Separating favorable from unfavorable prognostic markers in breast cancer: the role of E-cadherin

Distant metastases are the major cause of morbidity and mortality in women with breast cancer. The ability to predict the metastatic proclivity is essential in choosing the optimal treatment. Tumor size and grade, which are frequently used markers in node-negative breast cancer patients, are inadequate markers for prognosis and individualized treatment design. The steps in metastatic progression include angiogenesis, invasion, and changes in adhesion characteristics. We developed a strategy for choosing biomarkers representing these steps in malignant progression to identify patients with occult metastases who will need chemotherapy and spare those women whose tumors have not developed the capacity to spread. To evaluate the added significance of E-cadherin to that of nm23-H1 and angiogenesis in determining metastatic proclivity, we used archival material from 168 node-negative breast cancer patients who were treated with mastectomy without any adjuvant chemotherapy or hormone therapy. Immunohistochemistry was used to detect E-cadherin and nm23-H1 expression, whereas angiogenesis was determined by microvessel count (MVC) after immunohistochemical staining. The median follow-up is 14 years. We found that E-cadherin is better in identifying the poor prognosis patients. The 14-year disease-free survival (DFS) is 84%, 80%, and 56% in patients with high, intermediate, and low E-cadherin. The worst prognosis group using nm23-H1 and MVC as biomarkers has a 14-year DFS of 62%. In this group, if E-cadherin is low, the 14-year DFS is further decreased to 44%. Nm23-H1 and MVC are better in identifying the good prognosis patients. The long-term DFS is >90% if MVC is low or if nm23-H1 is high. Multivariate analysis shows that E-cadherin, nm23-H1, and MVC are more significant prognostic biomarkers than tumor size or grade. Loss of E-cadherin appears to be a latter step in the metastatic progression compared to angiogenesis and the loss of nm23-H1 expression.

Antiplatelet therapy for preventing stroke in patients with non-valvular atrial fibrillation and no previous history of stroke or transient ischemic attacks

BACKGROUND

Atrial fibrillation (AF) carries an increased risk of stroke; antiplatelet agents are proven effective for stroke prevention in other settings.

OBJECTIVES

The objective of this review was to determine the efficacy and safety of antiplatelet therapy for prevention of stroke in patients with chronic non-valvular AF.

SEARCH STRATEGY

We searched the Cochrane Stroke Group Specialised Register of Trials, MEDLINE database (June 1999), and the database of the Antithrombotic Trialists Collaboration, as well as reference lists of relevant articles.

SELECTION CRITERIA

All randomized trials comparing antiplatelet therapies to placebo in patients with non-valvular AF and no history of transient ischemic attack (TIA) or stroke.

DATA COLLECTION AND ANALYSIS

Trials for inclusion were independently selected by two reviewers who also extracted each outcome and double-checked the data. The Peto method was used for combining odds ratios. All analysis were, as far as possible, "intention-to-treat". Since the published results of two trials included 3-8% of participants with prior stroke or TIA, unpublished results excluding these participants were obtained from the Atrial Fibrillation Investigators.

MAIN RESULTS

Among 1680 participants without prior stroke/TIA, randomized to aspirin (N = 838) or placebo in two trials, aspirin was associated with nonsignificantly lower risks of ischemic stroke (OR = 0.71, CI 95% 0. 46 - 1.10), all stroke (OR = 0.70, CI 95% 0.45 - 1.08) all disabling/fatal stroke (OR =0.88, CI 95% 0.48 - 1.58) and the constellation of stroke, MI or vascular death (OR = 0.76, CI 95% 0. 54 - 1.05 ). Considering all randomized participants including those with prior stroke or TIA, reductions in these events by aspirin were consistently smaller and marginally statistically significant: ischemic stroke (OR = 0.77, CI 95% 0.60-1.00), all stroke (OR = 0.76, CI 95% 0.61 - 0.93), all disabling/fatal stroke (OR = 0.87, CI 95% 0.64 - 1.19) and the combined outcome (OR = 0.79, CI 95% 0.64 - 0. 99). No increase in major hemorrhage was seen, but the number of hemorrhagic events was small.

REVIEWER'S CONCLUSIONS

Considering all randomized data, aspirin modestly (by about 20%) reduces stroke and major vascular events in nonvalvular AF. For primary prevention among AF patients with an average stroke rate of 4.5%/year, about 10 strokes would be prevented yearly for every 1000 given aspirin.

Oral anticoagulants for preventing stroke in patients with non-valvular atrial fibrillation and no previous history of stroke or transient ischemic attacks

BACKGROUND

Non-valvular atrial fibrillation (AF) is associated with an increased risk of stroke.

OBJECTIVES

The objective of this review was to characterize the efficacy and safety of oral anticoagulation (OAC) with vitamin K antagonists for the primary prevention of stroke in patients with chronic AF.

SEARCH STRATEGY

We searched the Cochrane Stroke Group Specialised Register of Trials (June 1999), MEDLINE database, and the database of the Antithrombotic Trialists Collaboration, as well as reference lists of relevant articles.

SELECTION CRITERIA

All randomized controlled trials comparing the value of OAC versus control in patients with non-valvular chronic atrial fibrillation and no history of transient ischemic attack (TIA) or stroke.

DATA COLLECTION AND ANALYSIS

Trials for inclusion were independently selected by two reviewers who also extracted each outcome and double-checked the data. The Peto method was used for combining odds ratios. All analysis were, as far as possible, "intention-to-treat". Since the published results of four trials included 3-8% of participants with prior stroke or TIA, unpublished results excluding these participants were obtained from the Atrial Fibrillation Investigators.

MAIN RESULTS

Of 2313 participants without prior cerebral ischemia from five trials, about half (n = 1154) were randomized to adjusted-dose OAC with an estimated mean INRs ranging between 2.0-2.6 during 1.5 years/participant average follow-up. Participant features and study quality were similar between trials. OAC was associated with large, highly statistically significant reductions in ischemic stroke (OR = 0.34, 95% CI 0.23 - 0.52), all stroke (OR = 0.39, 95% CI 0.26 - 0. 59), all disabling or fatal stroke (OR = 0.47, 95% CI 0.28 - 0.80), and the combined endpoint of all stroke, MI or vascular death (OR = 0.56, 95% CI 0.42 - 0.76). The observed rates of intracranial and extracranial hemorrhage not significantly increased by OAC therapy, but confidence intervals were wide.

REVIEWER'S CONCLUSIONS

Adjusted-dose OAC (achieved INRs between 2-3) reduces stroke as well as disabling/fatal stroke for patients with nonvalvular AF, and these benefits were not substantially offset by increased bleeding among participants in randomized clinical trials. Limitations include relatively short follow-up and imprecise estimates of bleeding risks from these selected participants. For primary prevention in AF patients who have an average stroke rate of 4%/year, about 25 strokes and about 12 disabling fatal strokes would be prevented yearly for every 1000 given OAC.

Antithrombotic therapy to prevent stroke in patients with atrial fibrillation: a meta-analysis

PURPOSE

To characterize the efficacy and safety of anticoagulants and antiplatelet agents for prevention of stroke in patients with atrial fibrillation.

DATA SOURCES

Randomized trials identified by using the search strategy developed by the Cochrane Collaboration Stroke Review Group.

STUDY SELECTION

All published randomized trials testing antithrombotic agents to prevent stroke in patients with atrial fibrillation.

DATA EXTRACTION

Data on interventions, number of participants, duration of exposure and occurrence of all stroke (ischemic and hemorrhagic), major extracranial bleeding, and death were extracted independently by two investigators.

DATA SYNTHESIS

Sixteen trials included a total of 9874 participants (mean follow-up, 1.7 years). Adjusted-dose warfarin (six trials, 2900 participants) reduced stroke by 62% (95% CI, 48% to 72%); absolute risk reductions were 2.7% per year for primary prevention and 8.4% per year for secondary prevention. Major extracranial bleeding was increased by warfarin therapy (absolute risk increase, 0.3% per year). Aspirin (six trials, 3119 participants) reduced stroke by 22% (CI, 2% to 38%); absolute risk reductions were 1.5% per year for primary prevention and 2.5% per year for secondary prevention. Adjusted-dose warfarin (five trials, 2837 participants) was more efficacious than aspirin (relative risk reduction, 36% [CI, 14% to 52%]). Other randomized comparisons yielded inconclusive results.

CONCLUSIONS

Adjusted-dose warfarin and aspirin reduce stroke in patients with atrial fibrillation, and warfarin is substantially more efficacious than aspirin. The benefit of antithrombotic therapy was not offset by the occurrence of major hemorrhage among participants in randomized trials. Judicious use of antithrombotic therapy, tailored according to the inherent risk for stroke, importantly reduces stroke in patients with atrial fibrillation.

Measurement of the wavelength dependence of beam divergence for photonic crystal fiber

We report measurements of the wavelength dependence of beam divergence for single-mode photonic crystal fiber. These measurements confirm predictions of strongly wavelength-dependent beam divergence, consistent with the effective-index model for the photonic crystal cladding material.

Factors associated with ischemic stroke during aspirin therapy in atrial fibrillation: analysis of 2012 participants in the SPAF I-III clinical trials. The Stroke Prevention in Atrial Fibrillation (SPAF) Investigators

BACKGROUND AND PURPOSE

Nonvalvular atrial fibrillation (AF) is a strong, independent risk factor for stroke, but the absolute rate of stroke varies widely among AF patients, importantly influencing the potential benefit of antithrombotic prophylaxis. We explore factors associated with ischemic stroke in AF patients taking aspirin.

METHODS

We performed multivariate logistic regression analysis of 2012 participants given aspirin alone or in combination with low, inefficacious doses of warfarin in the Stroke Prevention in Atrial Fibrillation I-III trials followed for a mean of 2.0 years, during which 130 ischemic strokes were observed.

RESULTS

Age (relative risk [RR]=1.8 per decade, P<0.001), female sex (RR=1.6, P=0.01), history of hypertension (RR=2.0, P<0.001), systolic blood pressure >160 mm Hg (RR=2.3, P<0.001), and prior stroke or transient ischemic attack (RR=2.9, P<0.001) were independently associated with increased stroke risk. Regular consumption of >/=14 alcohol-containing drinks per week was associated with reduced stroke risk (adjusted RR=0.4, P=0.04). Among SPAF III participants, estrogen hormone replacement therapy was associated with a higher risk of ischemic stroke (adjusted RR=3.2, P=0.007). With the use of these variables, a risk stratification scheme for primary prevention separated participants into those with high (7.1%/y, 22% of the cohort), moderate (2.6%/y, 37% of the cohort), and low (0.9%/y, 41% of the cohort) rates of stroke. Ischemic strokes in low-risk participants were less often disabling (P<0.001).

CONCLUSIONS

Patients with AF who have high and low rates of stroke during treatment with aspirin can be identified. However, validation of our risk stratification scheme is necessary before it can be applied with confidence to clinical management. Postmenopausal estrogen replacement therapy and moderate alcohol consumption may additionally modify the risk of stroke in AF, but these findings require confirmation.

Reduction in ischemic vascular complications with a hydrophilic-coated intra-aortic balloon catheter

Hydrophilic coatings improve the handling characteristics of angioplasty equipment, but until recently this technology has not been available for intra-aortic balloon (IAB) catheters. To determine whether a new hydrophilic coating is associated with a reduction in IAB-related complications, we prospectively evaluated 188 patients undergoing insertion of this new IAB catheter. Complications related to IAB insertion were recorded and compared to data from 682 patients previously treated with an uncoated IAB catheter of the same shaft diameter and balloon size. By multivariate analysis the hydrophilic-coated IAB catheter was associated with a 72% reduction in ischemic vascular complications (relative risk 0.28, 95% CI 0.08-0.96, P= 0.04). There were also trends toward reductions in IAB rupture and the need for vascular surgical repair for bleeding or ischemia. While further investigation is warranted, hydrophilic coatings that reduce the coefficient of friction during IAB catheter insertion may also reduce subsequent ischemic vascular complications.

Left atrial diameter in nonvalvular atrial fibrillation: An echocardiographic study. Stroke Prevention in Atrial Fibrillation Investigators

BACKGROUND

The left atrium (LA) is usually enlarged in patients with nonvalvular atrial fibrillation (AF), but factors associated with LA diameter are incompletely defined.

METHODS AND RESULTS

This transthoracic echocardiographic cohort study includes 3465 participants with nonvalvular AF in 3 multicenter clinical trials. LA diameter determined by M-mode echocardiography was correlated with clinical and echocardiographic features by cross-sectional multivariate regression analyses. The mean LA diameter was 47 +/- 8 mm, on average 6 mm larger in those with AF at the time of echocardiography than in those with sinus rhythm (48 vs 42 mm, P <. 001). Patient age and body weight were independently predictive of LA diameter (P <.0001), but sex, body surface area, and body mass index were not. The estimated independent contribution of atrial rhythm to LA diameter was approximately 2.5 mm. Prolonged duration of AF, left ventricular dilatation and increased muscle mass, mitral regurgitation, annular calcification, and hypertension were additional independent predictors of LA diameter.

CONCLUSIONS

Multiple factors appear to contribute to LA enlargement in patients with nonvalvular AF, including the presence and persistence of the dysrhythmia.

Biochemical markers of alcohol abuse

Excessive alcohol consumption is a major health problem in the UK leading to both serious morbidity and mortality. This study compared newer potential biochemical markers of excessive alcohol consumption [carbohydrate-deficient transferrin (CDT), mitochondrial AST (mAST) and alpha glutathione-s-transferase (alpha-GST)] with conventional markers (AST, ALT, GGT, MCV). Patients (n = 85) were enrolled in the study and subdivided into several groups on the basis of alcohol consumption. Patients with non-alcoholic liver disease (NALD) (n = 40) were also enrolled. All the markers, with the exception of the ratio mAST/total AST were significantly higher in heavy drinkers/alcoholics compared to teetotallers/social drinkers (p < 0.05). mAST and AST/ALT ratio were significantly higher in alcoholics compared to NALD (p < 0.01), whereas ALT was higher in the NALD group (p < 0.05). Multivariate discriminant function analysis (Wilks method) demonstrated that the logarithmic functions of AST/ALT ratio and mAST could correctly classify 87.9% of cases into either the alcoholic or NALD groups. ROC plot analysis showed that AST, mAST and GGT were the best markers at distinguishing heavy consumption of alcohol from lesser levels and that AST/ALT ratio and mAST were the best in distinguishing alcoholics from NALD. In conclusion, none of the newer biochemical markers, with the exception of mAST, offers any major advantage over the conventional markers.

Prospective evaluation of factors associated with intraaortic balloon rupture

The authors undertook a prospective analysis of all intraaortic balloon catheter (IAB) insertions at Hahnemann University Hospital during an 18 month period. Attention was directed to balloon rupture and factors associated with this complication. A total of 384 insertions were attempted in 363 patients: 19 patients (5.2%) experienced balloon rupture. The mean time to rupture was 2.1 +/- 3.3 days (range 0-15 days). All ruptured IAB catheters were removed percutaneously without subsequent complications. Ten balloons were subjected to leak testing and scanning electron microscopy. All but one rupture appeared to be the result of balloon abrasion against atherosclerotic plaque. The puncture site occurred at variable distances from the proximal end of the balloon at 9.4 +/- 8.3 cm. Comparison of patients with and without balloon rupture revealed several significant (p < 0.04) differences by univariate analysis (Table 1). No procedure related variables (IAB catheter size 9 versus 11 Fr, sheathless insertion, duration of counterpulsation) were associated with rupture. Stepwise logistic regression analysis revealed body surface area as the only independent predictor of balloon rupture (p = 0.007). Intraaortic balloon rupture with 40 cc balloons, is directly related to the size of the patient. Evaluation of smaller balloons in patients with body surface area < or = 1.8 m2 appears warranted to minimize IAB rupture.

The Cardiac Arrhythmia Suppression Trial: Implications for nursing practice

BACKGROUND

Care of patients with ventricular arrhythmia after myocardial infarction requires careful nursing management, including assisting with arrhythmia monitoring and testing. Because ventricular premature depolarization is a known risk factor for sudden cardiac death, it was hypothesized that the suppression of asymptomatic or mildly symptomatic ventricular premature depolarization would improve survival in these patients.

OBJECTIVE

To review the Cardiac Arrhythmia Suppression Trial findings and provide implications for nursing practice for patients after myocardial infarction.

METHODS

The Cardiac Arrhythmia Suppression Trial was a multicenter, randomized, placebo-controlled trial designed to determine whether the suppression of ventricular premature depolarizations in postmyocardial infarction patients would improve survival. Three class I antiarrhythmic drugs were used: encainide, flecainide, or moricizine. Patients for whom the drug suppressed their arrhythmia 80% or more were randomly assigned to that drug and dose or its matching placebo and were followed every 4 months (main study). Patients with 1% to 79% suppression were randomly assigned to the drug or its placebo that best treated their arrhythmia and followed every 4 months.

RESULTS

Suppression of asymptomatic or mildly symptomatic ventricular premature depolarization in patients using encainide, flecainide, or moricizine failed to improve patient survival and was even harmful in some cases.

CONCLUSIONS

Our results showed that in the absence of effective antiarrhythmic drug therapy, supportive nursing care and arrhythmia monitoring is important until appropriate therapy for the management of these arrhythmias in patients who have had a myocardial infarction can be found. Clinical trials are essential to provide an evaluation of therapies and direction for further studies, as well as a basis for practicing clinicians.

The Cardiac Arrhythmia Suppression Trial: Implications for nursing practice

BACKGROUND: Care of patients with ventricular arrhythmia after myocardial infarction requires careful nursing management, including assisting with arrhythmia monitoring and testing. Because ventricular premature depolarization is a known risk factor for sudden cardiac death, it was hypothesized that the suppression of asymptomatic or mildly symptomatic ventricular premature depolarization would improve survival in these patients. OBJECTIVE: To review the Cardiac Arrhythmia Suppression Trial findings and provide implications for nursing practice for patients after myocardial infarction. METHODS: The Cardiac Arrhythmia Suppression Trial was a multicenter, randomized, placebo-controlled trial designed to determine whether the suppression of ventricular premature depolarizations in postmyocardial infarction patients would improve survival. Three class I antiarrhythmic drugs were used: encainide, flecainide, or moricizine. Patients for whom the drug suppressed their arrhythmia 80% or more were randomly assigned to that drug and dose or its matching placebo and were followed every 4 months (main study). Patients with 1% to 79% suppression were randomly assigned to the drug or its placebo that best treated their arrhythmia and followed every 4 months. RESULTS: Suppression of asymptomatic or mildly symptomatic ventricular premature depolarization in patients using encainide, flecainide, or moricizine failed to improve patient survival and was even harmful in some cases. CONCLUSIONS: Our results showed that in the absence of effective antiarrhythmic drug therapy, supportive nursing care and arrhythmia monitoring is important until appropriate therapy for the management of these arrhythmias in patients who have had a myocardial infarction can be found. Clinical trials are essential to provide an evaluation of therapies and direction for further studies, as well as a basis for practicing clinicians.

Prospective evaluation of complications associated with percutaneous intraaortic balloon counterpulsation

In summary, current, prospective experience with 691 consecutive patients revealed that female gender, peripheral vascular disease, cardiac index, and diabetes were the only independent predictors of risk after percutaneous IAB insertion. Neither sheathless insertion nor smaller IAB catheter size was associated with a lower complication rate. There may be a threshold of catheter size associated with a dramatic reduction in complications. If that exists, it has not yet been reached.

Toward vital status sweeps: a case history in sequential monitoring

We use data from the Cardiac Arrhythmia Suppression Trial (CAST) to demonstrate the sensitivity of sequential monitoring to the timeliness of survival data. In CAST vital status sweeps were not routinely performed prior to the times of sequential analysis. Examination of the delay between death and reporting of death shows that the change in the time of sequential analysis by even as few as several months can have dramatic impact on the results of the sequential analysis.

Pilot prospective evaluation of counterpulsation with different intra-aortic balloon volumes on cardiac performance in humans

Smaller intra-aortic balloons (IAB) may minimize peripheral vascular complications. To determine the influence of different IAB volumes on cardiac performance, we studied 20 hemodynamically stable patients on IAB counterpulsation. Variables were measured with either a 40cc or 32cc IAB displacement, at an assist ratio of 1:1 or 1:8: Heart rate, Ao and PA pressures, and Fick cardiac output. By echo-Doppler, the velocity time integral (VTI) across the LV outflow tract, a measure of stroke volume was also calculated. The mean age was 60 yr (range 18-77), height 5'6" (5'2"-5'11"), and body surface area 1.9M2 (1.5-2.3). Results presented as mean values were: [table: see text] *P < 0.005 1:1 vs 1:8 for both 40 and 32cc IAB.

CONCLUSION

IAB pumping at 1:1 with either 40 cc or 32 cc volume displacement yields similar degrees of improvement in cardiac performance. A larger cohort is required to determine if smaller balloons may decrease complications without compromising efficacy.

Balancing optical path lengths in broadband fiber interferometers

A simple model is used to show that control of dispersion in an all-fiber stellar interferometer is feasible. From the results we assume that an interferometer control system is available in which both temperature and strain are used to balance the interferometer. Within the restriction of a single polarization mode, it is shown that vacuum path errors before the coupling of starlight into the fibers as well as fiber-length differences and environmental differences between two fibers can be corrected to high order.

Tympanic membrane thermometry in the care of out-of-hospital patients

STUDY OBJECTIVES

To determine the effectiveness of tympanic membrane (TM) thermometry in the out-of-hospital setting and to characterize the patients with abnormal out-of-hospital temperatures.

DESIGN

Prospective, randomized, single-month study.

SETTING

Inner city.

PARTICIPANTS

Subjects transported by ambulance for whom consent was obtainable.

RESULTS

TM probes set to rectal equivalent were assigned to three of the ambulance units of the local health department on randomly selected shifts during August 1992, one half at night and one half during the day. Simultaneous left and right ear temperatures at the scene and at the hospital, ambient temperatures, and patient's hospital temperatures were recorded. Other data recorded included each patient's mental status, activity level, and environment temperature. Paramedics noted whether they suspected a temperature problem before using the probe and whether any treatment was directed toward the patient's temperature. Regression, bias analysis, and chi 2 testing were performed; P was considered significant if it was less than .05. Right and left ear TM temperatures were correlated both at the scene and at the hospital (r = .91 and .92, respectively). TM temperatures and hospital temperatures were also correlated (r = .83 for right ear and .78 for left ear). Evaluation of agreement indicated that TM and hospital methods were equal, with a bias of -0.55 degrees F for oral and +0.66 degrees F for rectal temperatures. Thirty-two subjects (17%) were hyperthermic at the scene; of these, 9 of 32 (28%) were suspected before use of the probe. The paramedics initially treated 5 of the 9 suspected to have a temperature-related problem before using the probe and none of the 23 who were not suspected before using the probe (chi 2, P < .001).

CONCLUSION

The TM probe functioned well despite a month of vigorous handling. Temperature correlation with the gold standard and between ears was acceptable in this setting. Presence of the probe did not help with the management of hyperthermic patients in this study.

Combined temperature and strain measurement with a dispersive optical fiber Fourier-transform spectrometer

We report simultaneous measurement of strain and temperature in single-mode optical fiber by broadband interferometry. A Mach-Zehnder interferometer, illuminated by a xenon-arc lamp, has a sensing element in one arm. Scanning an air path generates interferograms that are calibrated by a monochromatic reference interferogram. Values of group delay and dispersion, obtained from the phase of the fast Fourier transform of the sampled interferogram, give strain and temperature through a well-conditioned matrix transformation without phase ambiguity. We obtained measurement ranges and resolutions of 1500 +/- 12 microstrain and 25.0 +/- 0.4 K using a 0.8-m sensing element.