Thierry Janssen
Université libre de Bruxelles
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Featured researches published by Thierry Janssen.
The Journal of Urology | 1996
Gil Raviv; Thierry Janssen; Alexandre Zlotta; Fabien Descamps; Alain Verhest; Claude Schulman
PURPOSE We attempted to characterize patients diagnosed with prostatic intraepithelial neoplasia without concurrent cancer on biopsy who had prostate cancer on subsequent biopsy. MATERIALS AND METHODS The records of 93 patients with low and high grade prostatic intraepithelial neoplasia without concurrent cancer on initial biopsy were analyzed. The relationships among prostatic intraepithelial neoplasia grades, patient age, digital rectal examination, serum prostate specific antigen (PSA), transrectal ultrasound appearance and final pathological results were investigated. RESULTS Subsequent carcinoma was found on repeat biopsy in 13.3% of patients with low grade and 47.9% with high grade prostatic intraepithelial neoplasia (p < 0.001). In the former group digital rectal examination, patient age, serum PSA and transrectal ultrasound were not predictive of cancer. Transrectal ultrasound appearance, digital rectal examination and serum PSA were statistically different between high grade prostatic intraepithelial neoplasia with and without subsequent cancer (p < 0.001, p = 0.008 and p = 0.016, respectively, univariate analysis). On multivariate analysis of patients with high grade prostatic intraepithelial neoplasia only digital rectal examination and PSA were predictive of subsequent carcinoma. CONCLUSIONS High grade prostatic intraepithelial neoplasia is a strong predictor of subsequent cancer, especially in men with abnormal digital rectal examination and elevated serum PSA. Patients with high grade prostatic intraepithelial neoplasia should undergo repeat biopsy to exclude cancer. Further investigations are needed to optimize the treatment of patients with low grade prostatic intraepithelial neoplasia.
Cancer | 1996
Gil Raviv; Alexandre Zlotta; Thierry Janssen; Fabien Descamps; Juan Pablo Vanegas; Alain Verhest; Claude Schulman
Prostatic intraepithelial neoplasia (PIN) is considered to be a precursor of prostate carcinoma in which serum levels of prostate specific antigen (PSA) have been correlated with PIN grades. The aim of this study was to determine whether PSA and prostate specific antigen density (PSAD), obtained at the time of initial diagnosis of PIN without concurrent carcinoma, can be used as predictive factors to discriminate patients with subsequent cancer on repeat biopsy.
Human Pathology | 1996
Thierry Janssen; Michel Petein; Roland van Velthoven; Patrick van Leer; Marc Fourmarier; Juan Pablo Vanegas; André Danguy; Claude Schulman; Jean Lambert Pasteels; Robert Kiss
The histochemical binding pattern of the peanut (Arachis hypogaea) lectin (PNA) was quantitatively described by means of computer-assisted microscope analysis in 28 benign prostatic hyperplasias (BPH), 15 prostatic intraepithelial neoplasias (PIN), and 119 prostatic adenocarcinomas. PNA exhibits nonimmune but selective binding to glycoproteins with beta-D-galactosyl(1,3)-N-acetyl-D-galactosamine residues. We also investigated whether a relationship existed between the number of histochemical-related PNA acceptors and the histochemical prostate-specific antigen (PSA) stain intensity, and between the number of PNA receptors and DNA ploidy level. The results show that neoplastic prostate tissues and high-grade intraepithelial prostatic neoplasias (PIN2_3) exhibit a significantly higher number of PNA acceptors than benign prostatic hyperplasias and low (PIN1) grade prostatic intraepithelial neoplasias. A statistically significant correlation was observed between the number of histochemically related PNA acceptors and PSA immunostain intensity. Lastly, diploid prostatic tumors, whether benign or malignant, exhibited a significantly higher number of PNA acceptors than aneuploid ones. These results suggest that PNA acceptors play an important role in the biology of prostate tumors.
The Prostate | 1997
Thierry Janssen; Michel Petein; Roland van Velthoven; Robert De Decker; Christophe Assenmacher; André Corbusier; Jean Lambert Pasteels; Robert Kiss; Claude Schulman
A variety of hormones have demonstrated effects on prostatic tissue growth dynamics. Our goal was to define the effect of dihydrotestosterone (DHT), epidermal growth factor (EGF), and prolactin (PRL) on prostate cellular proliferation.
The Journal of Pathology | 1996
Christine Decaestecker; Roland Van Velthoven; Michel Petein; Thierry Janssen; Isabelle Salmon; Jean Lambert Pasteels; Philippe Van Ham; Claude Schulman; Robert Kiss
The aggressiveness of human bladder tumours can be assessed by means of various classification systems, including the one proposed by the World Health Organization (WHO). According to the WHO classification, three levels of malignancy are identified as grades I (low), II (intermediate), and III (high). This classification system operates satisfactorily for two of the three grades in forecasting clinical progression, most grade I tumours being associated with good prognoses and most grade III with bad. In contrast, the grade II group is very heterogeneous in terms of their clinical behaviour. The present study used two computer‐assisted methods to investigate whether it is possible to sub‐classify grade II tumours: computer‐assisted microscope analysis (image cytometry) of Feulgen‐stained nuclei and the Decision Tree Technique. This latter technique belongs to the Supervised Learning Algorithm and enables an objective assessment to be made of the diagnostic value associated with a given parameter. The combined use of these two methods in a series of 292 superficial transitional cell carcinomas shows that it is possible to identify one subgroup of grade II tumours which behave clinically like grade I tumours and a second subgroup which behaves clinically like grade III tumours. Of the nine ploidy‐related parameters computed by means of image cytometry [the DNA index (DI), DNA histogram type (DHT), and the percentages of diploid, hyperdiploid, triploid, hypertriploid, tetraploid, hypertetraploid, and polyploid cell nuclei], it was the percentage of hyperdiploid and hypertetraploid cell nuclei which enabled identification, rather than conventional parameters such as the DI or the DHT.
In Vitro Cellular & Developmental Biology – Animal | 1996
Isabelle Camby; Thierry Janssen; Robert De Decker; Michel Petein; Gil Raviv; Jean Lambert Pasteels; Robert Kiss; André Danguy
SummaryWhile lectins are known to influence the cell growth of several types of normal and neoplastic tissues, their roles in the case of prostatic cancer cells remain relatively unexplored. In the present work, we report thein vitro influence of five lectins, namely peanut (PNA), wheat germ (WGA), Concanavalin A (Con A),Griffonia simplicifolia (GSA-IA4), andPhaseolus vulgaris (PHA-L) agglutinins, on the cell proliferation of one androgen-sensitive (LNCaP) and two androgen-insensitive (PC-3 and DU 145) human prostatic cancer cell lines cultured in either 10% or 1% fetal bovine serum (FBS)-supplemented media. The cell proliferation was assessed by means of the colorimetric 3-(4,5-dimethythiazol-2-yle)2,5-diphenyltetrazolium bromide. (MTT) assay. Four lectin concentrations were tested (i.e., 0.1, 1, 10, and 100 μg/ml) at five experimental states (i.e., 2, 3, 5, 7, and 9 d following the addition of each lectin to the culture media). Our results demonstrated that the five lectins under study had a globally significant dose-dependent toxic effect on prostatic cancer cell proliferation. Nevertheless, low doses of GSA-IA4 and PHA-L significantly (P<0.05 toP<0.001) increased the cell proliferation of confluent PC-3 cells. Increasing the FBS from 1% to 10% in the culture media significantly antagonized lectin-induced toxicity in the three prostatic cell lines. In conclusion, the present data strongly suggest that some lectins might influence the proliferation of prostatic carcinoma cells. In addition, because lectins are present in our diet, and are able to pass into the systemic circulation and thus reach the prostate, the present results suggest that some lectins might exert an influence on prostate cancer growth under clinical conditions.
Acta urologica Belgica | 1996
Gil Raviv; Thierry Janssen; Alexandre Zlotta; Louis L; Fabien Descamps; Alain Verhest; Claude Schulman
European Urology | 1996
Roland Van Velthoven; Michel Petein; W. Oosterlinck; Gil Raviv; Thierry Janssen; Hendrik Roels; Jean Lambert Pasteels; Claude Schulman; Robert Kiss
Acta urologica Belgica | 1995
Thierry Janssen; Robert Kiss; Claude Schulman
Analytical cellular pathology : the journal of the European Society for Analytical Cellular Pathology | 1996
Michel Petein; Christine Decaestecker; Valérie Segers; Thierry Janssen; Marc Fourmarier; Patrick van Leer; Roland Van Velthoven; Claude Schulman; Jean Lambert Pasteels; Robert Kiss