Gerhard Hommel

Azathioprine combined with prednisolone or monotherapy with prednisolone in active Crohn's disease

BACKGROUND The role of azathioprine (AZA) in the treatment of active Crohns disease (CD) is still controversial. This study examined whether AZA combined with standard prednisolone therapy improved the therapeutic outcome compared with monotherapy with prednisolone. METHODS Forty-two patients with a Crohns Disease Activity Index (CDAI) of > 150 were randomized into two groups. Both received 60 mg of prednisolone daily in a tapering regimen to a maintenance dose of 10 mg. In addition, group 1 received 2.5 mg AZA/kg body wt and group 2 received a placebo over the whole study period of 4 months. RESULTS At the end of the trial, 16 of 21 patients (76%) in group 1 were in remission (CDAI < 150), compared with 8 of 21 (38%) in group 2 (P = 0.03). The CDAI in group 1 dropped from 290 +/- 97 (SD) to 72 +/- 84 and from 285 +/- 110 to 155 +/- 105 in group 2. The differences between activity indices in groups 1 and 2 became statistically significant after 8 weeks. The average prednisolone dose per day was 20.9 mg in group 1 and 26.7 mg in group 2 (P = 0.02). No major side effects were observed in this study. CONCLUSION The combination of prednisolone and AZA was superior to the treatment with prednisolone alone in active CD. Patients receiving AZA showed remission more frequently, more quickly, and with lower doses of prednisolone.

Adaptive Modifications of Hypotheses After an Interim Analysis

It is investigated how one can modify hypotheses in a trial after an interim analysis such that the type I error rate is controlled. If only a global statement is desired, a solution was given by Bauer (1989). For a general multiple testing problem, Kieser, Bauer and Lehmacher (1999) and Bauer and Kieser (1999) gave solutions, by means of which the initial set of hypotheses can be reduced after the interim analysis. The same techniques can be applied to obtain more flexible strategies, as changing weights of hypotheses, changing an a priori order, or even including new hypotheses. It is emphasized that the application of these methods requires very careful planning of a trial as well as a critical discussion of the scientific aims in order to avoid every manipulation.

Confidence Interval or P-Value?: Part 4 of a Series on Evaluation of Scientific Publications

BACKGROUND An understanding of p-values and confidence intervals is necessary for the evaluation of scientific articles. This article will inform the reader of the meaning and interpretation of these two statistical concepts. METHODS The uses of these two statistical concepts and the differences between them are discussed on the basis of a selective literature search concerning the methods employed in scientific articles. RESULTS/CONCLUSIONS P-values in scientific studies are used to determine whether a null hypothesis formulated before the performance of the study is to be accepted or rejected. In exploratory studies, p-values enable the recognition of any statistically noteworthy findings. Confidence intervals provide information about a range in which the true value lies with a certain degree of probability, as well as about the direction and strength of the demonstrated effect. This enables conclusions to be drawn about the statistical plausibility and clinical relevance of the study findings. It is often useful for both statistical measures to be reported in scientific articles, because they provide complementary types of information.

The relationship of p53 expression to the prognosis of 418 patients with gastric carcinoma

Background. Mutations of the p53 gene belong to the most common genetic alterations in human cancer that have been implicated in tumorigenesis and tumor progression. Although p53 expression appears to be correlated with prognosis in patients with breast cancer and some other types of cancer, its prognostic role in gastric cancer is still uncertain. In the present study, therefore, the prognostic impact of p53 expression was evaluated in 418 patients with curatively resected gastric carcinomas without residual tumor (RO‐resection).

Long term follow up after percutaneous closure of PFO in 357 patients with paradoxical embolism: Difference in occlusion systems and influence of atrial septum aneurysm

BACKGROUND Percutaneous transcatheter closure of patent foramen ovale (PFO) in cryptogenic stroke or TIA is an alternative to medical therapy especially in patients with atrial septal aneurysm (ASA). The differences in time to complete occlusion for various closure devices in PFO alone and PFO plus ASA are of natural interest. METHODS AND RESULTS Between January, 1st 1998 and November, 30th 2006 percutaneous PFO closure was performed in 357 patients with a history of > or =1 paradoxical embolism using three different devices: Amplatzer PFO-(n=199), Starflex-(n=48) and Helex Occluder (n=110). All patients were assigned to a post-interventional protocol with contrast-enhanced transesophageal echocardiography (TOE) at 1 and 6 months and every 6 to 12 months in case of incomplete closure. Definite closure was confirmed in at least two consecutive TOE studies. The closure time curves between the three devices were significantly different (p=0.0072). Devices of 25 mm or less had a better occlusion rate. The difference between the closure time curves of PFO and PFO+ASA concerning each device type was significant for Helex (p=0.006) and Starflex (p=0.030). In regard to the occlusion time for large devices Helex succeeded later than Amplatzer and Starflex (p=0.0029). Concerning the cumulative follow up period of 1265 patient years the recurrence/re-event rate of cerebral and peripheral thromboembolic events was 0.7% per patient year. No relation to residual PFO shunting or to thrombus formation was seen. There were no peri-interventional technical complications. In five patients of the Starflex group thrombi were detected in the four week TOE controls. CONCLUSION The closure rate is dependent on occluder size and type plus the occurrence of an atrial septum aneurysm.

Incidence of the Factor V Leiden-mutation, Coagulation Inhibitor Deficiency, and Elevated Antiphospholipid-antibodies in Patients with Preeclampsia or HELLP–Syndrome

LETTER TO THE EDITORS-IN-CHIEF Incidence of the Factor V Leiden-mutation, Coagulation Inhibitor Deficiency, and Elevated Antiphospholipid-antibodies in Patients with Preeclampsia or HELLP–Syndrome Georg–Friedrich von Tempelhoff1, Lothar Heilmann1, Eberhard Spanuth1, Erich Kunzmann1 and Gerhard Hommel2 1Department of Obstetrics and Gynecology, City Hospital of Ruesselsheim and 2Institute for Medical Statistic and Documentation, University of Mainz, Germany.

Blood coagulation during adjuvant epirubicin/cyclophosphamide chemotherapy in patients with primary operable breast cancer.

PURPOSE Influences of adjuvant epirubicin/cyclophosphamide (EC) chemotherapy on blood coagulation were investigated in patients with operable breast cancer and the incidence of thromboembolic events was recorded. PATIENTS AND METHODS In 50 consecutive node-positive breast cancer patients, serial coagulation studies (fibrinogen method of Clauss, antithrombin III, protein C amidolytic methods, D dimer enzyme-linked immunoadsorbent assay [ELISA] techniques, and plasminogen activator inhibitor [PAI] activity u-PA inhibition test) and impedance plethysmography (IPG) for screening of deep vein thrombosis (DVT) were performed preoperatively and postoperatively, before each of six cycles of adjuvant chemotherapy (60 mg/m2 epirubicin and 600 mg/m2 cyclophosphamide) and 3 months thereafter. Seventy-two healthy women served as controls. RESULTS During chemotherapy, the phlebographically proven DVT incidence was 10% (n = 2 after second cycle; n = 3 after third cycle). Preoperative levels of D-dimer, fibrinogen, and the PAI activity were significantly higher than in healthy women and only mean levels of the D-dimer were significantly higher in patients with DVT compared with patients without DVT. Postoperatively, only D-dimer and fibrinogen levels significantly increased, while in the course of chemotherapy, these levels were significantly decreased. Mean D-dimer levels and PAI increased steadily in patients with DVT. Preoperatively and during chemotherapy, levels of antithrombin III and protein C were within the normal range. Only one patient with DVT had decreased protein C levels throughout chemotherapy. CONCLUSION Monitoring with sophisticated coagulation tests during adjuvant EC chemotherapy for breast cancer does not identify patients at higher risk for DVT development. Preoperatively, in patients with later DVT, an imbalance of hemostasis is already present; thus, thrombosis might predominantly be initiated by malignancy-induced hypercoagulability and secondarily by the influence of EC chemotherapy. Prospective randomized trials must determine whether prophylactic anticoagulation during EC chemotherapy reduces the incidence of DVT.

Linear regression analysis: part 14 of a series on evaluation of scientific publications.

BACKGROUND Regression analysis is an important statistical method for the analysis of medical data. It enables the identification and characterization of relationships among multiple factors. It also enables the identification of prognostically relevant risk factors and the calculation of risk scores for individual prognostication. METHODS This article is based on selected textbooks of statistics, a selective review of the literature, and our own experience. RESULTS After a brief introduction of the uni- and multivariable regression models, illustrative examples are given to explain what the important considerations are before a regression analysis is performed, and how the results should be interpreted. The reader should then be able to judge whether the method has been used correctly and interpret the results appropriately. CONCLUSION The performance and interpretation of linear regression analysis are subject to a variety of pitfalls, which are discussed here in detail. The reader is made aware of common errors of interpretation through practical examples. Both the opportunities for applying linear regression analysis and its limitations are presented.

What are cancer patients’ preferences about treatment at the end of life, and who should start talking about it? A comparison with healthy people and medical staff

Goals of the workIn order to strengthen cancer patients’ autonomy and to improve quality of palliative care, it is necessary to know what are the patients’ preferences for treatment at the end of life, whether they accept the idea of advance directives, and who should initiate the process of fulfilling such a document.Patients and methodsWe compared cancer patients’ preferences with respect to particular treatment options at the end of life, acceptance of the idea of advance directives, and preferences for whom should initiate writing such a document with that of healthy controls, nursing staff, and physicians (n=100 each group) using a structured questionnaire.ResultsCancer patients wanted treatment with antibiotics and infringing treatments such as chemotherapy and dialysis significantly more often than healthy controls, nursing staff, and physicians (p<0.01 and p<0.001, respectively). Determinants associated with the wish to opt for these treatments were reduced health condition and older age. The groups did not differ with respect to their acceptance of advance directives; 58–75% of all those surveyed wanted their physicians to initiate a discussion about writing such a document if they thought it appropriate.ConclusionsCancer patients’ preferences for treatment at the end of life significantly differ compared to other groups. Oncologists should initiate a discussion about an advance directive when/if the course of the illness seems to make this appropriate, which corresponds to the wish of the majority of cancer patients, healthy controls, and medical staff.

Expression and prognostic value of the CD44 splicing variants v5 and v6 in gastric cancer

In the present study, the expression and prognostic role of the CD44 splicing variants v5 and v6 were immunohistochemically investigated in 418 curatively resected gastric carcinomas. CD44v5 was expressed in 65·3 per cent (n=273) and CD44v6 in 77·0 per cent (n=322) of the tumours. Whereas the expression of CD44v5 was correlated with advanced pT categories, with lymph node involvement, and with the presence of blood and lymphatic vessel invasion, such a correlation could not be found for the variant v6. As shown by univariate analysis, patients with CD44v5‐positive tumours had a significantly shorter overall survival than patients with CD44v5‐negative tumours (P=0·049). In contrast, expression of CD44v6 had no impact on prognosis (P=0·574). In a multivariate analysis including the prognostic parameters pT category and pN category, as well as blood and lymphatic vessel invasion, the prognostic impact of CD44v5 expression could not, however, be maintained. Although in the present study the expression of CD44v5 was correlated with a more aggressive tumour type, these data suggest that neither CD44v5 nor CD44v6 can predict survival in patients with gastric cancer, nor is their expression a suitable tool for identifying subgroups of patients who may be at higher risk.