Citations

Objective An understanding of the etiologic heterogeneity of colorectal cancer (CRC) is critical for improving precision prevention, including individualized screening recommendations and the discovery of novel drug targets and repurposable drug candidates for chemoprevention. Known differences in molecular characteristics and environmental risk factors among tumors arising in different locations of the colorectum suggest partly distinct mechanisms of carcinogenesis. The extent to which the contribution of inherited genetic risk factors for CRC differs by anatomical subsite of the primary tumor has not been examined. Design To identify new anatomical subsite-specific risk loci, we performed genome-wide association study (GWAS) meta-analyses including data of 48 214 CRC cases and 64 159 controls of European ancestry. We characterised effect heterogeneity at CRC risk loci using multinomial modelling. Results We identified 13 loci that reached genome-wide significance (p<5×10 −8 ) and that were not reported by previous GWASs for overall CRC risk. Multiple lines of evidence support candidate genes at several of these loci. We detected substantial heterogeneity between anatomical subsites. Just over half (61) of 109 known and new risk variants showed no evidence for heterogeneity. In contrast, 22 variants showed association with distal CRC (including rectal cancer), but no evidence for association or an attenuated association with proximal CRC. For two loci, there was strong evidence for effects confined to proximal colon cancer. Conclusion Genetic architectures of proximal and distal CRC are partly distinct. Studies of risk factors and mechanisms of carcinogenesis, and precision prevention strategies should take into consideration the anatomical subsite of the tumour.

MYC gene amplification and somatic mutations are frequent in both adult and pediatric AML although how MYC drives and contributes to the development and maintenance of AML has not been resolved. Transcription factor EB (TFEB) is a master regulator of genes that control autophagy and lysosome biogenesis, a central catabolic recycling pathway that regulates cell survival. Given the oncogenic effects of MYC in AML and that the induction of autophagy compromises AML cell growth and survival, we tested if the oncogenic effect of MYC depends on its suppression of TFEB transcription programs in AML. In support of this hypothesis, inducible MYC expression in K562 and THP-1 leukemia cells was sufficient to suppress expression of TFEB and its target genes. Further and conversely, MYC knockdown in NB4 AML cells provoked increased expression of TFEB mRNA and protein, as well as increased expression of TFEB target genes. Notably, dose response studies demonstrated that expression of TFEBS211A, constitutively nuclear form of TFEB that is refractory to control by mTORC1 signaling, dramatically impairs proliferation of HL60, OCI-AML2 and OCI-AML3 AML cells. In addition, induction of TFEBS211A provoked rampant apoptosis. Of important, overexpression of TFEBS211A in HL-60 and OCI-AML3 cells was also sufficient to promote monocytic and granulocytic differentiation, as judged by morphological changes and the acquisition of mature monocytic and granulocytic markers including CD11b, Gr1, and CD15. To identify TFEB targets that might contribute to myeloid/granulocytic differentiation, we performed RNA-seq analysis of HL60 leukemia cells engineered to inducibly express the TFEBS211A transgene. Using a cut-off of fold change&gt;4 with q&lt;0.01, a total of 1152 genes were differentially regulated following the induction of TFEBS211A in HL60 cells. As expected, this included the robust induction of nearly all TFEB target genes associated with the autophagy-lysosome pathway, but also of STAT1, KLF4, KLF6, CEBPB, CSF1 and GATA2 genes that are necessary and/or sufficient to provoke terminal monocytic and granulocytic differentiation of AML cells. Surprisingly, among genes induced by TFEB in HL60 cells is IDH1, which catalyzes the production of α-ketoglutarate (α-KG), a required substrate of the TET family of dioxygenases that convert 5-methylcytosine (5mC) to 5-hydroxymethylcytosine (5hmC). In particular, TFEBS211A expression provoked increases in levels of α-KG and significant increases in global levels of 5hmC in genomic DNA of HL60 leukemia cells both ex vivo and in vivo. Furthermore, TFEB-mediated induction of IDH1/2 mRNA and protein, and of IDH1 promoter activity, was antagonized by inducible expression of MYC. To assess the global effects of TFEB on 5mC/5hmC landscapes, we performed paired reduced representation bisulfite (BS)- and oxidation bisulfite (oxBS)-sequencing. As predicted, TFEBS211A induced both loss and gains of 5mC, but there were more losses (n = 722) than gains (n = 459) across all 22 chromosomes. Quite remarkably, and consistent with TFEB-provoked increases of 5hmC signals, TFEBS211A exclusively induced 5hmC gains (in a total of 863 genes), and 37% and 36% of these 5hmC gains occurred in promoter regions and CpG islands, and across all 22 chromosomes. Comparison of BS- and oxBS-seq versus RNA-seq analyses of HL60 cells expressing TFEB revealed significant changes in mRNA levels and concomitant differential changes in 5mC and 5hmC marks in KLF4, KLF6, STAT3, TP73, andFOXO1 that have pivotal roles in controlling myeloid cell differentiation and death. Collectively, these findings demonstrate that MYC suppresses TFEB expression and function in AML cells, and that TFEB functions as a tumor suppressor that provokes AML cell differentiation and death. Strikingly, these responses rely on epigenetic control, where TFEB directly induces the transcription of IDH1 and IDH2 to provoke global hydroxylation of 5-methylcytosine and the expression of genes that drive terminal differentiation and apoptosis. Thus, a MYC-TFEB-IDH1/2-TET2 circuit controls AML cell fate. Disclosures Murphy: Merck: Research Funding; Puma Biotech: Research Funding. Ballabio:CASMA Therapeutics: Other: Co-Founder. Kaufmann:Takeda Pharmaceuticals: Research Funding.

Introduction The COVID-19 pandemic has significantly affected many aspects of healthcare, including medical education and training. Its impact on hematology/oncology (HO) fellowship programs has not yet been characterized. Methods The American Society of Hematology (ASH) and American Society of Clinical Oncology (ASCO) sent an anonymous survey in June 2020 to all HO program directors (PDs) addressing program changes during the COVID-19 pandemic and their perception of impact on trainees' experience, education, and mental health. The survey included 32 multiple-choice and open-ended questions. Participants who completed the survey received a $10 gift card. Quantitative descriptive analyses of multiple-choice questions were conducted. Open-ended responses were analyzed qualitatively using NVivo software. Results Of 233 invited PDs, 103 (44%) respondents completed the survey; 22 additional surveys were incomplete and not included in the analysis. Table 1 summarizes PDs and program characteristics. In response to the pandemic, 42% (N=43) of programs removed fellows from outpatient clinics and 63% (N=65) changed research location to home (Figure 1). Most PDs reported their fellows were participating in telehealth for HO care (79%, N=81) and 21% (N=22) had their fellows re-deployed to cover medicine and other non-HO services. To support fellows' mental health most programs held additional virtual meetings (76%, N=78) and social events (52%, N=54). Twenty one percent of PDs (N=22) reported their program's professional development funds were completely cut or frozen and 17% (N=17) had funds cut slightly. Most PDs reported the pandemic negatively impacted fellowship overall (67% slight to significant negative impact, N=69), 72% identified clinical education as negatively impacted (72% slight to significant negative impact, N=74), and 35% (N=36) reported significant negative impact on research training/productivity. Twenty three percent (N=24) of PDs thought their fellows were not able to make good use of their time during the pandemic, professionally speaking. One third (33%, N=34) of PDs anticipated the pandemic would lead to lack of fellow clinical preparedness, 24% (N=25) with need to make up clinical rotations, and 15% (N=15) anticipated a negative impact on HO board pass rates. Post-pandemic, most PDs plan to maintain some virtual educational sessions (73%, N=75) and telehealth in fellows' continuity clinic (55%, N=57). Among PDs, the prevalence of burnout increased from 16% (N=16) pre-pandemic to 45% (N=46) during the pandemic (p&lt;0.0001). Seventeen percent (N=18) of PDs witnessed moderate signs of fellow burnout and 52% (N=54) witnessed minor signs of fellow burnout during the pandemic. Several educational and research constraints were identified via qualitative analysis: limited in-person clinical rotations, supervision of telehealth encounters, training year promotion and making up clinical time, limited professional development activities, board exam cancellations, and inability to perform research. Additional PD-identified trainee concerns included: ability to obtain childcare, separation from family, and Visa concerns among international fellows. PDs anticipated that financial constraints leading to cuts or removal of discretionary funds may have negative consequences for fellows' professional development activities and could force PDs to decrease program size in the future. PD recommendations for ASH and ASCO included: reducing or eliminating fellow membership fees, providing free access to educational materials and meetings, eliminating in-training examination fees, providing virtual sessions on career development, telehealth and wellness, virtual journal clubs, PD webinars focused on navigating fellowship issues and virtual interviews, and extending ASCO YIA funding for a second year. Conclusions PDs reported that their fellowship programs' clinical, educational, and research experiences have been impacted by the COVID-19 pandemic. PDs are concerned about the impact of budget cuts on fellows' professional and career development. PD burnout increased during the pandemic and most PDs observed at least mild burnout among their fellows. Professional societies can support fellowship programs by limiting fees and costs associated with membership, exams, and meetings, and increasing virtual opportunities for both fellows and PDs. Disclosures Velazquez Manana: Portola Pharmaceuticals: Other: Immediate family member stock ownership; Midatech: Other: Immediate family member stock ownership; Corbus Pharmaceuticals: Other: Immediate family member stock ownership.

266 Background: CCA is a rare cancer for which there are limited effective therapies. IDH1 mutations occur in ~20% of intrahepatic CCAs, resulting in production of the oncometabolite D-2-hydroxyglutarate, which promotes oncogenesis. IVO (AG-120) is a first-in-class, oral, small-molecule inhibitor of mutant IDH1 (m IDH1). ClarIDHy aimed to demonstrate the efficacy of IVO vs PBO in pts with unresectable or metastatic m IDH1 CCA. The primary endpoint was met with significant improvement in progression-free survival (PFS) by independent radiology center (IRC) with IVO vs PBO (hazard ratio [HR] = 0.37, p < 0.0001). Objective response rate (ORR) and stable disease for IVO were 2.4% (3 partial responses) and 50.8% (n = 63) vs 0% and 27.9% (n = 17) for PBO. IVO pts experienced significantly less decline in physical and emotional functioning domains of quality of life at cycle 2 day 1 vs PBO pts (nominal p < 0.05). Methods: Pts with m IDH1 CCA were randomized 2:1 to IVO (500 mg PO QD) or matched PBO and stratified by prior systemic therapies (1 or 2). Key eligibility: unresectable or metastatic m IDH1 CCA based on central testing; ECOG PS 0–1; measurable disease (RECIST v1.1). Crossover from PBO to IVO was permitted at radiographic progression. Primary endpoint: PFS by IRC. Secondary endpoints included overall survival (OS; by intent-to-treat), ORR, PFS (by investigator), safety, and quality of life. The planned crossover-adjusted OS was derived using the rank-preserving structural failure time (RPSFT) model. Results: As of 31 May 2020, ~780 pts were prescreened for an IDH1 mutation and 187 were randomized to IVO (n = 126) or PBO (n = 61); 13 remain on IVO. Median age 62 y; M/F 68/119; 91% intrahepatic CCA; 93% metastatic disease; 47% had 2 prior therapies. 70% of PBO pts crossed over to IVO. OS data were mature, with 79% OS events in IVO arm and 82% in PBO. Median OS (mOS) was 10.3 months for IVO and 7.5 months for PBO (HR = 0.79; 95% CI 0.56–1.12; one-sided p = 0.093). The RPSFT-adjusted mOS was 5.1 months for PBO (HR = 0.49; 95% CI 0.34–0.70; p < 0.0001). Common all-grade treatment emergent adverse events (TEAEs, ≥ 15%) in the IVO arm: nausea 41%, diarrhea 35%, fatigue 31%, cough 25%, abdominal pain 24%, decreased appetite 24%, ascites 23%, vomiting 23%, anemia 18%, and constipation 15%. Grade ≥ 3 TEAEs were reported in 50% of IVO pts vs 37% of PBO pts, with grade ≥ 3 treatment-related AEs in 7% of IVO pts vs 0% in PBO. 7% of IVO pts experienced an AE leading to treatment discontinuation vs 9% of PBO pts. There were no treatment-related deaths. Conclusions: IVO was well tolerated and resulted in a favorable OS trend vs PBO despite a high rate of crossover. These data – coupled with statistical improvement in PFS, supportive quality of life data, and favorable safety profile – demonstrate the clinical benefit of IVO in advanced m IDH1 CCA. Clinical trial information: NCT02989857.

Background: Previous studies have defined preshock as isolated hypotension or isolated hypoperfusion, whereas shock has been variably defined as hypoperfusion with or without hypotension. We aimed to evaluate the mortality risk associated with hypotension and hypoperfusion at the time of admission in a cardiac intensive care unit population. Methods: We analyzed Mayo Clinic cardiac intensive care unit patients admitted between 2007 and 2015. Hypotension was defined as systolic blood pressure <90 mm Hg or mean arterial pressure <60 mm Hg, and hypoperfusion as admission lactate >2 mmol/L, oliguria, or rising creatinine. Associations between hypotension and hypoperfusion with hospital mortality were estimated using multivariable logistic regression. Results: Among 10 004 patients with a median age of 69 years, 43.1% had acute coronary syndrome, and 46.1% had heart failure. Isolated hypotension was present in 16.7%, isolated hypoperfusion in 15.3%, and 8.7% had both hypotension and hypoperfusion. Stepwise increases in hospital mortality were observed with hypotension and hypoperfusion compared with neither hypotension nor hypoperfusion (3.3%; all P <0.001): isolated hypotension, 9.3% (adjusted odds ratio, 1.7 [95% CI, 1.4–2.2]); isolated hypoperfusion, 17.2% (adjusted odds ratio, 2.3 [95% CI, 1.9–3.0]); both hypotension and hypoperfusion, 33.8% (adjusted odds ratio, 2.8 [95% CI, 2.1–3.6]). Adjusted hospital mortality in patients with isolated hypoperfusion was higher than in patients with isolated hypotension ( P =0.02) and not significant different from patients with both hypotension and hypoperfusion ( P =0.18). Conclusions: Hypotension and hypoperfusion are both associated with increased mortality in cardiac intensive care unit patients. Hospital mortality is higher with isolated hypoperfusion or concomitant hypotension and hypoperfusion (classic shock). We contend that preshock should refer to isolated hypotension without hypoperfusion, while patients with hypoperfusion can be considered to have shock, irrespective of blood pressure.

Background Several studies have shown improved outcomes in closed compared with open medical and surgical intensive care units. However, very little is known about the ideal organizational structure in the modern cardiac intensive care unit (CICU). Methods and Results We retrospectively reviewed consecutive unique admissions (n=3996) to our tertiary care CICU from September 2013 to October 2017. The aim of our study was to assess for differences in clinical outcomes between an open compared with a closed CICU. We used multivariable logistic regression adjusting for demographics, comorbidities, and severity of illness. The primary outcome was in‐hospital mortality. We identified 2226 patients in the open unit and 1770 in the closed CICU. The unadjusted in‐hospital mortality in the open compared with closed unit was 9.6% and 8.9%, respectively ( P =0.42). After multivariable adjustment, admission to the closed unit was associated with a lower in‐hospital mortality (odds ratio [OR], 0.69; 95% CI: 0.53–0.90, P =0.007) and CICU mortality (OR, 0.70; 95% CI, 0.52–0.94, P =0.02). In subgroup analysis, admissions for cardiac arrest (OR, 0.42; 95% CI, 0.20–0.88, P =0.02) and respiratory insufficiency (OR, 0.43; 95% CI, 0.22–0.82, P =0.01) were also associated with a lower in‐hospital mortality in the closed unit. We did not find a difference in CICU length of stay or total hospital charges ( P >0.05). Conclusions We found an association between lower in‐hospital and CICU mortality after the transition to a closed CICU. These results may help guide the ongoing redesign in other tertiary care CICUs.

Objective Young-onset colorectal cancer (YCRC) incidence is rising. Scant data exist on YCRC risk after presentation with concerning symptoms such as iron-deficiency anaemia (IDA) or haematochezia. We examined the association between IDA and YCRC, and haematochezia and YCRC. Design Cohort study of US Veterans aged 18–49 years receiving Veterans Health Administration (VHA) care 1999–2016. IDA analytic cohort was created matching individuals without incident IDA to those with IDA 4:1 based on sex, birth year and first VHA visit date (n=239 000). We used this approach to also create a distinct haematochezia analytic cohort (n=653 740). Incident YCRC was ascertained via linkage to cancer registry and/or cause-specific mortality data. We computed cumulative incidence, risk difference (RD) and HRs using Cox models in each cohort. Results Five-year YCRC cumulative incidence was 0.45% among individuals with IDA versus 0.05% without IDA (RD: 0.39%, 95% CI: 0.33%–0.46%), corresponding to an HR of 10.81 (95% CI: 8.15–14.33). Comparing IDA versus no IDA, RD was 0.78% for men (95% CI: 0.64%–0.92%) and 0.08% for women (95% CI: 0.03%–0.13%), and RD increased by age from 0.14% for <30 years to 0.53% for 40–49 years. YCRC cumulative incidence was 0.33% among individuals with haematochezia versus 0.03% without haematochezia (RD: 0.30%, 95% CI: 0.26%–0.33%), corresponding to an HR of 10.66 (95% CI: 8.76–12.97). Comparing haematochezia versus no haematochezia, RD increased by age from 0.04% for <30 years to 0.43% for 40–49 years. Conclusion Colonoscopy should be strongly considered in adults aged <50 years with IDA or haematochezia without a clinically confirmed alternate source.

Abstract MYC oncoproteins regulate transcription of genes directing cell proliferation, metabolism, and tumorigenesis. A variety of alterations drive MYC expression in acute myeloid leukemia (AML), and enforced MYC expression in hematopoietic progenitors is sufficient to induce AML. Here we report that AML and myeloid progenitor cell growth and survival rely on MYC-directed suppression of Transcription Factor EB (TFEB), a master regulator of the autophagy–lysosome pathway. Notably, although originally identified as an oncogene, TFEB functions as a tumor suppressor in AML, where it provokes AML cell differentiation and death. These responses reflect TFEB control of myeloid epigenetic programs by inducing expression of isocitrate dehydrogenase-1 (IDH1) and IDH2, resulting in global hydroxylation of 5-methycytosine. Finally, activating the TFEB–IDH1/IDH2–TET2 axis is revealed as a targetable vulnerability in AML. Thus, epigenetic control by an MYC–TFEB circuit dictates myeloid cell fate and is essential for maintenance of AML. Significance: Alterations in epigenetic control are a hallmark of AML. This study establishes that a MYC–TFEB circuit controls AML differentiation and epigenetic programs by inducing IDH1/IDH2 and hydroxylation of 5-methylcytosine, that TFEB functions as a tumor suppressor in AML, and that this circuit is a targetable vulnerability in AML. See related commentary by Wu and Eisenman, p. 116.