Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 347
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Pathologe ; 37(1): 17-26, 2016 Feb.
Artigo em Alemão | MEDLINE | ID: mdl-26809207

RESUMO

In 2005 the International Society of Urological Pathology (ISUP) held a concensus conference on Gleason grading in order to bring this grading system up to the current state of contemporary practice; however, it became clear that further modifications on the grading of prostatic carcinoma were necessary. The International Society of Urological Pathology therefore held a further consensus conference in 2014 to clarify these points. This article presents the essential results of the Chicago grading meeting.


Assuntos
Gradação de Tumores/métodos , Neoplasias da Próstata/patologia , Sociedades Médicas , Adenocarcinoma Mucinoso/patologia , Carcinoma Ductal/patologia , Chicago , Previsões , Humanos , Cooperação Internacional , Masculino , Gradação de Tumores/tendências , Próstata/patologia
2.
J Cancer Res Clin Oncol ; 134(10): 1071-8, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18392850

RESUMO

OBJECTIVES: Due to PSA screening and increased awareness, prostate cancer (PCa) is identified earlier resulting in smaller diagnostic samples on prostate needle biopsy. Because Gleason grading plays a critical role in treatment planning, we undertook a controlled study to evaluate interobserver variability among German pathologists to grade small PCas using a series of tissue microarray (TMA) images. METHODS: We have previously demonstrated excellent agreement in Gleason grading using TMAs among expert genitourinary pathologists. In the current study, we identified 331 TMA images (95% PCa and 5% benign) to be evaluated by an expert PCa pathologist and subsequently by practicing pathologists throughout Germany. The images were presented using the Bacus Webslide Browser on a CD-ROM. Evaluations were kept anonymous and participant's scoring was compared to the expert's results. RESULTS: A total of 29 German pathologists analysed an average of 278 images. Mean percentage of TMA images which had been assigned the same Gleason score (GS) as done by the expert was 45.7%. GSs differed by no more than one point (+/-1) in 83.5% of the TMA samples evaluated. The respondents were able to correctly assign a GS into clinically relevant categories (i.e. <7, 7, >7) in 68.3% of cases. A total of 75.9% respondents under-graded the TMA images. Gleason grading agreement with the expert reviewer correlated with the number of biopsies evaluated by the pathologist per week. Years of diagnostic experience, self-description as a urologic pathologist or affiliation with a university hospital did not correlate with the pathologist's performance. CONCLUSION: The vast majority of participants under-graded the small tumors. Clinically relevant GS categories were correctly assigned in 68% of cases. This raises a potentially significant problem for pathologists, who have not had as much experience evaluating small PCas.


Assuntos
Patologia Cirúrgica/normas , Neoplasias da Próstata/patologia , Análise Serial de Tecidos , Biópsia por Agulha , Alemanha , Humanos , Masculino , Variações Dependentes do Observador , Neoplasias da Próstata/epidemiologia , Reprodutibilidade dos Testes
3.
Urol Oncol ; 35(3): 121-122, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-28159497

RESUMO

PURPOSE: To assess long-term outcomes of men with favorable-risk prostate cancer in a prospective, active surveillance program. METHODS: Curative intervention was recommended for disease reclassification to higher cancer grade or volume on prostate biopsy. Primary outcomes were overall, cancer-specific, and metastasis-free survival. Secondary outcomes were the cumulative incidence of reclassification and curative intervention. Factors associated with grade reclassification and curative intervention were evaluated in a Cox proportional hazards model. RESULTS: A total of 1,298 men (median age = 66y) with a median follow-up of 5 years (range: 0.01-18.00y) contributed 6,766 person-years of follow-up since 1995. Overall, cancer-specific, and metastasis-free survival rates were 93%, 99.9%, and 99.4%, respectively, at 10 years and 69%, 99.9%, and 99.4%, respectively, at 15 years. The cumulative incidence of grade reclassification was 26% at 10 years and was 31% at 15 years; cumulative incidence of curative intervention was 50% at 10 years and was 57% at 15 years. The median treatment-free survival was 8.5 years (range: 0.01-18y). Factors associated with grade reclassification were older age (hazard ratio [HR] = 1.03 for each additional year; 95% CI: 1.01-1.06), prostate-specific antigen density (HR = 1.21 per 0.1 unit increase; 95% CI: 1.12-1.46), and greater number of positive biopsy cores (HR = 1.47 for each additional positive core; 95% CI: 1.26-1.69). Factors associated with intervention were prostate-specific antigen density (HR = 1.38 per 0.1 unit increase; 95% CI: 1.22-1.56) and a greater number of positive biopsy cores (HR = 1.35 for one additional positive core; 95% CI: 1.19-1.53). CONCLUSION: Men with favorable-risk prostate cancer should be informed of the low likelihood of harm from their diagnosis and should be encouraged to consider surveillance rather than curative intervention.


Assuntos
Antígeno Prostático Específico , Neoplasias da Próstata/epidemiologia , Adolescente , Criança , Pré-Escolar , Humanos , Lactente , Recém-Nascido , Masculino , Gradação de Tumores , Estudos Prospectivos , Conduta Expectante
4.
Prostate Cancer Prostatic Dis ; 20(3): 339-342, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28417979

RESUMO

BACKGROUND: To assess the utility of urinary prostate cancer antigen 3 (PCA3) as both a one-time and longitudinal measure in men on active surveillance (AS). METHODS: The Johns Hopkins AS program monitors men with favorable-risk prostate cancer with serial PSA, digital rectal examination (DRE), prostate magnetic resonance imaging and prostate biopsy. Since 2007, post-DRE urinary specimens have also been routinely obtained. Men with multiple PCA3 measures obtained over ⩾3 years of monitoring were included. Utility of first PCA3 score (fPCA3), subsequent PCA3 (sPCA3) and change in PCA3 were assessed for prediction of Gleason grade reclassification (GR, Gleason score >6) during follow-up. RESULTS: In total, 260 men met study criteria. Median time from enrollment to fPCA3 was 2 years (interquartile range (IQR) 1-3) and from fPCA3 to sPCA3 was 5 years (IQR 4-6). During median follow-up of 6 years (IQR 5-8), 28 men (11%) underwent GR. Men with GR had higher median fPCA3 (48.0 vs 24.5, P=0.007) and sPCA3 (63.5 vs 36.0, P=0.002) than those without GR, while longitudinal change in PCA3 did not differ by GR status (log-normalized rate 0.07 vs 0.06, P=0.53). In a multivariable model including age, risk classification and PSA density, fPCA3 remained significantly associated with GR (log(fPCA3) odds ratio=1.77, P=0.04). CONCLUSIONS: PCA3 scores obtained during AS were higher in men who underwent GR, but the rate of change in PCA3 over time did not differ by GR status. PCA3 was a significant predictor of GR in a multivariable model including conventional risk factors, suggesting that PCA3 provides incremental prognostic information in the AS setting.


Assuntos
Antígenos de Neoplasias/urina , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/urina , Idoso , Detecção Precoce de Câncer , Humanos , Estudos Longitudinais , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Gradação de Tumores , Fatores de Risco
5.
Cancer Res ; 50(21): 6830-2, 1990 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-2208148

RESUMO

Point mutations at codons 12, 13, or 61 of the Ha-, Ki-, and N-ras genes are able to convert these normal cellular genes into activated oncogenes. Previous studies have shown that ras gene mutations occur in a variety of human solid tumors and may be important in the pathogenesis of some of these tumors. In order to test the hypothesis that ras gene mutations may be associated with prostate cancer, we have used an oligodeoxynucleotide hybridization assay to detect wild-type and mutant alleles in genomic DNA from prostate tumors and prostate tumor cell lines amplified using the polymerase chain reaction. Twenty-four primary prostate tumors (23 acinar tumors and one ductal tumor) and five prostate tumor cell lines were examined for mutations at codons 12, 13, and 61 of the Ki-ras, Ha-ras, and N-ras genes. Two mutations were detected: an A----G transition causing a glutamine to arginine amino acid substitution at codon 61 of the Ha-ras gene in a primary prostatic duct adenocarcinoma and a G----T transversion causing a glycine to valine amino acid substitution at codon 12 of the Ha-ras gene in a prostate tumor cell line (TSU-PR1) derived from a lymph node metastasis. While the overall frequency of ras gene mutations in prostate tumors is low, when these mutations do occur they may have a role in the progression of disease or the development of the unusual ductal variant of prostatic adenocarcinoma.


Assuntos
Adenocarcinoma/genética , Genes ras/genética , Neoplasias da Próstata/genética , Sequência de Bases , DNA de Neoplasias/genética , Humanos , Masculino , Dados de Sequência Molecular , Mutação , Neoplasias da Próstata/cirurgia
6.
Cancer Res ; 53(2): 329-33, 1993 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-8417826

RESUMO

The administration of drugs directly into the central nervous system using polymers as drug carriers may improve the treatment of malignant brain tumors. In this study, the effect of the interstitial, localized delivery of 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) incorporated into controlled release polymers implanted adjacent to the 9L gliosarcoma was assessed in s.c. and intracranial (i.c.) models. In the s.c. experiment, the 9L gliosarcoma was implanted in the flank of rats and subsequently treated with BCNU either (a) delivered in controlled release polymers inserted adjacent to the tumor or (b) administered systemically by i.p. injections or by controlled release polymers inserted at a site distant from the tumor. The interstitial release of BCNU adjacent to the tumor in the flank resulted in a significant tumor growth delay of 16.3 days, as compared to a growth delay of 9.3 and 11.2 days obtained with the systemic administration of BCNU. In the i.c. experiment, the 9L gliosarcoma was implanted in the brain of Fischer 344 rats and treated either (a) with controlled release polymers containing BCNU inserted into the brain or (b) with the systemic i.p. administration of BCNU. The interstitial release of BCNU in the brain resulted in a significant 5.4- to 7.3-fold increased survival, compared with a 2.4-fold increased survival after the systemic administration of the same dose of BCNU. The two groups with i.c. tumors treated interstitially had 17 and 42% cures, but no long-term cures were obtained in the group treated with systemic therapy. The localized, controlled delivery of chemotherapeutic agents in the s.c. tissues and in the brain via polymeric carriers may be more effective than standard systemic chemotherapy. This approach could be used to deliver a wide variety of agents into the central nervous system to treat diverse neuropathological conditions which remain refractory to systemic therapy.


Assuntos
Antineoplásicos/administração & dosagem , Neoplasias Encefálicas/tratamento farmacológico , Carmustina/administração & dosagem , Glioma/tratamento farmacológico , Animais , Preparações de Ação Retardada , Masculino , Polímeros , Ratos , Ratos Endogâmicos F344 , Sarcoma Experimental/tratamento farmacológico , Análise de Sobrevida
7.
Cancer Res ; 55(22): 5213-6, 1995 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-7585577

RESUMO

Carcinoma in situ (CIS) of the urinary bladder is an aggressive lesion that frequently progresses to an invasive tumor, yet the underlying molecular changes in this lesion are largely unknown. In this study, we microdissected 31 cases of CIS and examined them for loss of heterozygosity (LOH) on 13 chromosomal arms. Twenty-nine microsatellite markers were chosen for this analysis based on their location in regions previously shown to be frequently lost in primary transitional cell carcinoma of the bladder. LOH of chromosome 9 was a frequent event in these samples, occurring in 77% of these lesions, with 19 of 31 cases showing deletion on the 9p arm (61%) and 17 of 28 cases displaying LOH on 9q (61%). Fine mapping at 9p21 demonstrated that CIS also displayed a high frequency of homozygous deletion surrounding the p16INK4A locus, like superficial papillary tumors, the other form of noninvasive lesion found in the bladder. However, loss of 14q (70%) was frequent in CIS yet extremely rare in papillary lesions (9%). Other chromosomal arms showing frequent LOH included 8p (65%), 17p (60%), 13q (56%), 11p (54%), and 4q (52%), whereas slightly lower frequencies of loss were observed for 11q (36%), 4p (32%), 3p (31%), 18q (29%), and 5q (20%). CIS lesions already possess many of the genetic alterations displayed by invasive transitional cell carcinomas, potentially accounting for the aggressive nature of these lesions.


Assuntos
Carcinoma in Situ/genética , Deleção Cromossômica , Neoplasias da Bexiga Urinária/genética , Alelos , Cromossomos Humanos Par 9 , Humanos
8.
Cancer Res ; 56(21): 5044-6, 1996 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-8895762

RESUMO

Collecting duct carcinoma (CDC) of the kidney is a rare malignant neoplasm of distal nephron origin. Previous studies of CDC have shown loss of heterozygosity on chromosomal arm 1q in 57% of the cases studied. To better characterize 1q loss in CDC, we performed high-density mapping of the entire long arm of chromosome 1 in 13 CDC tumor samples. We observed complete deletion of chromosomal arm 1q in 5 samples and partial deletion in 4 additional tumors. Our study further showed that the region of minimal deletion is located at 1q32.1-32.2. Sixty-nine percent (9 of 13) of the tumors showed loss of heterozygosity in this area. These data suggest that a gene or group of genes that contribute to the development of distal nephron tumors may be located within the 1q32.1-32.2 region.


Assuntos
Deleção Cromossômica , Mapeamento Cromossômico , Cromossomos Humanos Par 1 , Neoplasias Renais/genética , Túbulos Renais Coletores , Humanos
9.
Cancer Res ; 56(8): 1892-5, 1996 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-8620510

RESUMO

Tumors of varying malignant potential arise from the complex epithelial lining of the nephron. Although the molecular characteristics of renal clear cell carcinomas, which arise from the proximal tubule, have been studied, little is known about tumors that develop from other parts of the renal tubular system. To elucidate common molecular lesions that may contribute to the development or progression of nonproximal tubule renal tumors, we performed a detailed microsatellite allelotype of lesions thought to arise from the renal collecting duct. Eighteen collecting duct carcinomas (CDCs) and 13 renal oncocytomas were studied using highly informative microsatellite markers on all autosomal arms. Loss of heterozygosity (LOH) was identified on multiple chromosomal arms in CDCs and renal oncocytomas. Microsatellite analysis revealed LOH of 1q in 57% of informative CDCs. LOH was also observed on arms 6p (45%), 8p (40%), and 21q (40%). In renal oncocytomas, LOH of 1q occurred in approximately 30% of tumors, but 1p LOH was observed in 57% of informative cases analyzed. High levels of LOH were also observed on arms 8p, 14q, 19q, and 21q in the oncocytomas studied. Loss of chromosomal arm 3p was infrequent in both tumor types. Our results suggest that the molecular events that contribute to the development of distal nephron tumors are distinct from those associated with the etiology of proximal tubule renal cancers.


Assuntos
Deleção Cromossômica , Cromossomos Humanos , DNA Satélite/genética , Neoplasias Renais/genética , Repetições de Microssatélites/genética , Adenoma Oxífilo/genética , Alelos , Carcinoma/genética , Mapeamento Cromossômico , Cromossomos Humanos Par 1 , Marcadores Genéticos , Humanos , Túbulos Renais Coletores , Néfrons , Reação em Cadeia da Polimerase
10.
Cancer Res ; 56(13): 3091-102, 1996 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-8674067

RESUMO

A newly developed method of comparative genomic hybridization (CGH) employing quantitative statistical comparisons was applied to DNA from two different types of advanced prostate cancer tissue. Multiple CGH analyses were obtained for each chromosome in each tumor, and the results of point-by-point comparison of the mean tumor:normal color ratio to a control normal:normal color ratio in each of 1247 evenly distributed data channels constituting the entire human genome were interpreted as loss, gain, or no change in copy number in the tumor genome. Group I tissue was obtained from prostate cancer metastases from 20 patients, 19 of whom had received no prior prostate cancer treatment. This DNA also was analyzed by Southern and microsatellite allelotyping at 53 different loci on 20 different chromosome arms. CGH results agreed with allelotyping results at 92% of the informative loci studied. These samples, which contained highly enriched tumor DNA, showed the highest rates of alteration yet reported in several chromosomal regions known to be altered frequently in prostate cancer: 8q gain (85%), 8p loss (80%), 13q loss (75%), 16q loss (55%), 17p loss (50%), and 10q loss (50%). Group II tissue was obtained predominately from primary or recurrent tumor from 11 patients who had been treated with long-term androgen-deprivation therapy and developed androgen-independent metastatic disease. Quantitative CGH analysis on DNA from these tissues showed chromosomal alterations that were very similar to those found in group I, suggesting that untreated metastatic tumors contain the bulk of chromosomal alterations necessary for recurrence to occur during androgen deprivation. In the entire data set, a number of previously undetected regions of frequent loss or gain were identified, including losses of chromosomes 2q (42%), 5q (39%), 6q (39%), and 15q (39%) and gains of chromosomes 11p (52%), 1q (52%), 3q (52%), and 2p (45%). Chi-squared analysis showed a significantly higher frequency of gain of the 4q25-q28 region in tumors from African-American patients, indicating a possible oncogene whose activation may play a role in the higher rate of progression seen in this ethnic group. Additional study of these frequently altered regions may provide insight into the mechanism of prostate cancer progression and lead to important tools for tumor-specific prognosis and therapy.


Assuntos
Alelos , Androgênios , Neoplasias Ósseas/genética , Neoplasias Ósseas/secundário , Aberrações Cromossômicas , DNA de Neoplasias/genética , Neoplasias Hormônio-Dependentes/genética , Neoplasias Hormônio-Dependentes/secundário , Neoplasias da Próstata/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Southern Blotting , DNA de Neoplasias/análise , Genoma Humano , Humanos , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Hibridização de Ácido Nucleico , Neoplasias da Próstata/patologia , Reprodutibilidade dos Testes
11.
Cancer Res ; 53(17): 3869-73, 1993 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-7689419

RESUMO

Allelic loss studies have been instrumental in identifying tumor suppressor gene loci in a variety of cancers. In this study we analyzed prostate cancer specimens from 52 patients for allelic loss using 8 polymorphic probes for the short arm of chromosome 8. Overall, 32 of 51 (63%) informative tumors showed loss of at least one locus on chromosome 8p. The most frequently deleted region is observed at chromosome 8p22-8p21.2. Loss of one allele is identified in 14 of 23 (61%) tumors at D8S163, in 15 of 32 (47%) tumors at lipoprotein lipase, and in 20 of 29 (69%) tumors at MSR, all on 8p22. Loss of one allele is identified in 16 of 27 (59%) tumors at D8S220 at 8p21.3-8p21.2. In addition to frequent loss of one allele at the MSR locus, one metastatic prostate cancer sample demonstrated homozygous deletion of MSR sequences. Loci telomeric and centromeric to this region are largely retained. A chromosome 8p deletion map is constructed and defines the smallest region of overlap to a 14-cM interval at 8p22 between D8S163 and lipoprotein lipase, flanking the MSR locus. Evidence of chromosome 8q multiplication at locus D8S39 was detected in 5 of 32 (16%) tumors, all of which demonstrated loss with at least one probe on chromosome 8p. This study extends the previous finding of frequent loss of chromosome 8p in prostate cancer by defining a common region of loss of heterozygosity at 8p22 and a homozygous deletion of the MSR locus contained within this region. This is the first homozygous deletion identified in the genome of a human prostate cancer and the highest rate of loss yet reported on chromosome 8p in cancer. These results strongly suggest the presence of a tumor suppressor gene in this region which is frequently inactivated in prostate cancer.


Assuntos
Alelos , Deleção Cromossômica , Cromossomos Humanos Par 8 , Neoplasias da Próstata/genética , Biomarcadores Tumorais/sangue , Mapeamento Cromossômico , Homozigoto , Humanos , Masculino , Antígeno Prostático Específico/sangue , Neoplasias da Próstata/sangue
12.
Cancer Res ; 53(4): 744-6, 1993 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-7679049

RESUMO

The nuclear matrix represents the structural component of the nucleus that determines nuclear shape and higher order DNA organization. We have previously shown tissue specificity in nuclear matrix proteins (NMP), in rat sex accessory tissues, and in a rat model of prostate cancer. This study compares NMP patterns for fresh human normal prostate, benign prostatic hyperplasia (BPH), and prostate cancer for 21 men undergoing surgery for clinically localized prostate cancer or BPH. NMP patterns were compared using high resolution two-dimensional polyacrylamide gel electrophoresis. We identified by molecular weight and isoelectric point 14 different proteins that were consistently present or absent among the various tissues. One protein (PC-1), a M(r) 56,000 protein with an isoelectric point of 6.58, appeared in 14 of 14 different nuclear matrix preparations from prostate cancer and was not detected in normal prostate (0 of 13) or BPH (0 of 14). The NMP patterns are consistent with a model of disease progression in which BPH shares many of the nuclear matrix changes observed in prostate cancer.


Assuntos
Proteínas Nucleares/análise , Próstata/química , Hiperplasia Prostática , Neoplasias da Próstata/química , Antígenos Nucleares , Eletroforese em Gel Bidimensional , Humanos , Ponto Isoelétrico , Masculino , Peso Molecular
13.
Cancer Res ; 56(16): 3814-22, 1996 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-8706029

RESUMO

Inactivation of the p53 gene has been implicated in prostate cancer progression. To determine the role of p53 inactivation in the progression of clinical prostatic carcinomas, we assessed 67 tumors derived from patients with clinically localized disease for chromosome 17p and p53 gene allelic loss, p53 gene mutations using single-strand conformational polymorphism and direct sequencing, and p53 protein expression using immunohistochemical staining. Of 55 informative tumors, 10 demonstrated loss of 17p or the p53 gene; however, only a single tumor had a mutation in its remaining p53 allele. Significant p53 overexpression was observed in 2 of 38 tumors, and 9 others had faint staining of a few nuclei ( < 1%). p53 overexpression occurred in no informative tumor with allelic loss or mutation. In a 1-7-year follow-up, positive immunohistochemical staining did not confer an increased risk of recurrence (risk of recurrence, 0.86, P = 0.78), whereas allelic loss of chromosome 17p appeared to be highly correlated with recurrence (risk of recurrence, 3.7, P = 0.003). In an unrelated group of 42 patients with metastatic prostate cancer, p53 overexpression was found in 26 tumors (62%), and 15(36%) had high grade staining. Neither the presence nor the degree of expression correlated with time to progression or time to death. This series suggests that p53 gene inactivation is rare in primary prostatic tumors, not essential to the development of prostate cancer metastases, and of limited use as a prognostic marker in patients with primary or metastatic disease. Another gene or genes on chromosome 17p may be involved in prostate cancer progression.


Assuntos
Genes p53 , Mutação , Neoplasias da Próstata/genética , Sequência de Bases , Deleção Cromossômica , Cromossomos Humanos Par 17 , Humanos , Imuno-Histoquímica , Masculino , Dados de Sequência Molecular , Metástase Neoplásica , Polimorfismo Conformacional de Fita Simples , Proteína Supressora de Tumor p53/análise
14.
Oncogene ; 35(33): 4302-11, 2016 08 18.
Artigo em Inglês | MEDLINE | ID: mdl-26751776

RESUMO

The cascade that culminates in macrometastases is thought to be mediated by phenotypic plasticity, including epithelial-mesenchymal and mesenchymal-epithelial transitions (EMT and MET). Although there is substantial support for the role of EMT in driving cancer cell invasion and dissemination, much less is known about the importance of MET in the later steps of metastatic colonization. We created novel reporters, which integrate transcriptional and post-transcriptional regulation, to test whether MET is required for metastasis in multiple in vivo cancer models. In a model of carcinosarcoma, metastasis occurred via an MET-dependent pathway; however, in two prostate carcinoma models, metastatic colonization was MET independent. Our results provide evidence for both MET-dependent and MET-independent metastatic pathways.


Assuntos
Transição Epitelial-Mesenquimal , Metástase Neoplásica , Animais , Proliferação de Células , Feminino , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Neoplasias/patologia
15.
Clin Cancer Res ; 2(2): 389-98, 1996 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9816182

RESUMO

The frequency of bcl-2 protein expression was evaluated using immunocytochemical staining during the progression of human and rat prostate cancer from an androgen-sensitive nonmetastatic to an androgen-independent metastatic phenotype. Previous studies (A. S. Shabaik et al., J. Urol. Pathol., 3: 17-27, 1995) demonstrated that 0 of 20 high-grade prostatic intraepithelial neoplasias and only 3 (7%) of 41 pathologically localized stage B human prostatic cancers had detectable bcl-2 staining. In the present study, 5 (17%) of 30 lymph node metastases from pathologically disseminated D1 disease and 14 (52%) of 27 bone metastases from pathologically disseminated D2 disease expressed detectable bcl-2 protein. These data demonstrate that there is a statistically significant (P < 0.05) association between expression of bcl-2 and the progression of human prostatic cancer cells to a metastatic phenotype. Such bcl-2 expression is not absolutely required, however, for either androgen independence or metastatic ability by human prostatic cancer cells. Likewise, within a series of eight distinct Dunning R3327 rat prostatic cancer sublines, which differ widely in their progressional state, there is also a significant association (P < 0. 05) between bcl-2 expression and progression (four of six androgen-independent rat sublines expressed bcl-2 protein). Again in this rodent system, bcl-2 expression is not an absolute requirement for either androgen independence or metastatic ability. For example, the androgen-independent highly metastatic Dunning AT-3 subline, while expressing bax protein, does not express bcl-2 protein. If such AT-3 cells are genetically engineered to express bcl-2, these expressing cells are now cross-resistant to a variety of mechanistically diverse noxious insults (e.g., viral infection or exposure to antimetabolites, alkylating agents, or agents which elevate the intracellular free Ca2+). The ability of bcl-2 to inhibit the programmed death of AT-3 cells induced by these agents involves a late step in the death process, since the early induction of expression of a series of genes associated with apoptosis is not impaired by bcl-2 expression. These data demonstrate that the development of androgen independence and/or metastatic ability can be associated with the expression of bcl-2 protein but that bcl-2-independent mechanisms also exist for such progression.


Assuntos
Neoplasias da Próstata/química , Proteínas Proto-Oncogênicas c-bcl-2/análise , Animais , Apoptose , Divisão Celular , Fragmentação do DNA , Humanos , Imuno-Histoquímica , Masculino , Neoplasias da Próstata/patologia , Ratos , Transfecção
16.
Clin Cancer Res ; 1(5): 473-80, 1995 May.
Artigo em Inglês | MEDLINE | ID: mdl-9816006

RESUMO

The daily percentage of cells proliferating and dying were determined for normal, premalignant, and cancerous prostatic cells within the prostate as well as for prostatic cancer cells in lymph node, soft tissue, and bone metastases from untreated and hormonally failing patients. These data demonstrate that normal prostatic glandular cells have an extremely low but balanced rate of cell proliferation and death (i.e., both <0.20%/day). This results in a steady-state, self-renewing condition in which there is no net growth, although the glandular cells are continuously being replaced (i.e., turnover) every 500 +/- 79 days. Transformation of these cells into high-grade prostatic intraepithelial neoplastic cells initially involves an unbalanced increase in the daily percentage of cells proliferating versus dying, such that net continuous growth occurs (i.e., mean doubling time, 154 +/- 22 days). As these early proliferation lesions continue to grow into late stage high-grade prostatic intraepithelial neoplastic cells, the daily percentage of cells dying increases further to a point equaling the daily percentage of proliferation. This results in cessation of net growth while inducing a 6-fold increase in the turnover time of these cells (i.e., 56 +/- 12 days), increasing their risk of further genetic changes. The transition of late stage high-grade prostatic intraepithelial neoplastic cells into localized prostatic cancer cells involves no further increase in proliferation but a decrease in death resulting in net continuous growth of localized prostatic cancers with a mean doubling time of >/=475 days. As compared to localized prostatic cancer cells, metastatic prostatic cancer cells within lymph nodes or bones of untreated patients have an increase in daily rate of proliferation coupled with a reduction in their daily percentage of cell death, producing net growth rates with a mean doubling time of 33 +/- 4 days and 54 +/- 5 days, respectively. Remarkably, there is no further increase in proliferation in hormonally failing patients, but instead an increase in the daily percentage of androgen-independent prostatic cancer cells dying within soft tissue or bone metastases. These changes result in doubling times which are two to three times longer (i.e., 126 +/- 21 and 94 +/- 15 days) in these lymph node and bone metastatic sites, respectively, compared to similar sites in hormonally untreated patients. These data demonstrate that the daily percentage of proliferation for either androgen-dependent or -independent metastatic prostatic cancer cells is remarkably low (i.e., <3. 0%/day), consistent with why antiproliferative chemotherapy has been of such limited value against such metastatic cells. These results also suggest that prostatic carcinogenesis starts in the second to third decade of life and may require over 50 years for progression to pathologically detectable metastatic disease.


Assuntos
Lesões Pré-Cancerosas/patologia , Neoplasias da Próstata/patologia , Ciclo Celular , Morte Celular , Divisão Celular , Progressão da Doença , Humanos , Cinética , Masculino , Estadiamento de Neoplasias , Neoplasias da Próstata/cirurgia , Células Tumorais Cultivadas
17.
Cancer Epidemiol Biomarkers Prev ; 7(6): 531-6, 1998 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-9641498

RESUMO

Prostate intraepithelial neoplasia (PIN) is a purported prostate cancer precursor lesion and a candidate biomarker for efficacy assessment in prostate cancer chemoprevention trials. Loss of expression of the pi-class glutathione S-transferase enzyme GSTP1, which is associated with the hypermethylation of deoxycytidine residues in the 5'-regulatory CG island region of the GSTP1 gene, is a near-universal finding in human prostate cancer. GSTP1 expression was assessed by immunohistochemistry in 60 high-grade PIN samples adjacent to and distant from prostate adenocarcinoma. Whereas abundant enzyme polypeptide expression was evident in all normal prostatic tissues, all samples of high-grade PIN and adenocarcinoma were completely devoid of GSTP1. DNA from 10 high-grade PIN lesions was analyzed for GSTP1 CG island methylation changes using a PCR technique targeting a polymorphic (ATAAA)n repeat sequence in the promoter region of the GSTP1 gene. Somatic GSTP1 CG island methylation changes were detected in DNA from 7 of the 10 PIN lesions. Allele discrimination was possible for 5 of the 10 DNA samples: 2 of the 5 samples exhibited DNA methylation changes at both alleles; whereas 3 samples displayed no DNA methylation changes at either allele. GSTP1 CG island methylation changes were present in each of the five homozygous samples. Hypermethylation of the 5'-regulatory region of the GSTP1 gene may serve as an important molecular genetic biomarker for both prostate cancer and PIN. The finding of frequent GSTP1 methylation changes in PIN and prostate cancer supports a role for PIN lesions as a prostate cancer precursor and may provide insight to the molecular pathogenesis of prostate cancer.


Assuntos
Adenocarcinoma/enzimologia , Biomarcadores Tumorais/genética , Glutationa Transferase/genética , Neoplasia Prostática Intraepitelial/enzimologia , Neoplasias da Próstata/enzimologia , Adenocarcinoma/genética , Adenocarcinoma/patologia , Metilação de DNA , Regulação Enzimológica da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Humanos , Imuno-Histoquímica , Masculino , Reação em Cadeia da Polimerase , Neoplasia Prostática Intraepitelial/genética , Neoplasia Prostática Intraepitelial/patologia , Neoplasias da Próstata/genética , Neoplasias da Próstata/patologia
18.
Am J Med ; 75(4): 639-44, 1983 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-6624771

RESUMO

Delayed rupture of myocardial infarcts, more than 10 days after infarction, is only rarely observed at autopsy. Of 1,814 hearts examined after postmortem arteriography from autopsy subjects at the Johns Hopkins Hospital, 704 had 1,140 infarcts. Three (0.2 percent) infarcts were complicated by subepicardial aneurysms, and two of these had ruptured. The infarcts were 21 to 60 days old and had an abrupt dissection of the inferior left ventricular myocardium with a narrow fibrous lined channel comprising the mouth and neck of the aneurysm. The components of the aneurysm wall differed in all three cases. In two, epicardium prevented acute ventricular rupture. In the third case, myocardial fibers were present in the fibrous wall proximally. Adherent parietal pericardium was absent. Previous authors have required the lack of myocardium within the wall to define those lesions, often called pseudoaneurysms. Aneurysms with myocardium have been labeled true aneurysms or pseudo-false aneurysms. A more unifying concept of this lesion is proposed. The unique constellation of features consisting of an abrupt interruption of the myocardium, a narrow neck, and a propensity to rupture spontaneously distinguishes the subepicardial aneurysm regardless of its wall's components. The ability to surgically correct the potentially lethal subepicardial aneurysms necessitates a more accurate categorization of and familiarity with the lesion.


Assuntos
Aneurisma Cardíaco/etiologia , Infarto do Miocárdio/complicações , Idoso , Feminino , Aneurisma Cardíaco/patologia , Humanos , Masculino , Infarto do Miocárdio/patologia , Ruptura Espontânea
19.
Am J Surg Pathol ; 14(7): 626-32, 1990 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-2356922

RESUMO

Capsular margins of resection in radical prostatectomy specimens performed for carcinoma of the prostate are difficult to assess because of the scant soft tissue removed with the prostate. There is little objective information as to the validity of what are designated as positive or negative capsular margins of resection. From January 1, 1984 through June 30, 1989 there were 40 radical prostatectomies performed in which the prostate was initially removed leaving the neurovascular bundle within the patient in order to preserve potency. However, based on the surgeons' gross examination of the prostate at the time of radical prostatectomy, the neurovascular bundle was then subsequently removed during the same operation and submitted to pathology as a separate specimen. In these 40 cases the capsular margin in the region of the neurovascular bundle was assessed blindly without knowledge of tumor presence or absence in the subsequently resected neurovascular bundle, and then compared to whether the neurovascular bundle contained tumor. Of the 10 cases called positive based on review of the radical prostatectomy, only six neurovascular bundles (60%) contained tumor. Eight cases had equivocal margins with tumor extending just to the inked margin, and only one (12.5%) had tumor in the neurovascular bundle. All 20 cases with negative assigned margins had complete removal of tumor from this area with none of the neurovascular bundles containing tumor. This study demonstrated that negative capsular margins in radical prostatectomy specimens often contain only a scant amount of soft tissue. Of the 33 cases with true negative margins, the amount of soft tissue between the inked margin and tumor was only greater than 1 mm in two cases and less than or equal to 1 m in 20 cases (less than 0.5 mm in 13 cases with less than 0.25 mm in eight of these cases). Furthermore, 11 cases with tumor extending to the inked margin of resection showed no residual tumor in additional tissue removed from these regions.


Assuntos
Próstata/patologia , Prostatectomia/métodos , Vasos Sanguíneos/inervação , Vasos Sanguíneos/patologia , Estudos de Avaliação como Assunto , Humanos , Masculino , Sistema Nervoso/patologia , Próstata/irrigação sanguínea , Neoplasias da Próstata/patologia , Neoplasias da Próstata/cirurgia
20.
Am J Surg Pathol ; 25(4): 527-37, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11257629

RESUMO

This review article covers the full range of issues concerning malpractice as it relates to pathologists. Following a brief summary as to the incidence and general statistics on the outcome of lawsuits as well as common pathology misdiagnoses resulting in lawsuits, the definition of malpractice is discussed. These include duty, breech of standard of care, proximal cause, and damage. Details are provided as to what a pathologist should do from the initial threat of a lawsuit, to the initial lawsuit, and through the initial physician/lawyer meeting. An in-depth analysis as to how pathologists should handle themselves through the discovery process and, in particular, deposition is provided. Plaintiff attorneys' goals at deposition are covered in depth. These goals include: 1) education about the pathologist's case and strategies; 2) impeachment of the pathologist's credibility; and 3) judgment as to how effective a witness the pathologist will be at trial. Various types of plaintiff's attorney at deposition are summarized. Also discussed is the post-deposition meeting with the legal representative, whether to settle, and specific issues relating to trial. Finally, general tips on how to avoid a lawsuit in pathology are reviewed.


Assuntos
Jurisprudência , Patologia/legislação & jurisprudência , Patologia/normas , Erros de Diagnóstico/legislação & jurisprudência , Feminino , Humanos , Masculino , Imperícia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA