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Biomedical subjects

M B Wischnewsky

Publications and source records attributed to M B Wischnewsky.

8 recordsLinked to original sources
PubMed2005

Primary chemotherapy with gemcitabine as prolonged infusion, non-pegylated liposomal doxorubicin and docetaxel in patients with early breast cancer: final results of a phase II trial.

BACKGROUND: Combinations of anthracyclines, taxanes and gemcitabine have shown high activity in breast cancer. This trial was designed to evaluate a modified combination regimen as primary chemotherapy. Non-pegylated liposomal doxorubicin (NPLD) was used instead of conventional doxorubicin to improve cardiac safety. Gemcitabine was given 72 h after NPLD and docetaxel as a prolonged infusion over 4 h in order to optimize synergistic effects and accumulation of active metabolites. PATIENTS AND METHODS: Forty-four patients with histologically confirmed stage II or III breast cancer were treated with NPLD (60 mg/m(2)) and docetaxel (75 mg/m(2)) on day 1 and gemcitabine as 4-h infusion (350 mg/m(2)) on day 4. Treatment was repeated every 3 weeks for a maximum of six cycles. All patients received prophylactically recombinant granulocyte colony-stimulating factor. Patients with axillary lymph node involvement after primary chemotherapy received adjuvant treatment with cyclophosphamide, methotrexate and fluorouracil. RESULTS: The clinical response rate was 80%, and complete remissions of the primary tumor occurred in 10 patients (25%). Breast conservation surgery was performed in 19 out of 20 patients (95%) with an initial tumor size of less than 3 cm and in 14 patients (70%) with a tumor size <or=3 cm. Seven patients had histologically confirmed complete responses accounting for a pCR rate of 17.5%. Expression of Ki--67 was the most important predictive parameter for response with high 38.9% breast pCR rate in patients with elevated Ki--67 expression. Although the predominant toxicity was myelosuppression with grade 3/4 neutropenia in 61% of patients few neutropenic complications resulted. Non-hematological toxicity was generally moderate with grade 3 or 4 toxicity in 10.0% of cycles. Most common non-hematologic toxicities were nausea, vomiting, alopecia, mucositis, asthenia and elevation of liver enzymes. CONCLUSION: The evaluated schedule provides a safe and highly effective combination treatment for patients with early breast cancer, which is suitable for phase III studies.

Adult↗
PubMed2002

Prediction of response to hormonal treatment in metastatic breast cancer.

Prediction of outcome and individualization of therapeutic strategies are challenging problems in oncology. Predictive parameters for response to hormonal treatment include the expression of hormone receptor, the extent and location of metastatic spread, disease-free interval, patient age, response to prior hormonal therapy, grading, and more recently, some molecular markers like the expression of HER-2/neu. The use of conventional statistics for prediction of response to hormonal treatment is limited by non-linearities and complex interactions between predictive factors. Modern computational mathematical models like artificial neural networks, entropy-based inductive algorithms or chi(2) interaction detection algorithms can describe these interactions and generate classification models and decision structures. They can be used to predict the clinical outcome for individual patients. In contrast to conventional methods, the level of confidence for the predictions can reach 90% and more. This might be an important step towards further individualization of therapeutic strategies.

Antineoplastic Agents, Hormonal↗
PubMed2001

ABC stenosis morphology classification and outcome of coronary angioplasty: reassessment with computing techniques.

BACKGROUND: The American College of Cardiology/American Heart Association (ACC/AHA) stenosis morphology classification (MC) stratifies coronary lesions for probability of success and complications after coronary angioplasty (PTCA). Modern computing techniques were used to evaluate the individual predictive value of MC in random PTCA cases. METHODS AND RESULTS: MC was attributed to the target lesions by consensus of 2 observers. The predictive value regarding procedural success (PS) and major adverse cardiac events (MACE) of MC was analyzed by conventional logistic regression analyses and by inductive machine learning models. The study was adequately powered for the methods applied with 325 target lesions of 250 cases. Overall, PS decreased and MACE increased from type A to type C lesions. Regression analysis identified no single factor as predictive. Logistic regression showed an error rate of 42%. Machine learning techniques achieved an individual predictive error of only 10%, which could be further reduced to 2% by addition of parameters. For PS, MC parameters showed a high ranking for building the model. For MACE, variables of the medical history showed more impact. CONCLUSIONS: MC per se cannot individually predict PS or MACE. However, when all MC parameters are integrated together with additional lesion-specific and history variables, a high individual predictive value can be achieved. This technique may be clinically helpful for risk stratification in the catheterization laboratory and improvement of classification systems in interventional cardiology.

Algorithms↗
PubMed1999

A prognostic computer model to individually predict post-procedural complications in interventional cardiology: the INTERVENT Project.

AIMS: The purpose of this part of the INTERVENT project was (1) to redefine and individually predict post-procedural complications associated with coronary interventions, including alternative/adjunctive techniques to PTCA and (2) to employ the prognostic INTERVENT computer model to clarify the structural relationship between (pre)-procedural risk factors and post-procedural outcome. METHODS AND RESULTS: In a multicentre study, 2500 data items of 455 consecutive patients (mean age: 61.1+/-8.3 years: 33-84 years) undergoing coronary interventions at three university centres were analysed. 80.4% of the patients were male, 16.7% had unstable angina, and 5.1%/10.1% acute/subacute myocardial infarction. There were multiple or multivessel stenoses in 16.0%, vessel bending >90 degrees in 14.5%, irregular vessel contours in 65.0%, moderate calcifications in 20.9%, moderate/severe vessel tortuosity in 53.2% and a diameter stenosis of 90%-99% in 44.4% of cases. The in-lab (out-of-lab) complications were: 0.4% (0.9%) death, 1.8% (0.2%) abrupt vessel closure with myocardial infarction and 5.5% (4.0) haemodynamic disorders. CONCLUSION: Computer algorithms derived from artificial intelligence were able to predict the individual risk of these post-procedural complications with an accuracy of >95% and to explain the structural relationship between risk factors and post-procedural complications. The most important prognostic factors were: heart failure (NYHA class), use of adjunctive/alternative techniques (rotablation, atherectomy, laser), acute coronary ischaemia, pre-existent cardiac medication, stenosis length, stenosis morphology (calcification), gender, age, amount of contrast agent and smoker status. Pre-medication with aspirin or other cardiac medication had a beneficial effect. Techniques, such as laser angioplasty or atherectomy were predictors for post-procedural complications. Single predictors alone were not able to describe the individual outcome completely.

Adult↗
PubMed1999

Audit and quality control in angioplasty in Europe: procedural results of the AQUA Study 1997: assessment of 250 randomly selected coronary interventions performed in 25 centres of five European countries. AQUA Study Group, Nucleus Clinical Issues, Working Group Coronary Circulation, of the European Society of Cardiology.

AIMS: Percutaneous transluminal coronary angioplasty (PTCA) has become the most widely used major intervention in western medicine. However, there is disparate use of this technique among different European countries and the U.S.A. In an attempt at quality assurance, the working group Coronary Circulation of the European Society of Cardiology has carried out a study on appropriateness, necessity, and performance of PTCA in Europe. The present paper reports on the procedural results of this survey. METHODS: In a multicentre case-control study in Europe, 750 patients (544 men, 206 women) with documented vascular disease of the From the countries participating in the European Registry of Coronary Intervention, the three countries with the highest absolute PTCA volume (Germany, France, and the United Kingdom) and two randomly selected countries (Belgium and Italy) were chosen for investigation. In these countries, five centres were selected at random according to the following criteria: one centre with >1000, three centres with 300-1000, and one centre with <300 procedures per year. In each of these, 10 cases from the first half of 1997 were randomly identified and all pertinent documentation was collected. RESULTS: In 250 cases, 325 stenoses were addressed as target lesions. Single vessel disease was present in 41%. History included stable angina in 49%, unstable angina in 32%, atypical chest pain in 6%, no anginal pain in 12%, and acute/subacute myocardial infarction in 13%. The percentage of patients with either positive stress test and/or unstable angina, acute/subacute infarction, previous infarction (within 6 months) or coronary revascularization amounted to 98%. Single vessel intervention accounted for 90%. In 41% balloon-only angioplasty was performed and in 54% at least one stent was implanted with considerable variation among countries. The use of other new devices amounted to only 3%. In 92%, the operators documented a successful procedure. Major complications (myocardial infarction, emergency bypass surgery, or death) were found in 4.8%. CONCLUSIONS: Based on scrutinized hospital and operator data, the present study revealed a satisfactorily high percentage of justifiable indications, an adequate procedural success rate, and an acceptably low complication rate. Further analysis by an expert panel will address appropriateness, necessity, and procedural performance of the individual cases.

Angioplasty, Balloon, Coronary↗
PubMed1997

A prognostic computer model to predict individual outcome in interventional cardiology. The INTERVENT Project.

It is not yet possible to predict an individual's outcome from percutaneous transluminal coronary angioplasty or alternative/adjunctive coronary interventional techniques. The purpose of the INTERVENT project is to redefine complications associated with coronary interventions, to set up a prognostic computer model to predict individual outcome and to compare the results to those of conventional statistical techniques. 2500 data items were analysed in 455 consecutive patients (mean age: 61.1 +/- 8.3 years; range 33-84 years; 80.4% male, 16.7% unstable angina, 5.1%/10.1% acute/subacute myocardial infarction) undergoing coronary interventions at three university centres. In-lab/out-of-lab complication rates were 0.4%/0.9% (death), 1.8%/0.2% (abrupt vessel closure with myocardial infarction) and 5.5%/4.0% (haemodynamic complications). Computer algorithms derived by applying techniques from artificial intelligence were able (1) to reduce the set of possible relevant risk factors from 2500 to about 40, (2) to predict individual risk with an accuracy of > 95% and (3) to explain the structural relationship between outcome and risk factors. Patient data from two centres were used to construct and test the algorithm. Data from a third centre were used to evaluate the algorithm. The most important predictors-were acute myocardial infarction, heart failure (NYHA class > II), unstable angina, complex lesions, high low density lipoprotein cholesterol and duration of coronary heart disease. Neither age nor gender impaired the percutaneous transluminal coronary angioplasty results in acute ischaemic syndromes; however, for stable angina, procedural risk increased with age. There was little risk from primary percutaneous transluminal coronary angioplasty in acute myocardial infarction in patients with NYHA heart failure classes I-II; however, the risk was high for patients in NYHA classes > II, either with or without additional thrombolysis. Alternative/adjunctive intervention techniques were no predictors for in-lab-, but were predictors for post-procedural complications.

Adult↗
PubMed1997

Quality monitoring, standardized documentation and management with a computerized system in oncology.

Within the last years the prerequisite was prepared to develop a computerized tumor--patient documentation system including quality monitoring and oncological therapy recommendations for every day use. In medicine today, there is an increasing need for quality oriented low cost and transparent management--what is especially true in the field of oncology. The German Federal Authority of Health demands the documentation of all tumor disorders for the establishment of an cancer registry. For these reasons our study group established the program "OncoDoc" in cooperation with the laboratory for Artificial Intelligence of the University Bremen.

Artificial Intelligence↗