Biomedical subjects

G Sauter

Publications and source records attributed to G Sauter.

At least 55 records · Page 3Linked to original sources

PubMed2000

Prognostic utility of the recently recommended histologic classification and revised TNM staging system of renal cell carcinoma: a Swiss experience with 588 tumors.

BACKGROUND: A new, internationally accepted histologic classification of renal cell carcinoma (RCC) and a new edition of the TNM staging system were introduced in 1997. In the latter, there was a dramatic change in the pT classification of organ-confined renal cancer in which the break point between category pT1 and pT2 was increased from 2.5 cm to 7 cm. METHODS: To study the significance of the new pT classification and the new recommendations for histologic classification, 588 nephrectomy specimens were reevaluated to define morphologic prognostic parameters in RCC. pT classification (TNM 1997), histologic subtype, histologic tumor grade, presence of necrosis, and sarcomatoid differentiation were assessed. RESULTS: The histopathologic review according to the new classification revealed 487 conventional (clear cell) (83%), 64 papillary (11%), 31 chromophobe (5%), and 6 collecting duct (1%) RCCs. Clinical follow-up was available for 470 RCCs. The new pT classification (1997) was strongly correlated with patient survival (P < 0.0001). Histologic grade, presence of necrosis, and sarcomatoid differentiation provided independent prognostic information on the clear cell subtype of renal cancer. Sarcomatoid differentiation, but not tumor necrosis, portended a dismal prognosis for patients with papillary RCC. Chromophobe RCC was associated with a significantly better prognosis than clear cell RCC (P = 0.05). Papillary RCC with scanty cytoplasm and small cells (type 1) behaved less aggressively than papillary tumors with eosinophilic cytoplasm and large cells (type 2; P < 0.001). CONCLUSIONS: Accurate histologic classification according to the new recommendations has implications because the prognostic importance of other histologic features that are of independent significance varies with tumor subtype. The data suggest that the new pT classification allows good separation of prognostic groups of patients with renal cancer.

Carcinoma, Renal Cell↗

PubMed2000

Allelic loss at the D9S171 locus on chromosome 9p13 is associated with progression of papillary renal cell carcinoma.

Papillary renal cell carcinomas (RCCs) have characteristic clinical and morphological features that separate them from the more common clear cell RCCs. The details of the molecular changes in papillary RCC progression are not well understood. In this study, four highly polymorphic microsatellite markers [D9S970 (9p12-9p13), D9S171 (9p13), D9S1748 (9p21) and D9S156 (9p21)] were used to determine the frequency and prognostic significance of 9p deletions in 37 papillary RCCs. Allelic deletions were detected in eight cases (22%). The highest rate of loss of heterozygosity (LOH) was observed in 6 of 29 informative patients (21%) at the D9S171 locus on 9p13. Only two patients displayed allelic loss at D9S1748, which resides in close proximity to p16(INK4). Two of 24 informative papillary RCCs (8%) showed LOH for D9S970. LOH at D9S171 (9p13) was associated with short patient survival (p=0.008), independently of tumour grade and stage. These data suggest a tumour suppressor gene centromeric to 9p21 that may contribute to papillary RCC progression.

Carcinoma, Papillary↗

PubMed2000

Marked genetic similarities between hepatitis B virus-positive and hepatitis C virus-positive hepatocellular carcinomas.

Hepatocellular carcinoma (HCC) is one of the most common neoplasms worldwide. Well-established risk factors include infections with two very different viruses: the DNA virus causing hepatitis B (HBV) and the RNA virus inducing hepatitis C (HCV). In order to determine whether genetic differences exist between HBV- and HCV-induced HCC, 41 HCC samples of known vival status were examined by comparative genomic hybridization (CGH). The analysis revealed frequent deletions of 1p (24%), 4q (39%), 6q (41%), 8p (44%), 9p (24%), 11q (24%), 12q (22%), and 13q (39%), as well as common gains of 1q (46%), 6p+ (20%), 8q+ (41%), 11q (27%), and 17q+ (37%). There was no significant difference in the number and type of chromosomal imbalances between 25 HCV- and 16 HBV-infected tumours. This is consistent with models suggesting that HBV and HCV cause cancer through non-specific inflammatory and regenerative processes, rather than through virus-specific interactions with defined target genes. Chromosomal imbalances were also unrelated to the grade and stage of HCC. This may suggest that most gross genomic alterations occur early during HCC development and that further progression of these tumours may be associated with other types of genetic changes, not detectable by CGH. In summary, these data show that characteristic gross genomic changes occur in HCC, but these alterations at present do not appear to have diagnostic or prognostic applications.

Adult↗

PubMed2000

High-throughput tissue microarray analysis of cyclin E gene amplification and overexpression in urinary bladder cancer.

Studies by comparative genomic hybridization revealed that the 19q13 chromosomal region is frequently amplified in bladder cancer. The cyclin E gene (CCNE), coding for a regulatory subunit of cyclin-dependent kinase 2, has been mapped to 19q13. To investigate the role of cyclin E alterations in bladder cancer, a tissue microarray of 2,317 specimens from 1,842 bladder cancer patients was constructed and analyzed for CCNE amplification by fluorescence in situ hybridization and for cyclin-E protein overexpression by immunohistochemistry. Fluorescence in situ hybridization analysis showed amplification in only 30 of the 1,561 evaluable tumors (1.9%). Amplification was significantly associated with stage and grade (P: < 0.0005 each). Immunohistochemically detectable cyclin E expression was strong in 233 (12.4%), weak in 354 (18.9%), and negative in 1, 286 of the 1,873 interpretable tumors. The majority (62.1%) of CCNE-amplified tumors were strongly immunohistochemistry-positive (P: < 0.0001). The frequency of protein expression increased from stage pTa (22.2%) to pT1 (45.5%; P: < 0.0001) but then decreased for stage pT2-4 (29.4%; P: < 0.0001 for pT1 versus pT2-4). Low cyclin E expression was associated with poor overall survival in all patients (P: < 0.0001), but had no prognostic impact independent of stage. It is concluded that cyclin E overexpression is characteristic to a subset of bladder carcinomas, especially at the stage of early invasion. This analysis of the prognostic impact of CCNE gene amplification and protein expression in >1,500 arrayed bladder cancers was accomplished in a period of 2 weeks, illustrating how the tissue microarray technology remarkably facilitates the evaluation of the clinical relevance of molecular alterations in cancer.

Adult↗

PubMed2000

Clinical significance of interobserver differences in the staging and grading of superficial bladder cancer.

OBJECTIVE: To assess the reliability of the histological diagnosis of bladder cancer by assessing the interobserver variability of staging and grading in pTa/pT1 tumours and evaluating the clinical significance of discrepancies. MATERIALS AND METHODS: All sections from 301 superficial bladder carcinomas were reviewed by one pathologist. The prognostic relevance of grade and stage from both the initial and review diagnosis were determined in 128 patients for whom there was long-term follow-up information. RESULTS: There were significant interobserver differences in both the grading and staging of tumours. From a total of 235 tumours that were initially considered pT1, the reviewer classified 35% as pTa, 56% as pT1, 6% as pT1- (at least pT1), and 3% as pT2-4. In 39% of all biopsies there were interobserver differences in tumour grade. The prognostic significance of grade and stage differed between the initial pathology report and the reviewer's diagnosis. The reviewer's staging allowed a better estimate of the risk of subsequent tumour progression than the initial staging. Progression was significantly more common in 49 tumours in which the reviewer agreed with stage pT1 than in 29 tumours that were down-staged from pT1 to pTa (P = 0.0116). However, the initial tumour grade (P = 0.0386) but not the reviewer's grade (P = 0.2645) was significantly linked to progression. CONCLUSIONS: These results show that grading and staging by different pathologists have varying prognostic implications. If possible, biopsies from bladder tumours should be independently evaluated by two different pathologists before radical therapy is administered.

Adult↗

PubMed2000

Metastatic patterns of prostate cancer: an autopsy study of 1,589 patients.

The prognosis of prostate cancer is mainly determined by the presence or absence of metastases. Nevertheless, the metastatic pathways in prostate cancer are not entirely understood. Among 19,316 routine autopsies performed from 1967 to 1995 on men older than 40 years of age, the reports from those 1,589 (8.2%) with prostate cancer were analyzed. Hematogeneous metastases were present in 35% of 1,589 patients with prostate cancer, with most frequent involvement being bone (90%), lung (46%), liver (25%), pleura (21%), and adrenals (13%). Several lines of evidence suggested the existence of a backward metastatic pathway through veins from the prostate to the spine in addition to classical hematogeneous tumor spread via the vena cava. First, there was an inverse relationship between spine and lung metastases, suggesting that metastasis to the spine is independent of lung metastasis. Second, the maximum frequency of spine involvement occurred in smaller tumors (4 to 6 cm) as compared with the maximum spread to lung (6 to 8 cm) and liver (>8 cm), suggesting that spine metastases precede lung and liver metastases in many prostate cancers. Third, there was a gradual decrease in spine involvement from the lumbar to the cervical level (97% v 38%), which is consistent with a subsequent upward metastatic spread along spinal veins after initial lumbar metastasis. The results of this study show that bone, lung, and liver are the most frequent sites of distant prostate cancer metastases. Besides the cava-type of metastasis through lung passage, there are strong arguments for the existence and clinical significance of a backward venous spread to the spine, which is likely to occur early in the metastatic process.

Adult↗

PubMed2000

Genetic and molecular markers of urothelial premalignancy and malignancy.

The molecular genetic changes reported in bladder tumors can be classified as primary and secondary aberrations. Primary molecular alterations may be defined as those directly related to the genesis of cancer. These are frequently found as the sole abnormality and are often associated with particular tumors. There are characteristic primary abnormalities involved in th production of low-grade/well-differentiated neoplasms, which destabilize cellular proliferation but have little effect on cellula "social" interactions or differentiation, as well as the rate of cell death or apoptosis. Other molecular events lead to high-grad neoplasms which disrupt growth control, including the cell cycle and apoptosis, and which have a major impact on biological behavior. A primary target leading to low-grade papillary superficial bladder tumors resides on chromosome 9, while p53 gene alterations are commonly seen in flat carcinoma in situ. Other molecular alterations must be elucidated, as many non-invasive neoplasms have neither chromosome 9 nor p53 alterations. Novel approaches utilizing tissue microdissection techniques an molecular genetic assays are needed to shed further light on this subject. Secondary genetic or epigenetic abnormalities may be fortuitous, or may determine the biological behavior of the tumor. Multiple molecular abnormalities are identified in most human cancers studied, including bladder neoplasms. The accumulation, rather than the order, of these genetic alterations may be the critical factor that grants synergistic activity. In this regard, it is noteworthy that many of the genes that are altered act upon the two recognized critical growth and senescenc pathways, TP53 and RB. These particular molecular aberrations may be especially important to evaluate for their use in the management of bladder cancer because of their commonality in progressive forms of the disease. Thus, clinical trials are underway to explore their use in specific situations, particularly in the surgical management of locally advanced disease, and to determine whether adjuvant chemotherapy in such patients may be of benefit. The use of molecular alterations in the management of non-invasive bladder neoplasms remains to be firmly established. Our knowledge of molecular alterations important in bladder cancer progression is far from complete, and further study is necessary to further elucidate cruci pathways involved in progression and therapeutic response. As per preneoplastic conditions, difficulties in identifying and interpreting the significance of phenotypic changes have imposed certain limitations, as has an evolving nomenclature and issues of reproducibility in interpreting morphologica criteria. Nevertheless, molecular alterations involving chromosome 9q and the INK4A locus in papillary superficial tumors vs changes in chromosomes 14q and 8q, p53 and RB in flat carcinoma in situ lesions may indicate a molecular basis for early events that lead to varying pathways in urothelial tumorigenesis. Studies aimed at revealing the clinical relevance of genet instability, as well as molecular or epigenetic alterations, in urothelium and preneoplastic lesions of otherwise morphologicall normal appearance are needed to further advance knowledge in the field. Clinical advances in bladder cancer will be facilitated by novel animal models paralleling the human disease. Molecular diagnostics, particularly specific antigen expression, fluorescence in situ hybridization and microsatellite analyses, have show great promise as screening and follow-up methodologies, and may supplement urine cytology in the diagnosis and characterization of new and recurrent disease. In addition, the use of high-throughput genomic/proteomic assays, linked to comprehensive databases, and coupled with robust bioinformatics will be key elements in elucidating the components of regulatory and signaling pathways involved in bladder tumorigenesis and cancer progression.

Carcinoma in Situ↗

PubMed2000

Calretinin as a marker for cardiac myxoma. Diagnostic and histogenetic considerations.

To study the usefulness of calretinin as an immunohistochemistry marker in the diagnosis of cardiac myxoma (CM) and the origin of myxoma cells, we examined 24 CMs and 9 fetal hearts with immunohistochemical methods on formalin-fixed paraffin-embedded tissues. We compared 24 CMs with 10 mural thrombi, 6 jaw myxomas, and 2 papillary fibroelastomas. Calretinin expression was identified in 100% of CMs and was negative in all cases of mural thrombi, jaw myxoma, and papillary fibroelastoma. Calretinin expression by the neoplastic cells in CM was strong and diffuse and had a cytoplasmic and a nuclear pattern. Calretinin expression in fetal hearts was found in autonomic ganglia cells in the subepicardial tissue of the atria and atrial appendages, along the interatrial and atrioventricular sulci, and in the atrial septum. Results clearly indicate that calretinin can be used as a marker for the diagnosis of CM and that it is a powerful tool for the differential diagnosis, most importantly with mural myxoid thrombi. Furthermore, the positive expression of calretinin by the autonomic neurons in the fetal heart and CM supports the concept that myxoma cells may originate from endocardial sensory nerve tissue.

Adolescent↗

PubMed1999

Chromosomal imbalances are associated with a high risk of progression in early invasive (pT1) urinary bladder cancer.

Many cytogenetic alterations are known to occur in urinary bladder cancer, but the significance of most of them is poorly understood. To define these chromosomal regions where clinically relevant genes may be located, a series of 54 pT1 urinary bladder carcinomas with clinical follow-up information (median, 52 months; range, 5-167 months) were examined by comparative genomic hybridization. The most frequent alterations included DNA sequence copy number gains at 1q22-24 (33%), 20q11.2-ter (33%), 8q22 and 17q21 (28% each), and 6p22 (15%) as well as deletions at Y (37%), 9p (31%), 9q22-33 and 11p14-ter (28% each), 11q23 (26%), 8p (24%), 13q31 (19%), 2q35-ter (17%), and 2q22-33 (11%). Whereas the histological grade was unrelated to prognosis (P = 0.9752), the risk of tumor progression was significantly associated with the number of deletions per tumor (P = 0.0014). Individual cytogenetic alterations that were linked to subsequent tumor progression included gains of 3p22-24 (P = 0.0112) and 5p (P = 0.0003) as well as losses of 4p11-15 (P = 0.0052), 5q15-23 (P = 0.0410), 6q22-23 (P = 0.0090), 10q24-26 (P = 0.0232), and 18q12-23 (P = 0.0005). Genes with a role for bladder cancer progression may be located at these regions.

Carcinoma↗

PubMed1999

Hormone therapy failure in human prostate cancer: analysis by complementary DNA and tissue microarrays.

BACKGROUND: The molecular mechanisms underlying the progression of prostate cancer during hormonal therapy have remained poorly understood. In this study, we developed a new strategy for the identification of differentially expressed genes in hormone-refractory human prostate cancer by use of a combination of complementary DNA (cDNA) and tissue microarray technologies. METHODS: Differences in gene expression between hormone-refractory CWR22R prostate cancer xenografts (human prostate cancer transplanted into nude mice) and a xenograft of the parental, hormone-sensitive CWR22 strain were analyzed by use of cDNA microarray technology. To validate the data from cDNA microarrays on clinical prostate cancer specimens, a tissue microarray of specimens from 26 prostates with benign prostatic hyperplasia, 208 primary prostate cancers, and 30 hormone-refractory local recurrences was constructed and used for immunohistochemical detection of protein expression. RESULTS: Among 5184 genes surveyed with cDNA microarray technology, expression of 37 (0.7%) was increased more than twofold in the hormone-refractory CWR22R xenografts compared with the CWR22 xenograft; expression of 135 (2.6%) genes was reduced by more than 50%. The genes encoding insulin-like growth factor-binding protein 2 (IGFBP2) and 27-kd heat-shock protein (HSP27) were among the most consistently overexpressed genes in the CWR22R tumors. Immunohistochemical analysis of tissue microarrays demonstrated high expression of IGFBP2 protein in 100% of the hormone-refractory clinical tumors, in 36% of the primary tumors, and in 0% of the benign prostatic specimens (two-sided P =.0001). Overexpression of HSP27 protein was demonstrated in 31% of the hormone-refractory tumors, in 5% of the primary tumors, and in 0% of the benign prostatic specimens (two-sided P =.0001). CONCLUSIONS: The combination of cDNA and tissue microarray technologies enables rapid identification of genes associated with progression of prostate cancer to the hormone-refractory state and may facilitate analysis of the role of the encoded gene products in the pathogenesis of human prostate cancer.

Animals↗

PubMed1999

Chromosomal imbalances in noninvasive papillary bladder neoplasms (pTa).

Almost 70% of urinary bladder neoplasms present as low-grade papillary noninvasive tumors (stage pTa). To determine which genomic alterations can occur in pTa tumors of different grades and to evaluate the prognostic significance of chromosomal imbalances, we analyzed 113 pTa tumors (40 grade 1, 55 grade 2, 18 grade 3) by comparative genomic hybridization. pTaG1 (1.9 +/- 2.0) and pTaG2 (3.1 +/- 2.9) tumors had only few genomic alterations with 9q- (44%), 9p- (36%), and -Y (21%) being most prevalent. Neither the total number of aberrations nor any individual alteration was linked to the risk of recurrence in 95 pTaG1/G2 tumors with clinical follow-up information. pTaG3 tumors were characterized by a high number of alterations (7.7 +/- 4.5; P < 0.0001 for G3 versus G2). Several chromosomal imbalances that have previously been reported to be typical for invasive bladder neoplasms were significantly more frequent in pTaG3 than in pTaG2 tumors, including 2q-, 5p+, 5q-, 6q-, 8p-, 10q-, 18q-, and 20q+. A malfunction of genes at these loci may contribute to the development of high-grade urothelial neoplasias. However, there is no evidence for a direct role of these alterations for development of invasive tumor growth.

Carcinoma in Situ↗

PubMed1999

Prognostic value of genomic alterations in invasive cervical squamous cell carcinoma of clinical stage IB detected by comparative genomic hybridization.

The clinical behavior of invasive cervical carcinoma of clinical stage IB varies considerably in tumors presenting without regional lymph node metastases. The early identification of patients at higher risk for poor outcome may prove useful because these patients would benefit from aggressive adjuvant treatments. In this study, comparative genomic hybridization was applied to evaluate whether genomic aberrations have prognostic significance in cervical carcinoma. Genomic alterations were evaluated in 62 cervical carcinomas of clinical stage IB. DNA sequence losses were most prevalent at chromosomes 4q (53%), 3p (52%), 13q (45%), 4p (44%), Xq (44%), 5q (40%), 18q (37%), and 6q (35%). Several genomic alterations were associated with poor clinical outcome or metastasis. The total number of DNA aberrations/tumor (P < 0.02) and the number of DNA sequence losses/tumor (P < 0.04) were associated with disease-specific survival. 9p deletions were significantly more frequent in carcinomas with lymph node metastasis than in node-negative tumors (P < 0.03). Losses of chromosome 11p (P < 0.0001) and 18q (P < 0.01) were associated with poor prognosis in cervical carcinomas without lymph node metastasis. These data suggest that inactivation of tumor suppressor genes on chromosomes 9p, 11p, and 18q may play a role in the progression of cervical carcinoma.

Carcinoma, Squamous Cell↗

PubMed1999

Survey of gene amplifications during prostate cancer progression by high-throughout fluorescence in situ hybridization on tissue microarrays.

Prostate cancer development and progression is driven by the accumulation of genetic changes, the nature of which remains incompletely understood To facilitate high-throughput analysis of molecular events taking place in primary, recurrent, and metastat prostate cancer, we constructed a tissue microarray containing small 0.6-mm cylindrical samples acquired from 371 formalin-fixed blocks, including benign prostatic hyperplasia (n = 32) and primary tumors (n = 223), as well as both locally recurrent tumors (n = 54) and metastases (n = 62) from patients with hormone-refractory disease. Fluorescence in situ hybridization (FISH) was applied to the analysis of consecutive tissue microarray sections with probes for five different genes. High-level (> or =3X) amplifications were very rare (<2%) in primary prostate cancers However, in metastases from patients with hormone-refractory disease, amplification of the androgen receptor gene was seen in 22%, MYC in 11%, and Cyclin-D1 in 5% of the cases. In specimens from locally recurrent tumors, the corresponding percentages were 23, 4, and 8%. ERBB2 and NMYC amplifications were never detected at any stage of prostate cancer progression. In conclusion, FISH to tissue microarray sections enables high-throughput analysis of genetic alterations contributing to cancer development and progression. Our results implicate a role for amplification of androgen receptor in hormonal therapy failure and that of MYC in the metastatic progression of human prostate cancer.

Cyclin D1↗

PubMed1999

["Burned out" testicular tumor: a rare form of germ cell neoplasias].

Burned-out tumour of the testis is a rare form of a germ-cell malignancy of testicular localisation which can regress or disappear. This is a rare form of germ-cell neoplasm. We report on 2 patients with such a tumour. The histological findings, on clinical manifestations, on difficult differential diagnosis from primary retroperitoneal germ-cell tumour, therapy, and outcome of this malignancy are discussed. In the absence of palpable testicular tumour the symptomatology is due to metastasis. Burned-out tumour of the testis must be considered in a patient with retroperitoneal lymph node involvement and histology of "germ-cell tumour". In these patients sonography of scrotal contents may be useful to identify intratesticular abnormalities. These are often the site of the primary tumour. If burned-out tumour of the testis is suspected, the indication for surgery is given. If the frozen section is not "normal testicular tissue", orchiectomy should be performed. The metastasis is treated according to the histology and clinical stage of the tumour. It is important to distinguish burned-out tumour of the testis from true extragonadal germ-cell tumours. Primary removal of the testicular tumour is necessary because of the high rate of persistent testicular malignancy, which may be as much as 50% despite systemic chemotherapy.

Adult↗

PubMed1999

Cyclin D1 overexpression lacks prognostic significance in superficial urinary bladder cancer.

The biological behaviour of urinary bladder neoplasms cannot be adequately predicted by histological criteria alone. Cyclin D1 is a cell-cycle regulating protein known to be overexpressed in a proportion of bladder carcinomas. To evaluate the prognostic significance of cyclin D1 expression and its relationship with tumour phenotype, 392 bladder carcinomas were analysed by immunohistochemistry. Clinical follow-up information was available in 337 patients with superficial bladder tumours (stages pTa/pT1). Cyclin D1 positivity was seen in 176 of 392 carcinomas. Cyclin D1 overexpression was strongly linked to papillary tumour growth, low stage, and low histological grade (p<0.005 each). Multivariate analysis showed that papillary tumour growth was the only parameter which was independently linked to cyclin D1 positivity. There was no significant difference in proliferative activity (Ki67 labelling index) between cyclin D1-negative and -positive tumours. Cyclin D1 positivity was not linked to the risk of recurrence or tumour progression, either in pTa or in pT1 carcinomas. It is concluded that cyclin D1 positivity distinguishes a large subgroup of papillary bladder tumours, but there is no evidence of prognostic significance for increased cyclin D1 expression.

Analysis of Variance↗

PubMed1999

Chromosomal imbalances in small cell carcinomas of the urinary bladder.

Small cell carcinomas (SCCs) represent a rare histological subtype of urinary bladder cancer. Little is known abut the genetic alterations in these tumours. To identify chromosomal aberrations that are typically present in SCC of the urinary bladder, ten tumours were analysed by comparative genomic hybridization (CGH). CGH allows screening for all relative DNA copy number gains and losses present in a tumour. SCCs of the bladder were characterized by a high number of genomic alterations (mean: 11.3 per tumour). Deletions were most frequent at 10q (7 of 10 tumours deleted), 4q, 5q (5/10 each), and 13q (4/10). These regions may carry tumour suppressor genes with relevance for this particular tumour type. Gains of DNA sequences were most prevalent at 8q (5/10), 5p, 6p, and 20q (4/10 each). High level amplifications were found at 1p22-32, 3q26.3, 8q24, and 12q14-21. These loci may pinpoint the localization of oncogenes with relevance for small cell bladder cancer. The analysis of one tumour having areas of both SCC and transitional cell carcinoma strongly suggests that SCC can develop from TCC through the acquisition of additional genetic alterations.

Carcinoma, Small Cell↗

PubMed1999

Evaluation of the clonal relationship between primary and metastatic renal cell carcinoma by comparative genomic hybridization.

The outcome of patients with renal cell carcinoma is limited by the development of metastasis after nephrectomy. To evaluate the genetic basis underlying metastatic progression of human renal cell carcinoma in vivo, we performed a comparative genomic hybridization analysis in 32 clear-cell renal-cell carcinoma metastases. The most common losses involved chromosomes 3p (25%), 4q (28%), 6q (28%), 8p (31%), and 9p (47%). The most common gains were detected at 17q (31%) and Xq (28%). There was one high-level gene amplification at chromosome 11q22-23. The mean number of aberrations in lymph node (4.8 +/- 2.8) and lung metastases (6.2 +/- 4.0) was lower than in other hematogenous metastases (11.5 +/- 8.7, P < 0.05), suggesting that hematogenous dissemination is linked to an acquisition of complex genomic alterations. As genetic differences between primary tumors and metastases give information on genetic changes that have contributed to the metastatic process, relative DNA sequence copy number changes in 19 matched tumor pairs were compared. Genomic changes, which frequently occurred in metastases but not in the corresponding primary tumor were losses of 8p and 9p and gains of 17q and Xq. An abnormal function of genes in these regions may contribute to the metastatic process. According to a statistical analysis of shared genetic changes in matched tumor pairs, a high probability of a common clonal progenitor was found in 11 of 19 patients (58%). Six metastases (32%) were genetically almost completely different from the primary, suggesting that detection of genomic alterations in primary tumors gives only a restricted view of the biological properties of metastatic renal cell carcinoma.

Carcinoma, Renal Cell↗

PubMed1999

High-throughput tissue microarray analysis to evaluate genes uncovered by cDNA microarray screening in renal cell carcinoma.

Many genes and signaling pathways are involved in renal cell carcinoma (RCC) development. However, genetic tumor markers have not gained use in RCC diagnostics and prognosis prediction. Identification and evaluation of new molecular parameters are of utmost importance in cancer research and cancer treatment. Here we present a novel approach to rapidly identify clinically relevant molecular changes in cancer. To identify genes with relevance to RCC, a cDNA array analysis was first performed on 5184 cDNA clones on a filter to screen for genes with differential expression between the renal cancer cell line CRL-1933 and normal kidney tissue. There were 89 differentially expressed genes in the cancer cell line, one of them coding for vimentin, a cytoplasmic intermediate filament. In a second step, a renal cancer tissue microarray containing 532 RCC specimen was used to determine vimentin expression by immunohistochemistry. Vimentin expression was seen frequently in clear cell (51%) and papillary RCC (61%), but rarely in chromophobe RCC (4%) and oncocytomas (12%). Furthermore, vimentin expression was significantly associated with poor patient prognosis (P < 0.007) independent of grade and stage. These results obtained from minute arrayed tumor samples match well with previous findings on vimentin expression in renal tumors. It is concluded that the combination of tumor arrays and cDNA arrays is a powerful approach to rapidly identify and further evaluate genes that play a role in tumor biology.

Carcinoma, Renal Cell↗