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Dieter Weichenhan,
Andreas Gast,
Allan V Espinosa,
Matthew D Ringel,
Joseph Po-Hsien Huang,
Carl D Morrison,
Dirk Schadendorf,
Khelifa Arab,
Rainer Claus, Laura T Smith,
Thomas Hielscher,
Rajiv Kumar,
Christoph Plass
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Khelifa Arab,
Laura T Smith,
Andreas Gast,
Dieter Weichenhan,
Joseph Po-Hsien Huang,
Rainer Claus,
Thomas Hielscher,
Allan V Espinosa,
Matthew D Ringel, Carl D Morrison,
Dirk Schadendorf,
Rajiv Kumar,
Christoph Plass
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ABSTRACT: Metastatic melanoma is a fatal disease due to the lack of successful therapies and biomarkers for early detection and its incidence has been increasing. Genetic studies have defined recurrent chromosomal aberrations, suggesting the location of either tumor suppressor genes or oncogenes. Transcription factor 21 (TCF21) belongs to the class A of the basic helix-loop-helix family with reported functions in early lung and kidney development as well as tumor suppressor function in the malignancies of the lung and head and neck. In this study, we combined quantitative DNA methylation analysis in patient biopsies and in their derived cell lines to demonstrate that TCF21 expression is downregulated in metastatic melanoma by promoter hypermethylation and TCF21 promoter DNA methylation is correlated with decreased survival in metastatic skin melanoma patients. In addition, the chromosomal location of TCF21 on 6q23-q24 coincides with the location of a postulated metastasis suppressor in melanoma. Functionally, TCF21 binds the promoter of the melanoma metastasis-suppressing gene, KiSS1, and enhances its gene expression through interaction with E12, a TCF3 isoform and with TCF12. Loss of TCF21 expression results in loss of KISS1 expression through loss of direct interaction of TCF21 at the KISS1 promoter. Finally, overexpression of TCF21 inhibits motility of C8161 melanoma cells. These data suggest that epigenetic downregulation of TCF21 is functionally involved in melanoma progression and that it may serve as a biomarker for aggressive tumor behavior.
Carcinogenesis 07/2011; 32(10):1467-73. · 5.70 Impact Factor
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ABSTRACT: To determine whether DNA mismatch repair (MMR) modifies the response to chemotherapy or radiotherapy in patients with endometrial cancer.
Immunohistochemistry (IHC) for the DNA MMR proteins MLH1, MSH2, MSH6, and PMS2 was performed on a tissue microarray of specimens of primary endometrial cancer. MMR deficiency was defined as lack of expression of one or more proteins. Expression of all proteins classified a tumor as having an intact MMR system. Recurrence rates were calculated for women treated with platinum-based chemotherapy or pelvic external beam radiation. Comparisons were made using the log-rank test. Multiple comparisons were controlled for by utilizing the Bonferroni correction method.
Four hundred seventy-seven cases of endometrial cancer were evaluated on a tissue microarray (TMA). One hundred fifty-eight patients (41%) received chemotherapy. Sixty-six patients (17%) received pelvic teletherapy. Overall and progression-free survival were not different between patients whose tumors had intact MMR and those with defective MMR when stratified by adjuvant treatment with radiation or chemotherapy. Subgroup analyses stratified by histology (non-endometrioid versus endometrioid) and stage did show significant survival differences. There was a significant increase in overall (p=0.003) and progression-free (p=0.004) survival in those with MMR-deficient, non-endometrioid tumors treated with teletherapy compared to those with an intact MMR system. Improved progression-free survival was noted in patients with intact MMR with stage III/IV disease treated with adjuvant chemotherapy (p=0.031).
Subgroups of patients with non-endometrioid endometrial cancer and defective MMR may have improved survival after adjuvant radiotherapy. Patients with advanced stage endometrial cancer and defects in mismatch repair may receive less benefit from adjuvant chemotherapy.
Gynecologic Oncology 02/2010; 117(2):234-8. · 3.89 Impact Factor
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ABSTRACT: A complication of stem cell transplantation is chronic graft-vs.-host disease (GvHD), developing months to years after transplant; the two commonest manifestations are lichenoid GvHD and scleroderma. The purpose of this study was to characterize early-onset lichenoid GvHD.
A retrospective study identified patients diagnosed with early-onset lichenoid GvHD. This diagnosis was correlated with type of transplant and concurrent or prior episodes of acute GvHD.
Patients in whom a sex mismatch was present between donor and recipient were included, representing a study population of 17. All received an allogeneic peripheral blood stem cell transplant (PBSCT). All patients had biopsy proven lichenoid GvHD within 60 days or less following transplantation. All had concurrent gastrointestinal symptoms which was biopsy proven GvHD in thirteen of the cases. FISH XY studies revealed that the infiltrating lymphocytes were of donor origin in 12 of the cases, mixed in three and of host origin in two cases.
Early-onset lichenoid GvHD is exclusive to the PBSCT setting and appears to be mediated by donor lymphocytes, reflecting the higher numbers of donor T cells encountered in PBSCT. We consider this reaction pattern a distinctive subtype of acute GvHD.
Journal of Cutaneous Pathology 10/2009; 37(5):549-58. · 1.56 Impact Factor
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ABSTRACT: Gene amplification, a common mechanism for oncogene activation in cancers, has been used in the discovery of novel oncogenes. Low-level copy number gains are frequently observed in head and neck squamous cell carcinomas (HNSCCs) where numerous amplification events and potential oncogenes have already been reported. Recently, we applied restriction landmark genome scanning to study gene amplifications in HNSCC and located novel and uncharacterized regions in primary tumor samples. Gain on chromosome 8q22.3, the location of YWHAZ (14-3-3zeta), is found in 30-40% HNSCC cases. Data obtained from fluorescence in situ hybridization and immunohistochemistry on HNSCC tissue microarrays confirmed frequent low-level YWHAZ copy number gain and protein overexpression. YWHAZ mRNA was frequently upregulated in patients' tumor tissues. Furthermore, YWHAZ RNAi significantly suppressed the growth rate of HNSCC cell lines, and overexpression of YWHAZ in HaCaT immortalized human skin keratinocytes promotes overgrowth, as well as morphological changes. Reduced YWHAZ levels increased the G1/G0-phase proportion, decreased the S-phase proportion and the rate of DNA synthesis. Based on this evidence, we suggest that YWHAZ is a candidate proto-oncogene and deserves further investigation into its role in HNSCC carcinogenesis.
International Journal of Cancer 03/2009; 125(3):603-11. · 5.44 Impact Factor
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ABSTRACT: Post-transplant lymphoproliferative disease (PTLD) is a recognized complication of the immunosuppressive regimens associated with solid organ transplantation. The vast majority of these lesions represent monomorphic B-cell lymphoproliferative disease. Rarely, however, T-cell malignancies may emerge, the commonest being anaplastic large-cell lymphoma (ALCL).
We describe two patients who developed a post-transplant ALCL several years after transplantation. Comprehensive phenotypic and molecular studies were conducted. The technique of capillary gel electrophoresis was employed.
One patient died of unrelated causes, while the other patient did achieve clinical remission. The neoplastic cell populace was composed of CD4-positive cytotoxic T cells exhibiting CD30 positivity. There were very few B cells. Striking and prominent clonally restricted infiltrates were identified whereby there was both a heavy chain and T-cell beta gene rearrangement. There was no evidence of lytic Epstein-Barr virus (EBV) infection.
T-cell-associated PTLD does not appear to be directly attributable to EBV infection. Iatrogenic immune dysregulation may result in excessive T-cell proliferation to various antigenic stimuli, hence resembling other drug-associated cell lymphoproliferative conditions such as angioimmunoblastic lymphadenopathy. The dual rearrangement may have some implications regarding the cell of origin.
Journal of Cutaneous Pathology 01/2008; 34 Suppl 1:1-8. · 1.56 Impact Factor
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Muller Fabbri,
Ramiro Garzon,
Amelia Cimmino,
Zhongfa Liu,
Nicola Zanesi,
Elisa Callegari,
Shujun Liu,
Hansjuerg Alder,
Stefan Costinean,
Cecilia Fernandez-Cymering,
Stefano Volinia,
Gulnur Guler, Carl D Morrison,
Kenneth K Chan,
Guido Marcucci,
George A Calin,
Kay Huebner,
Carlo M Croce
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ABSTRACT: MicroRNAs (miRNAs) are small, noncoding RNAs that regulate expression of many genes. Recent studies suggest roles of miRNAs in carcinogenesis. We and others have shown that expression profiles of miRNAs are different in lung cancer vs. normal lung, although the significance of this aberrant expression is poorly understood. Among the reported down-regulated miRNAs in lung cancer, the miRNA (miR)-29 family (29a, 29b, and 29c) has intriguing complementarities to the 3'-UTRs of DNA methyltransferase (DNMT)3A and -3B (de novo methyltransferases), two key enzymes involved in DNA methylation, that are frequently up-regulated in lung cancer and associated with poor prognosis. We investigated whether miR-29s could target DNMT3A and -B and whether restoration of miR-29s could normalize aberrant patterns of methylation in non-small-cell lung cancer. Here we show that expression of miR-29s is inversely correlated to DNMT3A and -3B in lung cancer tissues, and that miR-29s directly target both DNMT3A and -3B. The enforced expression of miR-29s in lung cancer cell lines restores normal patterns of DNA methylation, induces reexpression of methylation-silenced tumor suppressor genes, such as FHIT and WWOX, and inhibits tumorigenicity in vitro and in vivo. These findings support a role of miR-29s in epigenetic normalization of NSCLC, providing a rationale for the development of miRNA-based strategies for the treatment of lung cancer.
Proceedings of the National Academy of Sciences 11/2007; 104(40):15805-10. · 9.68 Impact Factor
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ABSTRACT: Tumor suppressor CCAAT enhancer binding protein alpha (C/EBPalpha) is a transcription factor involved in cell cycle control and cellular differentiation. In a recent study, microarray expression profiling on head and neck squamous cell carcinoma (HNSCC) samples identified significant C/EBPalpha down-regulation, correlating with poor prognosis. However, the mechanisms of C/EBPalpha down-regulation remained elusive. C/EBPalpha has been previously found to provide an antiproliferative role in lung cancer, and our laboratory showed that its down-regulation involves epigenetic mechanisms. This prompted us to investigate the involvement of epigenetics in down-regulating C/EBPalpha in HNSCC. Here, we show that C/EBPalpha is down-regulated in HNSCC by loss of heterozygosity and DNA methylation, but not by gene mutation. We found a consistently methylated upstream regulatory region (-1,399 bp to -1,253 bp in relation to the transcription start site) in 68% of the HNSCC tumor samples, and DNA demethylation using 5-aza-2'-deoxycytidine treatment was able to significantly restore C/EBPalpha mRNA expression in the HNSCC cell lines we tested. In addition, C/EBPalpha overexpression in a HNSCC cell line (SCC22B) revealed its ability to provide tumor suppressor activity in HNSCC in vitro and in vivo. In conclusion, we showed for the first time not only that C/EBPalpha has tumor suppressor activity in HNSCC, but also that it is down-regulated by DNA promoter methylation.
Cancer Research 06/2007; 67(10):4657-64. · 7.86 Impact Factor
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ABSTRACT: The sodium/iodide symporter (NIS) is a membrane glycoprotein mediating active iodide uptake in the thyroid gland and is the molecular basis for radioiodide imaging and therapeutic ablation of thyroid carcinomas. NIS is expressed in the lactating mammary gland and in many human breast tumors, raising interest in similar use for diagnosis and treatment. However, few human breast tumors have clinically evident iodide uptake ability. We previously identified PI3K signaling as important in NIS upregulation in transgenic mouse models of breast cancer, and the PI3K pathway is commonly activated in human breast cancer.
NIS expression, subcellular localization, and function were analyzed in MCF-7 human breast cancer cells and MCF-7 cells stably or transiently expressing PI3K p110alpha subunit using Western blot of whole cell lysate, cell surface biotinylation Western blot and immunofluorescence, and radioiodide uptake assay, respectively. NIS localization was determined in a human breast cancer tissue microarray using immunohistochemical staining (IHC) and was correlated with pre-existing pAkt IHC data. Statistical analysis consisted of Student's t-test (in vitro studies) or Fisher's Exact Test (in vivo correlational studies).
In this study, we demonstrate that PI3K activation in MCF-7 human mammary carcinoma cells leads to expression of underglycosylated NIS lacking cell surface trafficking necessary for iodide uptake ability. PI3K activation also appears to interfere with cell surface trafficking of exogenous NIS as well as all-trans retinoic acid-induced endogenous NIS. A correlation between NIS expression and upregulation of PI3K signaling was found in a human breast cancer tissue microarray.
Thus, the PI3K pathway likely plays a major role in the discordance between NIS expression and iodide uptake in breast cancer patients. Further study is warranted to realize the application of NIS-mediated radioiodide ablation in breast cancer.
BMC Cancer 02/2007; 7:137. · 3.01 Impact Factor
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ABSTRACT: To correlate survival and surgical-pathologic factors with DNA mismatch repair status in patients with endometrial cancer.
Specimens from 336 patients with endometrial cancer were used to create a tissue microarray. Immunohistochemistry with antibodies against the mismatch repair genes MLH1, MSH2, MSH6, and PMS2 were used to stain the tissue microarray. Clinical, pathologic, and survival data were collected and correlated with the immunohistochemistry results.
Mismatch repair deficiency was seen in 29% (84 of 294) of cases. Correlation was noted between lack of expression of MLH1 and an increased risk for lymphvascular space involvement (32% versus 21%, P=.05) and cervical involvement (26% versus 14%, P=.02). Lack of expression of either MLH1 or MSH2 was associated with thinner patients (85% had a body mass index less than 40 versus 73% of patients with normal expression, P=.02), as well as with the absence of a history of previous primary malignancy (0 verus 13 cases [4%], P=.023). The estimated disease-free survival is 88%; despite a small number of recurrences, there was a nonsignificant improvement in disease-free survival in tumors with an intact mismatch repair system (P=.1). Significantly improved disease-free survival was seen in patients with normal MLH1 and MSH2 expression compared with those with abnormal expression (92% versus 81%, P=.035).
Defects in DNA mismatch repair in endometrial cancer is correlated with negative prognostic factors and worse progression-free survival (without a difference in overall survival) compared with tumors with an intact mismatch repair system.
II-3.
Obstetrics and Gynecology 12/2006; 108(5):1208-15. · 4.73 Impact Factor
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ABSTRACT: T-cell prolymphocytic leukemia (T-PLL), formerly categorized as T-cell chronic lymphocytic leukemia, is a rare and aggressive hematologic malignancy. Although the skin is characteristically involved, it is not a well-recognized entity in the dermatologic literature.
Six cases of cutaneous T-PLL are presented from a clinical, light microscopic, and phenotypic perspective.
The patient population comprised 2 women and 4 men, with a mean age of 69.8 years. The disease was associated in all with skin involvement with facial preference; edema, purpura, and lesional symmetry were characteristic. The skin biopsies demonstrated a largely non-epidermotropic angiocentric lymphocytic infiltrate with accompanying hemorrhage. The cells showed irregular- to reniform-shaped nuclei with small nucleoli and eosinophilic rims of cytoplasm. Phenotypic studies revealed three prevailing profiles: CD4 dominant in 4, CD8 dominant in one, and co-expression of CD4 and CD8 in one. CD3 loss was seen in one case. All expressed T-cell leukemia 1 (TCL-1) and CD7; cutaneous lymphocyte antigen expression was discernible in a dot-like perinuclear array. All cases tested excluding one expressed TCL-1 and CD52. In two cases tested, T-cell receptor beta rearrangements were observed. Cytogenetic studies demonstrated a paracentromeric chromosome 14 inversion. Polysomy 8 and MYC amplification was seen in one case, manifesting an aggressive clinical course. Four patients died from their disease within 18 months of diagnosis.
Cytogenetic MYC amplification, FISH, and TCR beta studies were conducted on each of 2 cases, respectively, due to limitations of tissue block samples and/or peripheral blood. cMYC translocation studies were conducted on 3 of the 6 cases, again due to limitations imposed by the tissue samples on the cases. The last case was recently diagnosed and, therefore, long-term follow-up is not possible.
T-PLL is a distinctive post-thymic T-cell malignancy with frequent cutaneous tropism. A diagnosis is possible in almost all cases based on characteristic clinical, light microscopic, phenotypic, and cytogenetic features. While a chromosome 14 inversion is highly characteristic, additional inherent cytogenetic differences, such as trisomy 8 with CMYC over-amplification, may account for some case to case variation in clinical course.
Journal of the American Academy of Dermatology 10/2006; 55(3):467-77. · 3.99 Impact Factor
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ABSTRACT: Most cutaneous T-cell lymphomas are derived from mature postthymic T cells of the CD4 subtype. When other less common profiles are encountered, a diagnostic challenge is posed. Accurate categorization is critical because of the specificity of therapeutic regimens, including biologics. A 65-year-old woman was seen in 2001 because of a thigh mass manifesting an unusual phenotype eventually categorized as a mature postthymic CD8+ T-cell lymphoma with CD10 and weak CD20 expression. Molecular studies revealed T-cell receptor and heavy chain immunoglobulin rearrangement. Her cutaneous disease progressed despite several cycles of chemotherapy and radiation therapy. However, a therapeutic trial with denileukin diftitox resulted in a striking response. The importance of this case lies in the novel phenotype and dual T- and B-cell rearrangements. Rather than representing an aberrant phenotype, this tumor may represent the malignant counterpart of a benign population of weakly CD20+ T cells of the CD8 subset.
American Journal of Clinical Pathology 08/2006; 126(1):14-22. · 2.60 Impact Factor
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ABSTRACT: Expression of the WWOX gene, encompassing the common chromosome fragile site FRA16D, is altered in a large fraction of cancers of various types, including prostate cancer. We have examined expression and biological functions of WWOX in prostate cancer. WWOX mRNA and protein expression were significantly reduced in prostate cancer-derived cells (LNCaP, DU145, and PC-3) compared with noncancer prostate cells (PWR-1E), and WWOX expression was reduced in 84% of prostate cancers, as assessed by immunohistochemical staining. Down-modulation of WWOX expression in the prostate cancer-derived cells is due to DNA hypermethylation in the WWOX regulatory region. Treatment with 5-aza-2'-deoxycytidine (AZA), a DNA methyltransferase inhibitor, and trichostatin A, a histone deacetylase inhibitor, led to increased WWOX mRNA and protein expression in prostate cancer-derived cells, most strikingly in DU145 cells. Transfection-mediated WWOX overexpression in DU145 cells suppressed colony growth (P = 0.0012), and WWOX overexpression by infection with Ad-WWOX virus induced apoptosis through a caspase-dependent mechanism and suppressed cell growth. Lastly, ectopic expression of WWOX by Ad-WWOX infection suppressed tumorigenicity of xenografts in nude mice, and intratumoral AZA treatment halted tumor growth. The data are consistent with a role for WWOX as a prostate cancer tumor suppressor and suggest that WWOX signal pathways should be further investigated in normal and cancerous prostate cells and tissues.
Cancer Research 08/2006; 66(13):6477-81. · 7.86 Impact Factor
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ABSTRACT: Endometrial cancers with a component of serous histology generally occur in postmenopausal women and can present with advanced disease even in the absence of a deeply myoinvasive primary malignancy. We present a case of stage IIIC endometrial cancer with serous histology in a 17-year-old.
A 17-year-old presented with menorrhagia requiring blood transfusion and a transvaginal ultrasound demonstrated a 31 mm endometrial stripe within a bulky uterus. Endometrial curettage revealed a grade 2 endometrioid adenocarcinoma. The patient desired definitive surgical management for her disease; a stage IIIC endometrial cancer with focal low-grade serous carcinoma among a grade 2 endometrioid carcinoma was noted to be superficially myoinvasive. Multiple pelvic lymph nodes had evidence of metastatic serous adenocarcinoma. Platinum-based chemotherapy was administered, and the patient is without disease 24 months following therapy.
Advanced endometrial cancer with metastasis of serous carcinoma to the retroperitoneal lymph nodes can occur, albeit extraordinarily rarely, in very young women. This information is critically important when counseling a woman regarding conservative management of endometrial adenocarcinoma with the interest of preservation of her fertility.
Gynecologic Oncology 06/2006; 101(2):356-9. · 3.89 Impact Factor
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ABSTRACT: The identification of tumor suppressor genes has classically depended on their localization within recurrent regions of loss of heterozygosity. According to Knudson's two-hit hypothesis, the remaining allele is lost, either genetically or, more recently identified, through epigenetic events. To date, retrospective analyses have determined promoter methylation as a common alternative alteration in cancer cells to silence cancer-related genes. Here we report an application of restriction landmark genomic scanning that allows for DNA methylation profiling along a region of recurrent loss of heterozygosity at chromosome 6q23-q24. This approach resulted in the identification of a tumor suppressor gene, TCF21, which is frequently lost in human malignancies. We demonstrate that TCF21 is expressed in normal lung airway epithelial cells and aberrantly methylated and silenced in the majority of head and neck squamous cell carcinomas and non-small-cell lung cancers analyzed. TCF21 is known to regulate mesenchymal cell transition into epithelial cells, a property that has been shown to be deficient in carcinomas. We further demonstrate that exogenous expression of TCF21 in cells that have silenced the endogenous TCF21 locus resulted in a reduction of tumor properties in vitro and in vivo.
Proceedings of the National Academy of Sciences 02/2006; 103(4):982-7. · 9.68 Impact Factor
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ABSTRACT: Adenoviral gene therapy represents a novel approach for the treatment of aggressive thyroid carcinomas. Both coxsackie-adenovirus receptor (CAR) and integrins have been shown to be the major determinants for adenoviral infectivity in many types of cancer cells, yet conflicting results have been reported. In this report we examine these factors mediating adenoviral infection in thyroid cells and to evaluate CAR expression in various types of thyroid cancer. We found that neither expression levels of CAR nor integrins are solely predictive of adenoviral infectivity in thyroid cells. However, the absence of CAR was associated with poor adenoviral infectivity in immortalized rat FRTL-5 cells. Moreover, preincubation with alpha-CAR antibody decreased infectivity in FTC 238 cells, a human thyroid tumor line. These results indicate that CAR does play a role in adenoviral infection of thyroid cells. Immunohistochemical analysis revealed that CAR is expressed at the cell surface in the majority of malignant thyroid tumors. We further show that adenoviral infectivity in some thyroid cancer cells can be improved by poly-L-lysine. Our study warrants a functional method to evaluate adenoviral infectivity should be developed and instituted prior to clinical trials of adenoviral gene therapy in patients with advanced thyroid cancer.
Thyroid 10/2005; 15(9):977-87. · 4.79 Impact Factor
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ABSTRACT: Cervical adenocarcinoma in situ is often diagnosed in younger women who may wish to preserve the potential for fertility. Given that the rate of recurrent adenocarcinoma in situ is relatively low and the risk of invasive adenocarcinoma is extremely rare, conservative management in this population after a cone biopsy demonstrates negative margins has been accepted as an appropriate management strategy. This case challenges the concept of conservative management of cervical adenocarcinoma in situ.
A 42-year-old G2P2002 with previously normal annual cervical cytology had a Pap smear demonstrating atypical glandular cells of uncertain significance. A 1.5-cm lesion was noted at the endocervix, and a punch biopsy revealed adenocarcinoma in situ. A large cold knife cone biopsy confirmed cervical adenocarcinoma in situ with negative margins. Definitive therapy for in situ disease with an extrafascial hysterectomy was performed 12 days after conization, and demonstrated stage IB1 cervical adenocarcinoma. A radical parametrectomy, radical upper vaginectomy, and pelvic lymphadenectomy were without persistent disease.
Conservative management of cervical adenocarcinoma in situ after a cone biopsy with negative margins does not exclude the possibility of concurrent invasive cervical adenocarcinoma. This case challenges the current balance between risk and benefit associated with the conservative management of cervical adenocarcinoma in situ.
Gynecologic Oncology 08/2005; 98(1):158-60. · 3.89 Impact Factor
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ABSTRACT: Thyroid carcinoma is a common endocrine cancer with a favorable prognosis if subjected to timely treatment. However, the clinical identification of follicular thyroid carcinoma (FTC) among patients with benign thyroid nodules is still a challenge. Preoperative fine needle aspiration-based cytology cannot always differentiate follicular carcinomas from benign follicular neoplasias. Because current methods fail to improve preoperative diagnosis of thyroid nodules, new molecular-based diagnoses should be explored. We conducted a microarray-based study to reveal the genetic profiles unique to FTC and follicular adenomas (FAs), to identify the most parsimonious number of genes that could accurately differentiate between benign and malignant follicular thyroid neoplasia. We confirmed our data by quantitative RT-PCR and immunohistochemistry in two independent validation sets with a total of 114 samples. We were able to identify three genes, cyclin D2 (CCND2), protein convertase 2 (PCSK2), and prostate differentiation factor (PLAB), that allow the accurate molecular classification of FTC and FA. Two independent validation sets revealed that the combination of these three genes could differentiate FTC from FA with a sensitivity of 100%, specificity of 94.7%, and accuracy of 96.7%. In addition, our model allowed the identification of follicular variants of papillary thyroid carcinoma with an accuracy of 85.7%. Three-gene profiling of thyroid nodules can accurately predict the diagnosis of FTC and FA with high sensitivity and specificity, thus identifying promising targets for further investigation to ultimately improve preoperative diagnosis.
Journal of Clinical Endocrinology & Metabolism 06/2005; 90(5):2512-21. · 6.50 Impact Factor
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ABSTRACT: The two most common subtypes of thyroid cancer, follicular thyroid carcinoma (FTC) and papillary thyroid carcinoma, have been extensively studied, but our fundamental understanding of the molecular events in thyroid epithelial oncogenesis is still limited. Unreported data from our previous published global gene expression analysis revealed that the tumor suppressor gene aplysia ras homolog I (ARHI) is frequently underexpressed in FTCs. In this study, we elucidated the frequency and mechanism of ARHI silencing in benign and malignant thyroid neoplasia. We demonstrated that underexpression of ARHI occurs principally in FTCs (P = 0.0018), including its oncocytic variant (11 of 13), even at minimally invasive stage but not classic papillary thyroid carcinoma (two of seven) or follicular adenoma (FA) (three of 14). FTCs show strong allelic imbalance with reduction in copy number/loss of heterozygosity (LOH) in 69%, compared with less than 10% for FAs. In combination with our LOH data, bisulfite sequencing in a subset of samples revealed that FA displays a symmetric methylation pattern, likely representing one unmethylated allele and one presumptively imprinted allele, whereas FTC shows a virtually complete methylation pattern, representing LOH of the nonimprinted allele with only the hypermethylated allele remaining. Furthermore, we showed that pharmacologic inhibition of histone deacetylation but not demethylation could reactivate ARHI expression in the FTC133 FTC cell line. Therefore, our data suggest that silencing of the putative maternally imprinted tumor suppressor gene ARHI, primarily by large genomic deletion in conjunction with hypermethylation of the genomically imprinted allele, serves as a key early event in follicular thyroid carcinogenesis.
Journal of Clinical Endocrinology & Metabolism 03/2005; 90(2):1149-55. · 6.50 Impact Factor
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ABSTRACT: Recent breast cancer studies have highlighted the importance of interactions between cancer epithelium and tumor stroma. Recently, the focus of solid tumor investigations has shifted from mutations in carcinomatous epithelium to disturbances of tissue organization in cancer. The genetic basis of this microenvironment, however, remains to be clarified. To begin to resolve this problem, a total genome loss of heterozygosity (LOH) scan was done on epithelial and stromal DNA from 134 sporadic invasive breast carcinomas. In addition to detecting more frequent LOH at three loci in stroma than in epithelium, we found strong evidence that LOH frequencies were significantly elevated in specific regions of each chromosome. We detected 57 markers, which were preferentially lost either in stroma (n = 38) or epithelium (n = 19), relative to the background LOH frequencies on their respective chromosomes. This multiplicity of stromal cell LOH, and hence loss of genetic material, provides a possible mechanism for interpatient variation in host-stromal response to invading adenocarcinoma cells. This is consistent with a model in which initial, random LOH occurs equally among epithelium and stroma, but subsequent clonal selection is driven by factors, which appear to be distinctly different between malignant epithelial and surrounding stromal cells. Genetic alterations in stroma did not mimic those in epithelium, but they could play a different and parallel role in carcinogenesis and tumor progression, probably by modifying some features specific to breast cancer.
Cancer Research 11/2004; 64(20):7231-6. · 7.86 Impact Factor
