipids compared with the Q1–3 INT and comparable CONV groups. Over a mean of 26 years of follow-up, the numbers of major and total CVD events were not statistically different in Q4 compared with Q1–3 of either the INT or CONV group. By year 14, however, the incident CVD event curve became significantly higher in the Q4 INT group than in the Q1–3 INT groups (P = 0.024) and was similar to that for the CONV group. CONCLUSIONS For the first 13 years after DCCT, INT for type 1 diabetes reduced macrovascular events compared with CONV, even when excessive weight gain occurred. After this, total CVD events significantly increased in the Q4 INT group, becoming equivalent to those in the CONV group. Longer follow-up is needed to determine whether this trend continues and results in more major CVD events.

Abstract Medulloblastoma (MB) is a pediatric brain tumor comprising of four molecular subgroups, with Group 3 and 4 tumors characterized by particularly poor prognosis. While research has advanced our understanding of MB, there is still a pressing need for new knowledge of the functional processes underlying its progression due to a scarcity of therapeutics. Recent studies have identified Orthodenticle homeobox 2 (Otx2), a cerebellar transcription factor, to be highly expressed in MB Group 3/4 subtypes. Datamining studies from Northcott and Robinson datasets revealed co-expression of Otx2 and c-Myc in Group 3/4 tumors. DAB staining conducted in human MB specimens showed increased expression of Otx2 and c-Myc. Colocalization studies confirmed datamining results. Next, we used a clinical Otx2 inhibitor, all-trans retinoic acid (ATRA), in a PDX cell line, P9, and in UW228 cells. Western blot analysis demonstrated reduced levels of c-Myc along with Otx2. In another experiment, we used the c-Myc/Max inhibitor 10058-F4 and observed comparable results to Otx2 inhibition. Real time PCR and immunocytochemistry experiments confirmed the aforementioned results. Further, treatment with ATRA and 10058-F4 showed reduced proliferation and migratory abilities in p9 and UW228 when compared to their respective controls. Mass spectrometry conducted on immune-precipitated Otx2 in P9 cells revealed a plethora of novel interaction partners that drive tumor growth and progression. In addition, western blot analysis in ATRA treated cells showed reduced expression of Max, suggestive of the existence of a feedback loop that link with Otx2 and c-Myc. Collectively our studies highlight Otx2 as a potential contributor to the malignant phenotype and describe its role in mediating the aggressiveness of Group 3/4 medulloblastoma. Citation Format: Yining Lu, Maheedhara R. Guda, Swapna Asuthkar, Ian Purvis, Collin M. Labak, Neha Jain, David J. Daniels, Sarah E. Martin, Andrew J. Tsung, Kiran K. Velpula. Otx2 and c-Myc association drives tumor progression in medulloblastoma molecular subtypes 3/4 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3537. doi:10.1158/1538-7445.AM2017-3537

4086 Background: Mutations in DNA repair pathway were identified in 13% of Biliary Tract Cancers (BTC) [ Cancer2016;122:3838–3847]. High TMB tumors including melanoma, lung cancer and those with microsatellite instability (MSI-H) are associated with susceptibility to immune blockade using checkpoint inhibitors. TMB data in BTC is limited and its association with actionable somatic mutation (mut) profiles in BTC is unknown. Methods: Comprehensive genomic profiling (CGP) of 309 FFPE tissue blocks of BTC pts with a hybrid capture of all coding exons of 236 cancer-related genes and 47 introns of 19 genes rearranged in cancer was done using FoundationOne. Base substitutions, indels, gene fusion/rearrangements, TMB, and MSI status were assessed. TMB was calculated by counting mutations across a 1.25Mb region and classified into high (TMBH; ≥20 mut/Mb), intermediate (TMBI; 6 - 19mut/Mb) and low (TMBL; < 6mut/Mb). MSI high (MSIH) and Stable (MSS) status was assigned by a computational algorithm examining 114 intronic homopolymer loci. Patients with TMB ≥6 mut/Mb (N = 60) were included in the clinical correlative portion of this study. Results: Sixty patients with TMB ≥6 mut were identified out of 309 pts of which 9 (15%) were TMBH and 51 (85%) were TMBI. These included 3 (5%) MSIH and 18 (30 %) MSS. The median age was 59 years (range: 29-86), 35 (58%) were females, majority were intrahepatic cholangiocarcinoma (n = 31; 52%) and 28 (47%) presented with advanced disease at diagnosis. Twenty three (38%) pts had received radiation therapy, 28 (47%) surgery and 3 (5%) received immunotherapy. Most frequent co-existing mut seen was TP53 (N = 35; 58%). APC mut was seen in 7 (12%) pts. DNA repair pathway muts ( MSH6, BRCA1, BRCA2, ATM, MLH1, or MSH2 genes) were identified in 78% of TMBH versus 16% in TMBI cases (p < 0.0001). Frequency of PIK3CA mut differed significantly between TMBH and TMBI (44% vs 10%, p < 0.0001). Pts with TMBI had a significantly better median OS (110 weeks) as compared to TMBH (43 weeks) (p = 0.003). Conclusions: DNA repair pathway and PIK3CA mut maybe associated with TMBH in BTC. A better understanding of TMB and associated actionable mutations in BTC may be of value for the management of BTC patients with targeted agents and immunotherapy.

4076 Background: Gallbladder carcinoma (GBC) is commonly diagnosed at an advanced, unresectable disease stage and has a poor prognosis. Comprehensive genomic profiling (CGP) has a developing role in guiding systemic, precision anti-cancer therapy. Methods: We performed hybrid capture-based CGP on FFPE samples for 491 consecutive advanced GBCs. Mean coverage depth was >550X for up to 315 cancer-related genes plus 37 introns from 28 genes frequently rearranged in cancer. All 4 classes of genomic alterations (GA) were detected. Tumor mutational burden (TMB) was determined on up to 1.1 Mb of sequenced DNA. Results: Median age was 64 (range 25-88) and 69% (337/491) of patients were female. 96% (470), 2.9% (14), and 1.4% (7) of GBC patients had the diagnosis of adenocarcinoma, adenosquamous, or carcinoma not specified (NOS), respectively. Commonly altered genes were TP53 (62%), CDNK2A (31%), ARID1A (18%), and SMAD4 (15%), and most of the genetic aberrations (GA) were short variants. Potentially targetable SCNAs (including ERBB genes, MET, FGFRs, and the CCND1-FGF3/4/19 11q13 amplicon) were identified in 21% of cases (Table). Oncogenic BRAF, ALK, or FGFR2/3 rearrangements were found in 7 cases (1.4%). Moreover, 7.8% of cases had BRCA2 or ATM GA, and 0.8% had INI1loss suggesting benefit from PARP or EZH2 inhibitors, respectively. TMB was low; the 25th, 50th, and 75th percentiles were 2.5, 3.8 and 6.3 mutations/Mb, respectively. Less than 1% of cases had microsatellite instability. Radiological response to TKIs and immunotherapy was noted. Conclusions: In addition to the significant opportunity for anti-HER targeted therapies, other subsets of GBC cases harbored kinase GA (particularly SCNA), the 11q13 amplicon, or BRCA2/ ATM/ INI1mutations that are linked to therapeutic benefit. How the frequency of both driver SCNA and DNA repair alterations in GBC can be linked with inflammation awaits additional investigation. [Table: see text]