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T H Van Der Kwast

Publications and source records attributed to T H Van Der Kwast.

10 recordsLinked to original sources
PubMed2003

Ultrasound-guided fine needle aspiration cytology of axillary lymph nodes in breast cancer patients. A preoperative staging procedure.

Currently, axillary lymph node dissection is increasingly being replaced by the sentinel node procedure. This method is time-consuming and the full immunohistochemical evaluation is usually only first known postoperatively. This study was designed to evaluate the accuracy of preoperative ultrasound-guided fine needle aspirations (FNAs) for the detection of non-palpable lymph node metastases in primary breast cancer patients. We evaluated the material of 183 ultrasound-guided FNAs of non-palpable axillary lymph nodes of primary breast cancer patients. The cytological results were compared with the final histological diagnosis. Ultrasound-guided FNA detected metastases in 44% (37/85) of histologically node-positive patients, in 20% of the total patient population studied. These pecentages are likely to be higher when women with palpable nodes are included. Cytologically false-negative and false-positive nodes were seen in 28 (15%) and three cases (1.6%), respectively. Interestingly 25% (n=7) of the false-negative nodes, revealed micrometastases on postoperative histology. The sensitivity was 57%, the specificity 96%. We conclude that ultrasound-guided FNA of the axillary lymph nodes is an effective procedure that should be included in the preoperative staging of all primary breast cancer patients. Whether lymph nodes are palpable or not, it will save considerable operating time by selecting those who need a complete axillary lymph node dissection at primary surgery and would save a significant number of sentinel lymph node dissections (SLNDs).

Biopsy, Needle↗
PubMed2001

Expression and prognostic value of epidermal growth factor receptor, transforming growth factor-alpha, and c-erb B-2 in nephroblastoma.

BACKGROUND: Wilms tumor is one of the most common solid tumors in children. A transforming growth factor-alpha (TGF-alpha)/epidermal growth factor receptor (EGF-R) autocrine loop plays an important role in tumor growth. Abnormal expression of TGF-alpha, EGF-R and c-erb B-2 has been demonstrated in several human malignancies. METHODS: The immunohistochemical expression of TGF-alpha, EGF-R, and c-erb B-2 was studied in paraffin material of 62 clinical Wilms tumors. Patients had a mean follow-up of 5.7 years. RESULTS: Generally, TGF-alpha, EGF-R, and c-erb B-2 were expressed in tissue of the normal kidney and at variable levels in the three cell types of Wilms tumor, i.e., blastemal, epithelial, and stromal cells. Immunoreactive blastema cells were found in 48%, 44%, and 34% of tumors for TGF-alpha, EGF-R, and c-erb B-2, respectively. It was found that TGF-alpha, EGF-R, and c-erb B-2 blastemal and epithelial expression gradually increased from T1 to T3. The blastemal expression of TGF-alpha was statistically significantly correlated with clinicopathologic stages. Both univariate and multivariate analysis showed that blastemal TGF-alpha expression was indicative for clinical progression, but neither blastemal TGF-alpha, nor EGF-R or c-erb B-2 expression correlated with patients survival. Epithelial staining was of no prognostic value. The simultaneous expression of TGF-alpha/EGF-R was indicative for clinical progression at univariate level. CONCLUSIONS: Increased expression of TGF-alpha in the blastemal part of Wilms tumor correlated with tumor classification and clinical progression. These findings suggest that significant expression of TGF-alpha and EGF-R may play a role in promoting transformation and/or proliferation of Wilms tumor, perhaps by an autocrine mechanism. Therefore, their expression may be of value in identifying patients at high risk of tumor recurrence.

Biomarkers, Tumor↗
PubMed2001

Expression of multidrug resistance related proteins and proliferative activity is increased in advanced clinical prostate cancer.

PURPOSE: Advanced disseminated prostate cancer is highly resistant to cytotoxic chemotherapy. We identified proteins that may be involved in multidrug resistance in clinical prostate cancer. Expression of these proteins was examined in the context of tumor progression. MATERIALS AND METHODS: Paraffin embedded, formalin fixed prostate cancer specimens from archival sources of 3 distinct patient groups were examined. These groups were clearly distinct with regard to pathological stage and responsiveness to antihormonal therapy. Group 1 consisted of patients with organ confined prostate cancer treated with radical prostatectomy (early pathological stage T2N0M0). Group 2 patients had disseminated, early advanced prostate cancer and were treated with transurethral prostatic resection for urinary obstruction before receiving antihormonal therapy. Group 3 patients had disseminated prostate cancer with relapse despite antihormonal treatment (late advanced prostate cancer) and they underwent transurethral prostatic resection to relieve the symptoms of urinary obstruction. Immunohistochemical study was done to detect P-glycoprotein, multidrug resistance associated protein, lung resistance protein, glutathione-S-transferase pi, p53, Bcl-2, Bax, topoisomerase I, IIalpha and IIbeta, and Ki-67. RESULTS: Advanced tumors were distinguished from locally confined tumors because they exhibited significantly higher histological grade and proliferative activity. The expression of multidrug resistance associated protein, p53, topoisomerase IIalpha, Ki-67 and topoisomerase IIbeta was significantly related to a higher Gleason sum score. The number of cases expressing multidrug resistance associated protein, lung resistance protein, glutathione-S-transferase pi, p53, Bcl-2, topoisomerase IIalpha and Ki-67 was significantly increased in the group with advanced disseminated prostate cancer. Topoisomerase I and IIbeta were homogeneously and highly expressed at all stages of prostate cancer progression, while P-glycoprotein was not expressed in any tumors regardless of the patient group. CONCLUSIONS: Up-regulation of the expression of the drug transporters multidrug resistance associated protein and lung resistance protein, detoxifying enzyme glutathione-S-transferase pi, and apoptosis inhibiting proteins Bcl-2 and p53 may be an explanation of the resistance of disseminated progressive prostate cancer to chemotherapy. As shown by the up-regulation of Ki-67 and topoisomerase IIalpha, increased proliferation reflects the aggressiveness of metastatic prostate cancer. Research on agents that counteract multidrug resistance mechanisms and may sensitize prostate carcinoma to cytotoxic chemotherapy may possibly lead to more effective treatment of progressive disseminated prostate cancer.

ATP-Binding Cassette Transporters↗
PubMed2000

Staging prostate cancer.

Determining tumor stage provides a systematic way to describe the amount and the extent of a tumor at a certain point in time. In this short overview, the current version of the TNM system for prostate cancer is discussed. The TNM (tumor, lymph node, and metastasis) system is now used worldwide for determining tumor stage for prostate cancer. Tumor stage is essentially determined in two situations, at clinical evaluation of the patient (clinical stage) and after treatment by surgical removal of the prostate (pathological stage). In the ideal situation, clinical stage would be a reliable predictor of pathological stage, but in the current situation, tumors are clinically understaged in more than half of the cases. Additional clinical tools are needed to provide a firmer base on which the choice for patient treatment or management could be founded. Some of the criteria for the assessment of pathological stage are unclear. For instance, multifocal tumor, which occurs in more than half of the cases of prostate cancer, is not reckoned with in the current system, something that could hamper a correct and unambiguous assessment of pathological stage. In this report, we also discuss the criteria for extraprostatic extension, seminal vesicle invasion, and bladder neck invasion. Follow-up data obtained from a group of 123 patients that underwent radical prostatectomy at our hospital underline the importance of reporting the latter two.

Humans↗
PubMed2000

E-cadherin promotes intraepithelial expansion of bladder carcinoma cells in an in vitro model of carcinoma in situ.

High-grade transitional cell carcinomas (TCCs) of the urinary bladder are frequently associated with carcinoma in situ, which may replace large areas of the mucosa of the urinary tract. The invasive component of TCCs often reveals a loss of expression of the cell-cell adhesion molecule E-cadherin, but the role of E-cadherin in the development and expansion of intraepithelial neoplasia is unknown. To study the underlying mechanism of intraepithelial expansion (IEE), we have developed an IEE assay. Human TCC cell lines were investigated in this IEE assay for their capacity to replace the surrounding normal murine urothelial cells. In vitro IEE appeared to be prominent in three (SD, RT112, and 1207) of the four E-cadherin-positive cell lines. Although the two E-cadherin-negative cell lines (T24 and J82) were able to penetrate surrounding normal urothelium as single cells, they largely lacked the capacity of IEE. These results prompted us to investigate whether the cell-cell adhesion molecule E-cadherin is an important determinant for IEE. T24 cells that were transfected with full-length mouse E-cadherin cDNA displayed an enhanced IEE rate. Transfection did not influence their proliferative capacity, their pattern and level of integrin expression, or their ability to expand in the absence of surrounding urothelium. The data suggest that E-cadherin-mediated cohesiveness is an important factor in the IEE of bladder carcinoma cells. These observations argue for a dual, paradoxical role of E-cadherin in bladder tumorigenesis. On the one hand, E-cadherin promotes the expansion of intraepithelial neoplasia; on the other hand, its loss correlates with invasive behavior.

Animals↗
PubMed1997

In vitro modulation of implantation and intraepithelial expansion of bladder tumor cells by epidermal growth factor.

A major problem in the management of bladder cancer is the high risk for recurrence of bladder tumors after transurethral resection. This has generally been attributed to the attachment and subsequent expansion of exfoliated tumor cells to the traumatized bladder wall. An in vitro cocultivation model was used to study the implantation and growth of human tumor cells in traumatized murine urothelium. Furthermore, we investigated in a time-course experiment whether stimulation of the regenerative activity of the normal urothelium by a growth factor could affect implantation and subsequent growth of bladder tumor cells. After inoculation on injured confluent cultures of murine urothelium, human T24 and SD bladder carcinoma cells preferentially attached to the denuded areas. SD cells expanded into the normal urothelium as a sharply demarcated tumor, while T24 cells infiltrated as single cells. Treatment of the primary urothelium with epidermal growth factor (EGF) stimulated the proliferation of the primary urothelium and reduced the implantation and growth of T24 considerably. EGF reduced the implantation of the SD tumor cells but could not prevent the further expansion at the expense of surrounding normal urothelium. Since EGF had no effect on migration or proliferation of SD or T24 cells, its modulation of expansive growth is most probably due to an increase in the regeneration of normal urothelium. This study suggests that recurrence of transitional cell carcinomas might in some instances be inhibited by stimulation of the regeneration of traumatized urothelium. The reported in vitro cocultivation model may be useful for studying additional factors involved in intraepithelial expansion of carcinoma cells.

Animals↗
PubMed1996

Expression of platelet-derived growth factor (PDGF) and PDGF receptors in human malignant mesothelioma in vitro and in vivo.

The expression of platelet-derived growth factor (PDGF) and PDGF receptors was studied in human normal and malignant mesothelial cells in vitro and in vivo. Staining with anti-cytokeratin and ME1 antibodies and ultrastructural analysis confirmed the mesothelial nature of the cell lines used to study PDGF and PDGF receptor expression in vitro. Using antibodies, mesothelioma cell lines were found to express PDGF and both the PDGF alpha- and the PDGF beta-receptor, whereas cultured normal mesothelial cells expressed PDGF and PDGF alpha-receptor. This PDGF and PDGF receptor staining pattern largely reflects the earlier described mRNA expression in these cell lines. The only exception was the immunocytochemical detection of PDGF alpha-receptors in the mesothelioma cell lines, which is different from the inability to detect alpha-receptor transcripts on Northern blots. Expression was also investigated in mesothelial cells in vivo. Expression of PDGF was observed in malignant mesothelioma cells on frozen tissue sections. In pleural effusions, a double immunofluorescence staining procedure for PDGF and epithelial membrane antigen (EMA) revealed PDGF expression by EMA-positive malignant mesothelioma cells. PDGF beta-receptors and occasionally PDGF alpha-receptors were detected in frozen tissue sections of malignant mesotheliomas, whereas mesothelioma cells in effusions showed faint expression of only the PDGF beta-receptor. In contrast, in effusions containing non-malignant mesothelial cells, only a very low level of PDGF alpha-receptor could be detected. Taken together, these results indicate that the pattern of PDGF and PDGF receptor expression in mesothelial cells in vivo largely corresponds to expression of PDGF and its receptors in vitro. Malignant mesothelioma cell lines thus constitute a good model system for studies on the role of PDGF in this malignancy. Furthermore, the data reported in this paper are consistent with the idea that an autocrine growth stimulatory effect of PDGF via PDGF receptors may play a role in the pathogenesis of malignant mesothelioma.

Cryopreservation↗
PubMed1991

Ki-67 staining in histological subtypes of breast carcinoma and fine needle aspiration smears.

Thirty four cases of invasive breast carcinoma were analysed for heterogeneity of Ki-67 reactivity in a tumour, and proliferative activity in various histological subtypes was compared. The growth factions determined in areas of central and peripheral tumour were the same. Mucinous and lobular carcinoma showed lower Ki-67 activity than ductal carcinomas. When ductal carcinomas were subdivided according to their dominant growth pattern, the carcinomas with a solid or comedo growth pattern showed the highest proliferative activity. These results largely confirm data from previous cell kinetic studies on the incorporation of radioactively labelled thymidine. A correlation between the growth fraction determined by Ki-67 in fine needle aspiration smears and cryostat sections of corresponding tumours was shown, implying that the immunostaining of cytological smears gives a reliable impression of the growth fraction of a tumour and may therefore be used in prospective studies.

Adenocarcinoma, Mucinous↗
PubMedDate not supplied

Androgen receptor immunoexpression in the testes of subfertile men.

The localization and intensity of androgen receptor immunostaining was studied in the testes of 37 subfertile men with oligozoospermia and normal serum gonadotropin levels using a polyclonal antibody raised against a synthetic peptide corresponding to the first 20 N-terminal amino acid residues of the androgen receptor (AR). Furthermore, we investigated whether or not the immunoexpression of the AR in human Sertoli cells, in histologically normal testis tissue, is dependent on the stage of the spermatogenic cycle, as has been found in the rat. In the human testis, AR immunoexpression was observed in Sertoli cells, peritubular myoid cells, Leydig cells, and periarteriolar cells, but not in germinal cells. We found no evidence for a stage-dependent immunoexpression of AR in Sertoli cells. The intensity of AR immunoexpression varied substantially between biopsy specimens of different patients. There was, however, no correlation of the intensity of AR immunoexpression in either Sertoli cells or peritubular myoid cells with spermatogenic adequacy as measured by the method of Johnsen. When, in this study, the intensity of peritubular myoid cell staining was used as a standard to evaluate the intensity of Sertoli cell staining, no correlation was detected as well. Furthermore, serum gonadotropin levels were not correlated with AR immunoexpression levels in Sertoli cells and peritubular myoid cells. These results indicate that immunodetectability of the AR is not related to the condition of the spermatogenic epithelium in patients with oligozoospermia. Inappropriate expression of the AR is neither a cause nor a consequence of idiopathic infertility in the present group of patients.

Biopsy↗