Evolutionary patterns of chromosomal instability and mismatch repair deficiency in proximal and distal colorectal cancer.

AIM: Colorectal carcinomas (CRCs) progress through heterogeneous pathways. The aim of this study was to analyse whether or not the cytogenetic evolution of CRC is linked to tumour site, level of chromosomal imbalance and metastasis. METHOD: A set of therapy-naïve pT3 CRCs comprising 26 proximal and 49 distal pT3 CRCs was studied by combining immunohistochemistry of mismatch repair (MMR) proteins, microsatellite analyses and molecular karyotyping as well as clinical parameters. RESULTS: A MMR deficient/microsatellite-unstable (dMMR/MSI-H) status was associated with location of the primary tumour proximal to the splenic flexure, and dMMR/MSI-H tumours presented with significantly lower levels of chromosomal imbalances compared with MMR proficient/microsatellite-stable (pMMR/MSS) tumours. Oncogenetic tree modelling suggested two evolutionary clusters characterized by dMMR/MSI-H and chromosomal instability (CIN), respectively, for both proximal and distal CRCs. In CIN cases, +13q, -18q and +20q were predicted as preferentially early events, and -1p, -4 -and -5q as late events. Separate oncogenetic tree models of proximal and distal cases indicated similar early events independent of tumour site. However, in cases with high CIN defined by more than 10 copy number aberrations, loss of 17p occurred earlier in cytogenetic evolution than in cases showing low to moderate CIN. Differences in the oncogenetic trees were observed for CRCs with lymph node and distant metastasis. Loss of 8p was modelled as an early event in node-positive CRC, while +7p and +8q comprised early events in CRC with distant metastasis. CONCLUSION: CRCs characterized by CIN follow multiple, interconnected genetic pathways in line with the basic 'Vogelgram' concept proposed for the progression of CRC that places the accumulation of genetic changes at centre of tumour evolution. However, the timing of specific genetic events may favour metastatic potential.

13-year-old tuberous sclerosis patient with renal cell carcinoma associated with multiple renal angiomyolipomas developing multifocal micronodular pneumocyte hyperplasia.

BACKGROUND: The autosomal dominant tumor syndrome tuberous sclerosis complex is caused by the mutated TSC1 gene, hamartin, and the TSC2 gene, tuberin. Patients with this complex develop typical cutaneus symptoms such as peau chagrin or angiofibromas of the skin as well as other lesions such as astrocytomas in the brain and lymphangioleiomyomatosis in the lung. Only a few tuberous sclerosis patients have been described who showed a multifocal micronodular pneumocyte hyperplasia of the lung. Another benign tumor which often occurs together with tuberous sclerosis is the angiomyolipoma of the kidney. Furthermore, an increased incidence of renal cell carcinoma in connection with tuberous sclerosis has also been proven. CASE PRESENTATION: We report a 13-year-old white girl with epilepsy and hypopigmented skin lesions. Radiological studies demonstrated the typical cortical tubers leading to the diagnosis of tuberous sclerosis. In the following examinations a large number of angiomyolipomas were found in both kidneys. One lesion showed an increasing size and tumor like aspects in magnetic resonance imaging. The pathological examination of the following tumorectomy demonstrated an unclassified renal cell carcinoma. Four months postoperatively, a follow-up computer tomography revealed multiple bilateral pulmonary nodules. To exclude lung metastases of the renal cell carcinoma, multiple open-lung biopsies were performed. CONCLUSION: Here we report a diagnostically challenging case of a 13-year-old patient with tuberous sclerosis and angiomyolipomas of the kidney who developed an unclassified renal cell carcinoma as well as multifocal micronodular pneumocyte hyperplasia.

Genomic Complexity as a Biomarker to De-Escalate Adjuvant Imatinib Treatment in High-Risk Gastrointestinal Stromal Tumor.

PURPOSE: Adjuvant imatinib treatment is recommended for patients with localized gastrointestinal stromal tumor (GIST) at high risk of recurrence. Almost half of high-risk patients are cured by surgery alone, indicating a need for improved selection of patients for adjuvant therapy. The aim of this study was to investigate if genomic tumor complexity could be used as a prognostic biomarker. METHODS: The discovery cohort consisted of patients who underwent resection of primary GIST at Oslo University Hospital between 1998 and 2020. Karyotypes were categorized as simple if they had ≤ 5 chromosomal changes and complex if there were > 5 chromosomal aberrations. Validation was performed in an independent patient cohort where chromosomal imbalances were mapped using comparative genomic hybridization. RESULTS: Chromosomal aberrations were detected in 206 tumors, of which 76 had a complex karyotype. The most frequently observed changes were losses at 14q, 22q, 1p, and 15q. The 5-year recurrence-free survival (RFS) in patients classified as very low, low, or intermediate risk was 99%. High-risk patients with a simple tumor karyotype had an estimated 5-year RFS of 94%, and patients with a complex karyotype had an estimated 5-year RFS of 51%. A complex karyotype was associated with poor RFS in patients with and without adjuvant imatinib treatment and in multivariable analysis adjusted for tumor site, size, mitotic count, and rupture. The prognostic impact of genomic complexity was confirmed in the validation cohort. In both cohorts, the 5-year disease-specific survival was > 90% for high-risk patients with genomically simple tumors. CONCLUSION: Genomic tumor complexity is an independent prognostic biomarker in localized, high-risk GIST. Recurrences were infrequent for tumors with simple karyotypes. De-escalation of adjuvant imatinib treatment should be explored in patients with cytogenetically simple GISTs.

Epithelioid/mixed phenotype in gastrointestinal stromal tumors with KIT mutation from the stomach is associated with accelerated passage of late phases of the cell cycle and shorter disease-free survival.

In gastrointestinal stromal tumors (GISTs), the occurrence of an epithelioid/mixed phenotype has been correlated to PDGFRA mutations, gastric localization and favorable outcome. On the other hand, the prognostic significance of an epithelioid/mixed growth pattern occasionally observed in GISTs with KIT mutation is unclear. The aim of this study was to evaluate the prognostic significance of an epithelioid/mixed phenotype in correlation to anatomical localization, genotype, and expression of cell-cycle markers in a series of 116 primary GISTs with KIT mutation on a tissue microarray. Independent of their anatomical localization, the majority of KIT-mutated GISTs displayed a pure spindled phenotype (72%), with the remaining tumors showing an epithelioid/mixed growth pattern. In KIT-mutated GISTs from the stomach, the occurrence of an epithelioid/mixed growth pattern was significantly correlated with larger tumor diameters (P=0.005), higher mitotic counts (P=0.0001), high-risk category (P=0.001), higher expression of the G2-phase cell-cycle marker cyclin B1 (P=0.04), higher expression of the G1 to M-phase proliferation marker Ki67 (P=0.02) and a significantly shorter disease-free survival (P=0.003) compared with tumors with pure spindled morphology. In contrast, there were no significant differences between pure spindled and epithelioid/mixed GISTs from the small/large bowel. Our findings indicate that the epithelioid/mixed phenotype in KIT-mutant gastric GISTs represents a secondary tumor growth pattern associated with tumor progression and adverse outcome, probably through accelerated G1/S-phase restriction point passage.

Localization- and mutation-dependent microRNA (miRNA) expression signatures in gastrointestinal stromal tumours (GISTs), with a cluster of co-expressed miRNAs located at 14q32.31.

The molecular biology and clinical behaviour of gastrointestinal stromal tumours (GISTs) are associated with their anatomical localization (stomach or intestine), and also with the mutation status of the receptor tyrosine kinases KIT and PDGFRA. Twelve GISTs were evaluated for differential miRNA expression signatures by use of microarrays representing 734 human miRNAs. Thirty-two miRNAs were found to be differentially expressed according to localization and mutation status. Differential expression was further analysed and confirmed for four miRNAs (miR-132, miR-221, miR-222, and miR-504) by qRT-PCR in 49 additional GISTs. Differentially expressed miRNAs were functionally mapped to KIT/PDGFRA signalling and G1/S-phase transition of the cell cycle, revealing 22 predicted miRNA/mRNA interactions for ten gene targets from KIT/PDGFRA signalling, and 12 interactions for 12 gene targets of G1/S-phase transition. Moreover, the expression of 44 miRNAs clustered in a genetically imprinted region at 14q32.31 was found to be strongly correlated in the microarray analysis. This was confirmed for two selected miRNAs (miR-134 and miR-370) from the 14q32.31 cluster by qRT-PCR in 49 additional GISTs, and the expression of these two miRNAs was significantly lower in GISTs with 14q loss, and also in GISTs with tumour progress. miRNA profiling may prove to be a key determinant of the biology and clinical features of GISTs.

Expression of p16INK4A in gastrointestinal stromal tumours (GISTs): two different forms exist that independently correlate with poor prognosis.

AIMS: To determine the prognostic impact of p16INK4A expression in gastrointestinal stromal tumours (GISTs), which is currently being questioned, with both loss and overexpression said to be correlated with poor prognosis. METHODS AND RESULTS: Two different forms of p16INK4A were identified, presenting with predominantly nuclear and cytoplasmic expression pattern, respectively. The immunohistochemical expression of the two forms and their correlation with E2F1 and prognosis were analysed in a series of 120 GISTs with clinical follow-up. Low nuclear p16INK4A expression correlated with E2F1 up-regulation, higher mitotic counts, and tumour progression. The prognostic value of nuclear p16INK4A expression was only marginally significant (P=0.05). Strong expression of the cytoplasmic p16INK4A form was significantly associated with shorter disease-free survival (P=2x10(-5)). The prognostic impact of strong expression of the cytoplasmic p16INK4A form was independent of anatomical localization, tumour size and mitotic counts, and significant even among the cohort of tumours with high malignant potential. CONCLUSIONS: Low expression of the nuclear p16INK4A form and strong expression of the cytoplasmic p16INK4A form both represent two independent parameters each associated with tumour progression in GISTs. Low nuclear p16INK4A expression enables E2F1 up-regulation and consecutive accelerated cell proliferation. In contrast, strong cytoplasmic p16INK4A expression probably reflects a negative feedback loop as a result of (as yet unknown) oncogenic events.

Optimal thresholds of risk parameters for gastrointestinal stromal tumors.

BACKGROUND: Gastrointestinal stromal tumors (GIST) are the most frequent mesenchymal neoplasms of the gastrointestinal tract with highly variable potential for relapse. Tumor size and mitotic index (MI) are major risk factors that predict the outcome of GIST patients. Recent risk stratification schemes include some or all of the empirical size thresholds of 2 cm, 5 cm, and 10 cm and MI thresholds of 5 per 50 high-power fields (hpf) and 10 per 50 hpf. However, data that verify these numbers are sparse. METHODS: By exhaustive regression tree analysis, maximally selected rank statistics and survival difference analysis with bootstrap sampling on a naive GIST population of 161 patients with a mean follow-up of 44 months, current stratification schemes using tumor size and MI were analyzed herein. RESULTS: /Conclusions: Thresholds that optimally stratify the risk of recurrence are observed at tumor sizes of 4-5 cm and 10-11 cm and at mitotic indices of about 5 per 50 hpf and 10 per 50 hpf, respectively. While these data validate the canonical thresholds for size and MI used in risk stratification of GIST, transition regions as well as differences in the implementation of these thresholds between the different classification schemes proposed in the recent years should be considered when classifying GIST.

Distinct biphasic histomorphological pattern in gastrointestinal stromal tumours (GISTs) with common primary mutations but divergent molecular cytogenetic progression.

AIMS: The morphological diversity of gastrointestinal stromal tumours (GISTs) is well appreciated. The aim of this study was to shed light on the molecular pathogenesis of GISTs displaying a distinct biphasic histomorphological pattern, which is poorly understood. METHODS AND RESULTS: Six biphasic gastric GISTs (four high, one intermediate and one low risk for aggressive behaviour) were studied by histological, immunohistochemical, molecular and comparative genomic hybridization methods. The different tumour components were designated as primary and secondary compartments, based on cellularity and mitotic index. In addition, metastases from two patients were analysed separately. According to the classification of Miettinen et al., four biphasic histomorphological patterns were seen: (i) sclerosing spindle cell/dyscohesive or paraganglioma-like epithelioid (n = 2); (ii) sarcomatous spindle cell/pleomorphic sarcomatous spindle cell (n = 1); (iii) sarcomatous spindle cell/sarcomatous epithelioid (n = 2); and (iv) sclerosing epithelioid/hypercellular epithelioid/sarcomatous epithelioid (n = 1) morphology. In each case, both tumour compartments revealed the same KIT (n = 5) or platelet-derived growth factor receptor-alpha (n = 1) mutation, as well as common chromosomal imbalances reflecting their common clonal origin. Additional chromosomal imbalances were detected in the secondary tumour compartments and their respective metastases. CONCLUSIONS: Our results indicate that the intratumoral phenotypic diversity in GIST reflects histomorphological progression, which is associated with higher chromosomal instability, irrespective of the primary mutation.

CNS tumor 22 years after spinal neuroblastoma IV: diagnostic dilemma between recurrence and secondary malignancy.

We present the very unusual case of a young woman suffering from a brain tumor 22 years after a stage IV spinal neuroblastoma as an infant, demonstrating the difficulties of differentiating late neuroblastoma relapse from secondary supratentorial primitive neuroectodermal tumor (sPNET). Lacking specific immunohistochemical features, the first cerebral tumor at the age of 21 was regarded as sPNET, and we pursued a therapeutic approach consisting of neurosurgical resection as well as irradiation and high-dose alkylator-based chemotherapy according to the HIT2000 protocol. Two years later the patient suffered from a diffusely infiltrating local recurrence, changing its imaging appearance as well as its immunohistochemical characteristics, now revealing disseminated positivity for neuron-specific enolase and neural cell adhesion molecule. Moreover, the lack of PNET-specific translocations (EWS/FLI1 gene fusion) in both brain tumors as well as the development of hepatic metastases was more compatible with the diagnosis of a very late relapse 22 years after initial stage IV spinal neuroblastoma.

Establishment, characterization and drug sensitivity testing in primary cultures of human thymoma and thymic carcinoma.

Thymomas and thymic carcinomas are peculiar epithelial tumors of the anterior mediastinum. They may show aggressive clinical behavior and are a paradigm for the interaction between the tumor and the immune system. So far, adequate functional studies enabling a better understanding of this malignancy have not been performed, since human thymoma/thymic carcinoma cell lines have not been available. Here, the authors describe the establishment, characterization and functional analyses of epithelial cell lines from a Type B1-thymoma and a poorly differentiated thymic carcinoma. By Fluorescence-activated cell sorting (FACS) analyses, both cell lines were aneuploid. The aneuploid cell fraction of the thymic carcinoma cell line was characterized by a high proliferation index of 55.9%, in contrast to a lower proliferation rate of the aneuploid cell fraction of the thymoma (19.7%). Array-based comparative genomic hybridization (aCGH) and conventional cytogenetic analysis of the thymoma revealed only minor imbalances whereas the thymic carcinoma was characterized by a complex karyotype in the hyperdiploid range that was readily defined with multicolor FISH (mFISH). Application of a selective COX-2 inhibitor reduced cell viability in both cell lines in a dose-dependent manner. In conclusion, these first cell lines of a thymoma and a CD5-positive thymic carcinoma are useful tools for further in vitro studies of cellular, molecular and genetic aspects of the disease and for functional tests to evaluate new therapeutic targets.

Immune cells in primary gastrointestinal stromal tumors.

INTRODUCTION: Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract. They are regarded as having relatively uniform histology, although their potential for malignant behavior varies. Despite a strong promoting role of tumor-infiltrating innate immune cells in neoplastic progression, the presence of immune cells in GISTs has not yet been studied. METHODS: A total of 47 untreated, c-kit-positive primary GISTs were immunohistochemically analyzed to distinguish histiocytic and dendritic cells (DCs) (KIM-1P, fascin, and CD68) from cells of lymphoplasmacellular origin (CD3, CD20, and CD56). Furthermore, the gene expression of proinflammatory cytokines was characterized by real-time, reverse transcription-PCR analysis of total RNA extracted from frozen tissue samples. RESULTS: KIM-1P+ cells were the dominant immune cells (851+/-295 cells/mm2) and were scattered among the tumor cells. Most of the KIM-1P+ cells showed cellular projections characteristic of DCs. Fascin positivity identified a subgroup of DCs. In comparison to KIM-1P+ cells, there were significantly fewer CD68+ macrophages (196+/-217 cells/mm2). CD3+ T cells were the dominant lymphocytes (201+/-331 cells/mm2), whereas B cells (60+/-126 cells/mm2) were few. On transcriptional level, a concomitant gene expression of cytokines for the classical acute phase cytokines TNF-alpha and IL-6 was missing, thus supporting the rather innate status of immune cells. CONCLUSION: GISTs contain, beside T lymphocytes, a high number of monocyte-derived cells, which we suggest are, at least in part, immature DCs. Together with the lack of gene expression of inflammatory cytokines in tumor tissue our results point to a possible 'symbiotic relationship' between the tumor and the local immune cells.

Genetics of carney triad: recurrent losses at chromosome 1 but lack of germline mutations in genes associated with paragangliomas and gastrointestinal stromal tumors.

CONTEXT: Carney triad (CT) describes the association of paragangliomas (PGLs) with gastrointestinal stromal tumors (GISTs) and pulmonary chondromas. Inactivating mutations of the mitochondrial complex II succinate dehydrogenase (SDH) enzyme subunits SDHB, SDHC, and SDHD are found in PGLs, gain-of-function mutations of c-kit (KIT), and platelet-derived growth factor receptor A (PDGFRA) in GISTs. OBJECTIVE: Our objective was to investigate the possibility that patients with CT and/or their tumors may harbor mutations of the SDHB, SDHC, SDHD, KIT, and PDGFRA genes and identify any other genetic alterations in CT tumors. DESIGN: Three males and 34 females with CT were studied retrospectively. We sequenced the stated genes and performed comparative genomic hybridization on a total of 41 tumors. RESULTS: No patient had coding sequence mutations of the investigated genes. Comparative genomic hybridization revealed a number of DNA copy number changes: losses dominated among benign lesions, there were an equal number of gains and losses in malignant lesions, and the average number of alterations in malignant tumors was higher compared with benign lesions. The most frequent and greatest contiguous change was 1q12-q21 deletion, a region that harbors the SDHC gene. Another frequent change was loss of 1p. Allelic losses of 1p and 1q were confirmed by fluorescent in situ hybridization and loss-of-heterozygosity studies. CONCLUSIONS: We conclude that CT is not due to SDH-inactivating or KIT- and PDGFRA-activating mutations. GISTs and PGLs in CT are associated with chromosome 1 and other changes that appear to participate in tumor progression and point to their common genetic cause.

Multicentric sporadic gastrointestinal stromal tumors (GISTs) of the stomach with distinct clonal origin: differential diagnosis to familial and syndromal GIST variants and peritoneal metastasis.

Most sporadic gastrointestinal stromal tumors (GISTs) occur solitary, whereas a multicentric appearance is suspicious for a familial or syndromal setting such as with germline mutations of proto-oncogene tyrosine protein kinase Kit (KIT) or platelet derived growth factor receptor alpha (PDGFRA), or even for metastases. The aim of this study was to evaluate whether multicentric sporadic GISTs are of clonal origin. Four patients with 1 clinically apparent tumor (mean size 5.6 cm) and 1 to 3 further small incidental tumors (mean size 0.7 cm) were analysed by mutation analysis and comparative genomic hybridization for mutations of KIT and PDGFRA and chromosomal imbalances in their tumors. No clinicopathologic features have been found being indicative of one of the established familial or syndromal GIST variants. Each of the small GISTs were localized in the muscularis propria, and were visible from the serosal but not from the mucosal side. Different mutations of KIT and PDGFRA were present among individual tumors of each patient, and germline mutation of KIT and PDGFRA could be excluded. Comparative genomic hybridization revealed a mean count of 7 chromosomal imbalances in the clinically apparent tumors compared with a mean count of 0.3 in the small incidental counterparts. Sporadic GISTs can appear multicentric by coincidence. They are an important differential diagnosis to familial and syndromal GIST variants, or even to peritoneal metastases. Different mutations of KIT and PDGFRA among individual tumors in 1 patient refer to different clonal origin of multicentric sporadic GISTs. The type of mutation of KIT and PDGFRA was independent of tumor size, whereas small GISTs <1 cm rarely had genomic imbalances.

Follicular dendritic cell sarcoma of the spleen.

Diagnosis of primary spindle cell tumors of the spleen is challenging because of the limited immunologic and cytogenetic characterization of this rare entity. We report a case of primary follicular dendritic cell (FDC) sarcoma of the spleen in a 44-year-old woman. Indications for FDC included positive staining for CD21, Ki-M4P, CD14, and fascin. Expression of both standard FDC markers CD23 and CD35 was detected immunohistochemically using tyramide signal amplification. Cytogenetic analysis revealed multiple clonal chromosomal aberrations involving unbalanced translocations of chromosomes X, 3, 5, 7, 8, 9, and 10, leading to net gains at 3q, 7p, 8q, and 9q and net losses at Xp, 8p, 9p, and 10p. Loss at Xp has been described previously in another tumor with FDC features, suggesting that this aberration might play a common role in this malignancy.

Establishment and characterization of two distinct malignant mesothelioma cell lines with common clonal origin.

We describe two newly established malignant mesothelioma (MM) cell lines derived from a pleural effusion of a male. One cell line, designated as MM-Z03E, reveals an epithelioid cobblestone morphology, while the second one, designated as MM-Z03S and subcloned after in vivo selection, exhibits a sarcomatoid storiform growth pattern. Both cell lines showed the immunologic profile characteristic for MM (i.e., expression of cytokeratin, CK18, calretinin, and vimentin in both phenotypes). Cytogenetics, multicolor fluorescence in situ hybridization, comparative genomic hybridization, and oligonucleotide array CGH were performed on both cell lines. Aberrations shared by both cell lines included chromosomal losses of 1q34 approximately qter, 4, 9p, 10p, 13, 14, 16q, 18, and 22, as well as a complex structural aberration involving chromosome 17. Aberrations exclusive to MM-Z03E included gains of 3q11q27 and 5p, while gain of 9q and losses of 3q27qter, 11q, and 18 in MM-Z03S were exclusive to MM-Z03E. Both cell lines were able to develop solid transplant tumors in nude mice within 16 weeks, and immunophenotyping of tumor xenografts revealed an overall retained expression profile of the markers used. Remarkably, one xenograft from MM-Z03E revealed overexpression of p53 and widely invasive growth. In conclusion, both cell lines are useful in vivo and in vitro model systems to study the underlying genetic mechanisms of biphasic differentiation in MM, which can be of certain value considering the increasing relevance of assessing MM tumor biology for the clinical management of this disease.

Correlation of chromosomal imbalances by comparative genomic hybridization and expression of EGFR, PTEN, p53, and MIB-1 in diffuse gliomas.

The histological subclassification of gliomas is increasingly assisted by the underlying molecular genetics which has major importance in guiding clinical management of the disease. However, the assessment of several molecular events for improving clinical care remains a challenge. Herein, we report on comparative genomic hybridization (CGH) and immunohistochemical (IHC) assessment of EGFR, PTEN, p53, and MIB-1 expression in 13 oligodendrogliomas (10 WHO grade II, 3 WHO grade III), one oligoastrocytoma (WHO grade III) and 23 high-grade astrocytomas (3 WHO grade III, 20 glioblastoma multiforme). The most frequent imbalances in oligodendroglial tumors including the oligoastrocytic case were, in decreasing order of frequency, +7q, -1p, and -4q and in astrocytomas +7q, -10q, +7p, -9p, -10p, +20q, and +20p. Some individual imbalances were associated with increasing numbers of chromosomal changes, that were +7q in both oligodendrogliomas and astrocytomas, and -9p, -10q, +20p, and +20q in astrocytomas. The markers p53 and MIB-1 were significantly higher expressed in astrocytomas than in oligodendrogliomas and expression levels of p53 and EGFR were inversely associated within the astrocytic group. In addition, p53 overexpression correlated positively with +7q and negatively with -1p in the oligodendroglial group whereas EGFR overexpression correlated positively with -1p in the oligodendroglial and positively with +7p and -10p in the astrocytic group. Short overall survival was significantly associated with +7p and -10q in astrocytomas. Collectively, these results contribute to the increasing clinical relevance of assessing tumor biological markers in gliomas.

Spontaneous adrenal hemorrhage: a little-known complication of intracranial tumor surgery. Case report.

Nontraumatic adrenal hemorrhage in adults is uncommon and unexpected in the context of intracranial surgery. The authors report on a patient in whom hemodynamically relevant retroperitoneal bleeding developed within hours after an otherwise uneventful operation for a falcine meningioma. In this brief report they seek to draw attention to this rare but life-threatening complication, because rapid diagnosis can be life-saving.

Assessment of molecular events in squamous and non-squamous cell lung carcinoma.

Although considerable knowledge exists on the tumor biology of lung cancer, there is still a need to assess molecular events for the clinical management of the disease. We studied the pattern of chromosomal imbalances in 45 non-small cell lung carcinomas (NSCLC) by comparative genomic hybridization (CGH) and correlated the results with clinicopathological features including immunohistochemical (IHC) expression of the epidermal growth factor receptor (EGFR). Twenty-one tumors were squamous cell carcinomas (SCC) and 24 non-squamous cell lung carcinomas (NSCC) comprising 9 adenocarcinomas (ADC), 9 large cell carcinomas (LCC), 4 sarcomatoid carcinomas and 2 adenosquamous carcinomas. The mean number of individual imbalances was 7.1 for SCC (mean gains, 3.8; mean losses, 3.4) and 6.4 for NSCC (mean gains, 4.5; mean losses, 1.9). Several individual imbalances correlated significantly with increasing number of imbalances, that were +1q, -3p, +3q, -5q, -8p, +8q, +7p, +12p, and +14q. Altogether, the most frequent imbalances were +3q (49%), +5p (49%), -5q (36%), +8q (29%), -8p (24%), -3p (22%), +7p (22%), +12p (22%), +14q (20%), +18p (20%), +1q (18%), and +7q (18%). Among these, +3q and +18p correlated significantly with SCC, and +5p and +14q with NSCC. Remarkably, overlapping imbalances included +3q26, +7p11 in SCC and +1q21, +3q24, +12p11, and +14q12 in NSCC. EGFR expression was higher in SCC than in NSCC and correlated with +3q in the entire series. In addition, +12p correlated significantly with disease progress with the exception of nodal involvement in NSCC as well as with disease progress, regardless of nodal involvement, in the entire series. In conclusion, the present study contributes to the molecular biological characterization of NSCLC histological subtypes and through evaluation of molecular events to the recently emergent focus on novel markers for lung cancer treatment.

Distinct chromosomal profiles in metastasizing and non-metastasizing colorectal carcinomas.

BACKGROUND: The prognosis of colorectal cancer patients is to a considerable extent determined by the metastatic potency of the primary tumor. However, despite the fact that liver metastases are the leading cause of death for cancer patients, the molecular basis still remains poorly understood and independent prognostic markers have not been established. MATERIALS AND METHODS: Comparative genomic hybridization (CGH) was used to screen colorectal carcinomas without distant metastases (n=18) and carcinomas synchronously metastatic to the liver (n=18). We aimed to detect distinct chromosomal aberrations indicating a metastatic phenotype. RESULTS AND DISCUSSION: Metastatic tumors exhibited a significantly (P=0.03) higher ANCA value (13.8) if compared with non-metastatic cancers (10.0). Furthermore, we observed that losses of chromosomal regions 1p32-ter and 9q33-ter were present at much higher frequencies in metastatic than in non-metastatic cancers, respectively (P=0.02 and 0.04). CONCLUSION: These data indicate that metastatic tumors may be separated from non-metastatic colorectal cancers based on their genomic profile.

Effects of chemotherapy on the cytogenetic constitution of Wilms' tumor.

The management of Wilms' tumors consists of a combination of surgery, chemotherapy, and possibly radiotherapy. To date, chemotherapy is being risk stratified according to histologic subtype and stage. Although the cytogenetic characteristics of Wilms' tumors are well established, the cytogenetic effects related to chemotherapy are widely unknown. We herein report on comparative genomic hybridization findings in 41 primary Wilms' tumors of blastemal type, of which 19 had received preoperative chemotherapy (PCT group) and 22 did not (non-PCT group). Overall, imbalances could be detected in 32 tumors, with +1q (17 cases), +7q (10 cases), +7p (6 cases), and -7p (6 cases) as the most common changes. Among these, +7q and -7p were both significantly associated with metastatic disease at the time of surgery (P = 0.002 and 0.007, respectively), and +7q was also associated with higher stage (stages III + IV; P = 0.003). There were significant differences in the cytogenetic constitution of tumors between the two treatment groups. As a trend, tumors in the preoperative-chemotherapy group had fewer changes (mean, 2.7) than those in the non-preoperative-chemotherapy group (mean, 3.8), and the frequencies of imbalances at 7p or +7q, respectively, were significantly lower compared with tumors in the non-preoperative-chemotherapy group (2 of 19 versus 10 of 22, P = 0.019; 1 of 19 versus 9 of 22, P = 0.011). In contrast, -1q was common in both the preop-CT group (10 of 19) and the non-preop-CT group (7 of 22). The results suggest that Wilms' tumor clones with +1q are not obliterated by preoperative chemotherapy, whereas cytogenetically more complex clones with +7q and/or imbalances at 7p seem more responsive and are more likely to be eliminated by chemotherapeutic treatment.