Regional cancer cytogenetics: a report on 1,143 diagnostic cases

Banding cytogenetic analysis in pediatric patients with acute lymphoblastic leukemia (ALL) in a Brazilian population

BACKGROUND

Cytogenetic studies in Brazilian population about childhood acute lymphoblastic leukemia (ALL), the most common childhood malignancy, are scarce. Moreover, Brazilian race is very heterogeneous and is made by the confluence of people of several different origins, from the original Native Brazilians, with the influx of Portuguese colonizers, Black African slaves, and recent European, Arab and Japanese immigration. The purpose of this prospective, multicentric study was to assess the sociodemographic, clinic and cytogenetic characteristics of the children treated for ALL in the Northeast region of Brazil.

RESULTS

This study includes thirty patients between 4 months and 17 years old treated for ALL from January 1st, 2009 to November 30th, 2010. Cytogenetic analysis showed that in nineteen out of thirty patients (64%) presented some chromosome abnormalities, in which 53% corresponds to numerical abnormalities, 21% structural and numerical abnormalities, and 26% only structural changes. Moreover, seven patients presented complexes karyotype not yet described in the literature. Taken together these results show the importance of the cytogenetic analysis in ALL pediatric patients and illustrates that the studied population presented unexpected complexes karyotypes which were correlated to poor outcome.

CONCLUSION

The results demonstrate the importance of banding cytogenetics for ALL diagnosis despite the use of most modern techniques such as FISH and aCGH, and provide reliable insight into the ALL in Brazil.

G-CSF receptor (CSF3R) mutations in X-linked neutropenia evolving to acute myeloid leukemia or myelodysplasia

X-linked neutropenia (XLN) is a rare form of Congenital Neutropenia (CN) caused by inherited gain-of-function mutations of WAS. Here we report 2 cases of the original L270P X-linked neutropenia kindred that evolved to MDS or AML, with acquisition of G-CSFR (CSF3R) mutations and monosomy 7. Thus, leukemic transformation with acquisition of CSF3R mutations and monosomy 7 is not restricted to classical congenital neutropenia with autosomal inheritance, but can also occur in other genotypes of inherited neutropenia.

Different susceptibilities to 1,25-dihydroxyvitamin D3-induced differentiation of AML cells carrying various mutations

This study was designed to compare the differentiation-inducing potential of 1,25-dihydroxyvitamin D(3) (1,25D) with some analogs (VDAs) in a panel of acute myeloid leukemia (AML) cell lines and in blast cells isolated from patients with AML. Of the cell lines studied, HL60 proved to be the most sensitive to each of the differentiation-inducing agents when compared to THP-1, NB-4 and U-937 cell lines. Three of the VDAs tested (PRI-1906, PRI-2191 and PRI-2201) were similarly effective as 1,25D in all the cell lines tested. However, blast cells from AML showed a varying sensitivity towards 1,25D. For example, blast cells isolated from patients in which the whole or part of chromosome 7 was deleted were extremely sensitive to 1,25D and its analogs. In contrast, 1,25D failed to increase the expression of differentiation markers in blast cells isolated from patients carrying activating mutations in Flt3 gene. Since, the expression of vitamin D receptor (VDR) in cells with Flt3 mutations was increased to the same extent as in other AML cells this suggests that failure of these cells to differentiate lies downstream of the receptor. That blast cells with different cytogenetic abnormalities have dissimilar responses to 1,25D and its analogs, may have implications in the use of 1,25D as a 'differentiation therapy' for myeloid leukemias. The analog PRI-2191 (tacalcitol) was found to be the most potent in inducing patient's cells differentiation.

Cytogenetic Profile of Childhood Acute Lymphoblastic Leukemia in Oman

BACKGROUND

Chromosomal abnormalities have important diagnostic and prognostic significance in acute lymphoblastic leukemia (ALL). The purpose of this study was to define and classify the frequency and type of chromosomal abnormalities among newly diagnosed children with ALL and compare the results with those reported from other geographical regions of the world.

METHODS

Bone marrow chromosomal studies with GTG banding were performed in untreated ALL pediatric patients aged from 7 days to 14 years.

RESULTS

Among Omani children examined with ALL, 47 (81%) patients yielded results, with 26 (55.3%) showing an abnormal karyotype [10 (21.3%) pseudodiploid, 2 (4.3%) hypodiploid and 14 (29.7%) hyperdiploidy] and 21 (44.6%) had normal diploidy. Structural abnormalities were observed in 16 (34%), of which 11 (23.4%) cases were translocations, the most frequent being t(9;22) observed in three (6.4%) of our patients. Uncommon translocations such as t(9;15)(p11;q10), t(3;6)(p12;q11), t(1;6)(?31;?q23), t(1;19)(q12;q12), der(18)t(12;18)(q11;p11), and other structural aberrations add(2)(q22), add(6)(q16), add(18)(q22), add(14)(q32) along with deletions del(10)(q22), del(12)(p11), del(12)(p12), del(18)(q11) were also observed.

CONCLUSIONS

The study showed a good correlation and concordance between the ploidy distribution by cytogenetics and flow cytometry. The patterns of chromosomal anomalies in our patients showed some variations in the frequency of aberrations reported. It is therefore necessary that newer techniques like fluorescence in situ hybridization (FISH) along with reverse transcriptase polymerase chain reaction (RT-PCR) and spectral karyotyping will help us identify chromosomal aberrations not detected by conventional cytogenetic methods in the near future. To our knowledge, this is the first report from the Middle East of a cytogenetic study on childhood ALL.

Germ cell tumor showing partial trisomy 1 in a gonadectomized intersex child with monosomy X and double Y mosaicism

High incidence of germ cell tumors arising from dysgenetic gonads in patients with sexual chromosome abnormalities has been described, especially in patients with a Y chromosome bearing cell line. Here we report a 14-year-old patient with ambiguous genitalia. Constitutional karyotype showed 45,X/46,X,derY [?t(Yp;Yq)] mosaicism. The patient developed an abdominally located mixed malignant germ cell tumor 5 years after the removal of the dysgenetic gonads. Tumor karyotype showed partial trisomy 1q, a derivative 8q, and a hyperdiploidy with +X, +7, +12, +15, +19, +21, and an unidentified marker.

Cytogenetics in childhood acute lymphoblastic leukemia in Taiwan: a single-institutional experience

The aim of the study was to define the frequency and types of acquired chromosomal aberrations in a group of Taiwanese children with ALL. The sample population consisted of 78 patients under 18 years of age with newly diagnosed ALL who underwent cytogenetic studies at diagnosis and had adequate metaphase chromosomes for analysis at the authors' hospital from 1993 to 2001. Metaphase chromosomes were banded using the conventional trypsin-Giemsa banding technique. Analysis of ploidy revealed 16 (20.5%) patients with normal diploidy, 28 (35.9%) with pseudodiploidy, 6 (7.7%) with hyperdiploidy (47-50), 19 (24.4%) with hyperdiploidy (> 50), and 9 (9.4%) hypodiploidy. Near-haploidy was not observed. Of the patients with abnormal karyotypes, recurrent structural abnormalities were determined in 31 (50%) cases, with the most frequent t(9;22). In conclusion, the frequency and type of acquired chromosomal aberrations found in these Taiwanese children with ALL are similar to those reported in the literature.

Contribution of multiparameter genetic analysis to the detection of genetic alterations in hematologic neoplasia. An evaluation of combining G-band analysis, spectral karyotyping, and multiplex reverse-transcription polymerase chain reaction (multiplex RT-PCR)

We investigated 150 acute myeloid leukemia (AML) patients and 48 acute lymphoblastic leukemia (ALL) patients by multiplex RT-PCR to 7evaluate the adjuvant diagnostic effect, vis-à-vis G-banding and spectral karyotyping (SKY), and the potentials of this method for providing means for monitoring residual disease by real-time quantitative RT-PCR. An abnormal G-banded karyotype was found in 57% of AML and 68% of ALL cases. Ninety-six patients were investigated by SKY in parallel which extended or confirmed the G-banding finding in 94/96 cases. In patients with an abnormal G-banded karyotype, classification of chromosomes involved in structural aberrations by SKY was possible in 98% of the cases and SKY extended the G-banded karyotype in 34% of cases. In 32 cases, an mRNA hybrid was detected by PCR. These cases constitute 16% of the cases investigated at diagnosis (AML: 11% and ALL: 31%). In 13 of these cases, we detected an mRNA hybrid the equivalent of which was not found by G-banding or SKY (AML: 4% and ALL: 13%). By including multiplex RT-PCR, we were able to detect abnormalities in 62% of the investigated patients as opposed to 59% by G-banding. Genetic techniques complement each other and selection of relevant and targeted primer kits for the multiplex RT-PCR assay is recommended.

Economic assessment on the management of chronic lymphocytic leukaemia

In the last decade, several new promising treatments for chronic lymphocytic leukaemia (CLL) have been developed. Healthcare costs are increasing and new treatments tend to be very expensive; therefore, information about the cost effectiveness in treatments for CLL is urgently needed. The authors performed a literature review on the currently available economic evaluations on CLL treatments. A total of 65 articles were found, of which 11 could be included. These articles were evaluated on the basis of six methodological requirements for economic evaluations, enabling readers to judge the value of the studies. Only a small amount of information was available on the costs of CLL treatments. Future economic evaluations should be performed according to the methodological requirements for these studies, which should also be properly documented.

Genetic testing in the myelodysplastic syndromes: molecular insights into hematologic diversity

The myelodysplastic syndromes (MDS) are associated with a diverse set of acquired somatic genetic abnormalities. Bone marrow karyotyping provides important diagnostic and prognostic information and should be attempted in all patients who are suspected of having MDS. Fluorescent in situ hybridization (FISH) studies on blood or marrow may also be valuable in selected cases, such as patients who may have 5q- syndrome or those who have undergone hematopoletic stem cell transplantation. The MDS-associated cytogenetic abnormalities that have been defined by karyotyping and FISH studies have already contributed substantially to our current understanding of the biology of malignant myeloid disorders, but the pathobiological meaning of common, recurrent chromosomal lesions such as del(5q), del(20q), and monosomy 7 is still unknown. The great diversity of the cytogenetic findings described in MDS highlights the molecular heterogeneity of this cluster of diseases. We review the common and pathophysiologically interesting genetic abnormalities associated with MDS, focusing on the clinical utility of conventional cytogenetic assays and selected FISH studies. In addition, we discuss a series of well-defined MDS-associated point mutations and outline the potential for further insights from newer techniques such as global gene expression profiling and array-based comparative genomic hybridization.

High concordance from independent studies by the Children's Cancer Group (CCG) and Pediatric Oncology Group (POG) associating favorable prognosis with combined trisomies 4, 10, and 17 in children with NCI Standard-Risk B-precursor Acute Lymphoblastic Leukemia: a Children's Oncology Group (COG) initiative

Chromosome aberrations have a major role in pediatric acute lymphoblastic leukemia (ALL) risk assignment. The Children's Cancer Group (CCG) and the Pediatric Oncology Group (POG) independently assessed the significance of trisomy for chromosomes 4, 10, and 17 in National Cancer Institute (NCI) Standard- and High-Risk ALL. Data from 1582 (CCG) and 3902 (POG) patients were analyzed. Eight-year event-free survivals (EFS) of 91% (CCG) and 89% (POG) (P < 0.001) were achieved in patients assigned to NCI Standard Risk whose leukemic cells had simultaneous trisomies 4, 10, and 17. Both groups showed the degree of favorable prognostic importance increased with the actual number of favorable trisomies. POG analyses also demonstrated hyperdiploidy (> or =53 chromosomes) was less of an independently significant prognostic factor in the absence of these key trisomies. This finding supported conclusions from previous CCG and POG studies that specific trisomies are more important than chromosome number in predicting outcome in pediatric B-precursor ALL. In NCI Higher Risk patients, the number of favorable trisomies was not prognostically significant, but showed the same trend. Moreover, specific trisomies 4, 10, and 17 remain associated with favorable prognosis in Standard-Risk B-precursor ALL, even in the context of very different treatment approaches between the groups.

Chromosome aberrations in canine multicentric lymphomas detected with comparative genomic hybridisation and a panel of single locus probes

Recurrent chromosome aberrations are frequently observed in human neoplastic cells and often correlate with other clinical and histopathological parameters of a given tumour type. The clinical presentation, histology and biology of many canine cancers closely parallels those of human malignancies. Since humans and dogs demonstrate extensive genome homology and share the same environment, it is expected that many canine cancers will also be associated with recurrent chromosome aberrations. To investigate this, we have performed molecular cytogenetic analyses on 25 cases of canine multicentric lymphoma. Comparative genomic hybridisation analysis demonstrated between one and 12 separate regions of chromosomal gain or loss within each case, involving 32 of the 38 canine autosomes. Genomic gains were almost twice as common as losses. Gain of dog chromosome (CFA) 13 was the most common aberration observed (12 of 25 cases), followed by gain of CFA 31 (eight cases) and loss of CFA 14 (five cases). Cytogenetic and histopathological data for each case are presented, and cytogenetic similarities with human non-Hodgkin's lymphoma are discussed. We have also assembled a panel of 41 canine chromosome-specific BAC probes that may be used for accurate and efficient chromosome identification in future studies of this nature.

Prognostic implications of t(10;11) translocations in childhood acute myelogenous leukemia: a report from the Children's Cancer Group

PURPOSE

This was a retrospective analysis of outcome based on cytogenetics for a Children's Cancer Group phase 3 trial of acute myelogenous leukemia (AML) (CCG-2891).

PATIENTS AND METHODS

A retrospective analysis of outcome for newly diagnosed children with AML and myelodysplastic syndrome (MDS) was performed using data collected from CCG-2891. The authors identified 11 patients whose blasts carried t(10;11) reciprocal translocations or other complex rearrangements involving 10p and 11q among 470 eligible patients entered with acceptable, centrally reviewed cytogenetics. A bone marrow specimen was used for each case of cytogenetic analysis in which 20 banded (either G-banded or Q-banded) metaphases were completed on each subject. All 11 patients had characteristic monocytoid morphology (M4 or M5) and tended to be young (0.1-7.9 years; median 0.9 years).

RESULTS

All 11 patients entered remission, but remissions tended to be short; 9 patients relapsed within 12 months (median 4 months). The relapse rate of 82% was significantly higher for this group of patients compared with 46% for the group at large. The relapse rate for this group of patients having t(10;11) reciprocal translocations or other complex rearrangements involving 10p and 11q was also significantly higher compared with subjects with other 11q23 chromosomal abnormalities. The CNS relapse rate of 55% was higher for this group of patients compared with 3% for all other patients in the study. The CNS relapse rate was higher for the subjects who had t(10;11) reciprocal translocations or other complex rearrangements involving 10p and 11q compared with subjects with all other chromosome 11 abnormalities. Three children survived, two in second remissions (4.7 and 6.3 years after relapse) and one in first remission (7.0 years after diagnosis). Survival and event-free survival for the patients with t(10;11) reciprocal translocations or other complex rearrangements involving 10p and 11q was 27 +/- 27% and 9 +/- 17% at 6 years, respectively, and was not statistically different from all other patients with cytogenetics. Similarly, the survival and event-free survival for the patients with t(10;11) translocations and other rearrangements of chromosomes 10 and 11 was 27 +/- 27% and 9 +/- 17% at 6 years, respectively, and was not statistically different from the 11q23 group of subjects.

CONCLUSIONS

Further research is needed to determine the various changes that are occurring at the molecular level for patients with t(10;11) translocations and other rearrangements of chromosomes 10 and 11 to gain insight into the mechanisms causing this clinical phenotype associated with a poor prognosis.

Cytogenetic findings and their clinical relevance in myelofibrosis with myeloid metaplasia

The prognostic significance of bone marrow cytogenetic lesions in myelofibrosis with myeloid metaplasia (MMM) was investigated in a retrospective series of 165 patients. An abnormal karyotype was demonstrated in 57% of patients. At diagnosis (n = 92), 48% of the patients had detectable cytogenetic abnormalities, and clonal evolution was frequently demonstrated in sequential studies. More than 90% of the anomalies were represented by 20q-, 13q-, +8, +9, 12p-, and abnormalities of chromosomes 1 and 7. Of these, 20q-, 13q- and +8 were the most frequent sole abnormalities, each occurring in 15-25% of the abnormal cases. Trisomy 9 and abnormalities of chromosomes 1 and 7 were equally prevalent but were usually associated with additional cytogenetic lesions. Chromosome 5 abnormalities were infrequent but were over-represented in the group of patients exposed to genotoxic therapy. In a multivariate analysis that incorporated other clinical and laboratory variables, the presence of an abnormal karyotype did not carry an adverse prognosis. Instead, +8, 12p-, advanced age and anaemia were independent prognostic determinants of inferior survival. In particular, survival was not adversely affected by the presence of either 20q- or 13q-.

Cytogenetics in acute lymphoblastic leukemia in Mexican children: an institutional experience

BACKGROUND

Cytogenetic studies in acute lymphoblastic leukemia (ALL) have identified numerical and structural chromosomal abnormalities related to the disease's pathophysiologic characteristics. These findings correlate with prognosis and response to treatment in ALL patients. The purpose of this study was to define the frequency of chromosomal abnormalities in a group of Mexican children with ALL and to compare these data with those reported in the literature.

METHODS

Bone marrow chromosome studies with GTG bands were performed in 150 pediatric patients with ALL who were naive to antileukemic treatment and aged from 5 months to 16 years; the majority was diagnosed as L1.

RESULTS

Among 131 patients, 30 (22.9%) karyotypes were normal and the remaining 101 (77.1%) had abnormal karyotypes with numerical and/or structural abnormalities. Among patients with numerical abnormalities, the most frequent karyotypes were hyperdiploidy with 51-65 chromosomes (30 patients) and hyperdiploidy with 47-50 chromosomes (18 patients). Among recurrent, non-random, and primary structural abnormalities, the most frequent was t(9;22), followed by t(1;19). Aberrations involving band 11q23 were not detected, and only one of two patients with L3 had the t(8;14). Of the secondary non-random abnormalities, dup(1q), del(6q), and i(7)(q10) were found.

CONCLUSIONS

The frequency and type of chromosomal abnormalities found was comparable to those reported in the literature with similar methodology and pediatric populations; however, the number of cases analyzed should be increased to create a database of Mexican children with ALL, and several patients require molecular analysis to identify chromosomal abnormalities not detected through conventional cytogenetic studies.

Spectral karyotyping and multicolor fluorescence in situ hybridization reveal new tumor-specific chromosomal aberrations

Spectral karyotyping (SKY), multiple fluorescence in situ hybridization (M-FISH), cross-species color banding (Rx-FISH), multicolor chromosome banding, and other labeling techniques and strategies have been recent comprehensive technical developments in the field of molecular cytogenetics. The immediate goals of these methods are (1) to reliably characterize complex chromosomal rearrangements present in tumor karyotypes; (2) to screen for new tumor-specific chromosomal aberrations; (3) to improve genetic classification systems of different tumor types in correlation with clinical data, treatment regimens, detection of minimal residual disease, and prognosis; and (4) to identify new target regions for gene identification strategies. We present a brief overview of the different methods, including summaries of numerous published and submitted papers detailing specific cytogenetic aberrations associated with leukemias and lymphomas. To date, 640 tumor cases have been analyzed by SKY, including 410 hematologic malignancies, 146 solid tumors, and 45 mouse tumors.

Allelotype analysis of the myelodysplastic syndrome

Myelodysplastic syndromes (MDS) are a group of clonal hematologic disorders found predominantly in the elderly. The molecular mechanisms underlying the development of MDS remain obscure. In order to begin to identify tumor suppressor genes involved in these disorders, we performed a detailed microsatellite allelotype of chromosomal deletions associated with MDS. DNAs from both bone marrow and peripheral blood of 32 MDS patients were studied using 84 highly informative microsatellite markers on all autosomal arms, excluding the short arms of the acrocentric chromosomes. A high percentage of loss of heterozygosity (LOH) was identified on chromosome 5q (40% of informative cases), 7q (45%), 17p (23%) and 20q (20%), which corresponds to the most common cytogenetic abnormalities reported in MDS. In addition, a high incidence of LOH (> or =20%) was observed on chromosomal arms which had not been previously reported including 1p (36%), 1q (35%), and 18q (23%). This extensive allelotype analysis focuses attention on several novel genomic regions that probably contain novel tumor suppressor genes whose loss of function contributes to the development of MDS.

Development of a syngeneic mouse model for events related to ovarian cancer

Mouse ovarian surface epithelial cells (MOSEC) were obtained from virgin, mature mice by mild trypsinization and were repeatedly passaged in vitro. Early passage cells (<20 passages) exhibited a cobblestone morphology and contact inhibition of growth. After approximately 20 passages in vitro, cobblestone morphology and contact inhibition of growth was lost. Tumor forming potential was determined by s.c. and i.p. injection of early and late passage cells into athymic and syngeneic C57BL6 mice. Subcutaneous tumors formed in approximately 4 months and were present only at the injection site. Intraperitoneal injection of late passage MOSEC into athymic and syngeneic mice resulted in growth of tumor implants throughout the abdominal cavity, and production of hemorrhagic ascitic fluid. Early passage MOSEC did not form tumors in vivo. Histopathologic analysis of tumors revealed a highly malignant neoplasm containing both carcinomatous and sarcomatous components. Late passage MOSEC expressed cytokeratin and did not produce ovarian steroids in response to gonadotropin stimulation in vitro. Ten clonal lines were established from late passage MOSEC. Each clone formed multiple peritoneal tumors and ascitic fluid after i.p. injection into C57BL6 mice. Three cell lines examined cytogenetically were polyploid with near-tetraploid modal chromosome numbers. Common clonal chromosome gains and losses included +5, +15, +19 and -X, -3, -4. One cell line had a clonal translocation between chromosomes 15 and 18 and another had a small marker chromosome; common structural abnormalities were not observed. These data describe the development of a mouse model for the study of events related to ovarian cancer in humans. The ability of the MOSEC to form extensive tumors within the peritoneal cavity, similar to those seen in women with Stage III and IV cancer, and the ability of the MOSEC to produce tumors in mice with intact immune systems, makes this model unique for investigations of molecular and immune interactions in ovarian cancer development.

A new complex variant Philadelphia chromosome, t(1;9;22)ins(17;22), characterized by fluorescence in situ hybridization in an adult ALL

A new complex variant Philadelphia chromosome was detected in a 65-year-old man with acute, pre-B, lymphoblastic leukemia (ALL). The classic cytogenetic analysis identified an apparently balanced three-way translocation t(1;9;22)(q25;q34;q11.2). Fluorescence in situ hybridization (FISH) studies confirmed the translocation and showed bcr/abl fusion on the der(22). However, these studies revealed that the distal part of the bcr gene was not translocated onto chromosome 1 at 1q25, but inserted into chromosome 17 at 17p12-13. This complex variant translocation was described as a t(1;9;22)(q25;q34;q11.2)ins(17;22)(p12-13;q11.2q11.2). Secondary changes including +8, an inversion of the derivative chromosome 9, a translocation t(14;20)(q11;q13), and an additional derivative 22 were also identified in most of the abnormal cells. The patient died from systemic fungemia and multiorgan failure 9 months after the diagnosis of ALL. The clinical significance of complex variant Philadelphia chromosomes in ALL is reviewed and discussed.

Translocation (12;17)(q13;q23) in de novo acute myeloid leukemia with trilineage myelodysplasia

12q13 abnormalities have been reported to be associated with a variety of benign and malignant solid tumors. Recently, they have been shown to be a nonrandom karyotypic change in acute myeloid leukemia. We report a case of de novo acute myeloid leukemia with trilineage myelodysplasia showing t(12;17)(q13;q23) as the sole chromosomal abnormality. A review of the literature indicates that 12q13 translocation in acute myeloid leukemia is often associated with concomitant dysmyelopoietic changes. There is also evidence to suggest that 12q13 translocation occurs more frequently in acute myeloid leukemia with a prior history of mutagenic exposure or karyotypic indicators of secondary leukemia.

c-myc and chromosome 8 centromere studies of ovarian cancer by interphase FISH

Forty tumor specimens from patients with ovarian cancer were studied for amplification of the c-myc oncogene relative to chromosome 8 centromere number using dual-color FISH. Interphase cytogenetic analysis showed amplification of the c-myc oncogene in 40% (16/40) of tumors using the standard oncogene:centromere ratio method of analysis. Eleven of these showed moderate amplification of c-myc, and 5 samples showed high amplification. Eight of the sixteen (50%) amplified tumors were polysomic centromere 8 as were 14 of the 24 (58%) non-amplified tumors. In previously reported work with these samples, the oncogene HER-2/neu, the chromosome 17 centromere, and the tumor suppressor gene p53 had been studied. When using the standard oncogene:centromere ratio criteria, 5 samples had amplification of both the c-myc and the HER-2/neu oncogenes, 5 samples had HER-2/neu amplification but not c-myc, 11 samples had c-myc amplification but not HER-2/neu, and 19 samples had neither oncogene amplified. The p53 gene was found to be deleted in 22.5% (9/40) of samples. The loss of the p53 gene did not appear to have any clinical correlation. The presence of an extra centromere 8 also did not appear to have any clinical correlation. The Kaplan-Meier survival curve for those patients who have c-myc amplification, while not statistically significant, appears to show a trend toward poorer survival. The survival curve for patients whose tumors have HER-2/neu amplification shows no clinical significance. It is of great interest, however, that the Kaplan-Meier plot of survival for patients whose tumors have amplification of both c-myc and HER-2/neu shows a significant difference (P = 0.047). The median survival times of the doubly amplified patient group and the non-doubly amplified groups were 12 and 43 months, respectively. This is the first study of the oncogene c-myc using FISH. The results suggest that the amplification of c-myc may indicate a poorer patient survival and that the amplification of both c-myc and HER-2/neu in combination may be a better prognostic indicator of poor patient survival.

A single-center population-based consecutive series of 1500 cytogenetically investigated adult hematological malignancies: karyotypic features in relation to morphology, age and gender

During the 18-yr period 1976-93, a population-based series of 1586 adults with suspected or confirmed hematological malignancies were successfully cytogenetically investigated at a single center. Eighty-six cases were excluded due to unretrievable medical records or if analyzed only in remission or at relapse. The remaining 1500 medical records were reviewed regarding morphology and clinical parameters in order to investigate possible associations between karyotypic pattern (normal, 1, 2 or complex anomalies; specific abnormalities) and gender, age and morphological subgroups. The impact of time-period, i.e. 1976-87 vs. 1988-93, and referring center on cytogenetic findings was also studied. A total of 372 acute myeloid leukemias (AML), 389 myelodysplastic syndromes (MDS), 64 acute lymphoblastic leukemias (ALL) and 262 chronic myeloid leukemias (CML) were identified, altogether 1087 cases. Patients with other (n=261) or no hematological malignancies (n = 152) were excluded from the present analysis. Cytogenetic abnormalities were detected in 52% AML, 51 % MDS, 68% ALL and 97% CML, frequencies that did not differ significantly between the 2 time periods or referring centers. No significant age- or gender-related differences in karyotypic patterns were discerned in AML, MDS, ALL or CML, whereas the karyotypic patterns varied among the FAB groups in both AML (p= 0.001) and MDS (p < 0.001). The specific abnormalities t(8;21), t(15;17) and inv(16) were more common (p < 0.001) in younger AML patients and 5q- was more frequent in females with MDS (p<0.001). These findings indicate, in contrast to previous series, that neoplasia-associated karyotypic aberrations are not more common among older patients or in males.

A detailed physical and transcriptional map of the region of chromosome 20 that is deleted in myeloproliferative disorders and refinement of the common deleted region

Acquired deletions of the long arm of chromosome 20 are the most common chromosomal abnormality seen in polycythemia vera and are also associated with other myeloid malignancies. Such deletions are believed to mark the site of one or more tumor suppressor genes, loss of which perturbs normal hematopoiesis. A common deleted region (CDR) has previously been identified on 20q. We have now constructed the most detailed physical map of this region to date--a YAC contig that encompasses the entire CDR and spans 23 cM (11 Mb). This contig contains 140 DNA markers and 65 unique expressed sequences. Our data represent a first step toward a complete transcriptional map of the CDR. The high marker density within the physical map permitted two complementary approaches to reducing the size of the CDR. Microsatellite PCR refined the centromeric boundary of the CDR to D20S465 and was used to search for homozygous deletions in 28 patients using 32 markers. No such deletions were detected. Genetic changes on the remaining chromosome 20 may therefore be too small to be detected or may occur in a subpopulation of cells.