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Related Cases (relate + case)

Distribution by Scientific Domains

Medical Sciences	50%

Selected Abstracts

Professional and economic factors affecting access to mammography: A crisis today, or tomorrow?,

CANCER, Issue 3 2005
Results from a national survey
Abstract BACKGROUND Objective data and anecdotal reports have suggested that access to mammography may be declining because of facility closures and difficulty in recruiting and retaining radiologists and radiologic technologists. To gain insight into the practice patterns, use of emerging technologies, and concerns of breast imagers in current practice, the Society of Breast Imaging (SBI) conducted a national survey of breast imaging practices in the U.S. METHODS Between October 2003 and April 2004, the SBI conducted a survey of the SBI membership database, and received completed surveys from 575 breast imaging practices in the U.S. Responses to the survey regarding practice characteristics, the utilization of standard and emerging technologies, staffing, malpractice, finance, and morale were analyzed. RESULTS Job vacancies for radiologists who read mammograms were reported in 163 practices (29%), 59 of which (10%) had 2 or more openings. A higher proportion of practices with job openings had long appointment waiting times for asymptomatic women when compared with fully staffed practices. Unfilled fellowship positions also were common, with 41 of 65 practices that offer fellowships reporting 47 openings. Among 554 responding practices, 55% reported that someone in their practice was sued because of a mammography related case within the past 5 years, and 50% of practices reported that the threat of lawsuits made radiologist staffing "moderately" or "a lot" more difficult. Of 521 responding practices, 35% reported financial losses in 2002. One in 5 respondents reported that they would prefer to spend less time in mammography, and fewer than 1 in 3 would recommend a breast imaging fellowship to a relative or friend. Emerging technologies, such as breast magnetic resonance imaging and screening ultrasound, currently are being performed in many practices. CONCLUSIONS The survey results provide support for anecdotal reports that breast imaging practices face significant challenges and stresses, including shortages of key personnel, a lack of trainees, malpractice concerns, financial constraints, increased workload due to emerging technologies, low appeal of breast imaging as a career specialty, and the steady rise in the population of women of screening age. Cancer 2005. © 2005 American Cancer Society. [source]

Case-control single-marker and haplotypic association analysis of pedigree data

GENETIC EPIDEMIOLOGY, Issue 2 2005
Sharon R. Browning
Abstract Related individuals collected for use in linkage studies may be used in case-control linkage disequilibrium analysis, provided one takes into account correlations between individuals due to identity-by-descent (IBD) sharing. We account for these correlations by calculating a weight for each individual. The weights are used in constructing a composite likelihood, which is maximized iteratively to form likelihood ratio tests for single-marker and haplotypic associations. The method scales well with increasing pedigree size and complexity, and is applicable to both autosomal and X chromosomes. We apply the approach to an analysis of association between type 2 diabetes and single-nucleotide polymorphism markers in the PPAR-, gene. Simulated data are used to check validity of the test and examine power. Analysis of related cases has better power than analysis of population-based cases because of the increased frequencies of disease-susceptibility alleles in pedigrees with multiple cases compared to the frequencies of these alleles in population-based cases. Also, utilizing all cases in a pedigree rather than just one per pedigree improves power by increasing the effective sample size. We demonstrate that our method has power at least as great as that of several competing methods, while offering advantages in the ability to handle missing data and perform haplotypic analysis. Genet. Epidemiol. 28:110,122, 2005. © 2004 Wiley-Liss, Inc. [source]

Candidate-gene association studies with pedigree data: Controlling for environmental covariates

GENETIC EPIDEMIOLOGY, Issue 4 2003
S.L. Slager
Abstract Case-control studies provide an important epidemiological tool to evaluate candidate genes. There are many different study designs available. We focus on a more recently proposed design, which we call a multiplex case-control (MCC) design. This design compares allele frequencies between related cases, each of whom are sampled from multiplex families, and unrelated controls. Since within-family genotype correlations will exist, statistical methods will need to take this into account. Moreover, there is a need to develop methods to simultaneously control for potential confounders in the analysis. Generalized estimating equations (GEE) are one approach to analyze this type of data; however, this approach can have singularity problems when estimating the correlation matrix. To allow for modeling of other covariates, we extend our previously developed method to a more general model-based approach. Our proposed methods use the score statistic, derived from a composite likelihood. We propose three different approaches to estimate the variance of this statistic. Under random ascertainment of pedigrees, score tests have correct type I error rates; however, pedigrees are not randomly ascertained. Thus, through simulations, we test the validity and power of the score tests under different ascertainment schemes, and an illustration of our methods, applied to data from a prostate cancer study, is presented. We find that our robust score statistic has estimated type I error rates within the expected range for all situations we considered whereas the other two statistics have inflated type I error rates under nonrandom ascertainment schemes. We also find GEE to fail at least 5% of the time for each simulation configuration; at times, the failure rate reaches above 80%. In summary, our robust method may be the only current regression analysis method available for MCC data. Genet Epidemiol 24:273,283, 2003. © 2003 Wiley-Liss, Inc. [source]

"Spontaneous," delayed colon and rectal anastomotic complications associated with bevacizumab therapy

JOURNAL OF SURGICAL ONCOLOGY, Issue 2 2008
David A. August MD
Abstract Bevacizumab, a humanized monoclonal antibody used to treat recurrent and metastatic colorectal cancer, targets the vascular endothelial growth factor (VEGF) molecule. It is hypothesized that bevacizumab works by both depriving tumors of the neovascularity they require to grow, and by improving local delivery of chemotherapy through alterations of tumor vasculature permeability and Starling forces. Complications of bevacizumab treatment include bowel ischemia and perforation, but to date, these complications have only rarely been described as occurring at the site of presumably healed anastomoses following surgery. We report two cases of delayed, "spontaneous" low anterior colorectal anastomotic dehiscence and one right colon anastomotic colocutaneous fistula associated with bevacizumab therapy. After seeing three patients with complications arising from apparently healed low anterior colorectal or right colon anastomoses following initiation of bevacizumab therapy for treatment of metastatic colorectal cancer, we reviewed the experience of The Cancer Institute of New Jersey (CINJ) with use of bevacizumab in approximately 50 patients between April 2004 and December 2006. The three index cases had been treated surgically at CINJ but received chemotherapy elsewhere. None of the 50 patients receiving bevacizumab at CINJ who had previous colon or rectal anastomoses were identified as having this complication. The medical records of the three index cases were reviewed and analyzed. Additionally, a Medline search was performed to identify other reports documenting similar cases. Two reports of related cases were found in the literature. In two of our index cases who underwent low anterior anastomoses, the patients had received preoperative pelvic irradiation before their initial low anterior resection. In one of the two cases, the initial resection was complicated by an anastomotic leak requiring proximal diversion and then subsequent stoma takedown. In both cases, the dehiscence occurred more than 1 year after anastomosis, and became evident 1,10 months following initiation of bevacizumab treatment. In the third index case, a colocutaneous fistula arising from the anastomotic site presented 5 months following right colon resection and 3 months after starting adjuvant systemic therapy with FOLFOX (5-fluorouracil (5-FU), leucovorin, and oxaliplatin) and bevacizumab. Delayed colorectal anastomotic complications may occur in association with bevacizumab therapy. Contributing factors may include anastomotic leak at the time of the original operation and history of anastomotic irradiation. Clinicians treating patients who receive bevacizumab following colectomy for colorectal cancer should be aware of this possible life-threatening complication. These findings may also be relevant to the design of trials of the use of bevacizumab for the postoperative adjuvant treatment of patients with colorectal cancer. J. Surg. Oncol. 2008;97:180,185. © 2007 Wiley-Liss, Inc. [source]