PTEN loss is associated with follicular variant of Middle Eastern papillary thyroid carcinoma.

BACKGROUND: PTEN gene at chromosomes 10q23.3 is a tumour suppressor gene that is inactivated in many types of human cancers. The known mechanisms of PTEN inactivation are rendered to mutation, epigenetic silencing by aberrant methylation or gene deletion. Although PTEN role has been documented in many cancers, PTEN alteration in papillary thyroid carcinoma (PTC) has not been fully elucidated. The aim of this study is to comprehensively investigate PTEN alterations in a large cohort of Middle Eastern papillary thyroid cancer by immunohistochemistry and fluorescent in situ hybridisation (FISH). METHODS: PTEN protein expression was analysed by immunohistochemistry in a tissue microarray (TMA) format in a large cohort of more than 1000 patients with papillary thyroid cancer. Copy number changes in PTEN were analysed by FISH and data were correlated with clinicopathological parameters along with survival analysis. RESULTS: PTEN inactivation reflected by complete absence of staining was seen in 24.5% of PTC samples, whereas PTEN deletion was seen only in 4.8% of the tested samples by FISH. No association was seen between PTEN loss of protein expression and PTEN gene deletion. However, interestingly, PTEN loss of expression was significantly associated with the follicular variant subset of papillary thyroid cancer. CONCLUSION: Our study confirmed that PTEN might have a role in pathogenesis in a subset of PTC. PTEN loss of protein expression is a more common event in follicular variant of papillary thyroid cancer. Lack of association between PTEN loss of protein expression and PTEN gene deletion might indicate that gene deletion may not be the sole cause for PTEN loss of expression and these results might raise the possibility of other mechanism such as promoter methylation-mediated gene silencing to be responsible for PTEN inactivation.

ALK gene amplification is associated with poor prognosis in colorectal carcinoma.

BACKGROUND: Recently, the anaplastic lymphoma kinase (ALK) has been found to be altered in several solid and haematological tumours. ALK gene copy number changes and mutations in colorectal cancers (CRCs) are not well characterised. We aimed to study the prevalence of ALK copy number changes, translocations, gene mutations and protein expression in 770 CRC patients, and correlate these findings with molecular and clinico-pathological data. METHODS: ALK gene copy number variations and ALK expression were evaluated by fluorescence in situ hybridisation (FISH) and immunohistochemistry, respectively. RESULTS: Translocations of the ALK gene were not observed; 3.4% (26 out of 756) of the CRC patients tested had an increase in ALK gene copy number either amplification or gain. Interestingly, increased ALK gene copy number alteration was associated with poor prognosis (P=0.0135) and was an independent prognostic marker in multivariate Cox proportional hazards model. The study reveals a significant impact of ALK gene copy number alterations on the outcome of patients with CRC. CONCLUSION: The findings of our study highlight a potential role of targeting ALK in advanced CRCs by using ALK FISH and ALK IHC as a screening tool to detect ALK alterations. Based on these findings, a potential role of ALK inhibitor as a therapeutic agent in a subset of CRC merits further investigation.

Extraskeletal Ewing's sarcoma family of tumours in adults: analysis of 57 patients from a single institution.

AIMS: Extraskeletal Ewing's sarcoma (EES) is a rare form of soft tissue sarcoma. The aim of the present study was to assess the outcome and the prognosis of adult patients presenting with EES treated with multi-modality therapy. MATERIALS AND METHODS: All EES patients older than 15 years referred to our institution between January 1995 and December 2004 were reviewed. In total, 57 patients were identified. Their median age at diagnosis was 20 years (range 15-57). RESULTS: The median size of the primary tumour was 11 cm (range 4-30 cm). Eighteen patients (31%) had metastatic disease at initial presentation. Wide surgical resection with negative margins was achieved in 23 cases (40%). Chemotherapy consisting of vincristine, adriamycin, ifosfamide, actinomycin D was given in 50 patients (88%). Radiotherapy was delivered in 37 patients (65%). Forty-one patients (72%) achieved complete remission and 16 (28%) progressed on therapy. Twenty-one patients (51%) relapsed. Local recurrence was encountered in 15 patients (36%). At a median follow-up of 46 months (range 6-143 months), the 5-year event-free survival and overall survival rates were 35 and 47%, respectively. Metastases at presentation, tumour size and surgical resection margin associated significantly with overall survival and event-free survival. CONCLUSION: EES is an aggressive type of tumour with a high incidence of local recurrence and distant metastasis. This series showed that the outcome of adult EES is not unlike that of skeletal Ewing's sarcoma in terms of response to multi-modality treatment and the prognostic factors influencing treatment outcome. Adequate surgical resection, aggressive chemotherapy and adjuvant local radiation therapy, when indicated, constitute the optimal treatment to achieve the best results in this rare type of disease.

Novel and recurrent mutations in the AIRE gene of autoimmune polyendocrinopathy syndrome type 1 (APS1) patients.

Autoimmune polyendocrinopathy syndrome type 1 (APS1) is characterized by the presence of at least two out of three clinical features, which include Addison's disease, hypoparathyroidism, and chronic mucocutaneous candidiasis. This disorder is caused by mutations in the AIRE (autoimmune regulator) gene. While several AIRE mutations have been described in APS1 patients of various ethnic origins, the genetic cause of APS1 in Arab patients requires further investigation. This study describes seven Arab families, in which 18 patients had APS1. In addition to the cardinal features of APS1, some patients exhibited alopecia, diabetes mellitus, nephrocalcinosis and other phenotypes associated with APS1. DNA sequencing of the AIRE gene of patients from this study identified four novel and one recurrent mutation. These mutations likely result in loss of AIRE function in the patients. In addition, it was noted that the non-pathogenic c.834C> G mutation (rs1800520, encoding for p.Ser278Arg) occurs with high incidence in the AIRE gene of Arab individuals. Furthermore, this investigation demonstrates inflammation of the hair follicles in APS1 patients with alopecia universalis. We conclude that Arab APS1 patients carry novel and recurrent mutations in the AIRE gene.

RAD52 polymorphisms contribute to the development of papillary thyroid cancer susceptibility in Middle Eastern population.

Genetic polymorphisms of DNA repair genes seem to determine the DNA repair capacity. We hypothesized that polymorphisms of genes responsible for DNA repair may be associated with risk of thyroid cancer. To evaluate the role of genetic polymorphisms of DNA repair genes in thyroid cancer, we conducted a hospital-based case-control study in Saudi population. Two hundred and twenty-three incident papillary thyroid cancer cases and 229 controls recruited from Saudi Arabian population were analyzed for 21 loci in 8 selected DNA repair genes by PCR-restriction fragment length polymorphism including non-homologous end joining pathway genes LIGIV (LIGlV ASP62HIS, PRO231SER, TRP46TER), XRCC4 Splice 33243301G>A and XRCC7 ILE3434THR; homologous recombination pathway genes XRCC3 ARG94HIS and THR241MET, RAD51 UTR 15452658T>C, 15455419A>G, RAD52 2259 and GLN221GLU, conserved DNA damage response gene Tp53 PRO47SER, PRO72ARG, Tp53 UTR 7178189A>C and base excision repair gene XRCC1 ARG194TRP, ARG280HIS, ARG399GLN, ARG559GLN. RAD52 GLN221GLU genotypes CG and variants carrying G allele showed statistical significance and very high risk of developing thyroid cancer compared to wild type [CG vs CC; p<0.001, odds ratio (OR)=15.57, 95% confidence interval (CI)=6.56-36.98, CG+GG vs CC; p<0.001, OR=17.58, 95% CI=7.44-41.58]. Similarly, RAD52 2259 genotypes CT and variant allele T showed a significant difference in terms of risk estimation (CT vs CC; p<0.05, OR=1.53, 95% CI=1.03-2.28, CT+TT vs CC; p<0.001, OR=1.922, 95% CI=1.31-2.82). Remaining loci demonstrated no significance with risk. Of the 21 loci screened, RAD52 2259 and RAD52 GLN221GLU may be of importance to disease process and may be associated with papillary thyroid cancer risk in Saudi Arabian population.

S-phase kinase protein 2 is an attractive therapeutic target in a subset of diffuse large B-cell lymphoma.

S-phase kinase protein 2 (SKP2), an F-box protein, targets cell-cycle regulators including cycle-dependent kinase inhibitor p27KiP1 via ubiquitin-mediated degradation. SKP2 is frequently overexpressed in a variety of cancer cells and has been implicated in oncogenesis; however, its role in diffuse large B-cell lymphoma (DLBCL) has not been elucidated. Therefore, we investigated the role of SKP2 and its ubiquitin-proteasome pathway in a large series (301) of DLBCL patient samples and a panel of DLBCL cell lines. Using immunohistochemistry, SKP2 was detected in 41.6% of DLBCL tumours and was inversely associated with p27Kip1 protein level. The DLBCL subset with high SKP2 and low p27Kip1 showed a strong correlation with the proliferating index marker Ki-67 (p < 0.0001) and also with the germinal centre phenotype (p = 0.0147). Treatment of DLBCL cell lines with bortezomib or expression of SKP2-specific siRNA causes down-regulation of SKP2 and accumulation of p27Kip1, leading to suppression of growth by inducing apoptosis. Furthermore, treatment of DLBCL cells with bortezomib causes apoptosis via involving the mitochondrial pathway and activation of caspases. Finally, treatment of DLBCL cells with bortezomib down-regulated the expression of XIAP, cIAP1, and survivin. Altogether, these results suggest that SKP2 and the ubiquitin-proteasome pathway may be a potential target for therapeutic intervention in DLBCL.

Clinicopathological analysis of colorectal cancers with PIK3CA mutations in Middle Eastern population.

Activation of the phosphatidylinositol 3'-kinase (PI3K)/AKT pathway results in an increase in cell proliferation and survival. Somatic mutations within the PI3K catalytic subunit, PIK3CA are common cause of increasing PI3K activity and are believed to be oncogenic in many cancer types. Few reports addressed the association between PIK3CA mutations and tumor progression specifically in microsatellite instable (MSI) colorectal cancer (CRC). In the present study, we have evaluated PIK3CA mutational status in a series of 410 Middle Eastern CRC and 13 colon cell lines to study the prevalence of PIK3CA mutations in MSI cases, PTEN expression in CRC and possibility of therapeutic targeting of this set of patients. PIK3CA mutations were found in four of the cell lines tested and 51 colorectal carcinomas (12.2%). Three of these four mutated cell lines were MSI. PTEN was inactivated in 66.1% of the CRC. Furthermore, we observed a strong association between PIK3CA mutations and MSI status (P=0.0046) while PTEN loss was more frequent in microsatellite stable (MSS) CRC (P=0.043). A high prevalence of genetic alterations in PI3K/AKT pathway in Saudi cohort of CRC, predominance of PIK3CA mutations in the MSI subgroup and their possible involvement in development/progression of this subset of CRC are some of the significant findings of our study.

Genome-wide expression analysis of Middle Eastern papillary thyroid cancer reveals c-MET as a novel target for cancer therapy.

In an attempt to find genes that may be of importance in malignant progression of papillary thyroid carcinoma (PTC) in the Middle East, which therefore can be targeted in cancer therapy, we screened and validated the global gene expression in PTC using cDNA expression arrays and immunohistochemistry (IHC) on tumour tissue microarrays. Twenty-nine PTC tissue specimens were compared with seven non-cancerous thyroid specimens by use of cDNA microarray. Results for selected genes were confirmed by quantitative real-time PCR. Protein expression of selected genes was further studied using a tissue microarray consisting of 536 PTCs and compared with histologically non-cancerous tissue samples. One hundred and ninety-six genes were overexpressed in PTC tissues relative to non-cancerous thyroid tissues. The genes that were up-regulated in PTC were involved in cell cycle regulation, cell signaling, and oncogenesis. Among these genes, c-MET was identified by immunohistochemical methods as a protein that is overexpressed in 37% of PTCs and was significantly associated with more aggressive behaviour, eg higher stage, nodal involvement, and tall cell variant (p value = 0.01, 0.01 and 0.04, respectively). In this study, 55% of the PTC cases expressed activated AKT (P-AKT), which suggests that activated AKT may play an important role in PTC tumourigenesis. The fact that most of the PTC cases that had activated AKT showed overexpression of c-MET (p = 0.027) leads us to hypothesize that c-MET may be an alternative mechanism of AKT activation in Middle Eastern PTCs. Finally, our data suggest that c-MET dysregulation is associated with aggressive behaviour and may serve as a molecular biomarker and potential therapeutic target in this disease.

Fine-needle aspiration of the testis in azoospermic men: the value of measuring serum follicle stimulating hormone and testicular size.

Testicular fine-needle aspiration biopsy (FNAB) is used as a primary tool in assessing azoospermic infertile men in our institution. If the FNA is negative for sperm, a subsequent testicular biopsy specimen and wet preparation are obtained with possible immediate fertilization. To our knowledge, the value of these techniques in the context of testicular size and serum levels of follicle stimulating hormone (FSH) has not been explored. We reviewed 453 FNA biopsies of the testis performed for the identification of sperm in infertile azoospermic males between 1999 and 2000. We identified cases that had all three procedures (FNA, wet preparation and biopsy) performed. These were the patients that were compared for testicular size using Seager orchiometry and serum levels of FSH. Of the 453 FNAs reviewed, 128 (21%) had all three procedures performed. Seventy-two cases (56%) were negative in all three tests, 26 (20%) cases were positive in all tests, and 30 cases (23%) had different results. These 30 cases were excluded. The testicular size in the negative group ranged from 4 to 16 ml (median, 10 ml) and the positive group had testicular sizes ranging from 10 to 25 ml (median, 15 ml; P = 0.0001). The negative group had serum FSH levels ranging from 3 to 52 IU/l (median, 19 IU/l) whereas the positive group had serum levels ranging from 3 to 26 IU/l (median, 10 IU/l; P = 0.0001). Our findings suggest that in infertile azoospermic men, a testicular size of <10 ml combined with a serum FSH level of >19 IU/l, the chances of retrieving sperm are minimal using all three diagnostic modalities. The use of this cutoff point would lead to a 30-50% reduction in the number of procedures performed. This reduction would have a significant impact on the management of these patients with a significant decrease in cost, logistics, and patient anxiety.

Primary diagnosis and REAL/WHO classification of non-Hodgkin's lymphoma by fine-needle aspiration: cytomorphologic and immunophenotypic approach.

The Revised European American lymphoma (REAL) and World Health Organization (WHO) classification of non-Hodgkin's lymphoma (NHL) relies on the constellation of cytologic, phenotypic, genotypic, and clinical characteristics of NHL. For the most part, the classification does not rely on architectural pattern for classification of neoplasms. This classification makes it possible to diagnose and classify lymphomas by fine-needle aspiration (FNA). In this study, we attempted to evaluate the accuracy of FNA in diagnosing and classifying NHL within the context of the REAL/WHO classifications. Cases included only those in which FNA was the primary diagnosis, followed by a surgical biopsy for confirmation. Flow cytometry (FCM) for phenotyping was carried out whenever material was available. Two groups of pathologists were identified. Group A consisted of pathologists with background training in cytopathology and/or hematopathology (three pathologists). Group B consisted of experienced surgical pathologists with no training in cytopathology and/or hematopathology (four pathologists). Seventy-four cases were included in the study. FCM phenotyping was performed in 53 cases (71%). Large cell lymphoma constituted 63% of the cases. The remaining lymphomas included Burkitt's, small lymphocytic, lymphoblastic, follicle center cell, Ki-1, mantle cell, marginal zone, and natural killer cell lymphoma. The diagnosis of lymphoma was rendered for all cases. The correct classification was seen in 63% of the cases. Classification was more accurate in immunophenotyped than in nonimmunophenotyped cases (84% vs 33%; P = 0.00004). Group A pathologists showed higher incidence of proper classification than group B (80% vs 56%; P = 0.046). The diagnosis and classification of NHL can be achieved in a large number of cases on FNA material. This accuracy can be increased if cytomorphologic criteria are established for different entities of NHL aided by FCM for phenotyping.

FISH analysis in chromophobe renal-cell carcinoma.

Loss of chromosomes 1, 2, 6, 10, 13, 17, and 21 is a characteristic finding in chromophobe renal-cell carcinoma (ChRCC). Previously, cytogenetic and molecular genetic techniques were used in demonstrating the chromosomal monosomies in ChRCCs. We performed interphase fluorescent in situ hybridization (FISH) using centromeric probes for chromosomes 1, 2, 6, and 10 on touch imprint smears from six histologically proven ChRCCs. All six ChRCC tumors showed one FISH signal corresponding to one copy number for each of these chromosomes. The percent cells with one FISH signal ranged from 48-88% (chromosome 1), 36-89% (chromosome 2), 26-98% (chromosome 6), and 64-99% (chromosome 10). In addition, 3 of the 6 cases were further studied with centromeric probes for chromosomes 13, 17, and 21. All three revealed monosomy of these three chromosomes. We conclude that interphase FISH performed on touch imprint smears is a relatively simple, rapid, and reliable method for detecting chromosome abnormalities which are specific for ChRCCs.

Epstein-Barr virus-associated leiomyosarcoma of the thyroid in a child with congenital immunodeficiency: a case report.

We report an unusual case of multifocal leiomyosarcoma involving the thyroid gland, liver, and right lung in a child with congenital immunodeficiency disease. The smooth muscle nature of these neoplasms was confirmed by immunohistochemistry and electron microscopic studies. In situ hybridization showed large amounts of Epstein-Barr virus messenger RNA within the tumor cells. Although Epstein-Barr virus-associated smooth muscle tumors have been reported in children with AIDS and after organ transplantation, we are unaware of any case report in congenital immunodeficiency disease.

Sinonasal T-Cell lymphomas: A clinicopathologic study of a possibly distinct entity.

BACKGROUND: Most cases of sinonasal lymphomas reported in the literature which show positive expression for Epstein-Barr virus are CD2+, CD3-, CD43+ and CD56+, and also show a germ-line T-cell receptor genotype. Five-year survival is usually around 50%. We report a group of patients with T-cell sinonasal lymphoma that showed distinct immunophenotypic and molecular profiles and a more aggressive behavior. PATIENTS AND METHODS: Nineteen cases representing approximately 75% of sinonasal lymphoma diagnosed and treated at our institution between 1988 and 1997 were studied. They comprised 12 males and 7 females, with an age range of 10 to 73 years (median 46 years). The remaining cases (about 25%) were B-cell lymphomas. The morphology of the cases was evaluated together with a limited immunophenotyping. In situ hybridization for EBV mRNA was performed in 18 cases. Polymerase chain reaction (PCR) for T-cell receptor (TCR) gene rearrangement was performed in 15 cases. Clinical follow-up information was available on 14 patients. All cases showed a pattern of large-cell lymphoma, and three exhibited an immunoblastic morphology. The tumors showed extensive soft tissue invasion, necrosis and ulceration. While perineural invasion was a prominent feature, perivascular invasion was not noticed. RESULTS: Seventeen tumors (84%) were CD3 positive. PCR analysis showed TCR gene rearrangement in 7 of 15 cases (46%). Fifteen cases (79%) were positive for EBV. The 14 patients with available clinical information had extensive local diseases, with stages ranging from IE to IIIE, where none showed positive bone marrow involvement. The 14 patients received chemotherapy with or without radiation therapy. Ten of the 14 patients (71%) died of the disease after a median of seven months, including all seven patients with positive TCR gene rearrangement. CONCLUSION: Our findings suggest that sinonasal T-cell lymphoma represents a heterogeneous group of diseases with different phenotypic, genotypic and biological characteristics. Cases that show TCR gene rearrangement may represent a more aggressive subtype of the disease.

Use of FISH analysis for diagnosis of renal cell carcinoma subtypes.

BACKGROUND: Cytogenetic and molecular genetic techniques have been used in demonstrating the chromosomal abnormalities which characterize specific subtypes of renal cell carcinoma (RCC). The aim of this study was to determine the efficiency of fluorescent in situ hybridization (FISH) technique in characterizing various subtypes of RCC based on the presence of specific chromosome abnormalities found in each RCC subtype. MATERIALS AND METHODS: FISH was performed on touch imprint smears from eight renal cell carcinomas histologically confirmed by established criteria. RESULTS: In four tumors with histologic features of chromophobe renal cell carcinoma (ChRCC), interphase FISH was performed using centromeric probes for chromosomes 1, 2, 6, 10, 12, 17 and 21. All four ChRCC tumors showed one FISH signal corresponding to one copy number for each of these chromosomes. Two papillary RCCs included in this study showed trisomy 7 and 17, and loss of chromosome Y, using the corresponding chromosome centromeric probes. Similarly, we tested two clear cell RCCs for chromosome 3 short arm deletion with DNA probe 3p21.3. Both tumors showed loss of 3p21.3 signal. CONCLUSION: We conclude that interphase FISH performed on touch imprint smears is a relatively simple, rapid and reliable method for detecting chromosome abnormalities which are specific for various subtypes of RCC.

Intracranial calcification in Raine syndrome: radiological pathological correlation.

We report the seventh known patient with Raine syndrome, a recently recognised, lethal sclerosing bone dysplasia associated with severe craniofacial dysmorphism and intracranial calcification in whom the CT findings are correlated with the gross and microscopic abnormalities found in the brain at autopsy.