Outcomes of the "BRCA Quality Improvement Dissemination Program": An initiative to improve patient receipt of cancer genetics services at five health systems

OBJECTIVE

A quality improvement initiative (QII) was conducted with five community-based health systems' oncology care centers (sites A-E). The QII aimed to increase referrals, genetic counseling (GC), and germline genetic testing (GT) for patients with ovarian cancer (OC) and triple-negative breast cancer (TNBC).

METHODS

QII activities occurred at sites over several years, all concluding by December 2020. Medical records of patients with OC and TNBC were reviewed, and rates of referral, GC, and GT of patients diagnosed during the 2 years before the QII were compared to those diagnosed during the QII. Outcomes were analyzed using descriptive statistics, two-sample t-test, chi-squared/Fisher's exact test, and logistic regression.

RESULTS

For patients with OC, improvement was observed in the rate of referral (from 70% to 79%), GC (from 44% to 61%), GT (from 54% to 62%) and decreased time from diagnosis to GC and GT. For patients with TNBC, increased rates of referral (from 90% to 92%), GC (from 68% to 72%) and GT (81% to 86%) were observed. Effective interventions streamlined GC scheduling and standardized referral processes.

CONCLUSION

A multi-year QII increased patient referral and uptake of recommended genetics services across five unique community-based oncology care settings.

Abstract P6-02-04: Use of breast surveillance between women with pathogenic variants and variants of uncertain significance in breast cancer susceptibility genes

Background: Surveillance is a fundamental tool in the early detection and secondary prevention of many cancers. For women at increased genetic risk of breast cancer, mammography and breast magnetic resonance imaging (MRI) serve as the standard screening modalities. Use of surveillance mammography and MRI has been understudied among women with variant of uncertain significance (VUS) compared to pathogenic and likely pathogenic variants (P/LP). To address this gap, we examined the use of breast cancer surveillance and breast surgery in women who underwent multiple gene sequencing in a multicenter cohort of patients. We also expanded the surveillance literature by assessing correlates of breast MRI and mammography among women with VUS and investigating how rates of imaging changed over time after genetic testing. Methods: Using data from two cancer settings, we calculated use of risk reducing mastectomy (RRM) and surveillance for all women at genetically elevated risk of breast cancer, regardless of their personal history of breast cancer, with VUS or P/LP variants in a breast cancer susceptibility gene of high penetrance (BRCA1, BRCA2, PALB2, PTEN, TP53) and moderate penetrance (ATM, CDH1, CHEK2, NBN, NF1, STK11). The primary outcome was longitudinal use of surveillance mammography and breast MRI for women during the 13-month span after genetic testing, and each subsequent 13-month period up to 6 years afterwards. Results: Of 889 women, those with and without personal history of breast cancer were similar with regards to race/ethnicity, marital status, and high- or average-risk status. However, women with a personal history of breast cancer were on average older (54.1 vs 48.2 years), had longer follow-up time since genetic testing (3.4 vs 3.0 years), and were more likely to have VUS (62.5% vs 37.7%) compared to those without personal history of breast cancer. VUS carriers were less likely to undergo RRM compared to those with P/LP (HR=0.17, p=< 0.001) and high-risk women were more likely to undergo RRM than average-risk women (HR=3.91, p=0.005). Longitudinally, surveillance use among unaffected women decreased from 49.8% in the first year to 31.2% in the sixth year after genetic testing. In comparison, a greater proportion of women with a personal history of breast cancer underwent surveillance, which increased from 59.3% in the first year to 63.6% in the sixth year after genetic testing. Mammography rates did not differ between women with P/LP and VUS within the first 13 months after genetic testing and up to 4 years afterwards. Over the first four years after genetic testing, women with VUS were less likely to undergo annual MRIs compared to P/LP. This observation was true for women without a personal history of breast cancer (OR=0.34, p=0.003; OR=0.37, p=0.03; OR=0.19, p=0.004 for years 1, 2, and 3 respectively) as well as for women with a personal history of breast cancer (OR=0.31, p<=0.001; OR=0.33, p=0.002; OR=0.37, p=0.012; OR=0.3, p=0.14 for years 1, 2, 3, and 4 respectively). Conclusion: In this study of surveillance mammography and breast MRI use among women at elevated risk of breast cancer, we found that women with P/LP variants in breast cancer susceptibility genes are more likely to undergo annual breast MRI compared to those with VUS, whereas there was no difference between the groups in their use of annual surveillance mammography. This study is one of the first to examine maintenance of breast surveillance in a sample of women at elevated risk of breast cancer with non-negative genetic test results in BRCA1/2 as well as non-BRCA1/2 genes, while adjusting for personal and family history of cancer. In addition, we found that VUS, whether in high or moderate penetrance breast cancer susceptibility genes, was associated with lower use of annual breast MRI compared to P/LP variants, and equivalent use of annual mammography. These results add important evidence to dispel the myth of VUS-associated mismanagement of care.

Citation Format: Sukh Makhnoon, Minxing Chen, Brooke Levin, Megan Ensinger, Kristin Mattie, Generosa Grana, Sanjay Shete, Banu K. Arun, Susan K. Peterson. Use of breast surveillance between women with pathogenic variants and variants of uncertain significance in breast cancer susceptibility genes [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P6-02-04.

A multicenter study of clinical impact of variant of uncertain significance reclassification in breast, ovarian and colorectal cancer susceptibility genes

BACKGROUND

Clinical interpretation of genetic test results is complicated by variants of uncertain significance (VUS) that have an unknown impact on health but can be clarified through reclassification. There is little empirical evidence regarding VUS reclassification in oncology care settings, including the prevalence and outcomes of reclassification, and racial/ethnic differences.

METHODS

This was a retrospective analysis of persons with and without a personal history of cancer carrying VUS (with or without an accompanying pathogenic or likely pathogenic [P/LP] variant) in breast, ovarian, and colorectal cancer predisposition genes seen at four cancer care settings (in Texas, Florida, Ohio, and New Jersey) between 2013 and 2019.

RESULTS

In 2715 individuals included in the study, 3261 VUS and 313 P/LP variants were reported; 8.1% of all individuals with VUS experienced reclassifications and rates varied significantly among cancer care settings from 4.81% to 20.19% (overall p < 0.001). Compared to their prevalence in the overall sample, reclassification rates for Black individuals were higher (13.6% vs. 19.0%), whereas the rates for Asian individuals were lower (6.3% vs. 3.5%) and rates for White and Hispanic individuals were proportional. Two-year prevalence of VUS reclassification remained steady between 2014 and 2019. Overall, 11.3% of all reclassified VUS resulted in clinically actionable findings and 4.6% subsequently changed individuals' clinical managements.

CONCLUSIONS

The findings from this large multisite study suggest that VUS reclassification alters clinical management, has implications for precision cancer prevention, and highlights the need for implementing practices and solutions for efficiently returning reinterpreted genetic test results.

Implementation and outcome evaluations of a multi-site improvement program in cancer genetics

Program evaluation can identify the successes and challenges of implementing clinical programs, which can inform future dissemination efforts. A cancer genetics improvement program, disseminated from the Lead Team's institution to five health systems (Participating Sites), was genetic counselor led, using virtual implementation facilitation to support Participating Sites' performance of quality improvement (QI) activities over several years. Program implementation and outcome evaluations were performed and included evaluation of program delivery and initial effects of the program on Participating Sites. A logic model guided evaluation of program implementation (inputs, activities, outputs, delivery/fidelity, and coverage/reach) and initial outcomes (short-term and intermediate outcomes). Data were collected from program documents and an Evaluation Survey of Participating Site team members (21 respondents), compared against the Lead Team's expectations of participation, and analyzed using descriptive statistics. All program inputs, outputs, and activities were available and delivered as expected across the five Participating Sites. The most frequently used activities and inputs were facilitation-associated meetings and meeting resources, which were rated as useful/helpful by the majority of respondents. Nearly all respondents noted improvement in short-term outcomes following participation: 82.4% reported increased awareness of clinical processes, 94.1% increased knowledge of QI methods, 100% reported increased perceived importance of QI, 94.1% increased perceived feasibility of QI, and 76.5% reported increased problem-solving skills and self-efficacy to use QI at their site. Intermediate outcomes (identifying barriers, developing interventions, improved teamwork, and capacity) were achieved following program participation as indicated by the results of the program document review and Evaluation Survey responses. Implementation challenges at Participating Sites included staffing constraints, difficulties obtaining buy-in and participation, and developing interventions over time. The multi-site improvement program was delivered and implemented with high levels of fidelity and resulted in improved short and intermediate outcomes. Future research will evaluate long-term, patient-level outcomes associated with site-specific QI interventions.

Use of breast surveillance between women with pathogenic variants and variants of uncertain significance in breast cancer susceptibility genes

BACKGROUND

Use of surveillance mammography and magnetic resonance imaging (MRI) has been understudied among women with variant of uncertain significance (VUS) compared to pathogenic and likely pathogenic variants (P/LP).

METHODS

Using data from two cancer settings, we calculated use of risk-reducing mastectomy (RRM) and surveillance during each 13-month span after genetic testing up to 6 years afterwards for a cohort of genetically elevated risk women.

RESULTS

Of 889 women, VUS carriers were less likely to undergo RRM compared to those with P/LP (hazard ratio [HR], 0.17; p = <.001) and high-risk women were more likely to undergo RRM than average-risk women (HR, 3.91; p = .005). Longitudinally, surveillance use among unaffected women decreased from 49.8% in the first year to 31.2% in the sixth year after genetic testing. In comparison, a greater proportion of women with a personal history of breast cancer underwent surveillance, which increased from 59.3% in the first year to 63.6% in the sixth year after genetic testing. Mammography rates did not differ between women with P/LP and VUS within the first 13 months after genetic testing and up to 4 years afterward. Over the first 4 years after genetic testing, women with VUS were less likely to undergo annual MRIs compared to P/LP.

CONCLUSION

The authors found that VUS, whether in high or moderate penetrance breast cancer susceptibility genes, was associated with lower use of annual breast MRI compared to P/LP variants and equivalent use of annual mammography. These results add important evidence regarding VUS-related breast surveillance.

Single-center comparison of cancer genetics referral rates for patients with pancreatic cancer following implementation of a best practice advisory: A quality improvement project

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Background: Despite guidelines recommending germline genetic testing (GT) and genetic counseling for individuals with pancreatic ductal adenocarcinoma (PDAC), referrals remain suboptimal. This can have negative implications on treatment, particularly for patients with actionable mutations. This project aims to compare the referral rate to genetic services of MD Anderson Cancer Center at Cooper pre- and post-implementation of an electronic health record (EHR) physician best practice advisory (BPA) recommending a cancer genetics referral order for PDAC patients. Methods: Medical records, cancer genetics referrals (CGR), and germline and somatic testing results were retrospectively reviewed for patients with a PDAC diagnosis in 2019-2020, and prospectively for those diagnosed after BPA implementation from October 2021 through May 2022. The primary outcome was the rate of CGR, and the secondary outcomes were genetic counseling encounters and GT completion. Descriptive statistics were used for analysis. Results: Prior to BPA initiation, CGR were offered to 44 (24.3%) of 181 eligible patients with 39 (88.6%) of those accepting CGR. Germline testing represented 90.9% (30 patients) of the GT performed in the pre-BPA group. Post-BPA, CGR were offered to 23 (51.1%) of 45 eligible patients with 20 (86.95%) of those accepting CGR. Germline testing represented 100% (13 patients) of the GT performed in the post-BPA group. Conclusions: Only 24.3% of patients diagnosed with PDAC between 2019-2020 were referred to cancer genetics, showing that even after updated NCCN guidelines in 2018 the CGR rate remained low. Following BPA implementation, CGR increased to 51.1% over 8 months for newly diagnosed patients. Germline testing increased by 10%. These preliminary results show that implementing a physician BPA can increase CGR and germline GT, which could have positive implications on treatment. Limitations include a lack of a standardized referral process for the pre-BPA group and a limited timeframe to obtain GT for the post-BPA group.[Table: see text]

A multicenter study of clinical impact of variant of uncertain significance reclassification in breast, ovarian, and colorectal cancer susceptibility genes

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Background: Up to 10% of all cancers are attributable to germline mutations and identifying mutation carriers is critical for cancer prevention. Clinical interpretation of genetic test results is complicated by variants of uncertain significance (VUS) with unknown impact on health, which can be clarified through reclassification. However, there is little empirical evidence regarding VUS reclassification in oncology care settings, including the prevalence and outcomes of reclassification, racial/ethnic differences, and the proportion of patients who undergo cancer preventive healthcare management as a result of VUS reclassification. Methods: Retrospective analysis of persons carrying VUS (with or without an accompanying pathogenic or likely pathogenic [P/LP] variant) in breast, ovarian, and colorectal cancer genes who underwent genetic counseling at four geographically dispersed cancer care settings (in Texas, Florida, Ohio, and New Jersey) between 2013 and 2019, and followed until 2020. Results: Among 2,715 individuals, 3,261 VUS and 313 P/LP variants were reported and 11% (300/2,715) had a P/LP in addition to VUS. In total, 8.1% of all individuals with VUS experienced reclassifications, 87.1% of which were downgraded to benign or likely benign and 12.9% were upgraded to P/LP. Reclassification rates varied significantly among cancer care settings from 4.81% to 20.19% (overall p < 0.001). The reclassification pattern across genes suggests that VUS in most genes underwent reclassification at a rate proportional to their prevalence in the overall sample and occurred commonly in ATM, BRCA2, BRCA1, and CHEK2. Compared to their prevalence in the sample, reclassification rates were higher for Blacks (13.6% vs 19.0%), lower for Asians (6.3% vs 3.5%), and proportional for Whites and Hispanics. Median time to reclassification decreased steadily between 2014 and 2019 from 3.08 to 0.91 years. Overall, 11.3% of all reclassified VUS resulted in clinically actionable findings and 4.6% subsequently changed individuals’ clinical managements including prophylactic surgeries and intensive screenings for cancer prevention and early detection. Conclusions: In this large multisite study, VUS reclassification changed clinical management for 0.4% of all individuals. VUS reclassification may alter clinical management, has implications for precision cancer prevention, and highlights the need for standardized clinical practice guidelines and policies for returning reclassified results to patients.

Uptake of cancer risk management strategies among women who undergo cascade genetic testing for breast cancer susceptibility genes

BACKGROUND

Uptake of cancer risk management based on inherited predispositions, which encompasses bilateral mastectomy (BLM), bilateral salpingo-oophorectomy (BSO), and intensified screening, is the primary motivation for cascade testing for hereditary breast and ovarian cancer (HBOC). However, long-term outcome data for cascade testers are lacking.

METHODS

Medical records were abstracted for all unaffected women with pathogenic variants in HBOC genes from 2 cancer hospitals (2013-2019) with at least 1 year of follow-up to compare the uptake of surgery and screening between cascade and noncascade testers.

RESULTS

Cascade testers (79.8%) were younger than noncascade testers (mean age, 37.6 vs 43.5 years; P = .002). Among women aged ≥40 years, 43% underwent BLM, and 71.6% underwent BSO, with no significant difference in uptake between cascade and noncascade testers. The mean time to BSO among cascade testers was shorter among women aged ≥40 years versus those aged <40 years (11.8 vs 31.9 months; P = .04); no such difference was observed among noncascade testers. Mammography and breast magnetic resonance imaging rates were low in the recorded 6 years for both groups after genetic counseling.

CONCLUSIONS

Management uptake among cascade testers is high with rates comparable to those for unaffected BRCA-positive women. A large proportion of women act on cascade test results, and this represents a novel report of utilization of cancer management strategies.

Expanding the genotypic and phenotypic spectrum in a diverse cohort of 104 individuals with Wiedemann-Steiner syndrome

Wiedemann-Steiner syndrome (WSS) is an autosomal dominant disorder caused by monoallelic variants in KMT2A and characterized by intellectual disability and hypertrichosis. We performed a retrospective, multicenter, observational study of 104 individuals with WSS from five continents to characterize the clinical and molecular spectrum of WSS in diverse populations, to identify physical features that may be more prevalent in White versus Black Indigenous People of Color individuals, to delineate genotype-phenotype correlations, to define developmental milestones, to describe the syndrome through adulthood, and to examine clinicians' differential diagnoses. Sixty-nine of the 82 variants (84%) observed in the study were not previously reported in the literature. Common clinical features identified in the cohort included: developmental delay or intellectual disability (97%), constipation (63.8%), failure to thrive (67.7%), feeding difficulties (66.3%), hypertrichosis cubiti (57%), short stature (57.8%), and vertebral anomalies (46.9%). The median ages at walking and first words were 20 months and 18 months, respectively. Hypotonia was associated with loss of function (LoF) variants, and seizures were associated with non-LoF variants. This study identifies genotype-phenotype correlations as well as race-facial feature associations in an ethnically diverse cohort, and accurately defines developmental trajectories, medical comorbidities, and long-term outcomes in individuals with WSS.

A Rare TP53 Mutation Predominant in Ashkenazi Jews Confers Risk of Multiple Cancers

Germline mutations in TP53 cause a rare high penetrance cancer syndrome, Li-Fraumeni syndrome (LFS). Here, we identified a rare TP53 tetramerization domain missense mutation, c.1000G>C;p.G334R, in a family with multiple late-onset LFS-spectrum cancers. Twenty additional c.1000G>C probands and one c.1000G>A proband were identified, and available tumors showed biallelic somatic inactivation of TP53. The majority of families were of Ashkenazi Jewish descent, and the TP53 c.1000G>C allele was found on a commonly inherited chromosome 17p13.1 haplotype. Transient transfection of the p.G334R allele conferred a mild defect in colony suppression assays. Lymphoblastoid cell lines from the index family in comparison with TP53 normal lines showed that although classical p53 target gene activation was maintained, a subset of p53 target genes (including PCLO, PLTP, PLXNB3, and LCN15) showed defective transactivation when treated with Nutlin-3a. Structural analysis demonstrated thermal instability of the G334R-mutant tetramer, and the G334R-mutant protein showed increased preponderance of mutant conformation. Clinical case review in comparison with classic LFS cohorts demonstrated similar rates of pediatric adrenocortical tumors and other LFS component cancers, but the latter at significantly later ages of onset. Our data show that TP53 c.1000G>C;p.G334R is found predominantly in Ashkenazi Jewish individuals, causes a mild defect in p53 function, and leads to low penetrance LFS. SIGNIFICANCE: TP53 c.1000C>G;p.G334R is a pathogenic, Ashkenazi Jewish-predominant mutation associated with a familial multiple cancer syndrome in which carriers should undergo screening and preventive measures to reduce cancer risk.

A case of ovarian endometrioid adenocarcinoma with yolk sac differentiation and Lynch syndrome

Ovarian endometrioid adenocarcinoma with yolk sac component has been reported in fewer than twenty cases in the literature. A majority of the diagnoses are described in postmenopausal women without specific reference to germline genetic testing. We describe, to our knowledge, the first case in the English literature of a premenopausal woman that presented with an ovarian endometrioid adenocarcinoma with focal yolk sac component and was subsequently found to have a germline MSH2 mutation confirming a diagnosis of Lynch syndrome. Concurrent diagnosis of ovarian endometrioid adenocarcinoma with yolk sac tumor and Lynch syndrome is an extremely rare finding in a young patient and requires careful follow-up. Genetics evaluation and testing may be reasonable for individuals with this rare or mixed tumor pathology at young age of onset and can have clinical utility in guiding future cancer treatment or surveillance.

Smoking, alcohol and caffeine in relation to two hormonal indicators of ovarian age during the reproductive years

OBJECTIVE

To examine whether or not cigarette smoking, alcohol and caffeine intake are related to two indicators of ovarian age-anti-Müllerian hormone (AMH) and follicle stimulating hormone (FSH).

STUDY DESIGN

Cross-sectional study of 477 women with a recent index spontaneous abortion (SA) (105 trisomic, 93 non-trisomic) or livebirth (LB) (279) with hormones measured on days 2-4 of an apparently normal menstrual cycle after the index pregnancy.

RESULTS

Current smoking is associated with about a 15% increase in median FSH (β for ln(FSH)=0.14, 95% CI 0.03,0.25). It is not significantly related to AMH (β for ln(AMH)=-0.25, 95% CI -0.56,0.06). Neither alcohol 2-7days per week nor caffeine 122-<553mg per day is independently related to AMH or FSH.

CONCLUSIONS

The observation that current smoking is associated with FSH, but not with AMH, suggests that current smoking either impairs the development of antral follicles or dysregulates the hypothalamic-pituitary-ovarian axis. The absence of an association with AMH argues against mechanisms related to accelerated follicle atresia.

Portraiture and social understanding

Purpose

– The purpose of this paper is to discuss the possible explanations for deficits in social understanding evident in individuals with autism spectrum disorder (ASD). A potential intervention technique is proposed that has not yet been examined in this population: viewing and drawing portraits. This portraiture-based intervention seeks to address some of the core issues set forth in each of the theories explaining impaired social functioning. Furthermore, this intervention is intended to specifically increase exposure to facial stimuli in a safe and controlled environment. Instructions about how to look closely at a social partner’s face and how to glean salient emotional information from the facial expression displayed can be developed through a focused exploration of drawing and viewing portraits. Current techniques such as eye tracking and fMRI are discussed in the context of this proposed intervention.

Design/methodology/approach

– This paper reviews existing research about ASD and seeks to present a new proposal for an intervention using portraiture. First the paper discusses existing interventions and reviews the current research about potential causes/areas of deficiency in individuals on the spectrum. This paper subsequently proposes a new type of intervention and discusses the reasons underpinning its potential success in the context of existing research.

Findings

– This was a proposed study so no empirical findings have been reported. However, observations of individuals on the spectrum engaging with artwork are discussed in this paper.

Originality/value

– No other research or study has been proposed in current literature relating specifically to the use of portraits (looking at and creating) to help individuals with ASD.

Sindbis viral vectors target hematopoietic malignant cells

Sindbis viral vectors target and inhibit the growth of various solid tumors in mouse models. However, their efficacy against blood cancer has not been well established. Here, we show that Sindbis vectors infect and efficiently trigger apoptosis in mouse BW5147 malignant hematopoietic T-cells, but only at low levels in human lymphoma and leukemia cells (Jurkat, Karpas, CEM, DHL and JB). The Mr 37/67 kD laminin receptor (LAMR) has been suggested to be the receptor for Sindbis virus. However, JB cells, which are infected by Sindbis at low efficiency, express high levels of LAMR, revealing that additional factors are involved in Sindbis tropism. To test the infectivity and therapeutic efficacy of Sindbis vectors against malignant hematopoietic cells in vivo, we injected BW5147 cells intraperitoneally into (C3HXAKR) F1 hybrid mice. We found that Sindbis vectors targeted the tumors and significantly prolonged survival of tumor-bearing mice. We also tested the Sindbis vectors in a transgenic CD4-Rgr model, which spontaneously develop thymic lymphomas. However, infectivity in this model was less efficient. Taken together, these results demonstrate that Sindbis vectors have the potential to target and kill hematopoietic malignancies in mice, but further research is needed to evaluate the mechanism underlining the susceptibility of human lymphoid malignancies to Sindbis therapy.

Trisomic pregnancy and intermediate CGG repeat length at the FMR1 locus

BACKGROUND

We hypothesized that trisomy arises as a function of the size of the oocyte pool, with risk increased among women with diminished pools. Diminished pools may cause primary ovarian failure, which has been associated with premutation and intermediate CGG repeat length at the Fragile X mental retardation (FMR1) locus. Thus, we hypothesized that the risk of trisomic pregnancy is increased among women with intermediate CGG repeat length on the FMR1 gene.

METHODS

The analysis drew on data from two hospital-based case-control studies. We compared 207 women with trisomic spontaneous abortions (SAs) to three comparison groups: 82 women with other chromosomally abnormal SAs, 99 women with chromosomally normal SAs and 537 women with live births (LBs), age matched to women with SAs. We defined the length of the CGG repeat in four ways: the biallelic mean, the genotypic mean, the length on allele 2 and the length on allele 1. We analyzed CGG repeat length as a categorical variable. All analyses were adjusted for site, age and ethnicity.

RESULTS

CGG repeat length did not differ significantly between women with trisomic SAs and any of the three comparison groups. For the biallelic mean, the adjusted odds ratio relating trisomy (versus LB controls) to the highest category (35.5-59.5 repeats) versus the modal category (26.5-30.0 repeats) was 1.5 (95% confidence interval (CI): 0.7, 3.1). Comparisons with the two SA control groups also showed increased odds of more repeats among trisomy cases. Results were similar when repeat length was defined by the genotypic mean or by the repeat length on allele 2. For allele 1, the odds of short (9-19) repeat length were lower, but not significantly so, for trisomy cases compared with LB controls. Excluding women with premutations (n= 2) from the analysis yielded an adjusted odds ratio of 1.4 (95% CI: 0.7, 2.9) for the biallelic mean.

CONCLUSIONS

Our data are equivocal. The direction of associations is consistent with the hypothesis that repeat length in the intermediate range is associated with trisomy. However, differences between the trisomy cases and the comparison groups are neither large nor statistically significant. Our data rule out odds ratios larger than about 3.

Trisomic pregnancy and elevated FSH: implications for the oocyte pool hypothesis

BACKGROUND

Some studies, but not all, support the hypothesis that trisomy frequency is related to the size of the oocyte pool, with the risk increased for women with fewer oocytes (older ovarian age). We tested this hypothesis by comparing hormonal indicators of ovarian age among women who had trisomic pregnancy losses with indicators among women with non-trisomic losses or chromosomally normal births. The three primary indicators of advanced ovarian age were low level of anti-Müllerian hormone (AMH), high level of follicle-stimulating hormone (FSH) and low level of inhibin B.

METHODS

The analysis drew on data from two hospital-based case-control studies. Data were analyzed separately and the evidence from the two sites was combined. We compared 159 women with trisomic pregnancy losses to three comparison groups: 60 women with other chromosomally abnormal losses, 79 women with chromosomally normal losses and 344 women with live births (LBs) age-matched to women with losses. We analyzed the hormone measures as continuous and as categorical variables. All analyses adjust for age in single years, day of blood draw, interval in storage and site.

RESULTS

AMH and inhibin B did not differ between women with trisomic losses and any of the three comparison groups. Mean ln(FSH) was 0.137 units (95% confidence interval (CI): 0.055, 0.219) higher for trisomy cases compared with LB controls; it was also higher, though not significantly so, for trisomy cases compared with women with other chromosomally abnormal losses or chromosomally normal losses. The adjusted odds ratio in relation to high FSH (≥ 10 mIU/ml) was significantly increased for trisomy cases versus LB controls (adjusted odds ratio (OR): 3.8, 95% CI: 1.6, 8.9).

CONCLUSIONS

The association of trisomy with elevated FSH is compatible with the oocyte pool hypothesis, whereas the absence of an association with AMH is not. Alternative interpretations are considered, including the possibility that elevated FSH may disrupt meiotic processes or allow recruitment of abnormal follicles.

Sequential medical trials

A model for sequential clinical trials is discussed. Three proposed stopping rules are studied by the Monte Carlo method for small patient horizons and mathematically for large patient horizons. They are shown to be about equally effective and asymptotically optimal from both Bayesian and frequentist points of view and are markedly superior to any fixed sample size procedure.

Selecting the highest probability in binomial or multinomial trials

Some sequential procedures are considered for selecting the binomial population with largest success probability or for selecting the multinomial outcome with highest cell probability. Procedures with and without sequential elimination of inferior populations are evaluated with respect to the expected probability of the population selected.

Enhanced specific delivery and targeting of oncolytic Sindbis viral vectors by modulating vascular leakiness in tumor

Genetic instability of cancer cells generates resistance after initial responses to chemotherapeutic agents. Several oncolytic viruses have been designed to exploit specific signatures of cancer cells, such as important surface markers or pivotal signaling pathways for selective replication. It is less likely for cancer cells to develop resistance given that mutations in these cancer signatures would negatively impact tumor growth and survival. However, as oncolytic viral vectors are large particles, they suffer from inefficient extravasation from tumor blood vessels. For larger particles, such as viral vectors, their ability to reach cancer cells is an important consideration in achieving specific oncolytic targeting and potential vector replication. Our previous studies indicated that the Sindbis viral vectors target tumor cells via the laminin receptor (LAMR). Here, we present evidence that modulating tumor vascular leakiness, using VEGF and/or metronomic chemotherapy regimens significantly enhances tumor vascular permeability and directly enhances oncolytic Sindbis vector targeting in tumor models. Since host-derived vascular endothelium cells are genetically stable and less likely to develop resistance to chemotherapeutics, a combined metronomic chemotherapeutics and oncolytic viruses regimen should provide a new approach for cancer therapy. This mechanism could explain the synergistic treatment outcomes observed in clinical trials of combined therapies.

Detecting colorectal cancer by 1H magnetic resonance spectroscopy of fecal extracts

Colorectal cancer is one of the most common cancers in the western world. Its early detection has been found to improve the prognosis of the patient, providing a wide window of opportunity for successful therapeutic interventions. However, current diagnostic techniques all have some limitations; there is a need to develop a better technique for routine screening purposes. We present a new methodology based on magnetic resonance spectroscopy of fecal extracts for the non-invasive detection of colorectal cancer. Five hundred twenty-three human subjects (412 with no colonic neoplasia and 111 with colorectal cancer, who were scheduled for colonoscopy or surgery) were recruited to donate a single sample of stool. One-dimensional (1)H magnetic resonance spectroscopy (MRS) experiments were performed on the supernatant of aqueous dispersions of the stool samples. Using a statistical classification strategy, several multivariate classifiers were developed. Applying the preprocessing, feature selection and classifier development stages of the Statistical Classification Strategy led to approximately 87% average balanced sensitivity and specificity for both training and monitoring sets, improving to approximately 92% when only crisp results, i.e. class assignment probabilities > or =75%, are considered. These results indicate that (1)H magnetic resonance spectroscopy of human fecal extracts, combined with appropriate data analysis methodology, has the potential to detect colorectal neoplasia accurately and reliably, and could be a useful addition to the current screening tools.

Quantitative objective markers for upper and lower motor neuron dysfunction in ALS

OBJECTIVE

To investigate the value of objective biomarkers for upper (UMN) and lower (LMN) motor neuron involvement in ALS.

METHODS

We prospectively studied 64 patients with ALS and its subsets using clinical measures, proton MR spectroscopic imaging ((1)H MRSI), diffusion tensor imaging, transcranial magnetic stimulation, and the motor unit number estimation (MUNE) at baseline and every 3 months for 15 months and compared them with control subjects.

RESULTS

(1)H MRSI measures of the primary motor cortex N-acetyl-aspartate (NAA) concentration were markedly reduced in ALS (p = 0.009) and all UMN syndromes combined (ALS, familial ALS [fALS], and primary lateral sclerosis; p = 0.03) vs control values. Central motor conduction time to the tibialis anterior was prolonged in ALS (p < 0.0005) and combined UMN syndromes (p = 0.001). MUNE was lower in ALS (p < 0.0005) and all LMN syndromes combined (ALS, fALS, and progressive muscular atrophy; p = 0.001) vs controls. All objective markers correlated well with the ALS Functional Rating Scale-Revised, finger and foot tapping, and strength testing, suggesting these markers related to disease activity. Regarding changes over time, MUNE changed rapidly, whereas neuroimaging markers changed more slowly and did not significantly differ from baseline.

CONCLUSIONS

(1)H MR spectroscopic imaging measures of the primary motor cortex N-acetyl-aspartate (NAA) concentration and ratio of NAA to creatine, central motor conduction time to the tibialis anterior, and motor unit number estimation significantly differed between ALS, its subsets, and control subjects, suggesting they have potential to provide insight into the pathobiology of these disorders.

Smoking, alcohol and caffeine in relation to ovarian age during the reproductive years

BACKGROUND

We sought to determine whether smoking, alcohol and caffeine are related to four indicators of ovarian age: antral follicle count (AFC), follicle stimulating hormone (FSH), inhibin B and estradiol.

METHODS

Analyses drew on ultrasound scans and sera from 188 women, aged 22-49. We used least squares regression to estimate differences in AFC and hormone levels for women who smoke cigarettes or who drink alcohol or caffeine.

RESULTS

Current smoking is related to elevated FSH (beta for ln(FSH) = 0.21, 95% CI 0.04, 0.39), but not to AFC, inhibin B or estradiol. Neither alcohol nor caffeine is related to any ovarian age indicator. Exploratory analyses suggest that the association of current smoking with FSH varies with age: comparing current with never smokers, at ages 30, 35, 40 and 45, estimated differences in mean FSH are 0.3, 1.3, 3.2 and 6.9 mIU/ml.

CONCLUSIONS

The association of current smoking with FSH may reflect accelerated oocyte atresia, impaired follicle quality or dysregulation of the hypothalamic-pituitary-ovarian axis. Identification of the causal mechanism has implications for prevention or treatment of conception delay, infertility and morbidity associated with early menopause.

Geographical clustering of pancreatic cancers in the Northeast Nile Delta region of Egypt

The northeast Nile Delta, Egypt's most polluted region, appears to have a high incidence of pancreatic cancer. We sought to determine whether there is any geographic clustering of pancreatic cancers there and, if so, whether such clustering might be associated with environmental pollution. Using data from the medical records of the Gastrointestinal Surgical Center of Mansoura University in the Dakahleia Province of Egypt and detailed geographical maps of the northeast Nile Delta region, we plotted the residences of all 373 patients who had pancreatic cancer diagnosed between 1995 and 2000. The study region has 15 administrative districts, whose centroid coordinates, population, and number of pancreatic cancer patients were determined for this study. Monte Carlo simulation identified statistically significant clustering of pancreatic cancer in five subdivisions located near the Nile River and Delta plains. This clustering was independent of population size and formed two larger clusters. When data were analyzed by sex, clustering of pancreatic cancer was observed in the same five subdivisions for men but only two subdivisions showed clustering for women. Together, our data suggest that there is clustering of pancreatic cancer cases in the northeast Nile delta region and that this clustering may be related to water pollution. Our data also warrant future studies of the association between water pollution and pancreatic cancer in the region.

A two-stage design for a phase II clinical trial of coenzyme Q10 in ALS

BACKGROUND

The combination of a small pool of patients at any given time with the availability of many potential neuroprotective agents to be tested in ALS requires efficient phase II trial designs.

OBJECTIVE

To describe the design of the Clinical Trial of High Dose Coenzyme Q10 (CoQ10) in ALS (QALS study)--a phase II, randomized, placebo-controlled, double-blind, multicenter clinical trial.

METHODS

The study design features two stages. The first stage (dose selection) identifies which of two doses of CoQ10 (1800 mg or 2700 mg) is preferred using a selection procedure rather than a formal hypothesis test. The second stage (early efficacy test) compares the preferred dose of CoQ10 against placebo using a non-superiority or futility design. Data from patients assigned to the preferred dose of CoQ10 in the first stage are also used in the second stage. The primary outcome measure is the decline in Amyotrophic Lateral Sclerosis Functional Rating Scale-revised (ALSFRSr) score from baseline to 9 months.

RESULTS

The total sample size required is 185 patients, as compared to a much larger sample size estimated to be necessary using a conventional superiority design (total: 852 patients). The authors report a bias correction made necessary by the inclusion of patient data from the first stage in the second stage.

CONCLUSIONS

Several features of the Clinical Trial of High Dose Coenzyme Q10 in ALS study design promote efficiency. These features may be beneficial in phase II trials in amyotrophic lateral sclerosis and other fields.

The Aer-O-Scope: proof of the concept of a pneumatic, skill-independent, self-propelling, self-navigating colonoscope in a pig model

BACKGROUND AND STUDY AIMS

Considerable training is needed to enable endoscopists to use the currently available commercial colonoscopes and sigmoidoscopes effectively and safely. The aim of this study was to evaluate the safety and efficacy of the propulsion mechanism incorporated into the Aer-O-Scope (GI View Ltd., Ramat Gan, Israel)--a novel self-propelled, self-navigating colonic endoscope for diagnostic purposes.

MATERIALS AND METHODS

Twenty young female pigs underwent complete bowel preparation followed by a sedated examination using the new device. Ten pigs underwent two consecutive procedures, with a wash-out period of 7 days between each procedure. The total number of procedures was 30. Two prototypes of the Aer-O-Scope, with different cable lengths and vehicle balloon sizes (n = 20 and n = 10 for prototypes I and II, respectively) were used. Each examination was followed by a standard colonoscopy for safety evaluation. The insertion length of the Aer-O-Scope was determined by fluoroscopy images.

RESULTS

The colon was adequately clean in 25 procedures. Maximum insertion was achieved in 21 procedures (84%)--80% with prototype I (n = 15) and 90% with prototype II (n = 10). The time to maximum insertion averaged 8.9 +/- 4.4 min (10 +/- 4.6 and 6.6 +/- 2.9 min for prototypes I and II; P < 0.05), and the withdrawal time averaged 3.4 +/- 2.1 and 4.2 +/- 3.4 min, respectively. The driving pressures for prototypes I and II averaged 46.3 and 34.5 mbar, respectively. The follow-up conventional colonoscopy identified no mucosal tears or perforations. Minor mucosal petechiae were noted in 43% of the cases. No adverse events were noted up to 7 days after the procedure.

CONCLUSIONS

The propulsion mechanism used in this novel self-propelled, self-navigating colonoscope was effective and safe in pigs.

Predictors of antral follicle count during the reproductive years

BACKGROUND

We sought to identify indicators of antral follicle count which would be serviceable to clinicians seeking to estimate the number of ovarian follicles without relying on sonographic counts.

METHODS

We examined the relations of chronological age and four potential indicators of ovarian age-ovarian volume, FSH, dimeric inhibin B and estradiol-to antral follicle count in 176 recently pregnant women. We identified the regression models which best predict low antral follicle count (< or =10 follicles).

RESULTS

Chronological age, ovarian volume, FSH and inhibin B were each significantly associated with antral follicle count. Fifty-three (30.1%) women had < or =10 antral follicles. In the total sample, at the cutpoint corresponding to 80% sensitivity, the positive predictive value for a regression model with all four variables was 60%. All regression models performed less well in women <35 years (13.9% with low count) than in women > or =35 years (52.0% with low count). In older women, the positive predictive value for the model with all four variables was 79%, compared with 60% for a model with chronological age alone.

CONCLUSIONS

Our models provide a basis for advising women aged > or =35 years who are either trying to conceive or wish to learn whether they may postpone childbearing.

The ALSFRSr predicts survival time in an ALS clinic population

OBJECTIVE

To determine whether the Amyotrophic Lateral Sclerosis Functional Rating Scale-revised (ALSFRSr), a predictor of survival time in ALS clinical trials, predicts survival time in an ALS clinic population.

METHODS

The authors prospectively evaluated 267 consecutive patients with ALS at first visit to an ALS clinic using the ALSFRSr and pulmonary function testing. The association of ALSFRSr score at baseline with death or tracheostomy in ALS was examined using Cox proportional hazards models, adjusting for age at baseline, sex, and symptom duration.

RESULTS

Of 267 patients with ALS, 103 (39%) reached the endpoint, defined as either death (79 patients) or tracheostomy (24 patients), during a mean follow-up of 1.0 +/- 0.7 years. Among the 103 patients who reached the endpoint during follow-up, 77 (75%) had a baseline ALSFRSr score of less than 38 (the median baseline score of all patients), compared to 53 of 164 (32%) who remained alive without tracheostomy. Patients with a total ALSFRSr score below the median had a 4.4-fold increased risk of death or tracheostomy compared to those who scored above the median (HR: 4.38, 95% CI: 2.79 to 6.86, p < 0.001). Both the total ALSFRSr score at baseline (HR: 0.94, 95% CI: 0.91 to 0.98, p < 0.001) and forced vital capacity at baseline (HR: 0.99, 95% CI: 0.98 to 1.00, p = 0.02) were associated with death or tracheostomy when included in the same Cox model.

CONCLUSIONS

In an ALS clinic population, the total Amyotrophic Lateral Sclerosis Functional Rating Scale-revised score at baseline is a strong predictor of death or tracheostomy independently of forced vital capacity and after adjustment for age at baseline, sex, and symptom duration.

Trisomic pregnancy and the oocyte pool

BACKGROUND

We tested the hypothesis that trisomy risk is increased for women with fewer oocytes (older ovarian age) than other women of the same chronological age.

METHODS

Our study compared three indicators of ovarian age-number of antral follicles, level of dimeric inhibin B, level of FSH-among women who had trisomic pregnancy losses (n = 54) with those among women who had other losses (24 with other chromosomally abnormal loses, 21 with chromosomally normal losses) or who had chromosomally normal births (n = 65).

RESULTS

Ovarian age indicators did not differ between women with trisomic spontaneous abortions and the three comparison groups. Compared with live birth controls, adjusting for chronological age, we estimate that, on average, among trisomy cases the geometric means of 1 + follicle count, inhibin B and FSH are about 7.5% higher, 16.6% higher and 5.5% lower, respectively, with all 95% confidence intervals including zero. The sample size was sufficient to detect moderate differences (0.52 standard errors of regression) between trisomy cases and live birth controls.

CONCLUSIONS

Although our data do not support our hypothesis, they leave open the possibility that changes in follicular development unrelated to the size of the oocyte pool influence abnormal chromosome segregation.

A randomised, double blind, placebo controlled study of celecoxib, a selective cyclooxygenase 2 inhibitor, on duodenal polyposis in familial adenomatous polyposis

BACKGROUND

Non-selective cyclooxygenase (COX) inhibitors (non-steroidal anti-inflammatory drugs) inhibit large bowel carcinogenesis in patients with familial adenomatous polyposis (FAP). Their role in the duodenum of these patients is less certain. The disease modifying activity of specific COX-2 inhibitors has not been explored in humans.

PATIENTS AND METHODS

This was a randomised, double blind, placebo controlled study of celecoxib (100 mg twice daily (n=34) or 400 mg twice daily (n=32)) versus placebo (n=17), given orally twice daily for six months to patients with FAP. Efficacy was assessed qualitatively by blinded review of shuffled endoscopy videotapes comparing the extent of duodenal polyposis at entry and at six months and quantitatively by measurement of the percentage change in duodenal area covered by discrete and plaque-like adenomas from photographs of high and low density polyposis.

RESULTS

Shuffled and blinded video review showed a statistically significant effect of 400 mg twice daily celecoxib compared with placebo treatment (p=0.033) with all five independent observers scoring a beneficial effect. Overall, patients taking celecoxib 400 mg twice daily showed a 14.5% reduction in involved areas compared with a 1.4% for placebo (p=0.436). However, patients with clinically significant disease at baseline (greater than 5% covered by polyps) showed a 31% reduction in involved areas with celecoxib 400 mg twice daily compared with 8% on placebo (p=0.049).

CONCLUSIONS

A panel of five endoscopists found a significant reduction in duodenal polyposis after six months of treatment with celecoxib 400 mg twice daily. COX-2 inhibition may help this otherwise untreatable condition.

A gender-specific HIV/STD risk reduction intervention for women in a health care setting: short- and long-term results of a randomized clinical trial

This study assessed the short- and long-term effect of a gender-specific group intervention for women on unsafe sexual encounters and strategies for protection against HIV/STD infection. Family planning clients (N = 360) from a high HIV seroprevalence area in New York City were randomized to an eight-session, a four-session or a control condition and followed at one, six and 12 months post-intervention. Using an intention-to-treat analysis, women who were assigned to the eight-session group had about twice the odds of reporting decreased or no unprotected vaginal and anal intercourse compared to controls at one month (OR = 1.93, 95% confidence interval [CI] = 1.07, 3.48, p = 0.03) and at 12-month follow-up (OR = 1.65, 95% CI = 0.94, 2.90, p = 0.08). Relative to controls, women assigned to the eight-session condition reported during the previous month approximately three-and-a-half (p = 0.09) and five (p < 0.01) fewer unprotected sex occasions at one- and 12-month follow-up, respectively. Women in the eight-session group also reduced the number of sex occasions at both follow-ups, and had a greater odds of first time use of an alternative protective strategy (refusal, outercourse, mutual testing) at one-month follow-up. Results for the four-session group were in the expected direction but overall were inconclusive. Thus, gender-specific interventions of sufficient intensity can promote short- and long-term sexual risk reduction among women in a family planning setting.

Planning cancer prevention strategies based on epidemiologic characteristics: an Egyptian example

BACKGROUND AND METHODS

We describe the epidemiology, cancer prevention strategies, and educational messages to be learned from four characteristic cancers in Egypt: urinary bladder, liver, lung, and early-onset colorectal cancers.

RESULTS

For bladder cancer, effective and convenient treatment of schistosomiasis, using social marketing and mass media in public and medical education has contributed dramatically to primary prevention of bladder cancer in Egypt. For liver cancer, educating hospital administrators to remove structural barriers to good practice may help the control of hepatitis transmission and related liver cancer. For lung cancer, the 50-year American experience for controlling tobacco smoking, beginning with physicians, could be very effective in Egypt and other countries with increasing smoking rates in the young so as to avert the expected epidemics of lung cancer. For colorectal cancer, more attention to physician and public education about the importance of interviewing colorectal cancer patients about a family history of cancer and the screening of at-risk families could be very effective in early detection of colorectal cancer.

CONCLUSION

Countries with similar cancer epidemiology experience should make use of successful cancer prevention and education strategies that could be translated from the Egyptian experience.

[Candida carriage in the oral mucosa of a student population: adhesiveness of the strains and predisposing factors]

The aim of this study was to establish oral carriage of Candida and possible factors associated to their virulence in young adults and their relation with local and general situations considered as predisposing factors. Samples were obtained from dorsum tongue in 70 students attending the Faculty of Dentistry (University of Buenos Aires) average age: 23, all in healthy oral conditions. Of these, 21.42% were Candida positive. These samples were seeded in CHROMagar. Candida identification was completed in milk agar and Fungichrom 1. The following species were identified: 11 Candida albicans (C.a), 2 Candida parapsilosis (C.p) and 1 Candida glabrata (C.g). In one case, 2 species (C.a and C.g) were isolated in the same sample. Virulence was determined as adherence capacity by biofilm or in vitro plaque formation and hydrophobicity. Different host factors were analyzed statistically to establish their importance as predisposing factors to allow Candida colonization. Adherence of C.a. was found to be similar in all C.a. strains, whereas significant differences were found between C.a. and C.p. and between C.a. and C.g. Only the antiseptic mouthrinse and the diet were significant among the considered factors.

Contrasting molecular pathology of colorectal carcinoma in Egyptian and Western patients

Colorectal carcinoma is uncommon in Egypt, but a high proportion of cases occurs before age 40 years and in the rectum. We compared the molecular pathology of 59 representative Egyptian patients aged 10-72 to Western patients with sporadic, young-onset, or hereditary non-polyposis colorectal cancer syndrome (HNPCC)-associated carcinoma and found significant differences. Most Egyptian cancers were rectal (51%) and poorly differentiated (58%). High levels of microsatellite instability (MSI-H) were frequent (37%) and attributable in some cases (36%) to methylation of the promoter of the hMLH1 mismatch repair gene, but no MSI-H cancer had loss of hMSH2 mismatch repair gene product of the type seen with germline hMSH2 mutation in HNPCC. K-ras mutation was uncommon (11%). In subset analyses, high frequencies of MSI-H in rectal carcinomas (36%) and p53 gene product overexpression in MSI-H cancers (50%) were found. MSI-H and K-ras mutation in Egyptians under age 40 were unusual (17% and 0%, respectively), and schistosomiasis was associated with MSI and K-ras mutation. Cluster analysis identified 2 groups: predominantly young men with poorly differentiated mucinous and signet-ring cell colorectal carcinoma lacking K-ras mutation; older patients who had well- or moderately differentiated adenocarcinoma often with MSI-H, K-ras mutation and schistosomiasis. Our findings show that the molecular pathology of colorectal cancer in older as well as younger Egyptians has unique differences from Western patients, and schistosomiasis influences the molecular pathogenesis of some tumours.

A comparison of warfarin and aspirin for the prevention of recurrent ischemic stroke

BACKGROUND

Despite the use of antiplatelet agents, usually aspirin, in patients who have had an ischemic stroke, there is still a substantial rate of recurrence. Therefore, we investigated whether warfarin, which is effective and superior to aspirin in the prevention of cardiogenic embolism, would also prove superior in the prevention of recurrent ischemic stroke in patients with a prior noncardioembolic ischemic stroke.

METHODS

In a multicenter, double-blind, randomized trial, we compared the effect of warfarin (at a dose adjusted to produce an international normalized ratio of 1.4 to 2.8) and that of aspirin (325 mg per day) on the combined primary end point of recurrent ischemic stroke or death from any cause within two years.

RESULTS

The two randomized study groups were similar with respect to base-line risk factors. In the intention-to-treat analysis, no significant differences were found between the treatment groups in any of the outcomes measured. The primary end point of death or recurrent ischemic stroke was reached by 196 of 1103 patients assigned to warfarin (17.8 percent) and 176 of 1103 assigned to aspirin (16.0 percent; P=0.25; hazard ratio comparing warfarin with aspirin, 1.13; 95 percent confidence interval, 0.92 to 1.38). The rates of major hemorrhage were low (2.22 per 100 patient-years in the warfarin group and 1.49 per 100 patient-years in the aspirin group). Also, there were no significant treatment-related differences in the frequency of or time to the primary end point or major hemorrhage according to the cause of the initial stroke (1237 patients had had previous small-vessel or lacunar infarcts, 576 had had cryptogenic infarcts, and 259 had had infarcts designated as due to severe stenosis or occlusion of a large artery).

CONCLUSIONS

Over two years, we found no difference between aspirin and warfarin in the prevention of recurrent ischemic stroke or death or in the rate of major hemorrhage. Consequently, we regard both warfarin and aspirin as reasonable therapeutic alternatives.

Colorectal cancer screening by primary care physicians in two medical care organizations

The objectives of this study were to (1) evaluate self-reported practices of colorectal cancer (CRC) screening among primary care physicians (PCPs) in medical organizations and (2) identify factors associated with screening performance. We surveyed a census sample of 204 PCPs from two medical organizations in Houston, TX. Outcomes were PCPs' self-reports of screening with fecal occult blood test (FOBT) and/or flexible sigmoidoscopy (FS).2-7 Independent variables included physician demographics, perception of screening efficacy, level of agreement with screening guidelines, and perceptions of screening barriers. Variables were compared using Student's t-tests, Chi-square, and Fisher's exact tests. Regression was used to examine factors associated with PCPs' reports of screening. Our response rate was 56% (n = 115). Many PCPs reported recommending and/or performing/ordering screening with both FOBT (82%) and FS (87%). They more often reported believing that FS was "very effective" for reducing mortality than was FOBT (76% vs. 37%). Physicians perceived that barriers to patient compliance with CRC screening were stronger than barriers to making screening recommendations. Significant test-specific differences in reported barriers to screening were found. Results revealed high awareness and self-reported practice of CRC screening in this study population. Further examination of how barriers influence CRC screening practices by PCPs in medical organizations will be important for improving population screening rates.