Tumour genomic and microenvironmental heterogeneity for integrated prediction of 5-year biochemical recurrence of prostate cancer: a retrospective cohort study.

BACKGROUND Clinical prognostic groupings for localised prostate cancers are imprecise, with 30-50% of patients recurring after image-guided radiotherapy or radical prostatectomy. We aimed to test combined genomic and microenvironmental indices in prostate cancer to improve risk stratification and complement clinical prognostic factors. METHODS We used DNA-based indices alone or in combination with intra-prostatic hypoxia measurements to develop four prognostic indices in 126 low-risk to intermediate-risk patients (Toronto cohort) who will receive image-guided radiotherapy. We validated these indices in two independent cohorts of 154 (Memorial Sloan Kettering Cancer Center cohort [MSKCC] cohort) and 117 (Cambridge cohort) radical prostatectomy specimens from low-risk to high-risk patients. We applied unsupervised and supervised machine learning techniques to the copy-number profiles of 126 pre-image-guided radiotherapy diagnostic biopsies to develop prognostic signatures. Our primary endpoint was the development of a set of prognostic measures capable of stratifying patients for risk of biochemical relapse 5 years after primary treatment. FINDINGS Biochemical relapse was associated with indices of tumour hypoxia, genomic instability, and genomic subtypes based on multivariate analyses. We identified four genomic subtypes for prostate cancer, which had different 5-year biochemical relapse-free survival. Genomic instability is prognostic for relapse in both image-guided radiotherapy (multivariate analysis hazard ratio [HR] 4·5 [95% CI 2·1-9·8]; p=0·00013; area under the receiver operator curve [AUC] 0·70 [95% CI 0·65-0·76]) and radical prostatectomy (4·0 [1·6-9·7]; p=0·0024; AUC 0·57 [0·52-0·61]) patients with prostate cancer, and its effect is magnified by intratumoral hypoxia (3·8 [1·2-12]; p=0·019; AUC 0·67 [0·61-0·73]). A novel 100-loci DNA signature accurately classified treatment outcome in the MSKCC low-risk to intermediate-risk cohort (multivariate analysis HR 6·1 [95% CI 2·0-19]; p=0·0015; AUC 0·74 [95% CI 0·65-0·83]). In the independent MSKCC and Cambridge cohorts, this signature identified low-risk to high-risk patients who were most likely to fail treatment within 18 months (combined cohorts multivariate analysis HR 2·9 [95% CI 1·4-6·0]; p=0·0039; AUC 0·68 [95% CI 0·63-0·73]), and was better at predicting biochemical relapse than 23 previously published RNA signatures. INTERPRETATION This is the first study of cancer outcome to integrate DNA-based and microenvironment-based failure indices to predict patient outcome. Patients exhibiting these aggressive features after biopsy should be entered into treatment intensification trials. FUNDING Movember Foundation, Prostate Cancer Canada, Ontario Institute for Cancer Research, Canadian Institute for Health Research, NIHR Cambridge Biomedical Research Centre, The University of Cambridge, Cancer Research UK, Cambridge Cancer Charity, Prostate Cancer UK, Hutchison Whampoa Limited, Terry Fox Research Institute, Princess Margaret Cancer Centre Foundation, PMH-Radiation Medicine Program Academic Enrichment Fund, Motorcycle Ride for Dad (Durham), Canadian Cancer Society.

Fluid-structure interaction of an elastic pipe immersed inside a coaxial rigid pipe: a model for the Tullio phenomenon

An axisymmetric, elastic pipe is filled with an incompressible fluid and is immersed in a second, coaxial rigid pipe which contains the same fluid. A pressure pulse in the outer fluid annulus deforms the elastic pipe which invokes a fluid motion in the fluid core. It is the aim of this study to investigate streaming phenomena in the core which may originate from such a fluid-structure interaction. This work presents a numerical solver for such a configuration. It was developed in the OpenFOAM software environment and is based on the Arbitrary Lagrangian Eulerian (ALE) approach for moving meshes. The solver features a monolithic integration of the one-dimensional, coupled system between the elastic structure and the outer fluid annulus into a dynamic boundary condition for the moving surface of the fluid core. Results indicate that our configuration may serve as a mechanical model of the Tullio Phenomenon (sound-induced vertigo).

Physician adoption of a practice guideline: Effect on the cost of medical care for adult patients with diabetes

In the demanding environment of healthcare reform, reduction of unwanted physician practice variation is promoted, often through evidence-based guidelines. Guidelines represent innovations that direct change(s) in physician practice; however, compliance has been disappointing. Numerous studies have analyzed guideline development and dissemination, while few have evaluated the consequences of guideline adoption. The primary purpose of this study was to explore and analyze the relationship between physician adoption of the glycated hemoglobin test guideline for management of adult patients with diabetes, and the cost of medical care. The study also examined six personal and organizational characteristics of physicians and their association with innovativeness, or adoption of the guideline. ^ Cost was represented by approved charges from a managed care claims database. Total cost, and diabetes and related complications cost, first were compared for all patients of adopter physicians with those of non-adopter physicians. Then, data were analyzed controlling for disease severity based on insulin dependency, and for high cost cases. There was no statistically significant difference in any of eight cost categories analyzed. This study represented a twelve-month period, and did not reflect cost associated with future complications known to result from inadequate management of glycemia. Guideline compliance did not increase annual cost, which, combined with the future benefit of glycemic control, lends support to the cost effectiveness of the guideline in the long term. Physician adoption of the guideline was recommended to reduce the future personal and economic burden of this chronic disease. ^ Only half of physicians studied had adopted the glycated hemoglobin test guideline for at least 75% of their diabetic patients. No statistically significant relationship was found between any physician characteristic and guideline adoption. Instead, it was likely that the innovation-decision process and guideline dissemination methods were most influential. ^ A multidisciplinary, multi-faceted approach, including interventions for each stage of the innovation-decision process, was proposed to diffuse practice guidelines more effectively. Further, it was recommended that Organized Delivery Systems expand existing administrative databases to include clinical information, decision support systems, and reminder mechanisms, to promote and support physician compliance with this and other evidence-based guidelines. ^

A Confirmatory Factor Analytic Study Examining the Dimensionality of Educational Achievement Tests

It is important to check the fundamental assumption of most popular Item Response Theory models, unidimensionality. However, it is hard for educational and psychological tests to be strictly unidimensional. The tests studied in this paper are from a standardized high-stake testing program. They feature potential multidimensionality by presenting various item types and item sets. Confirmatory factor analyses with one-factor and bifactor models, and based on both linear structural equation modeling approach and nonlinear IRT approach were conducted. The competing models were compared and the implications of the bifactor model for checking essential unidimensionality were discussed.

MEETING THE NEEDS OF HANDICAPPED CHILDREN: A STUDY OF EDUCATIONAL AND HEALTH CARE SERVICES PROVIDED TO PRE-KINDERGARTEN CHILDREN IN THE HOUSTON INDEPENDENT SCHOOL DISTRICT EARLY CHILDHOOD PROGRAM FOR THE HANDICAPPED (PARENT SATISFACTION, FUNCTIONAL STATUS, PSYCHOSOCIAL DEVELOPMENT)

The Education for All Handicapped Children Act of 1975, P.L. 94-142, created a new challenge for the nation's public school systems. During 1982-1983, a national study, called the "Collaborative Study of Children with Special Needs", was conducted in 5 metropolitan school districts to evaluate the effectiveness of education and health care services of children in kindergarten to 6th grade being provided under P.L. 94-142 programs. This dissertation (the Substudy) was undertaken to augment the findings of the Collaborative Study. The purpose of this study was to develop a database to provide descriptive information on the demographic, service and health characteristics of a small group of 3 and 4 year old handicapped children served by the Houston Independent School District (HISD) during 1982-1983.^ The study involved a stratified sample of 105 three and four year old children divided into 3 groups according to type of handicapping condition.^ The results of the study gave a clearer picture of the demographic characteristics of these Pre-K children. Specifically, sex ratio was approximately one, lower than the national norm. Family and socioeconomic characteristics were assessed.^ The study used an independence/dependence index composed of 11 items on the parent questionnaire to assess the level of functional independence of each child. An association was found between index scores and parent-reported effects of the child on family activity. Parents who said that their child's condition had affected the family's job situation, housing accomodations, vacation plans, marriage, choice of friends and social activities were also more likely to report less independence in the child. In addition, many of the Substudy children had extensive care-taking needs reflected in specific components of the index such as dressing, feeding, toileting or moving about the house.^ In general the results of the Pre-K Substudy indicate that at the early childhood level, the HISD special education program is functioning well in most areas and that parents are very satisfied with the program. (Abstract shortened with permission of author.)^

A DESCRIPTION AND EVALUATION OF EDUCATIONAL PROGRAMS FOR HEALTH MANPOWER IN NIGERIA

A descriptive study of the current educational programs of selected health personnel in Nigeria was made in 1986. Data on the content of educational programs was obtained from personal communication with the Heads of the various institutions and from their published materials (catalogs, course outlines and program descriptions). Adequacy of these programs was judged in the light of current health problems and needs of the population. Evaluation was based on the following criteria: (a) Selection of students to maximize their usefulness in the provision of health care. (b) Relevance of the curriculum to the tasks the trainee will be called upon to perform. (c) Types of courses that focus on community health needs. Using official reports, the health situation in the country was described to give a relative priority of health services.^ Findings indicate the following: (1) Health conditions in Nigeria are related to a high prevalence of illness and disease, unsanitary living conditions, a high ratio of infant mortality and a shortage of public health services. Priority needs for improvement call for attitudinal and environmental changes. (2) All health training programs have improved the relevance of education to community health needs by strengthening practical field experience, and teaching those courses which focus on disease prevention. (3) Prospective nurses and community health workers are selected on the basis of a number of personal and intellectual characteristics, but academic performance alone is the criterion for medical students. (4) The curriculum in the medical school needs to be restructured to cut back on time devoted to enriching the medical "background". Basic sciences need better integration with hospital work. (5) Managerial and organization courses have been well incorporated into the nursing and community health workers' curricula. (6) There is a marked overlap in the tasks the community health workers are expected to perform. This causes some redundancy in having four separate categories of these health personnel. ^