Randomized phase-III study of low-dose cytarabine and etoposide + /- all-trans retinoic acid in older unfit patients with NPM1-mutated acute myeloid leukemia

The aim of this randomized clinical trial was to evaluate the impact of all-trans retinoic acid (ATRA) in combination with non-intensive chemotherapy in older unfit patients (> 60 years) with newly diagnosed NPM1-mutated acute myeloid leukemia. Patients were randomized (1:1) to low-dose chemotherapy with or without open-label ATRA 45 mg/m2, days 8-28; the dose of ATRA was reduced to 45 mg/m2, days 8-10 and 15 mg/m2, days 11-28 after 75 patients due to toxicity. Up to 6 cycles of cytarabine 20 mg/day s.c., bid, days 1-7 and etoposide 100 mg/day, p.o. or i.v., days 1-3 with (ATRA) or without ATRA (CONTROL) were intended. The primary endpoint was overall survival (OS). Between May 2011 and September 2016, 144 patients (median age, 77 years; range, 64-92 years) were randomized (72, CONTROL; 72, ATRA). Baseline characteristics were balanced between the two study arms. The median number of treatment cycles was 2 in ATRA and 2.5 in CONTROL. OS was significantly shorter in the ATRA compared to the CONTROL arm (p = 0.023; median OS: 5 months versus 9.2 months, 2-years OS rate: 7% versus 10%, respectively). Rates of CR/CRi were not different between treatment arms; infections were more common in ATRA beyond treatment cycle one. The addition of ATRA to low-dose cytarabine plus etoposide in an older, unfit patient population was not beneficial, but rather led to an inferior outcome.The clinical trial is registered at clinicaltrialsregister.eu (EudraCT Number: 2010-023409-37, first posted 14/12/2010).

Assessment of imatinib as first-line treatment of chronic myeloid leukemia: 10-year survival results of the randomized CML study IV and impact of non-CML determinants

Chronic myeloid leukemia (CML)-study IV was designed to explore whether treatment with imatinib (IM) at 400 mg/day (n=400) could be optimized by doubling the dose (n=420), adding interferon (IFN) (n=430) or cytarabine (n=158) or using IM after IFN-failure (n=128). From July 2002 to March 2012, 1551 newly diagnosed patients in chronic phase were randomized into a 5-arm study. The study was powered to detect a survival difference of 5% at 5 years. After a median observation time of 9.5 years, 10-year overall survival was 82%, 10-year progression-free survival was 80% and 10-year relative survival was 92%. Survival between IM400 mg and any experimental arm was not different. In a multivariate analysis, risk group, major-route chromosomal aberrations, comorbidities, smoking and treatment center (academic vs other) influenced survival significantly, but not any form of treatment optimization. Patients reaching the molecular response milestones at 3, 6 and 12 months had a significant survival advantage. For responders, monotherapy with IM400 mg provides a close to normal life expectancy independent of the time to response. Survival is more determined by patients' and disease factors than by initial treatment selection. Although improvements are also needed for refractory disease, more life-time can currently be gained by carefully addressing non-CML determinants of survival.

Further delineation of chromosomal consensus regions in primary mediastinal B-cell lymphomas: an analysis of 37 tumor samples using high-resolution genomic profiling (array-CGH)

Primary mediastinal B-cell lymphoma (PMBL) is an aggressive extranodal B-cell non-Hodgkin's lymphoma with specific clinical, histopathological and genomic features. To characterize further the genotype of PMBL, we analyzed 37 tumor samples and PMBL cell lines Med-B1 and Karpas1106P using array-based comparative genomic hybridization (matrix- or array-CGH) to a 2.8k genomic microarray. Due to a higher genomic resolution, we identified altered chromosomal regions in much higher frequencies compared with standard CGH: for example, +9p24 (68%), +2p15 (51%), +7q22 (32%), +9q34 (32%), +11q23 (18%), +12q (30%) and +18q21 (24%). Moreover, previously unknown small interstitial chromosomal low copy number alterations (for example, -6p21, -11q13.3) and a total of 19 DNA amplifications were identified by array-CGH. For 17 chromosomal localizations (10 gains and 7 losses), which were altered in more than 10% of the analyzed cases, we delineated minimal consensus regions based on genomic base pair positions. These regions and selected immunohistochemistries point to candidate genes that are discussed in the context of NF-kappaB transcription activation, human leukocyte antigen class I/II defects, impaired apoptosis and Janus kinase/signal transducer and activator of transcription (JAK/STAT) activation. Our data confirm the genomic uniqueness of this tumor and provide physically mapped genomic regions of interest for focused candidate gene analysis.

Dose-escalated CHOP plus etoposide (Hi-CHOEP) is not superior to base-line CHOEP in young good-prognosis patients with aggressive lymphoma: Results of a randomized DSHNHL trial

7513

Background: The addition of etoposide to CHOP (CHOEP) resulted in improved outcome of young patients with good-prognosis aggressive lymphoma (NHL-B1 trial; Blood 2004, 104:626). In order to improve results further, the maximal dose-escalated version of CHOEP-21 tolerable without stem cell support in a preceding dose-escalation study (Hi-CHOEP: C: 1400 mg/m2, H: 65 mg/m2, O: 2 mg, E: 175 mg/m2 × 3, P: 100 mg × 5) was compared to baseline CHOEP-21 in a randomized trial. Methods: Intention-to-treat-analysis comparing CHOEP-21 (n = 194) with Hi-CHOEP (n = 195) in 389 young (18–60 years) patients with good-prognosis (aaIPI = 0,1) aggressive lymphoma. Results: Despite excellent adherence to the protocol (median relative dose of myelosuppressive drugs CHOEP-21: 98%; Hi-CHOEP: 93%), CR/CRu (78.4% vs. 79.5%; p = 0.783), and progressions (12.4% vs. 9.7%; p = 0.409) were not significantly different. After 37 months median observation, there was no difference in the primary endpoint time to treatment failure (64% vs. 68%; p = 0.639) nor overall survival (83% vs. 86%; p = 0.849). Neither low-risk nor low-intermediate risk patients profited from Hi-CHOEP. In a multivariate analysis, elevated LDH and advanced stage (III&IV) were confirmed as independent risk factors for TTF and survival. Hi-CHOEP was considerably more toxic than CHOEP-21 (grade 3 & 4 leukocytopenia 100% vs. 87.2%, p < 0.001, thrombocytopenia 80.8% vs. 9.6%, p < 0.001; infections 19.7% vs. 5.4%, p ≤ 0.001; therapy associated deaths 2.6% vs. 0%). Conclusions: Due to its equal efficacy and lower toxicity, CHOEP-21 is to be preferred over dose-escalated Hi-CHOEP. Our results indicate that dose escalation (in contrast to dose-densification and/or addition of rituximab) does not hold promise for young good-prognosis patients with aggressive lymphoma. Supported by Deutsche Krebshilfe.

[Table: see text]

DNA microarray analysis in malignant lymphomas

Recently, DNA microarray technology has opened new avenues for the understanding of lymphomas. By hybridization of cDNA to arrays containing >10,000 different DNA fragments, this approach allows the simultaneous evaluation of the mRNA expression of thousands of genes in a single experiment. Using sophisticated bioinformatic tools, the huge amount of raw data can be clustered resulting in (1) tumor subclassification, (2) identification of pathogenetically relevant genes, or (3) biological predictors for the clinical course. This approach already has provided novel insights into different entities of B-cell non-Hodgkin's lymphomas. Genomic DNA chip hybridization (matrix-CGH) is a complementary approach focussing on genomic aberrations. In this review, we discuss the impact of this new technology both with regard to methodological aspects as well as to novel findings influencing our understanding of lymphomas.

Induction by sphingomyelinase of shiga toxin receptor and shiga toxin 2 sensitivity in human microvascular endothelial cells

Shiga toxin-producing enterohemorrhagic Escherichia coli is the major cause of acute renal failure in young children. The interaction of Shiga toxins 1 and 2 (Stx1 and Stx2) with endothelial cells is an important step in the renal coagulation and thrombosis observed in hemolytic uremic syndrome. Previous studies have shown that bacterial lipopolysaccharide and host cytokines slowly sensitize endothelial cells to Shiga toxins. In the present study, bacterial neutral sphingomyelinase (SMase) rapidly (1 h) sensitized human dermal microvascular endothelial cells (HDMEC) to the cytotoxic action of Stx2. Exposure of endothelial cells to neutral SMase (0.067 U/ml) caused a rapid increase of intracellular ceramide that persisted for hours. Closely following the change in ceramide level was an increase in the expression of globotriaosylceramide (Gb3), the receptor for Stx2. A rapid increase was also observed in the mRNA for ceramide:glucosyltransferase (CGT), the first of three glycosyltransferase enzymes of the Gb3 biosynthetic pathway. The product of CGT (glucosylceramide) was also increased. In contrast, mRNA for the third enzyme of the pathway, Gb3 synthase, was constitutively produced and was not influenced by SMase treatment of HDMEC. These results describe a rapid response mechanism by which extracellular neutral SMase derived from either bacteria or eukaryotic cells may signal endothelial cells to become sensitive to Shiga toxins.

[A new dimension of DNA analysis: genomic profiling by matrix CGH]

Analysis of genetic alterations in tumor cells represent a first step to understand the molecular mechanism of cancer etiology and development. Due to the progress in genome research, it is feasible to assess the complexity of genomic changes on a large scale. Protocols for gene expression profiling using cDNA arrays have been developed allowing to test the activity of almost all human genes in tumor cells. Another important approach is matrix-CGH which was recently developed to assess gains and losses on the genomic level with high resolution. This method not only allows to narrow down the position of novel oncogenes or tumor suppressor-genes but also contributes to a refinement of tumor classifications. Since matrix-CGH can be performed under highly standardized conditions in a fully automatized way, it is suited for diagnostics in clinical laboratories.

Molecular-cytogenetic comparison of mucosa-associated marginal zone B-cell lymphoma and large B-cell lymphoma arising in the gastro-intestinal tract

Extranodal B-cell lymphoma of mucosa-associated lymphoid tissue (MALT) type may represent a model of lymphoma progression, because a small cell component frequently occurs in the large cell variants. We studied 52 extranodal B-cell lymphomas: 18 extranodal marginal zone B-cell lymphomas of MALT type (MZBL,MT), 7 MZBL,MT of the gastro-intestinal tract with a diffuse large B-cell component (giMZBLplusLBCL), and 27 diffuse large B-cell lymphomas of the gastro-intestinal tract without small cell component (giLBCL). Analytical techniques were comparative genomic hybridization (CGH) and fluorescence in situ hybridization (FISH). The translocation t(11;18) was found as the sole aberration in two MZBL,MT only. In contrast to this, t(11;18)-negative MZBL,MT were characterized by frequent gains on chromosome 3 and DNA amplifications on 2p13-p15. Furthermore, we found a clonal lymphoma progression from the small to the large cell component with accumulation of gains and losses of chromosomal material in the large cell component in giMZBLplusLBCL. Aberrations overlapping with MZBL,MT and giMZBLplusLBCL included losses on chromosome 13, amplifications of the REL proto-oncogene, or gains on chromosome 12. In addition, the large cell component revealed gains on 8q24, including amplifications of the MYC proto-oncogene, and losses on 2q. The giLBCL had frequent gains on chromosomes 12 and 9, as well as on 11q, and losses on 6q. We conclude that, based on the distinctive and partly overlapping patterns of genetic aberrations, MALT lymphomas can be divided into different genetic subgroups.

Clinical relevance of genomic aberrations in homogeneously treated high-risk stage II/III breast cancer patients

Little is known about the prognostic impact of chromosome aberrations in breast cancer. The aim of our study was to determine whether genomic aberrations of prognostic relevance can be identified in the context of a clinical study using molecular cytogenetics. Paraffin-embedded tumor samples of 44 patients with high-risk stage II/III breast cancer were analyzed by comparative genomic hybridization. All patients received identical therapy including dose-escalated chemotherapy followed by peripheral blood stem cell transplantation. The most frequent chromosomal aberrations were gains on chromosome arms 17q (24 cases), 1q (21 cases), 8q (17 cases), 20q (13 cases), 6p (9 cases) as well as losses on chromosome arms 13q (25 cases), 11q (20 cases), 5q (11 cases), 6q (11 cases), 9p (10 cases), 18q (10 cases), 8p (9 cases) and 16q (9 cases). In univariate analysis, the correlation with the clinical outcome revealed a higher risk for patients with tumors exhibiting 13q losses and a reduced risk for tumors exhibiting 16q losses (p = 0.020), 6q losses (p = 0.041) and estrogen-receptor positivity (0.051). In multivariate analysis using the Cox model, only the loss of 16q exhibited borderline significance (p = 0.065). These data show that comparative genomic hybridization can be performed in the context of a clinical trial. In our subgroup of high-risk breast cancer patients, chromosomal aberrations were valuable prognostic parameters.

Molecular aspects of B-cell lymphomas of the gastrointestinal tract

The B-cell lymphomas of the gastrointestinal (GI) tract have represented a field of extensive research ever since a close association was shown with such chronic inflammatory processes as Helicobacter pylori infection. Evidence suggested that the mucosa-associated lymphoid tissue induced by inflammation and autoimmune processes is the environment that gives rise to the small-cell lymphomas of the GI tract (eg, extranodal marginal zone B-cell lymphoma according to Revised European-American Classification of Lymphoid Neoplasms and the World Health Organization Classification of Neoplastic Diseases of the Hematopoietic and Lymphoid Tissue). The small B-cell lymphoma may then progress to highly malignant variants. The B-cell lymphomas of the GI tract may present a stepwise model for lymphomagenesis and progression. This review covers molecular biology and molecular cytogenetic aspects that lead to new insights into the biology of GI lymphomas and potential prognostic factors.

Microcystic adnexal carcinoma: report of 13 cases and review of the literature

BACKGROUND

Microcystic adnexal carcinoma (MAC) is a rare tumor of the skin. Clinically it often masquerades as a firm, subcutaneous nodule on the head and neck regions. Microscopically it extends far beyond assessed clinical margins spreading locally in the dermal, subcutaneous, and perineural tissue planes. The local recurrence rate by standard excision is about 50%. Recent preliminary reports indicate more favorable cure rates with Mohs micrographic surgery (MMS).

OBJECTIVE

To present our data on 13 cases (12 patients) of MAC treated by MMS. In addition, we reviewed the medical literature to summarize the accumulated experience of MMS treatment in the management of MAC. We also present a case of bilateral MAC of the face and describe a renal transplant recipient on immunosuppressive therapy who developed MAC of the nasal bridge.

METHODS

We reviewed and updated our series of MAC cases treated by MMS over the last 9 years. A total of 13 cases of MAC are reviewed. We also searched the literature for MAC treated by MMS with a follow-up of more than 2-years.

RESULTS

One patient had bilateral MAC of the nose and cheek. Another patient developed a MAC of the nasal bridge 20 years after renal transplantation. In this patient predisposing factors were radiation for teenage acne and immunosuppression therapy. A total of 13 cases of MAC were treated by MMS with no recurrences, with a mean follow-up of 5.0 years (range 1.1-8.0 years).

CONCLUSION

We update the medical literature with 13 MAC cases treated by MMS. To our knowledge there have been 148 cases of MAC reported in the world literature. Including our series, there have been 73 cases of MAC treated with MMS. There were only four treatment failures. Regional and/or distant metastasis from MAC is rare, with only one reported death. Following MMS, the 2-year success rate was 89.7% (35 of 39). The accumulated data continue to confirm that when MAC is discovered early and is readily accessible to excision by MMS and other subspecialty support, a favorable outcome can be expected.

Gain of chromosome arm 9p is characteristic of primary mediastinal B-cell lymphoma (MBL): comprehensive molecular cytogenetic analysis and presentation of a novel MBL cell line

Primary mediastinal B-cell lymphoma (MBL) is an aggressive Non-Hodgkin's Lymphoma, which has been recognized as a distinct disease entity. We performed a comprehensive molecular cytogenetic study analyzing 43 MBLs. By comparative genomic hybridization (CGH), the most common aberrations were gains of chromosome arms 9p and Xq, which were present in 56% and 40% of cases, respectively. Based on the limited resolution of CGH, this technique may underestimate the real incidence of aberrations. Therefore, we also did an interphase cytogenetic study with eight DNA probes mapping to chromosome regions frequently altered in B-cell lymphomas. With this approach, both 9p and Xq gains were found in more than 70% of cases (75% and 87%, respectively). The findings were compared with results obtained in 308 other B-cell lymphomas. Gains in 9p were identified in only six of the 308 cases, and only one of these lymphomas with 9p gains was not primarily extranodal in origin (P < 10-(20) for CGH data and P < 10-(11) for fluorescence in situ hybridization data). We also present a novel MBL cell line, MedB-1, which carries the genetic aberrations characteristic of this entity.

Renal cell carcinoma metastatic to the scalp: case report and review of the literature

BACKGROUND

Renal cell carcinoma metastatic to the skin is rare.

OBJECTIVE

To illustrate by a case report the clinical presentation and management of the disease.

METHODS

We present a case of renal carcinoma metastatic to the skin of the scalp that occurred 6 years after removal of her kidney. The tumor was diagnosed using frozen tissue and paraffin sections.

RESULTS

Cutaneous metastasis treated by excision.

CONCLUSION

Renal cell carcinoma may metastasize to the skin of the scalp. Our case illustrated an interesting ipsilateral metastasis that occurred 6 years after treatment of her primary tumor. Physicians, dermatologists, pathologists, and Mohs surgeons should be aware of this entity.

Merkel cell carcinoma of the skin and mucosa: report of 12 cutaneous cases with 2 cases arising from the nasal mucosa

BACKGROUND

Merkel cell carcinoma (MCC) is an uncommon skin tumor that most frequently arises on sun-exposed facial sites. It rarely occurs on mucous membranes of the head region. The primary MCC is usually treated by wide excision followed by radiation to the primary site and regional lymph nodes. Using traditional surgery the local recurrence rate ranges from 20 to 50%. In our clinic, Mohs surgery is used to excise the primary MCC completely, followed by radiation. Here we present our treatment experiences and outcomes.

OBJECTIVE

To document our experience of MCC treated by Mohs surgery. We present our series of 12 cases of MCC, 2 cases of which arose from mucosal sites of the nasal cavity.

METHODS

We reviewed 12 cases of MCC from the Mohs clinic database. We also reviewed the literature for cutaneous and mucosal MCC.

RESULTS

There were 12 cases of MCC: 10 cutaneous and 2 mucous. The site distribution of cutaneous MCC was eight on the head, one on the neck, and one on the groin. Of these, nine were treated by Mohs excision. Two patients developed local recurrence following Mohs treatment. The local recurrence rate was 22% (2 of 9). The sites of mucosal MCC were the nasal septum and nasopharynx. One case had a history of previous radiation and developed an MCC 40 years later. This case also demonstrated epidermotropic spread of Merkel cells to the overlying mucous epithelium. This patient required extensive intranasal and cranial surgery to remove the tumor. Both patients with mucosal MCCs died of their disease. The overall mucocutaneous survival of MCC at 1 year was 80% and at 2 years was 50%.

CONCLUSION

In our series, local control of the primary MCC was achieved in 70% of patients (7 of 10) using combined Mohs excision and radiation. Two recurrences had primary tumors larger than 3.5 cm in diameter, while the other case was nonresectable by Mohs surgery. Tumor size appeared to determine the degree of local control. When the postoperative Mohs defect was less than 3.0 cm in diameter, local and regional control appeared to be more favorable. When the primary facial MCC is relatively small, removal by Mohs surgery followed by radiation was effective, therapeutic, and less disfiguring. Mucosal MCC is rare and may occur as a long-term sequelae after radiation therapy to the skin.

Detection of secondary genetic aberrations in follicle center cell derived lymphomas: assessment of the reliability of comparative genomic hybridization and standard chromosome analysis

Secondary chromosomal aberrations in follicle center cell derived lymphomas (FCDL) usually involve gains and losses of genetic material and may be an important prognostic value. In the present study, we aimed to determine the power of comparative genomic hybridization (CGH) as compared to standard chromosome analysis (CA) to detect such secondary aberrations. The same lymph node cell suspensions prepared from 30 patients with FCDL were analyzed in parallel by CGH and CA based on R banding. In all, 73 discrepancies were found. Sixty-two imbalances were detected only by CA and 11 only by CGH. In cases with completely resolved karyotypes (n= 17), the median number of discrepancies between CGH and CA was one. However, when the karyotype was partially resolved (n = 12), the median was four (P < 0.01). Discrepant results were further studied by fluorescence in situ hybridization using locus-specific probes. These data confirm, that not only for the detection of balanced aberrations, but also for the detection of unbalanced aberrations in FCDL, standard chromosome analysis is still the 'gold standard'. In contrast, CGH is useful to detect chromosomal imbalances when no metaphases are found or no fresh material is available.

Comparative genomic hybridization for the analysis of leukemias and lymphomas

Cytogenetic methods have become increasingly important tools for both research in hematological malignancies and for the diagnostic workup of leukemias and lymphomas. The knowledge about specific chromosomal aberrations has been an essential prerequisite for the identification of pathogenetically relevant genes. Important examples are molecular genetic analyses of the breakpoint regions in chromosomal translocations, which resulted in the detection of protooncogenes such as ABL in chronic myeloid leukemia (CML) and acute lymphoblastic leukemia (ALL) [t(9,22)(q34;q11)], or MYC in Burkitt's lymphoma [t(8;14)(q24;q32); for a review see refs. 1 and 2].

Genomic aberrations and survival in chronic lymphocytic leukemia

BACKGROUND

Fluorescence in situ hybridization has improved the detection of genomic aberrations in chronic lymphocytic leukemia. We used this method to identify chromosomal abnormalities in patients with chronic lymphocytic leukemia and assessed their prognostic implications.

METHODS

Mononuclear cells from the blood of 325 patients with chronic lymphocytic leukemia were analyzed by fluorescence in situ hybridization for deletions in chromosome bands 6q21, 11q22-23, 13q14, and 17p13; trisomy of bands 3q26, 8q24, and 12q13; and translocations involving band 14q32. Molecular cytogenetic data were correlated with clinical findings.

RESULTS

Chromosomal aberrations were detected in 268 of 325 cases (82 percent). The most frequent changes were a deletion in 13q (55 percent), a deletion in 11q (18 percent), trisomy of 12q (16 percent), a deletion in 17p (7 percent), and a deletion in 6q (7 percent). Five categories were defined with a statistical model: 17p deletion, 11q deletion, 12q trisomy, normal karyotype, and 13q deletion as the sole abnormality; the median survival times for patients in these groups were 32, 79, 114, 111, and 133 months, respectively. Patients in the 17p- and 11q-deletion groups had more advanced disease than those in the other three groups. Patients with 17p deletions had the shortest median treatment-free interval (9 months), and those with 13q deletions had the longest (92 months). In multivariate analysis, the presence or absence of a 17p deletion, the presence or absence of an 11q deletion, age, Binet stage, the serum lactate dehydrogenase level, and the white-cell count gave significant prognostic information.

CONCLUSIONS

Genomic aberrations in chronic lymphocytic leukemia are important independent predictors of disease progression and survival. These findings have implications for the design of risk-adapted treatment strategies.

Comparative genomic hybridization: uses and limitations

Comparative genomic hybridization (CGH) has contributed significantly to the current knowledge of genomic alterations in hematologic malignancies. Characteristic patterns of genomic imbalances not only have confirmed recent classification schemes in non-Hodgkin's lymphoma, but they provide a basis for the successful identification of genes with previously unrecognized pathogenic roles in the development of different lymphomas. Based on its technical limitations, there is little reason to apply CGH to chromosomes of metaphase cells in routine diagnostic settings. However, the new approach of CGH to DNA microarrays, a procedure termed matrix-CGH, overcomes most of the limitations and opens new approaches for diagnostics and identification of genetically defined leukemia and lymphoma subgroups. Current efforts to develop leukemia specific matrix-CGH DNA chips, which are designed to meet the clinical needs, are presented and discussed.

Portosystemic shunting and persistent fetal vascular structures in aryl hydrocarbon receptor-deficient mice

A physiological examination of mice harboring a null allele at the aryl hydrocarbon (Ah) locus revealed that the encoded aryl hydrocarbon receptor plays a role in the resolution of fetal vascular structures during development. Although the aryl hydrocarbon receptor is more commonly studied for its role in regulating xenobiotic metabolism and dioxin toxicity, a developmental role of this protein is supported by the observation that Ah null mice display smaller livers, reduced fecundity, and decreased body weights. Upon investigating the liver phenotype, we found that the decrease in liver size is directly related to a reduction in hepatocyte size. We also found that smaller hepatocyte size is the result of massive portosystemic shunting in null animals. Colloidal carbon uptake and microsphere perfusion studies indicated that 56% of portal blood flow bypasses the liver sinusoids. Latex corrosion casts and angiography demonstrated that shunting is consistent with the existence of a patent ductus venosus in adult animals. Importantly, fetal vascular structures were also observed at other sites. Intravital microscopy demonstrated an immature sinusoidal architecture in the liver and persistent hyaloid arteries in the eyes of adult Ah null mice, whereas corrosion casting experiments described aberrations in kidney vascular patterns.

BCL10 is not the gene inactivated by mutation in the 1p22 deletion region in mantle cell lymphoma

The BCL10 gene has recently been cloned from the 1p22 breakpoint of the translocation t(1 ;14)(p22;q32) observed in mucosa-associated lymphoid tissue (MALT) lymphoma. BCL10 was shown to be a proapoptotic-signaling gene encoding a protein that contains an amino-terminal caspase recruitment domain (CARD). Mutations within the BCL10 coding region resulting in truncated BCL10 proteins with loss of their proapoptotic function and preservation of their NF-kappaB activating function were detected in MALT lymphoma. Based on these findings it was proposed that BCL10 might have tumor suppressor function. Deletions involving 1p22 are commonly observed in mantle cell lymphoma (MCL). To investigate its role in MCL we have analyzed a series of 15 MCL for deletion and mutation of BCL10. Monoallelic 1p22 deletions were detected by fluorescence in situ hybridization in five of the 15 cases and were shown to affect BCL10 in all cases. BCL10 was screened for mutations by DNA sequencing of RT-PCR amplified transcripts. In none of the 15 MCL cases studied were mutations found in the BCL10 coding region. A previously reported polymorphism exhibiting a silent 24C > G substitution was found in eight MCL cases and in four healthy probands. A missense mutation 13G >T resulting in a substitution of a serine by an alanine was seen in one of the controls. Our results strongly suggest that BCL10 is not the candidate tumor suppressor gene inactivated by deletion or mutation in band 1p22 in MCL.

Risk of false positive results in comparative genomic hybridization

Comparative genomic hybridization, a widely used method for screening for genomic imbalances, suffers from a lack of standardized evaluation. In order to compare a recently proposed data-driven procedure with the commonly used fixed cutoff values, we tested 257 events by both procedures as well as by fluorescence in situ hybridization using selected probes. With the data-driven procedure, a much higher fraction (42/218 vs. 8/218) of false positive results was obtained, whereas a higher sensitivity with respect to the detection of imbalances (30/39 vs. 19/39) was reached. Based on the significantly higher positive likelihood ratios and the positive predictive value, we strongly recommend the use of fixed diagnostic thresholds, because the alternative procedure generates an unacceptably high portion of incorrectly scored chromosomal imbalances. Genes Chromosomes Cancer 28:353-357, 2000.

The ATM gene in the pathogenesis of mantle-cell lymphoma

BACKGROUND

Mantle-cell lymphoma (MCL) is genetically characterized by the translocation t(11;14)(q13;q32) leading to an overexpression of cyclin-D1, but additional chromosomal abnormalities appear to be required for MCL pathogenesis.

PATIENTS AND METHODS

Deletions involving chromosome 11q, which were recently found as recurrent aberrations in MCL, were analyzed at the molecular level in a series of 81 MCL by fluorescence in situ hybridization (FISH) with probes from a contiguous set of yeast artificial chromosomes (YACs) spanning bands 11q14-q24.

RESULTS AND CONCLUSIONS

Loss of chromosome 11 material was observed in 37 of the 81 MCL cases (46%). The consensus deletion comprised YAC 801e11 containing the ATM gene. The minimal region of loss was further narrowed with P1-derived artificial chromosome (PAC) probes. This allowed the identification of a deletion confined to the genomic region of ATM, which, together with intragenic mutations found in the coding sequence, suggests a role of ATM as a tumor suppressor gene in MCL.

Primary gastric apoptosis-rich T-cell lymphoma co-expressing CD4, CD8, and cytotoxic molecules

In contrast to primary gastric lymphomas of B-cell type, little is known about primary gastric T-cell lymphomas. We describe three cases with remarkably similar features: diffuse growth, epitheliotropism, medium too large cell size, high apoptotic rates, and a CD3+, CD4+, CD8+, CD45RO+ immunophenotype. Clonal TCRgamma gene rearrangement was shown in two cases. Epstein-Barr virus infection was excluded in two cases. Taking advantage of fresh-frozen material, we analyzed two cases further, revealing CD5-, CD16+, CD56-, CD57-, CD25+, CD30+, CD103 (alphaEbeta7)+, bcl-2 protein+, CD95+, CD95 ligand(L)-. CD95L, however, was detected in histiocytic and fibroblastoid by stander cells. The lymphomas expressed granzyme B, perforin, and the TIA-1 antigen in various combinations. All three cases had a very unfavorable clinical course characterized by local recurrence and/or dissemination to other epithelial sites, leading to death within 6-12 months after the initial diagnosis despite surgery and aggressive antineoplastic treatment. These data suggest a novel variant of peripheral T-cell lymphoma operationally characterized as primary gastric, apoptosis-rich, CD103+, EBV-, T-cell lymphoma co-expressing CD4, CD8, CD16 and cytotoxic molecules.

t(11;14)-positive mantle cell lymphomas exhibit complex karyotypes and share similarities with B-cell chronic lymphocytic leukemia

Until now, few data on additional chromosomal aberrations in t(11;14)-positive mantle cell lymphomas (MCLs) have been published. We analyzed 39 t(11;14)-positive MCLs by either comparative genomic hybridization (CGH; n = 8), fluorescence in situ hybridization (FISH) with a set of DNA probes detecting the most frequent aberrations in B-cell neoplasms (n = 12), or both techniques (n = 19). The t(11;14) was present in all cases. In 37 of 39 cases, chromosomal imbalances were found. In 27 cases, complex karyotypes, i.e., >/= 3 aberrations, were identified. The most frequent aberrations were losses of 13q14-21 or 13q32-34 (27 cases), 9p21 (16 cases), and 11q22-23 (12 cases) and gains of 3q26-29 (19 cases), 8q22-24 (11 cases), and 18q21-22 (9 cases). In 26% of cases (7 of 27) analyzed by CGH, a total of 10 high-level DNA amplifications were identified. Although in comparison with B-cell chronic lymphopcytic leukemia (B-CLL) MCL is characterized by a much higher complexity of chromosomal aberrations, there are striking similarities: 13q14 deletions were identified in more than 50% of both MCL and B-CLL cases. In contrast, in our CGH database containing 293 B-cell lymphomas, this aberration was found in only 11% of other nodal lymphomas. Even more strikingly, 11q deletions, which are present in 20%-30 % of MCL and B-CLL, were found very rarely in other nodal B-cell lymphomas (CGH: 1 of 208 cases; FISH: 1 of 69 cases). These data show that MCL is characterized by specific secondary aberrations and that there may be similarities in the pathogenesis of MCL and B-CLL. Genes Chromosomes Cancer 27:285-294, 2000.

Molecular analysis of the CDR3 encoding region of the immunoglobulin heavy chain locus in cerebrospinal fluid cells as a diagnostic tool in lymphomatous meningitis

The diagnosis of leptomeningeal B-cell lymphoma is based on the identification of malignant B cells in the cerebrospinal fluid (CSF). Frequently, cytology does not allow clear distinction between neoplastic lymphoid cells and reactively transformed mononuclear cells. Individual B-cell clones can be identified on the basis of DNA sequences that encode the highly diverse complementarity-determining region (CDR3) of the immunoglobulin heavy chain locus (IgH). We studied CSF samples from 5 patients with B-cell malignancies and cytological evidence of leptomeningeal involvement, using polymerase chain reaction (PCR)-based high-resolution capillary electrophoresis and automated fluorescence analysis to detect PCR fragments. As controls, we assessed CSF specimens from 7 patients with inflammatory neurological diseases and three samples without pathological findings. In all patients with B-cell malignancies, a single PCR product was generated, indicating that CDR3-specific fragments were derived from monoclonal cell populations. CSF samples from patients with inflammatory diseases yielded multiple CDR3 amplicons, suggesting the presence of a polyclonal B-cell activation. No PCR product could be amplified in normal CSF samples. Automated fluorescence detection of CDR3 fragments is a highly sensitive and rapid method to distinguish neoplastic monoclonal and reactive polyclonal B-cell populations in the CSF.

Genomic imbalances including amplification of the tyrosine kinase gene JAK2 in CD30+ Hodgkin cells

Comparative genomic hybridization was applied for a comprehensive screening of frequently occurring net gains and losses of chromosomal subregions in small populations of CD30+ Hodgkin cells and their morphological variants. In 12 Hodgkin's lymphomas, recurrent gains were detected on chromosomal arms 2p, 9p, and 12q (in six, four, and five tumors, respectively) and distinct high-level amplifications were identified on chromosomal bands 4p16, 4q23-q24, and 9p23-p24. In Hodgkin cells with 9p23-p24 amplification, fluorescence in situ hybridization revealed an increased copy number of chromosomal sequences spanning the tyrosine kinase gene JAK2. Several of the imbalances described, in particular a gain in chromosomal arm 9p that includes JAK2 amplification, are similar to the genomic changes detected in primary mediastinal B-cell lymphoma.

Chromosomal aberrations in lymphomas of the gastrointestinal tract

B-cell lymphomas of the gastrointestinal (GI) tract have represented a field of extensive research ever since a close association was shown with chronic inflammatory processes such as Helicobacter pylori infection. Much evidence has accumulated to suggest that the mucosa-associated lymphoid tissue (MALT) induced by inflammation and autoimmune processes is the environment which gives rise to the small cell lymphomas of the GI tract (e.g. extranodal marginal B-cell lymphoma according to REAL). The small B-cell lymphoma may then progress to the large cell variants. Hence, B-cell lymphomas of the GI tract may present a model for lymphomagenesis and progression. In this review, recent cytogenetic data are discussed which yield new insights into the biology of gastrointestinal lymphomas.

Molecular characterization of 11q deletions points to a pathogenic role of the ATM gene in mantle cell lymphoma

Deletions involving the long arm of chromosome 11 (11q) have been recently found as recurrent chromosome aberrations in mantle cell lymphoma (MCL). In the current study, the incidence and molecular extent of 11q deletions were analyzed in a series of 81 MCL by fluorescence in situ hybridization with probes from a contiguous set of yeast artificial chromosomes (YACs). Loss of chromosome 11 material was observed in 37 of 81 cases (46%). The minimally deleted segment comprised YAC 801e11 containing the ATM gene. To further narrow the minimal region of loss, P1-derived artificial chromosomes mapping to the critical region were isolated and used as probes in cases without aberrations detectable with YACs. This allowed the identification of an ATM deletion that was beyond the resolution of YAC probes. The identification of a minimally deleted segment affecting ATM suggests a pathogenic role of ATM as a tumor suppressor gene in MCL.

Incidence and clinical significance of 6q deletions in B cell chronic lymphocytic leukemia

Deletions affecting the long arm of chromosome 6 (6q) are among the most commonly observed chromosomal aberrations in lymphoid malignancies and have been identified as adverse prognostic factor in subsets of tumors. Whereas at least two regions of minimal deletion have been established, one in 6q21-q23 and another in 6q25-q27, no tumor suppressor gene that might be involved in the pathogenesis of lymphoid malignancies has been so far identified from these segments. For B cell chronic lymphocytic leukemia (B-CLL) conflicting data have been reported regarding the incidence and prognostic significance of 6q deletions. In the current study we have used two YAC clones mapping to deletion regions in bands 6q21 and 6q27 as probes for fluorescence in situ hybridization (FISH) in a large series of B-CLL cases to analyze the incidence, localization and clinical significance of 6q aberrations. Among 285 patients with B-CLL studied we identified 21 cases (7%) with 6q deletions. All deletions were found with the probe mapping to 6q21 while the 6q27 region was deleted only in a third of these cases. Analysis of the clinical characteristics and laboratory parameters showed that the patients with 6q deletions had higher white blood cell counts and more extensive lymphadenopathy. However, the overall survival and the treatment-free intervals were similar in the two groups. We conclude that deletions in 6q21 occur in 7% of B-CLL and identify a subgroup of patients characterized by a larger tumor mass but no inferior outcome.

Deletions below 10 megabasepairs are detected in comparative genomic hybridization by standard reference intervals

Comparative genomic hybridization (CGH) is a widely used technique for studying chromosomal imbalances. The sensitivity of the technique is, however, relatively low. Deletions down to a size of 10-12 Mbp have been detected by the use of fixed diagnostic thresholds. In this study, we applied standard reference intervals as detection criteria on a number of deletions in the range of 3 Mbp to 14-18 Mbp. All deletions were detected. Thus, detection by standard reference intervals confers a considerably higher sensitivity to CGH analysis compared to fixed diagnostic thresholds. Genes Chromosomes Cancer 25:410-413, 1999.

Induction of neutrophil calcium mobilization by phosphatidic acid-enriched plasma membranes

The purpose of this investigation was to determine if phosphatidic acid (PA) confined to biological membranes could induce physiological responses similar to those induced by exogenous PA. Plasma membranes were treated with phospholipase D (PLD) to increase concentrations of PA within the membranes. Membranes were also treated with other phospholipases including phospholipase A2 (PLA2), and phospholipase C (PLC), which degrade phospholipids without generating PA. A phosphatidylinositol (PI) 3'-kinase inhibitor, LY294002, strongly and selectively inhibited intracellular calcium mobilization induced by PLD-treated membranes. This study suggests that PA-enriched plasma membranes, which exert their effects by activating a unique signaling pathway mediated by PI 3'-kinase, are potent, physiologically relevant initiators of neutrophil activation.

Subtotal maxillectomy for melanotic neuroectodermal tumor of infancy

Melanotic neuroectodermal tumor of infancy is a rare pigmented neoplasm occurring in infants before 1 year of age. It is a rapidly growing tumor that most frequently affects the craniofacial skeleton. Although melanotic neuroectodermal tumor of infancy is benign in the vast majority of cases, inadequate excision, occasional multicentricity, and a small malignant potential result in a fairly high recurrence rate. On the basis of data obtained from the literature and our clinical experience, we advocate an aggressive surgical approach consisting of complete surgical excision when vital structures are not involved. Histopathologic confirmation of complete excision is mandatory to minimize the risk of recurrence and provide the patient with curative treatment and minimal morbidity.