Genomic analysis of fibrolamellar hepatocellular carcinoma.

Pediatric tumors are relatively infrequent, but are often associated with significant lethality and lifelong morbidity. A major goal of pediatric cancer research has been to identify key drivers of tumorigenesis to eventually develop targeted therapies to enhance cure rate and minimize acute and long-term toxic effects. Here, we used genomic approaches to identify biomarkers and candidate drivers for fibrolamellar hepatocellular carcinoma (FL-HCC), a very rare subtype of pediatric liver cancer for which limited therapeutic options exist. In-depth genomic analyses of one tumor followed by immunohistochemistry validation on seven other tumors showed expression of neuroendocrine markers in FL-HCC. DNA and RNA sequencing data further showed that common cancer pathways are not visibly altered in FL-HCC but identified two novel structural variants, both resulting in fusion transcripts. The first, a 400 kb deletion, results in a DNAJB1-PRKCA fusion transcript, which leads to increased cAMP-dependent protein kinase (PKA) activity in the index tumor case and other FL-HCC cases compared with normal liver. This PKA fusion protein is oncogenic in HCC cells. The second gene fusion event, a translocation between the CLPTM1L and GLIS3 genes, generates a transcript whose product also promotes cancer phenotypes in HCC cell lines. These experiments further highlight the tumorigenic role of gene fusions in the etiology of pediatric solid tumors and identify both candidate biomarkers and possible therapeutic targets for this lethal pediatric disease.

Real-World Economic Burden Associated with Transplantation-Related Complications.

Approximately 20,000 hematopoietic cell transplantation (HCT) procedures are performed annually in the United States. Real-world data on the costs associated with post-transplantation complications are limited. Patients with hematologic malignancies aged ≥18 years undergoing autologous HCT (auto-HCT) or allogeneic HCT (allo-HCT) between January 1, 2011, and June 30, 2014, were identified in the Truven Health MarketScan Research Databases. Patients were required to have 12 months of continuous medical and pharmacy enrollment before and after HCT; patients who experience inpatient death within 12 months post-HCT were also included. Patients with previous HCT were excluded. Potential HCT-related complications were identified if they had a medical claim with a diagnosis code for relapse; infection; cardiovascular, renal, neurologic, pulmonary, hepatic, or gastrointestinal disease; secondary malignancy; thrombotic microangiopathy; or posterior reversible encephalopathy syndrome within 1 year post-HCT. Healthcare costs attributable to these complications were evaluated by comparing total costs in HCT recipients with complications and those without complications. The MarketScan Research Databases were further linked to the Social Security Administration's Master Death File to obtain patient death events in a subset of patients. A total of 2672 HCT recipients were included in the analysis. The mean ± SD age of recipients was 54.5 ± 11.6 years, and the majority of recipients (63.6%) underwent auto-HCT. Complications were identified in 81% of auto-HCT recipients and in 95.5% of allo-HCT recipients. Most complications occurred within 180 days post-HCT. Compared with Auto-HCT recipients without complications, those with complications incurred $51,475 higher adjusted total costs (P < .01). Compared with allo-HCT recipients without complications, those with complications incurred $181,473 higher adjusted total costs (P < .01). Among the patients with mortality data, auto-HCT recipients with complications had a higher mortality rate (13.4% vs 5.7%, P < .01) and a lower probability of survival (P < .01) compared with those without complications. In allo-HCT recipients, however, the mortality rate and probability of survival were not significantly different between those with complications and those without complications. HCT recipients with complications were associated with considerable economic burden in terms of direct healthcare costs in a commercially insured population, and in the case of auto-HCT, a higher mortality rate was observed in those with complications.

Improved outcomes after autologous bone marrow transplantation for children with relapsed or refractory Hodgkin lymphoma: twenty years experience at a single institution.

The purpose of this study is to evaluate the survival of pediatric patients undergoing autologous bone marrow transplantation (auBMT) for relapsed or refractory Hodgkin lymphoma (rrHL) and to identify factors that might contribute to their outcome. We reviewed the records and clinical course of 89 consecutive rrHL patients ≤ 21 years old who underwent auBMT at Stanford Hospitals and Clinics and the Lucile Packard Children's Hospital, Stanford between 1989 and 2012. We investigated, by multiple analyses, patient, disease, and treatment characteristics associated with outcome. Endpoints were 5-year overall and event-free survival. Our findings include that cyclophosphamide, carmustine, and etoposide (CBV) as a conditioning regimen for auBMT is effective for most patients ≤ 21 years old with rrHL (5-year overall survival, 71%). Transplantation after the year 2001 was associated with significantly improved overall survival compared with our earlier experience (80% compared with 65%). Patients with multiply relapsed disease or with disease not responsive to initial therapy fared less well compared with those with response to initial therapy or after first relapse. Administration of post-auBMT consolidative radiotherapy (cRT) also appears to contribute to improved survival. We are able to conclude that high-dose chemotherapy with CBV followed by auBMT is effective for the treatment of rrHL in children and adolescents. Survival for patients who undergo auBMT for rrHL has improved significantly. This improvement may be because of patient selection and improvements in utilization of radiotherapy rather than improvements in chemotherapy. Further investigation is needed to describe the role of auBMT across the entire spectrum of patients with rrHL and to identify the most appropriate preparative regimen with or without cRT therapy in the treatment of rrHL in young patients.

Real-world economic burden of hematopoietic cell transplantation among a large US commercially insured population with hematologic malignancies.

AIMS: Approximately 20,000 hematopoietic cell transplantation (HCT) procedures are performed in the US annually. This study aims to study the healthcare resource utilization and costs among commercially-insured patients with hematologic malignancies who received autologous HCT (auto-HCT) and allogeneic HCT (allo-HCT) in the US. MATERIALS AND METHODS: Adult patients with hematologic malignancies undergoing auto- or allo-HCT between January 1, 2011 and June 30, 2014 were identified in the Truven Health MarketScan Research Databases. Patients with 12 months of continuous pharmacy and medical enrollment pre- and post-HCT were included. Patients with prior HCT were excluded. Controls were selected from patients without any claims for HCT and matched with HCT recipients in a 3:1 ratio based on age, gender, insurance type, and Deyo-Charlson Comorbidity Index categories. Total healthcare resource uses and costs were compared between auto- or allo-HCT recipients and controls. RESULTS: In total, 10,527 patients (HCT, n = 2,672 vs control, n = 7,855) were included, with the majority of HCT recipients (63.6%) undergoing auto-HCT. During the 6-month pre-index and 12-month post-index period, auto-HCT recipients incurred $313,562 (p < .01) higher all-cause costs than controls, attributable to inpatient admission (54.1%), outpatient services (33.4%), and prescriptions (12.5%). The all-cause costs for allo-HCT recipients were $621,895 (p < .01) higher vs controls during the 18-month observation period, attributable to inpatient admissions (75.5%), outpatient services (22.1%), and prescriptions (2.4%). CONCLUSIONS: The use of HCT among patients with hematologic malignancies is associated with considerable economic burden in direct healthcare costs in a commercially insured population. Incremental costs for HCT recipients were mainly driven by costs related to hospitalization and other medical services.

Human hepatic organoids for the analysis of human genetic diseases.

We developed an in vitro model system where induced pluripotent stem cells (iPSCs) differentiate into 3-dimensional human hepatic organoids (HOs) through stages that resemble human liver during its embryonic development. The HOs consist of hepatocytes, and cholangiocytes, which are organized into epithelia that surround the lumina of bile duct-like structures. The organoids provide a potentially new model for liver regenerative processes, and were used to characterize the effect of different JAG1 mutations that cause: (a) Alagille syndrome (ALGS), a genetic disorder where NOTCH signaling pathway mutations impair bile duct formation, which has substantial variability in its associated clinical features; and (b) Tetralogy of Fallot (TOF), which is the most common form of a complex congenital heart disease, and is associated with several different heritable disorders. Our results demonstrate how an iPSC-based organoid system can be used with genome editing technologies to characterize the pathogenetic effect of human genetic disease-causing mutations.

Antibody-Based Treatment of Acute Myeloid Leukemia.

While antibody-based therapies have emerged as clinically effective approaches for several hematologic and solid malignancies, they have not played a significant role to date in the treatment of acute myeloid leukemia (AML). More recently, improvements in antibody-drug conjugate technology, bispecific antibodies, as well as identification of novel AML antigens have re-invigorated enthusiasm for antibody-based therapies for AML. This review describes experiences with former and existing antibody-based therapies for AML, including unconjugated antibodies, antibody-drug conjugates (ADCs), radio-labelled antibodies, and immune-engaging antibodies, and discusses the promise and challenges associated with each.

Loss of Pten Disrupts the Thymic Epithelium and Alters Thymic Function.

The thymus is the site of T cell development and selection. In addition to lymphocytes, the thymus is composed of several types of stromal cells that are exquisitely organized to create the appropriate environment and microenvironment to support the development and selection of maturing T cells. Thymic epithelial cells (TECs) are one of the more important cell types in the thymic stroma, and they play a critical role in selecting functional T cell clones and supporting their development. In this study, we used a mouse genetics approach to investigate the consequences of deleting the Pten tumor suppressor gene in the TEC compartment of the developing thymus. We found that PTEN deficiency in TECs results in a smaller thymus with significantly disordered architecture and histology. Accordingly, loss of PTEN function also results in decreased T cells with a shift in the distribution of T cell subtypes towards CD8+ T cells. These experiments demonstrate that PTEN is critically required for the development of a functional thymic epithelium in mice. This work may help better understand the effects that certain medical conditions or clinical interventions have upon the thymus and immune function.

Patient-reported outcomes of brentuximab vedotin in Hodgkin lymphoma and anaplastic large-cell lymphoma.

BACKGROUND: Patients with relapsed/refractory (R/R) Hodgkin lymphoma (HL) or R/R systemic anaplastic large-cell lymphoma (sALCL) treated with brentuximab vedotin (BV) experienced high remission rates in two Phase II trials. With increased response rates and survival times, patient-reported outcomes (PROs) and health-related quality of life (HRQoL) are becoming increasingly important and can help inform treatment decisions to enhance care of cancer patients. OBJECTIVE: The objective was to qualitatively assess HRQoL in long-term survivors treated with BV. METHODS: An eight-question survey assessing PRO-related aspects was developed and fielded to a subset of patients with HL or sALCL who remained in long-term follow-up after completing BV treatment in the two pivotal studies. RESULTS: The survey was completed by 25 of 38 patients (12 with HL, 13 with sALCL). The majority of patients reported that their energy level, outlook on life, difficulties with daily activities, ability to participate in physical activities, and overall HRQoL improved compared to those before BV treatment. LIMITATIONS: Small sample size and lack of a baseline questionnaire or validated assessment instrument limit broad applicability of these findings to large populations of patients with HL or sALCL. CONCLUSION: This is the first report of BV PRO data in R/R HL and sALCL. Given the patients' poor prognostic outcomes before stem cell transplant, these encouraging results warrant formal evaluation of PRO end points in BV trials.

Inactivation of the RB family prevents thymus involution and promotes thymic function by direct control of Foxn1 expression.

Thymic involution during aging is a major cause of decreased production of T cells and reduced immunity. Here we show that inactivation of Rb family genes in young mice prevents thymic involution and results in an enlarged thymus competent for increased production of naive T cells. This phenotype originates from the expansion of functional thymic epithelial cells (TECs). In RB family mutant TECs, increased activity of E2F transcription factors drives increased expression of Foxn1, a central regulator of the thymic epithelium. Increased Foxn1 expression is required for the thymic expansion observed in Rb family mutant mice. Thus, the RB family promotes thymic involution and controls T cell production via a bone marrow-independent mechanism, identifying a novel pathway to target to increase thymic function in patients.

Expression of the Arf tumor suppressor gene is controlled by Tgfbeta2 during development.

The Arf tumor suppressor (also known as Cdkn2a) acts as an oncogene sensor induced by ;abnormal' mitogenic signals in incipient cancer cells. It also plays a crucial role in embryonic development: newborn mice lacking Arf are blind due to a pathological process resembling severe persistent hyperplastic primary vitreous (PHPV), a human eye disease. The cell-intrinsic mechanism implied in the oncogene sensor model seems unlikely to explain Arf regulation during embryo development. Instead, transforming growth factor beta2 (Tgfbeta2) might control Arf expression, as we show that mice lacking Tgfbeta2 have primary vitreous hyperplasia similar to Arf(-/-) mice. Consistent with a potential linear pathway, Tgfbeta2 induces Arf transcription and p19(Arf) expression in cultured mouse embryo fibroblasts (MEFs); and Tgfbeta2-dependent cell cycle arrest in MEFs is maintained in an Arf-dependent manner. Using a new model in which Arf expression can be tracked by beta-galactosidase activity in Arf(lacZ/+) mice, we show that Tgfbeta2 is required for Arf transcription in the developing vitreous as well as in the cornea and the umbilical arteries, two previously unrecognized sites of Arf expression. Chemical and genetic strategies show that Arf promoter induction depends on Tgfbeta receptor activation of Smad proteins; the induction correlates with Smad2 phosphorylation in MEFs and Arf-expressing cells in vivo. Chromatin immunoprecipitation shows that Smads bind to genomic DNA proximal to Arf exon 1beta. In summary, Tgfbeta2 and p19(Arf) act in a linear pathway during embryonic development. We present the first evidence that p19(Arf) expression can be coupled to extracellular cues in normal cells and suggest a new mechanism for Arf control in tumor cells.