Georg Feichter
University of Basel
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American Journal of Clinical Pathology | 2005
Lukas Bubendorf; Phaedra Müller; Ladina Joos; Bruno Grilli; Sandrine Vogel; Michelle Herzog; Audrey Barascud; Georg Feichter; Peter Dalquen; Michael Tamm
The aim of the present study was to explore the diagnostic usefulness of the multitarget fluorescence in situ hybridization (FISH) test, LAVysion (Vysis, Downers Grove, IL), for the detection of lung cancer cells in cytologic specimens. Specimens from bronchial washings, bronchial brushings, and transbronchial fine-needle aspirates (TBNAs) from 100 patients with suspected lung cancer and from a control group of 71 patients with nonneoplastic lung disorders were analyzed. FISH positivity was defined as more than 5 cells with gains of at least 2 chromosomes or gene loci. FISH significantly improved the sensitivity of bronchial brushings from 49% to 73%. The specificities of FISH and cytologic examination were 87% and 100%, respectively. In contrast, FISH provided no additional diagnostic information in TBNAs and bronchial washings. There was no increased prevalence of genetic changes in contralateral bronchial washings from patients with lung cancer compared with the control group. The quantity of previous smoking had no effect on the prevalence of chromosomal changes.
Pathology Research and Practice | 1993
Holger Moch; Joachim Torhorst; Ursula Dürmüller; Georg Feichter; Guido Sauter; Fred Gudat
Tenascin is an extracellular matrix glycoprotein expressed during morphogenesis in embryonal life. It reappears in the stroma of benign and malignant tumors. The distribution of tenascin in variants of fibrocystic disease and infiltrating breast carcinoma was assessed in cryostat sections by immunofluorescence using a polyclonal antibody. The tenascin immunoreactivity was compared with various prognostic factors. In fibrocystic disease (n = 10), tenascin appeared as periductal and periacinar bands. In infiltrating carcinomas (n = 32) the tenascin expression was markedly increased. Tenascin immunoreactivity was noted around the ducts (78%), extended into the distal stroma (56%), or was distributed in smaller (reticular) septa around and within tumor-cell nests (34%). Nineteen percent of infiltrating carcinomas did not express tenascin. None of the patterns correlated with prognostic factors such as nodal metastasis, tumor necrosis, invasion of blood vessels, or with flow cytometry results, such as ploidy and S-phase fraction. However, a significantly higher reticular and periepithelial tenascin expression was noted in cases with increased stromal inflammatory reaction. These findings indicate that the appearance of tenascin is neither an indicator of malignancy nor predictive of invasiveness or metastasis but that it is related to local inflammatory response.
International Journal of Cancer | 1997
Athanassios Dellas; Elisabeth Schultheiss; Alfonso C. Almendral; Fred Gudat; Martin Oberholzer; Georg Feichter; Holger Moch; Joachim Torhorst
Recent results suggest that p53 inactivation is required for cervical‐carcinoma development. The mdm‐2 oncogene, which forms an auto‐regulatory feedback loop with the normal p53 protein, has been found amplified in human carcinomas, thus abolishing the anti‐proliferative function of p53. To investigate whether the mdm‐2/p53 interaction plays a role in cervical neoplasms, we performed an immunohistochemical study in archival fixed, embedded specimens that included 178 pre‐cancerous lesions (CIN) and invasive squamous‐cell carcinomas of clinical stage IB. In addition to p53, we assessed the p53‐associated protein, mdm‐2, and the Ki‐67 labelling index (LI). The presence of HPV was assessed by in situ DNA hybridization. Tumor expression of all nuclear proteins was scored as fraction of positive CIN or cancer nuclei. The analysis demonstrated a significant association of the Ki‐67 LI with grade of atypia in cervical neoplasms. p53 accumulation and mdm‐2 expression are higher in invasive carcinomas than in pre‐cancerous lesions. No correlation was observed with HPV status. An inverse correlation was found between increased tumor‐cell proliferation and mdm‐2 expression in invasive carcinomas (p < 0.0001). mdm‐2 expression was significantly associated with p53 accumulation (p < 0.02). However, the investigated nuclear proteins were not associated with overall survival in patients with invasive carcinomas. Cox stepwise‐regression analysis revealed regional lymph node status and depth of invasion to be independent parameters. Int. J. Cancer 74:421–425, 1997.
Virchows Archiv | 1997
Peter Dalquen; Holger Moch; Georg Feichter; M. Lehmann; Markus Solèr; Peter Stulz; Paul Jordan; Joachim Torhorst; Michael J. Mihatsch; Guido Sauter
Abstractu2002Inactivation of the p53 gene plays a key role in tumour biology, probably through a disturbed cell cycle control and an increased genetic instability in p53-inactivated tumours. To learn more about the relationship between p53 alterations, proliferation and genetic instability (DNA aneuploidy) in lung cancer patients, specimens of 220 surgically resected lung carcinomas with clinical follow-up information were examined by immunohistochemistry (p53; CM1) and flow cytometry. Nuclear p53 positivity – found in 49.5% of the tumours – was associated with both high S-phase fraction (SPF) and DNA ploidy aberrations. SPF was higher in p53-positive tumours (15.9 ± 10.2) than in p53-negative tumours (10.3 ± 8.7; P = 0.03). The rate of p53 positivity was higher in 101 DNA-aneuploid and DNA-multiploid tumours (55%) than in 27 diploid and peridiploid carcinomas (33%; P = 0.0512). These results are consistent with an in vivo role of p53 inactivation for increased proliferative activity and development of genomic instability in lung cancer. There was no association between SPF and prognosis. Although prognosis was worse in DNA-aneuploid and multiploid tumours than in diploid, peridiploid and tetraploid carcinomas (P = 0.029), DNA ploidy was not an independent predictor of poor prognosis in multivariate analysis. These data show that DNA-flow cytometry has little prognostic value for patients with resected non-small-cell lung carcinoma.
Acta Cytologica | 1997
Peter Dalquen; Betty Baschiera; Rosemarie Chaffard; Holger Dieterich; Georg Feichter; Karin Krämer; Joachim Torhorst
OBJECTIVEnThe reliability of immunocytochemical evaluation of proliferation activity was tested using the monoclonal antibody MIB-1 on cytologic specimens.nnnSTUDY DESIGNnThe study comprised 83 frozen tissue smears (FTSs) and 51 fine needle aspirates (FNAs) from 119 breast cancer patients. MIB-1 labeling indexes (LIs) were compared with various tumor parameters assessed on histologic material.nnnRESULTSnMIB-1 LIs established on cytologic smears were significantly different in ductal and lobular carcinomas (P = .024) and correlated significantly with mitotic activity (P < .0001), histologic grade (P < .0001) and S-phase fraction (P < .0001). Essentially the same results were obtained on FTSs and FNAs.nnnCONCLUSIONnProliferative activity can reliably be evaluated by FNA cytology, and the evaluation of MIB-1 LIs may complement cytologic grading of breast cancer. The evaluation of proliferation activity may, therefore, contribute to the selection of candidates for adjuvant chemotherapy.
Recent results in cancer research | 1993
Peter Dalquen; Guido Sauter; R. Epper; B. Kleiber; Georg Feichter; Fred Gudat
As the decision for immunocytochemistry is usually made on the basis of findings in Papanicolaou-stained smears and uncovering of the smears takes time, the immunocytochemical results are often reported with some delay. But they are of clinical interest only if reported within a short time. Therefore, immunocytochemistry on cytologic preparations must be carefully organized. The decision for immunocytochemistry must be made before the mounting medium has completely hardened to keep the time of uncovering short. The method of immunocytochemistry should fulfill the following prerequisites: 1. Cell sampling and fixation should be easy to handle for the clinician who sends the specimen to the laboratory. 2. Unspecific background staining, especially in cytologic preparations rich in blood and protein, should not occur. 3. The immunostaining method should be applicable to all kinds of cytologic material, fixed and stained smears included. 4. The nuclear structure of tumor cells should not be destroyed by the immunocytochemical procedure so that tumor cells after incubation are clearly distinguishable from normal cells showing a similar reaction as the tumor cells. There has hitherto been no such all-round method fulfilling all these prerequisites since the properties of the antigenic epitopes of the cells and of the antibodies recognizing them are too heterogeneous. Therefore several methods have to be considered and a variety of technical aspects such as fixation, storage of cytologic material, properties of tinctorial stains, of antibodies and of the antigenic epitopes must be studied to find out the two or three standard methods which meet the requirements in most cases. We recommend the ABC method for Papanicolaou-stained smears and the APAAP method for demonstration of lymphocyte markers. The indication of immunocytochemistry in diagnostic cytology is restricted by the limited number of specimens. Therefore, the following rules have to be observed: 1. The conventional light-microscopic examination must have priority over the immunocytochemical examination. 2. The cytologic specimens assigned for immunocytochemical examination must have been adequately fixed and stored. 3. As the number of smears is limited, the immunocytochemical examinations must be carefully planned and restricted to the absolutely necessary incubations. If possible, an informative smear has to be spared for documentation and future training of cytologists and cytotechnicians. 4. Immunocytochemical examinations in cytology are only justified if the diagnostic problem can be clearly defined. 5. The panel of antibodies should be selected carefully so that the results may give an answer to alternative questions. At least two antibodies should be applied.(ABSTRACT TRUNCATED AT 400 WORDS)
Cancer | 2006
Katharina Glatz; Spasenija Savic; Dieter Glatz; Gilbert Francz; Audrey Barascud; Bruno Grilli; Michelle Herzog; Peter Dalquen; Georg Feichter; Peter Spieler; Michael Tamm; Lukas Bubendorf
Equivocal atypia in respiratory cytology can be a diagnostic challenge. In such cases fluorescence in situ hybridization (FISH) may be used for the analysis of chromosomal aberrations and often allows a reliable distinction of benign and malignant cells.
Gynecologic Oncology | 1997
Athanassios Dellas; Holger Moch; Elisabeth Schultheiss; Georg Feichter; Alfonso C. Almendral; Fred Gudat; Joachim Torhorst
American Journal of Clinical Pathology | 2006
Katharina Glatz; Niels Willi; Dieter Glatz; Audrey Barascud; Bruno Grilli; Michelle Herzog; Peter Dalquen; Georg Feichter; Thomas C. Gasser; Tullio Sulser; Lukas Bubendorf
Chest | 2006
Spasenija Savic; Katharina Glatz; René Schoenegg; Peter Spieler; Georg Feichter; Michael Tamm; Lukas Bubendorf