EGFR-mutated lung adenocarcinomas from patients who progressed on EGFR-inhibitors show high engraftment rates in xenograft models.

OBJECTIVE: Patient-derived xenografts (PDX) are useful preclinical models to study cancer biology and mechanisms of drug response/resistance, particularly in molecularly targetable tumors. However, PDX engraftment may not be stochastic. We investigated clinical, histological and molecular features associated with PDX engraftment in a large cohort of EGFR-mutated lung adenocarcinoma (LUAD). MATERIAL AND METHODS: Samples were collected by different methods from patients at various disease stages and phases of treatment. PDX engraftment was defined as an ability to passage tumors twice in NOD-SCID mice. Uni- and multivariate logistic regression evaluated factors associated with engraftment. RESULTS: Among 138 EGFR-mutated LUAD implanted into NOD-SCID mice, the overall engraftment rate was only 10% (14/138). However, engraftment was significantly higher in specimens from surgical resections or core-needle biopsies collected from metastatic sites (5/5; 100%) or from patients who had progressed on EGFR-inhibitors (7/10; 70%). Engrafted tumors usually showed poor histological differentiation, a solid morphologic pattern, and presence of either EGFR T790 M and/or TP53 mutations. CONCLUSIONS: Population level analyses of mutant EGFR-PDX show that these models might not fully recapitulate the inter-patient heterogeneity of EGFR-LUAD. However, mutant EGFR-PDXs may be useful to address key clinical questions, notably development of resistance to EGFR-inhibitors and disease progression to distant metastases.

Assessment of the new thin convex probe endobronchial ultrasound bronchoscope and the dedicated aspiration needle: a preliminary study in the porcine lung.

BACKGROUND: Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) allows for accurate minimally invasive mediastinal lymph node staging of lung cancer. The current convex probe EBUS (CP-EBUS) has limitations in the access to certain N1 lymph nodes (lobar and segmental) because of its size. The aim of this study was to assess the new thin CP-EBUS (TCP-EBUS) and an aspiration needle for sampling of N1 lymph nodes in a porcine model. METHODS: The prototype TCP-EBUS (BF-Y0046, Olympus Medical Systems Corp.) with a thinner tip (5.9 mm) and larger bending angle (170 degrees upward) was used. Accessibility, operability, and TBNA capability of the TCP-EBUS were assessed and compared with the current CP-EBUS using porcine lungs. The endoscopic visibility range and the maximum reach were evaluated at the left upper lobe bronchus, tracheobronchus, and right lower lobe bronchus. The prototype aspiration needle (Olympus Medical Systems Corp.) was used for EBUS-TBNA. RESULTS: In all of the evaluated bronchi (n=9), the TCP-EBUS had a greater reach (14.7 mm in the endoscopic visibility range, 16.0 mm in the maximum reach) than the current CP-EBUS. The TCP-EBUS was able to visualize 1 to 3 distal bifurcations farther compared with the current CP-EBUS. Adequate lymph node sampling from lobar and segmental lymph nodes was possible using the aspiration needle. CONCLUSIONS: The TCP-EBUS has improved accessibility to peripheral bronchi with excellent operability and is capable of sampling lobar and segmental lymph nodes using the dedicated aspiration needle.

Localization of pulmonary nodules using navigation bronchoscope and a near-infrared fluorescence thoracoscope.

BACKGROUND: Video-assisted thoracoscopic wedge resection of multiple small, non-visible, and nonpalpable pulmonary nodules is a clinical challenge. We propose an ultra-minimally invasive technique for localization of pulmonary nodules using the electromagnetic navigation bronchoscope (ENB)-guided transbronchial indocyanine green (ICG) injection and intraoperative fluorescence detection with a near-infrared (NIR) fluorescence thoracoscope. METHODS: Fluorescence properties of ICG topically injected into the lung parenchyma were determined using a resected porcine lung. The combination of ENB-guided ICG injection and NIR fluorescence detection was tested using a live porcine model. An electromagnetic sensor integrated flexible bronchoscope was geometrically registered to the three-dimensional chest computed tomographic image data by way of a real-time electromagnetic tracking system. The ICG mixed with iopamidol was injected into the pulmonary nodules by ENB guidance; ICG fluorescence was visualized by a near-infrared (NIR) thoracoscope. RESULTS: The ICG existing under 24-mm depth of inflated lung was detectable by the NIR fluorescence thoracoscope. The size of the fluorescence spot made by 0.1 mL of ICG was 10.4 ± 2.2 mm. An ICG or iopamidol spot remained at the injected point of the lung for more than 6 hours in vivo. The ICG fluorescence spot injected into the pulmonary nodule with ENB guidance was identified at the pulmonary nodule with the NIR thoracoscope. CONCLUSIONS: The ENB-guided transbronchial ICG injection and intraoperative NIR thoracoscopic detection is a feasible method to localize multiple pulmonary nodules.

High prevalence of overweight and obesity in females with phenylketonuria.

The primary treatment for phenylketonuria (PKU) is a low phenylalanine diet together with an amino acid-based, phenylalanine-free formula. Thus, PKU patients tend to consume a diet enriched in carbohydrates which could predispose to obesity. Studies in the 1980s and 1990s demonstrated that school-age phenylketonuria (PKU) patients have a higher mean body weight compared to a control population. However, no recent studies in the United States PKU population have examined whether this trend has persisted or whether adolescents are also affected. To investigate whether pediatric PKU populations (ages 2-20 years) in two major metropolitan areas of the United States (Cleveland, OH and Houston, TX) have a higher than expected percentage of overweight (BMI≥85th percentile) relative to the general population in the United States (NHANES), a retrospective chart review of PKU patients born between 1990 and 2008 and followed in Cleveland, OH (Rainbow Babies and Children's Hospital/University Hospitals Case Medical Center) and in Houston, TX (Texas Children's Hospital) was performed. Based on data from the U.S., 40% of pediatric PKU patients were overweight or obese. However, the percentage of overweight females (55%) and obese females (33%) is 1.8× and 2.1× higher respectively than expected based on comparison data from U.S. children. Further studies are necessary to identify potential strategies for prevention of excessive weight gain in children with PKU, especially in females.

Development and validation of a questionnaire to assess carbohydrate and insulin-dosing knowledge in youth with type 1 diabetes.

OBJECTIVE The American Diabetes Association advocates insulin regimens for youth with type 1 diabetes that involve adjusting insulin dose based on carbohydrate intake and blood glucose level. Implementing these regimens requires knowledge about carbohydrate content of foods and subsequent calculations of insulin dose, skills that may be difficult to gauge in practice. Therefore, we sought to develop and validate a questionnaire, the PedCarbQuiz (PCQ), to assess carbohydrate and insulin-dosing knowledge in youth with type 1 diabetes. RESEARCH DESIGN AND METHODS After development by an expert panel, the PCQ was administered to 75 youth with type 1 diabetes or their parents. Reliability was assessed by Cronbach alpha and split-half testing. To assess validity, scores were correlated with A1C, expert assessments, parent educational level, and complexity of insulin regimen. RESULTS PCQ mean score was 87 +/- 9.7% (range 42-98%). Cronbach alpha was 0.88, and correlation of split halves was 0.59 (P < 0.0001). Higher PCQ scores correlated significantly with lower A1C (r = -0.29, P = 0.01) and expert assessments (r = 0.56, P < 0.001). Scores were significantly higher in parents with college degrees than in those without (P = 0.01) and in participants with more complex insulin regimens (P = 0.003). CONCLUSIONS The PCQ is a novel, easily administered instrument to assess knowledge about carbohydrates and insulin dosing calculations. Initial analyses support the reliability and validity of the PCQ.

Situational analysis of dietary challenges of the treatment regimen for children and adolescents with phenylketonuria and their primary caregivers.

A situational analysis was conducted to evaluate challenges with the treatment regimen (a low protein diet and special supplemental formula) for children and adolescents with phenylketonuria (PKU) and their caregivers. A semistructured interview was administered to 19 caregivers and 11 children with PKU to describe formula and dietary problems and their frequency, difficulty, and affective intensity. Information was also gathered on attempted solutions to problems and their perceived effectiveness. Caregivers who rated dietary problems as less frequent, difficult, and emotionally upsetting and strategies as more effective for solving problems had children with significantly lower phenylalanine (Phe) levels, a biological indicator of adherence (i.e., better adherence; all p values <.05). Caregivers who reported using strategies coded as representing an authoritarian parenting style to solve dietary problems were significantly more likely to have lower household incomes and older children with higher Phe levels than were those who did not report such strategies (all p values <.05).