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Biomedical subjects

P Grundy

Publications and source records attributed to P Grundy.

At least 19 recordsLinked to original sources
PubMed2001

Gain of 1q is associated with adverse outcome in favorable histology Wilms' tumors.

Although several genes/genetic loci involved in the etiology of Wilms' tumor have been identified, little is known of the molecular changes associated with relapse. We therefore undertook an analysis by comparative genomic hybridization (CGH) of 58 tumor samples of favorable histology Wilms' tumor taken at initial diagnosis and/or relapse. Tumors with anaplastic histology were excluded as this is known to be associated with p53 mutation and a poor prognosis. A control group of 21 Wilms' tumors that did not relapse was also analyzed. The overall frequency of gains or losses of genetic material detected by CGH was similar in both groups (77% in relapsing tumors and 70% in the nonrelapse group) as was the median number of changes per tumor (relapse group: n = 4, range, 1 to 19; nonrelapse group: n = 3, range, 1 to 8). However, gain of 1q was significantly more frequent in the relapse series [27 of 46 (59%) versus 5 of 21 (24%), P: = 0.019]. In 12 matched tumor pairs, the CGH profiles, including 1q gain, were similar at diagnosis and relapse, with little evidence for further copy number changes being involved in clonal evolution. The results suggest that 1q gain at diagnosis could be used to identify patients with favorable histology Wilms' tumor at increased risk of relapse who might benefit from early treatment intensification.

Chromosome Aberrations↗
PubMed2001

The survivin:fas ratio in pediatric renal tumors.

BACKGROUND/PURPOSE: Apoptosis factors inducing or preventing cell death may govern the behavior of certain tumors. Fas is a pro-apoptotic receptor that induces cell death when bound by its ligand and is expressed at greater levels in pediatric renal tumors of good prognosis. Survivin is a novel inhibitor of apoptosis that is expressed in a cell cycle-dependent manner and is abundantly expressed in several tumors of unfavorable histology. This study evaluates the expression of survivin, as well as the prognostic value of the survivin:fas ratio in various types and stages of pediatric renal tumors. METHODS: Multiple apoptosis mRNA species were quantified by Rnase protection assay (RPA) in 32 pediatric renal tumors and adjacent normal kidney specimens before chemotherapy: Wilms' tumor (WT), n = 9; clear cell sarcoma (CCS), n = 4; rhabdoid tumor of the kidney (RTK), n = 5; mesoblastic nephroma (MN), n = 3 and normal kidney, n = 11. Western Blot and immunocytochemistry were used to confirm survivin protein expression in a selective specimen survey. Follow-up data were obtained on patient outcomes, and antiapoptotic to proapoptotic ratios were calculated and correlated with clinical recurrence of disease. RESULTS: Pediatric renal tumors express greater levels of both pro- and antiapoptotic factors than normal kidney. Survivin and fas appeared to be expressed differentially in the tumor specimens sampled. Five of 10 (50%) tumors that went on to recur expressed survivin, whereas survivin was present in only 2 of 11 (18%) nonrecurrent tumors. Conversely, only 2 of 10 (20%) tumors that recurred were fas positive, whereas 5 of 11 (45%) tumors that did not recur expressed fas. The mean survivin:fas ratio was significantly greater in the 10 tumors that went on to recur after treatment (4 RTK, 3 CCS, 3 WT), than in tumors not recurring (2.16+/-1.4 v 1.0+/-1.07; P =.01, Kruskal-Wallis test). The positive predictive value of tumor recurrence was 85.7% (CI: 42.1%, 99.6%) and the negative predictive value was 71.4% (CI: 41.9%, 91.6%) when a cutoff ratio of 1.6 was considered. CONCLUSIONS: The survivin:fas mRNA ratio is of prognostic value in its ability to predict recurrent disease in children undergoing treatment for pediatric renal tumors. In this series, a ratio of greater than 1.6 predicted recurrent disease with a high probability irrespective of clinical stage or pathologic type. Determining the survivin:fas ratio may guide treatment, follow-up and counseling of patients with pediatric renal tumors.

Apoptosis↗
PubMed1999

Hemizygous deletions of chromosome band 16q24 in Wilms tumor: detection by fluorescence in situ hybridization.

Loss of heterozygosity (LOH) for markers on chromosome arm 16q in Wilms tumor has been linked to an increased risk of treatment failure. We therefore postulated that fluorescence in situ hybridization (FISH) with probes from this region might enhance current strategies for identifying high-risk patients at diagnosis. In a blinded comparative pilot study of 19 Wilms tumor samples from 18 patients with favorable histology, FISH and DNA polymorphism analysis yielded concordant results in 14 cases, either retention (n = 6) or loss (n = 8) of chromosome arm 16q markers. Discordant findings in 4 of the 5 remaining cases resulted from detection of LOH, but no loss by FISH. Two of these cases, directly comparable at marker D16S422, appeared to have tumor-specific uniparental disomy, in that 2 copies of D16S422 and the 16 centromere were evident, despite LOH. In 2 other cases, the discrepancies could be explained by LOH confined to loci distal to the D16S422 locus. In the fifth case, FISH detected 2 distinct populations of tumor cells, one characterized by normal diploidy and the other by monosomy 16, whereas DNA polymorphism analysis failed to indicate LOH altogether. Thus, FISH confirmed the presence of allelic loss (hence, the possible location of biologically important tumor suppressor genes) on the distal long arm of chromosome 16 in cases of favorable-histology Wilms tumor, with the advantages of technical simplicity, successful analysis of samples that were otherwise uninformative by analysis of DNA polymorphisms, and the addition of internal controls for chromosomal aneusomy. We suggest that combined analysis of the chromosome 16q region in Wilms tumor by FISH and DNA polymorphism analysis would improve evaluations to identify high-risk patients who might benefit from alternative therapy.

Child↗
PubMed1998

Constitutional WT1 mutations in Wilms' tumor patients.

PURPOSE: Patients with Wilms' tumors (WT) who carry constitutional mutations in the WT1 gene have been described in case reports and small case series. We sought to determine the frequency of constitutional WT1 mutations in a larger cohort, and to identify clinical manifestations associated with the risk for carrying a WT1 mutation. METHODS: We collected clinical data and blood samples from 201 patients with a history of WT. Southern blot analysis, single-strand conformation polymorphism (SSCP) analysis, and direct DNA sequencing were performed on DNA isolated from peripheral-blood lymphocytes from each patient. Odds ratios (ORs) for the carriage of a germline mutation of the WT1 gene were calculated for patients who had specific clinical risk factors compared with those who did not. RESULTS: Of 201 patients with WT in the cohort, eight patients were carriers of mutations in the WT1 gene. Six of the eight mutations were protein-truncating nonsense mutations. None of 56 patients with isolated unilateral WT was a carrier. The OR of carrying a WT1 mutation was elevated for patients with genitourinary anomalies (OR19.3; P < .002). Seven of 28 boys with WT with cryptorchidism carried WT1 mutations. No increased risk was observed for patients with nephrogenic rests, bilateral tumors, history of secondary cancers, or family history of WT. CONCLUSION: Germline WT1 mutations in patients with WT are associated with genitourinary anomalies, especially cryptorchidism and/or hypospadias. Patients with WT and no genitourinary anomalies are at low risk for carrying a WT1 mutation. Constitutional WT1 mutations that encode truncated WT1 proteins may predispose to the development of cryptorchidism, hypospadias, and WTs.

Adolescent↗
PubMed1998

Effect of duration of treatment on treatment outcome and cost of treatment for Wilms' tumor: a report from the National Wilms' Tumor Study Group.

PURPOSE: National Wilms' Tumor Study (NWTS)-4 was designed to evaluate the efficacy, toxicity, and cost of the administration of different regimens for the treatment of Wilms' tumor (WT). PATIENTS AND METHODS: Between August 6, 1986 and September 1, 1994, 905 previously untreated children aged younger than 16 years with stage II favorable histology (FH) WT (low-risk [LR]), stages III to IV FH WT, or stages I to IV clear-cell sarcoma of the kidney (high-risk[HR]) were randomized after the completion of 6 months of chemotherapy to discontinue (short) or continue for 9 additional months (long) treatment with chemotherapy regimens that included vincristine and either divided-dose (standard [STD]) courses (5 days) or single-dose (pulse-intensive [PI]) treatment with dactinomycin. HR patients also received either divided-dose (STD) courses (3 days) or single-dose (PI) treatment with doxorubicin. RESULTS: The 4-year relapse-free survival (RFS) rates after the second randomization for LR patients were 83.7% for the 190 patients treated with short and 88.2% for the 187 patients treated with long chemotherapy (P = .11). The 4-year RFS rates after the second randomization for HR FH patients were 89.7% for the 256 patients treated with short and 88.8% for the 246 patients treated with long chemotherapy (P = .87). The charge for treatment with the short PI treatment regimens for all children with stages I through IV FH WT was approximately one half of that with the long STD treatment regimens. CONCLUSION: The short administration schedule for the treatment of children with WT is no less effective than the long administration schedule and can be administered at a substantially lower total treatment cost.

Adolescent↗
PubMed1997

Aberrant imprinting of the insulin-like growth factor II receptor gene in Wilms' tumor.

Wilms' tumor (WT) is an embryonal renal malignancy, which overexpresses insulin-like growth factor II (IGF-II), a fetal mitogen. Relaxation of parental imprinting of IGF2, the gene encoding IGF-II, is found in Wilms' tumors, suggesting an important role for IGF2 dosage in tumorigenesis. The IGF2R gene encodes a nonmitogenic receptor which targets IGF-II to the lysosomes for degradation and, therefore, inhibits the mitogenic function of IGF-II. The human IGF2R is imprinted in a proportion of normal individuals. To test the hypothesis that IGF2R imprinting predisposes to Wilms' tumor through the effect of decreased IGF2R dosage on IGF-II inactivation, we examined IGF2R imprinting in Wilms' tumors. Two transcribed CA repeat polymorphisms were used to distinguish the two alleles in the RT-PCR product. We observed that in 7/16 of Wilms' tumor patients, the paternal IGF2R was markedly but not completely repressed in both tumor and normal kidney. In one additional case, IGF2R was likewise imprinted in the tumor but not in the normal kidney. A similar imprinting was observed in fetal tissues and placenta prior to 20 weeks fetal age but not in term placenta or postnatal blood cells, indicating abnormal persistence of a fetal pattern in the kidneys of Wilms' patients. Genetic analysis showed association of the imprinting with a cis-acting locus. The high frequency of aberrant persistence of IGF2R imprinting in the kidneys of Wilms' tumor patients, which may be an embryonic feature, suggests that it is a predisposing factor in tumorigenesis. This is in accordance with evidence that IGF2R is a tumour suppressor in other types of malignancies.

Alleles↗
PubMed1997

Transfusion- and community-acquired cytomegalovirus infection in children with malignant disease: a prospective study.

BACKGROUND: The use of cytomegalovirus (CMV)-"safe" blood has been recommended for CMV seronegative patients with newly diagnosed malignant disease for whom bone marrow transplantation is a future option. STUDY DESIGN AND METHODS: To evaluate this policy, 76 CMV-seronegative children with lymphoreticular malignancies or solid tumors were randomly assigned to receive either blood components that were not screened for CMV antibody or CMV-seronegative red cell (RBC) and platelet units. Subjects were followed for evidence of CMV infection by the use of enzyme-linked immunosorbent assays and virus isolation. Follow-up continued long after the blood transfusions to determine the risk of community-acquired CMV infection. RESULTS: No cases of transfusion-acquired CMV infection were documented. The prevalence of CMV IgG and IgM antibody in blood donors was 40.5 and 0.9 percent, respectively. Patients assigned to receive standard blood components and CMV-negative components were given a median (range) of 7 (1-30) and 9 (1-38) RBC units and 11 (0-123) and 14 (0-71) platelet units, respectively. The risk of transfusion-acquired CMV infection is estimated to be less than 1 in 698 donor exposures. Two patients developed asymptomatic community-acquired CMV infection, for an incidence of 1.7 percent per patient-year of follow-up. CONCLUSION: The risk of transfusion-acquired CMV infection in this population is low, largely because of the patients' low level of exposure to seropositive blood and the use of relatively white cell-reduced components for purposes other than CMV prevention. Such children at this center therefore continue to receive standard blood components. Strategies to prevent CMV seroconversion in these children should include parental education to minimize the risk of community-acquired infection.

Adolescent↗
PubMed1996

Purchasing. The wasted millions.

In the wake of the Child B rationing controversy, the Anti-Rationing Group challenged purchasers to allow them to scrutinise their practice. Eight health authorities accepted and, say Colin Roberts and colleagues, the results show public money being needlessly wasted on a staggering scale.

Community Health Services↗
PubMed1996

Identification of novel regions of deletion in familial Wilms' tumor by comparative genomic hybridization.

Wilms' tumor, an embryonic renal neoplasm diagnosed primarily in young children, can occur in either a noninheritable (sporadic) or a familial form, with the latter presenting earlier and more often at bilateral sites. Although familial Wilms' tumor is thought to develop through inherited and acquired mutational inactivation of the two alleles of predisposing tumor suppressor genes, only a small percentage of cases can be accounted for by mutations affecting the WT1 gene or linkage to the Beckwith-Weidemann syndrome of the BWS region on the short arm of chromosome 11. To find chromosomal regions that might contain genes important in the development of this disease, we used comparative genomic hybridization to analyze tumor specimens from familial cases for chromosomal regions that were consistently lost. Although inherited lesions of tumor suppressors are most often inactivating point mutations, accompanying somatic lesions in the malignant clones are often chromosomal deletions; therefore, consensus regions of loss in familial tumors are likely to harbor genes linked to familial predisposition. There were extensive genomic aberrations among the eight familial cases studied, with an average of 6.5 changes/tumor (range, 0-22). The most consistent findings with likely biological relevance were deletions of chromosomes 4 (consensus, 4q21-qter), 9 (consensus, 9p21-pter), 20p, and 3 (consensus, 3q12-q21). These regions have not been previously implicated in Wilms' tumor and may harbor novel genes that could aid attempts to understand the familial predisposition as well as the development and progression of these tumors.

Chromosome Deletion↗
PubMed1996

Imprinting of the gene encoding a human cyclin-dependent kinase inhibitor, p57KIP2, on chromosome 11p15.

Parental origin-specific alterations of chromosome 11p15 in human cancer suggest the involvement of one or more maternally expressed imprinted genes involved in embryonal tumor suppression and the cancer-predisposing Beckwith-Wiedemann syndrome (BWS). The gene encoding cyclin-dependent kinase inhibitor p57KIP2, whose overexpression causes G1 phase arrest, was recently cloned and mapped to this band. We find that the p57KIP2 gene is imprinted, with preferential expression of the maternal allele. However, the imprint is not absolute, as the paternal allele is also expressed at low levels in most tissues, and at levels comparable to the maternal allele in fetal brain and some embryonal tumors. The biochemical function, chromosomal location, and imprinting of the p57KIP2 gene match the properties predicted for a tumor suppressor gene at 11p15.5. However, as the p57KIP2 gene is 500 kb centromeric to the gene encoding insulin-like growth factor 2, it is likely to be part of a large domain containing other imprinted genes. Thus, loss of heterozygosity or loss of imprinting might simultaneously affect several genes at this locus that together contribute to tumor and/or growth- suppressing functions that are disrupted in BWS and embryonal tumors.

Base Sequence↗
PubMed1996

Two pairs of male monozygotic twins discordant for Wiedemann-Beckwith syndrome.

Wiedemann-Beckwith syndrome (WBS) is a congenital anomaly syndrome which classically consists of exomphalos, macroglossia, and gigantism. The syndrome is also associated with a variety of minor anomalies and affected individuals have an increased risk of developing rare embryonal cell tumors. To date, 15 monozygotic (MZ) twin pairs have been reported of which 13 are discordant for WBS. All except one pair of the discordant WBS twin pairs have been female. We report two pairs of male MZ twins, each discordant for WBS.

Adult↗
PubMed1996

Familial Wilms' tumor: a descriptive study.

Among 6,209 patients with Wilms' tumor entered on the National Wilms' Tumor Study (NWTS), 93 patients (1.5%) from 63 families had a positive family history. In 30 of these 63 families a (half) sibling or parent of the NWTS patient was confirmed to have had Wilms' tumor. Fifteen (16.1%) of the familial, but only 7.1% of sporadic cases, had bilateral disease. Mean ages at diagnosis were 15.8 vs. 35.2 months (P = 0.012) for bilateral vs. unilateral familial cases and 32.0 vs. 44.7 months for sporadic cases. Intralobar nephrogenic rests were found twice as frequently in association with the tumors of familial as with those of sporadic cases. Cases of bilateral and metastatic disease tended to cluster within specific families, suggesting heterogeneity in the genetic etiology. The number and age distribution of familial cases transmitted through the father were about the same as those of cases transmitted through the mother. This finding is inconsistent with models of genomic imprinting that involve familial transmission of a tumor-suppressor gene and it casts further doubt on the hypothesis that all bilateral cases are hereditary.

Adolescent↗
PubMed1996

Clinicopathologic correlates of loss of heterozygosity in Wilm's tumor: a preliminary analysis.

Wilms' tumor-specific loss of heterozygosity (LOH) for DNA markers located at chromosomes 11p13, 11p15, 16q, and 1p has been reported to occur in a minority of Wilms' tumors. We hypothesized that tumors classified by region of LOH would exhibit specific clinicopathologic patterns. We have therefore determined the constitutional and tumor genotypes for markers at 11p13, 11p15, 16q, and 1p in a large series of Wilms' tumor patients who were registered on a Pediatric Oncology Group study and on the National Wilms' Tumor Study, to determine whether tumor-specific LOH for any of these regions was associated with any specific phenotype. Of 286 cases, 27% had LOH at both 11p13 and p15 (BOTH), 3% at 11p13 only, 8% at 11p15 only, and 62% at neither. Significant associations were found between younger age at diagnosis and LOH for BOTH, but not for 11p15 only, and between the presence of intralobar nephrogenic rests and LOH for BOTH. The incidence of nephrogenic rests (all types combined) and of bilateral tumors was the same in tumors with or without LOH. There was a negative association between anaplastic histology and LOH for 11p. There was no association between LOH on 11p and outcome as assessed by relapse-free and overall survival. The associations between age at diagnosis and LOH are interpreted as suggesting the existence of a Wilms' tumor locus on 11p in addition to WT1 at 11p13 and the putative WT2 at 11p15. LOH for chromosome 16q was identified in 17% of 204 tumors and was associated with a significantly worse outcome. Outcome for patients with LOH for 1p was also worse but not significantly so.

Age Factors↗
PubMed1995

Molecular genetics of Wilms tumor.

The study of Wilms tumor-predisposing congenital syndromes has led to the identification of one tumor-suppressor gene, WT1, and to the localization of WT2. Molecular genetic analyses of these and sporadic Wilms tumors have clarified the role of WT1 in Wilms tumor with aniridia, genitourinary malformations, and mental retardation (WAGR)-syndrome patients, but much remains unclear in the case of WT2 and the Beckwith-Wiedemann syndrome. Loci on chromosomes 16q and 1p have now been implicated in the progression of Wilms tumor and may serve as molecular prognostic markers. It is now clear that Wilms tumors are genetically heterogeneous and may be multigenic in origin. Molecular analyses can now be used for genetic counseling in some children and may become useful in individualizing therapy.

Chromosome Mapping↗