Tumor Genetic Profile Research Articles

Abstract PL07-02: Rational cancer drug development for targeted drugs.

Abstract The discovery and the development of novel targeted agents for cancer therapeutics is rapidly evolving as a result of our improved understanding of cancer biology. Identification of the diverse genetic changes in different tumors including specific mutations that drive tumor growth is occurring at a rapid pace. This analysis coupled with a better understanding of the diverse mechanisms that lead to drug resistance may result in improved therapeutic interventions. In addition, recent data has provided new insights into identifying the diverse cell types that comprise the tumor microenvironment, characterizing the role of the immune system in both stimulating and inhibiting cancer growth and deciphering new mechanisms such as epigenetics and RNA-based silencing that are involved in tumorgenesis. These insights have provided us with new therapeutic options which have in some cases resulted in impressive clinical benefit. Even with these advances, a number of challenges remain in order to develop more effective cancer therapeutics. These include better defining key cellular targets that drive the growth of specific tumors, identifying appropriate patients with these genetic changes so as to better tailor therapeutic interventions, discovering more efficacious agents that are able to inhibit targets while providing a reasonable margin of safety so as to allow combination with other agents, and developing novel trial designs and endpoints incorporating biomarkers in order to facilitate clinical testing of targeted therapeutics. The use of biomarkers is critical in order to identify the key growth drivers of specific tumors and select the appropriate patients for therapy. In phase I trials, it is critical to use both pharmacokinetic and pharmacodynamic measures to establish the biologically effective dose of the drug being tested in terms of its ability to inhibit the target and alter tumor biology. Tumor biopsies and/or the use of surrogate tissues and appropriate in vitro assays are critical for this analysis. It is important to define whether a targeted agent alone will be sufficient to alter tumor growth or whether it will need to be combined with other targeted agents or chemotherapy. Preclinical data with appropriate cell lines that have been genetically characterized is essential to inform the clinical studies. Another major issue for both small and large molecule targeted therapeutics is the emergence of drug resistance. Repeat biopsies coupled with genetic analysis of tumors are important to better understand the mechanisms leading to drug resistance. This will inform the use of different therapeutic combinations or new agents to either reverse or prevent resistance. Finally, novel clinical trials designs are being developed given the changing paradigm in cancer drug development from a cytotoxic focus to one utilizing targeted agents. Biopsy and analysis of tumor tissues is critical to characterize genetic changes in tumors and identify specific patient subgroups that may benefit from treatment with targeted agents. The I-SPY 2 and the BATTLE trials are examples of adaptively designed trials where clinical response is correlated with a patient's tumor genetic profile. The utilization of next generation sequencing and the quantitative analysis of both RNA and protein expression in tumor tissues both pre and post treatment are critical to better understand how genetic changes correlate with clinical outcomes. As the development of novel targeted agents evolves, the regulatory landscape will also need to change. In addition to utilizing overall survival as the primary endpoint, endpoints such as progression free survival and molecular responses will become increasingly important. The use of in vitro diagnostics will be necessary to help guide therapeutic development in order to identify appropriate patients for specific therapies. As targeted agents move into earlier stages of disease treatment, appropriate statistical and correlative endpoints that predict clinical benefit will need to be utilized. Thus, as new insights allow a better understanding of the complexity of cancer biology, the discovery and clinical development of new therapeutics will also need to evolve in order to improve clinical outcomes for patients. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr PL07-02.

PLAG1 expression in cutaneous mixed tumors: an immunohistochemical and molecular genetic study

Cutaneous mixed tumors, also known as chondroid syringomas, are benign cutaneous adnexal tumors that exhibit remarkable histopathological similarities to pleomorphic adenoma of the salivary gland. Thus far, there is little information on the genetic profiles of cutaneous mixed tumors, although specific genetic aberrations including fusion genes involving PLAG1 and HMGA2 have been demonstrated in pleomorphic adenomas. In the present study, we conducted an immunohistochemical evaluation of PLAG1 and a reverse transcription-polymerase chain reaction (RT-PCR) assay to detect fusion gene transcripts associated with pleomorphic adenoma, including the CTNNB1-PLAG1, LIFR-PLAG1, CHCHD7-PLAG1, TCEA1-PLAG1, HMGA2-FHIT, HMGA2-NFIB, and HMGA2-WIF1 fusion transcripts; this was performed using formalin-fixed paraffin-embedded tumor tissue specimens of 16 cutaneous mixed tumors including one sample with an adenocarcinoma component. All 16 cutaneous mixed tumors were immunoreactive to PLAG1, which was predominantly expressed in cells with myoepithelial or chondroid differentiation accounting for >80% of cells, whereas PLAG1 expression in glandular or squamous tumor cells was restricted to <20% of cells. The carcinoma component in the mixed tumor was also positive for PLAG1. On the other hand, all eight cutaneous adnexal tumors other than the mixed tumor were negative for PLAG1. In RT-PCR analysis, no fusion gene transcripts involving PLAG1 or HMGA2 were identified in any of the cases. Concordant with previous studies, our results support the close relationship between cutaneous mixed tumors and pleomorphic adenomas of the salivary gland. However, the mechanism of PLAG1 expression in cutaneous mixed tumors appears to be possibly different from that of pleomorphic adenomas.

Novel Molecular and Computational Methods Improve the Accuracy of Insertion Site Analysis in Sleeping Beauty-Induced Tumors

The recent development of the Sleeping Beauty (SB) system has led to the development of novel mouse models of cancer. Unlike spontaneous models, SB causes cancer through the action of mutagenic transposons that are mobilized in the genomes of somatic cells to induce mutations in cancer genes. While previous methods have successfully identified many transposon-tagged mutations in SB-induced tumors, limitations in DNA sequencing technology have prevented a comprehensive analysis of large tumor cohorts. Here we describe a novel method for producing genetic profiles of SB-induced tumors using Illumina sequencing. This method has dramatically increased the number of transposon-induced mutations identified in each tumor sample to reveal a level of genetic complexity much greater than previously appreciated. In addition, Illumina sequencing has allowed us to more precisely determine the depth of sequencing required to obtain a reproducible signature of transposon-induced mutations within tumor samples. The use of Illumina sequencing to characterize SB-induced tumors should significantly reduce sampling error that undoubtedly occurs using previous sequencing methods. As a consequence, the improved accuracy and precision provided by this method will allow candidate cancer genes to be identified with greater confidence. Overall, this method will facilitate ongoing efforts to decipher the genetic complexity of the human cancer genome by providing more accurate comparative information from Sleeping Beauty models of cancer.

Genetic profile of second primary tumors and recurrences in head and neck squamous cell carcinomas

Second primary tumors and recurrences are an important problem in patients with head and neck squamous cell carcinoma. The purpose of this study was to determine the genetic changes in tumor samples to improve knowledge of tumor progression. Copy number changes of 37 genes were analyzed by multiplex ligation-dependent probe amplification (MLPA) in 36 primary tumors and their corresponding 21 second primary tumors and 15 recurrences. CCND1 and EMS1 amplifications and gain of BCL2L1 were the most common genetic alterations in the primary tumor, second primary tumor, and recurrence samples. Gains of ERBB2 and PTPN1 were associated with recurrences. Specific genetic profiles for each group have been found. Similarities between primary tumor and second primary tumor and dissimilarity between primary tumor and recurrence suggest that clinicopathological criteria do not always accurately differentiate these entities. Genetic profiling may aid in the diagnosis and prognosis of these difficult cases.

Abstract LB-169: Dissecting signaling pathways regulating translation in human glioblastoma

Abstract Glioblastoma multiform (GBM) is the most common and aggressive brain tumor entity, with a median survival of approximately one year. In the last decade, genetic profiling of brain tumors has improved our understanding of gliomagenesis and proposed many targeted therapies based on molecular interference with deregulated signaling networks. In a search for novel molecular targets, our kinome-focused microarray analysis identified overexpressed MAP kinase-interacting kinase 1 (MNK1) in primary GBM and its elevated protein level was confirmed in primary GBMs and in glioma cell lines. MNKs can bind to translation initiation factor eIF4G and phosphorylate the cap-binding protein eIF4E at Ser209 that is required for its oncogenic activity. Targeting MNK1 activity in GBM cells suppressed eIF4E phosphorylation, reduced proliferation and colony formation whereas, concomitant treatment with Mnk inhibitor CGP57380 and mTOR inhibitor rapamycin resulted in an additive effect on growth inhibition and cell cycle arrest. Analysis of polysomal profiles revealed inhibition of translation in CGP57380 and rapamycin treated cells. Microarray analysis of total and polysomal RNA from MNK1-depleted GBM cells identified mRNAs involved in regulation of TGF-β pathway. The translation of SMAD2 mRNA as well as TGF-β-induced cell motility was regulated by MNK1-signaling. TGF-β pathways regulate growth of glioma-initiating cells that are involved in tumorigenesis, resistance to cancer therapies and relapse. Our most recent analysis identified high activity of MNK1 pathway in human GBM-derived spheres. Furthermore, inhibition of MNK1 activity significantly reduced formation and growth of cancer spheres. Our model of gliomasphere growth regulation via MNK1-signaling pathways together with clinical implications will be presented and discussed. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr LB-169. doi:10.1158/1538-7445.AM2011-LB-169

Matrix Metalloproteinase Pharmacogenomics in Non-Small-Cell Lung Carcinoma

Non-small-cell lung carcinoma demonstrated considerable variability in its chemoresponse. However, the prospect of individualized medicine holds high hopes for improving patient survival. The study of tumor and patient genetic profiles, relative to drug-related genes, may offer new opportunities for tailoring treatments. Matrix metalloproteinases (MMPs) are zinc-containing endopeptidases, which degrade the extracellular matrix and basement membrane, and process bioactive mediators involved in promoting aspects of tumor growth. Polymorphisms in MMP genes known to influence the protein-expression patterns has been shown to influence therapy outcomes by altering signaling pathways. In this article, we address the polymorphic association of MMPs in response to chemotherapy in non-small-cell lung carcinoma. Advances in genome technology and their comprehensive and systematic deployment to elucidate the genomic basis of MMP differences promise to ultimately enhance the efficacy of chemotherapy while reducing its toxicity for the treatment of various cancers.

Genetic Tumor Profiling and Genetically Targeted Cancer Therapy

To discuss how understanding and manipulation of tumor genetics information and technology shapes cancer care today and what changes might be expected in the near future. Published articles, web resources, clinical practice. Advances in our understanding of genes and their regulation provide a promise of more personalized cancer care, allowing selection of the most safe and effective therapy in an individual situation. Rapid progress in the technology of tumor profiling and targeted cancer therapies challenges nurses to keep up-to-date to provide quality patient education and care.

Abstract P3-10-02: Circulating miRNA Signature: Potential Screening and Prognostic Tool for Breast Cancer

Abstract Introduction: Genetic profiling of breast tumors revolutionized the classification of breast cancer and unravelled the complexity of this phenotypically diverse disease. However there appears to be discordance between the various mRNA-based single sample predictors which stratify tumors into subgroups. Clinical decision making based on a tumor's mRNA expression is therefore concerning. The potential of mi(cro) RNAs as novel tumor markers has been the focus of recent scrutiny due to their tissue specificity, stability and superiority to mRNA in tumor classification. Additionally, the ability to quantify tumor-associated miRNAs in the circulation and their correlations with clinicopathologic variables, highlights their potential to improve upon existing breast tumor classification methods. Systemic miR-195 and let-7a have been shown to hold properties as breast tumor markers. The aim of this study was to identify a larger panel of miRNAs which augment the sensitivity and specificity of circulating miRNAs as diagnostic and prognostic markers for breast cancer. Methods: The expression levels of 9 miRNAs were evaluated in 345 preoperative cancer patients including 265 breast cancers and 80 non-breast malignancies, and 63 age-matched disease-free controls using RQ-PCR. MiRNA quantification was also performed on tumor tissue from 83 age and stage matched breast cancer patients. Advanced QBase Plus software and SPSS were used for biostatistical analysis of the data and correlation with clinicopathologic variables. Results: This study confirmed significantly deranged expression levels of systemic miR-195 and let-7a in an independent validation cohort of breast cancer patients (p &amp;lt; 0.001 and p &amp;lt; 0.001 respectively). In addition miR-181c and miR-342 were identified as breast cancer specific biomarkers. Elevated levels of this 4-miRNA signature in breast cancer patients, including those with in-situ carcinoma, increased the discriminatory power of this test for breast cancer (all types) to 94% (P&amp;lt;0.001). Circulating levels of these 4 miRNAs correlated with tumor miRNA expression, and decreased to basal levels by 2 weeks following curative tumor resection. Additionally circulating miRNA levels correlated with clinicopathological variables such as tumor size and hormone receptor status. A subset of 2 systemic miRNAs was predictive of the Luminal A subtype of breast cancer (ER/PR positive, Her2/neu negative) with 91% accuracy. Conclusion: This study validates the recent novel finding of dysregulated tumor-specific miRNAs in the circulation of breast cancer patients. Considering that the sensitivity of mammography is 75-90%, this circulating miRNA signature could improve upon existing breast cancer screening methods, given that it was significantly altered even in patients with in-situ carcinoma. These results indicate that circulating miRNA analysis holds immense potential in the future individualized management of breast cancer patients. Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P3-10-02.

Genetic profiling of CNS tumors extends histological classification

Genetic profiling of CNS tumors extends histological classification

Personalizing therapy for ovarian cancer

The treatment of ovarian cancer is uniform for almost all patients, with advanced stage (IC–IV) generally treated with surgical debulking followed by adjuvant chemotherapy consisting of carboplatin alone or in combination with paclitaxel. However, current trends in cancer treatment have demonstrated the benefit of personalized therapies, which take advantage of differences in tumor cell types and genetics. The advantage of the personalization of treatment has already been demonstrated in other cancer types through the identification of patient subpopulations and the creation of genetic tumor profiles. It is increasingly likely that such an approach could prove helpful for ovarian cancer patients. Research regarding the heterogeneity of ovarian tumors with respect to both grade and histology, including the unique classification of clear-cell and low-grade tumors, has helped to further the concept that different tumors require individualized attention. Furthermore, advances in the understanding of the genet...

Abstract 4186: Development of a novel, genetically faithful model of pediatric glioblastoma

Abstract Gliomas are among the most lethal human cancers, with high-grade tumors exhibiting a dismal 5-year survival rate. Mutations and amplifications of receptor tyrosine kinases such as PDGFR and EGFR, which drive Ras-MAPK pathway activity, are among the hallmark mutations of adult gliomas. However, pediatric glioblastomas often do not exhibit the oncogenic mutations found in adult tumors, suggesting that these tumors may have distinct mechanistic origins. The unique genetic characteristics of pediatric brain tumors may also affect their response to conventional treatment. Therefore, there is a need to generate mouse models that faithfully recapitulate the genetics of pediatric glioblastomas to identify potential avenues for improving treatment of these tumors. Recent genetic profiling of pediatric brain tumors has found activating mutations of the BRaf kinase in higher grade tumors but not low-grade juvenile pilocytic astrocytomas. By contrast, BRaf is not frequently altered in adult gliomas, suggesting that cells in the developing brain may be particularly susceptible to this mechanism of Ras pathway activation. In addition, BRaf mutation is closely linked to the loss of the tumor suppressor Ink4a/Arf, indicating a possible requirement for loss of this tumor suppressor in the development of high-grade gliomas. Here, we describe the generation of a model system allowing expression of oncogenic BRaf in spatially and temporally defined populations of neural stem cells. In BRaf CA/+; R26YFP animals, Cre-mediated recombination induces expression of the oncogenic V600E mutant form of Braf from the endogenous gene locus and simultaneously labels these cells via expression of YFP. By stereotaxically injecting Cre-expressing adenovirus into the neonatal or adult brain in these mice, we can induce oncogene expression in specific populations of neural progenitors and track its effects on infected cells. Data from multiple tumor types suggests that the activation of Ras-MAPK signaling via BRaf mutation is tightly linked to loss of the Ink4a/Arf tumor suppressor locus. We are also using viral introduction of Cre to activate oncogenic BRaf when Ink4a/Arf expression is absent. The phenotype of these mice will be compared to human pediatric gliomas to determine if this system provides an accurate model of the human disease. Such a model would provide a platform for testing targeted therapies against BRaf - a critical step in designing new treatments for pediatric glioblastoma. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 4186.

Genetic profiles in renal tumors

Renal cell carcinoma in adult comprises a heterogeneous group of tumors with variable clinical outcomes, which ranges from indolent to aggressively malignant. The application of molecular genetics techniques to the study of renal neoplasms has resulted in improved classification of these entities and better understanding of biological mechanisms responsible for tumor development and progression. In the present article we review the molecular genetic profiles of different renal cell tumors and discuss their relevance to the carcinogenesis mechanisms and to the clinical diagnosis of renal cell carcinoma. Understanding of the molecular genetics of renal tumors is beneficial in making accurate diagnoses, assessing prognoses, and selecting appropriate and targeted therapeutic options.

Assessment of K‐ras mutation

Some of the most significant therapeutic advances in the treatment of cancer have occurred in the management of colorectal metastases. The introduction of new cytotoxic chemotherapeutic and biologic agents has changed the approach to these patients from both an oncologic and a surgical perspective. In addition, an understanding of the molecular mechanisms by which these agents affect tumors is developing. This molecular information will be critical in the future in designing therapeutic regimens based on an individual tumor's genetic profile rather than treatment for a specific tumor type. The rapidly evolving treatment of colon cancer has provided several interesting genetic biomarkers/pathways/genes-/kinases that have been targeted or seem to play an important role. Of particular interest is the blockade of epidermal growth factor receptor (EGFR) with monoclonal antibodies. This treatment is efficacious when used alone or combined with chemotherapy. However, recent data revealed that patients with tumors positive for the K-ras mutation do not benefit from EGFR blockade. Compelling evidence has indicated that mutated K-ras is an important oncogene involved at the early stage of the development of colorectal cancer. Furthermore, mutations in the K-ras gene have been associated with aggressive tumor biology. K-ras mutational analysis is an important step in the overarching goal of developing personalized medicine. New treatment strategies are needed to more effectively treat patients with the K-ras mutation.

Malignant Glioma Arising at the Site of an Excised Cerebellar Hemangioblastoma after Irradiation in a von Hippel-Lindau Disease Patient

We describe herein a malignant glioma arising at the site of the resected hemangioblastoma after irradiation in a patient with von Hippel-Lindau disease (VHL). The patient was a 25 year-old male with multiple hemangioblastomas at the cerebellum and spinal cord, multiple pancreatic cysts and a renal cell carcinoma; he was diagnosed as having VHL disease. The largest hemangioblastoma at the right cerebellar hemisphere was completely removed, and he received high-dose irradiation postoperatively. The tumor recurred at the same site 7 years later, which was a malignant glioma with no evidence of hemangioblastoma. The malignant glioma showed molecular genetic profiles of radiation-induced tumors because of its diffuse p53 immunostaining and the loss of p16 immunoreactivity. The genetic study to find the loss of heterozygosity (LOH) of VHL gene revealed that only the cerebellar hemangioblastoma showed allelic losses for the gene. To the best of our knowledge, this report is the first to show a malignant glioma that developed in a patient with VHL disease after radiation therapy at the site of an excised hemangioblastoma. This report also suggests that radiation therapy should be performed very carefully in VHL patients with hemangioblastomas.

Molecular Medicine, Gene-Expression Profiling and Molecular Diagnostics: Putting the Cart Before the Horse

The terms ‘molecular medicine’ and ‘-omics technologies’ encompass a range of procedures that are promising to help delineate more precisely pathophysiological mechanisms, identify individuals at risk for disease and suggest novel targets for drug treatment. The enhanced consistency and ease of use of core technologies such as real-time PCR (qPCR) and microarrays are leading to the incorporation of molecular analyses into clinical practice [1]; the introduction of next-generation sequencing technology [2], which permits massively parallel sequencing of millions of sequences at once, is likely to see an acceleration of this trend. This is particularly true in cancer research, where there is expectant acknowledgment that epigenetic, genetic and gene-expression profiling of primary tumors, cancers and/or circulating nucleic acids and tumor cells is a helpful and critical new weapon in the perpetual endeavor to advance and finetune our clinical diagnostic potential [3]. For example, there have been extensive attempts aimed at identifying genetic markers and metastasis-associated mRNA signatures in solid tumors, and using them as prognostic indicators of distant cancer recurrence [4]. Other common applications aim to identify mRNA signatures associated with cancer risk or track changes in mRNA levels linked with response to therapy [5]. Consequently, there have been scores of publications reporting an abundance of supposed individual marker genes or diverse gene lists that are claimed to be associated with and even predictive of patient survival [6–9]. Unfortunately, very few of these genes or gene lists agree with one another and it is striking that, several years after metastasis-associated gene lists were first published in a number of solid cancers, there is still

Current Status of Prognostic Profiling in Breast Cancer

Breast cancer is a clinically heterogeneous disease that can affect individuals with seemingly identical clinicopathologic parameters differently. This clinical heterogeneity is driven to a large extent by abnormal gene expression within tumors. Investigators now have the ability to identify the gene-expression fingerprint of an individual's tumor. This information may be used to rationally design therapeutic targets in the future, and also to predict the clinical course of an individual's disease, including response to a specific treatment. Genetic profiles of tumors are now being correlated with clinical outcome, and several prognostic and predictive indicators have emerged based on this research. There are at least four commercially available predictive or prognostic tests, and several more are looming on the horizon. The data gathered from these tests augment standard diagnostic and prognostic information obtained from traditional clinical pathological variables. The advent of gene-profiling technologies started to change the conduct of clinical trials. In the not too distant future, prospective tissue collection for molecular analysis may become routine in order to stratify patients for treatment arms and to optimize treatment strategies based on molecular features of the cancer. Coordinated efforts among oncologists, pathologists, surgeons, laboratory scientists, statisticians, and regulators will be essential in the quest to incorporate genetic profiling and molecular hypotheses into clinical trial planning and conduct.

Current concepts in malignant pleural mesothelioma

Malignant pleural mesothelioma (MPM) is a rare but lethal cancer associated with asbestos exposure. Worldwide, the incidence of MPM is expected to increase over the next 20 years. The molecular and genetic profiling of MPM tumors and patients, and improved understanding of the pathogenesis of MPM may lead to novel diagnostic, preventative and therapeutic strategies. Treatment options for MPM remain limited and no consensus exists at this time. Multimodality therapy that combines surgery, chemotherapy and radiation offers the best chance for long-term survival in select patients.

Apolipoprotein D in CD34-positive and CD34-negative cutaneous neoplasms: a useful marker in differentiating superficial acral fibromyxoma from dermatofibrosarcoma protuberans

More recent techniques to characterize the genetic profile of soft-tissue tumors include the use of gene arrays. Using this technique, Apolipoprotein D (Apo D), a 33-kDa glycoprotein component of high-density lipoprotein, has been found to be highly expressed in dermatofibrosarcoma protuberans. To corroborate these results, we sought to ascertain the utility of Apo D by investigating its sensitivity and specificity in a variety of CD34-positive and CD34-negative cutaneous neoplasms including superficial acral fibromyxoma, sclerotic fibromas, and cellular dermatofibromas. Of interest, we found absence of Apo D expression in all four cases of superficial acral fibromyxoma. Of the remaining CD34-positive lesions, Apo D expression was noted in 35/36 (97%) cases of dermatofibrosarcoma protuberans, 3/5 (60%) giant-cell fibroblastomas, 4/4 (100%) sclerotic fibromas, 8/8 (100%) neurofibromas, and 1/1 (100%) solitary fibrous tumor. Of the CD34-negative lesions, Apo D expression was noted in 2/22 (9%) regular dermatofibroma, 23/45 (51%) cellular dermatofibroma, 10/10 (100%) malignant fibrous histiocytoma, 9/10 (90%) atypical fibroxanthoma, 7/8 (86%) cellular neurothekeoma, 9/9 (100%) malignant melanoma, 8/8 (100%) melanocytic nevi (100%), 0/2 superficial angiomyxoma, 0/15 fibromatosis, 0/1 nodular fasciitis, and 1/2 (50%) desmoplastic fibroblastomas. In summary, our findings indicate that Apo D expression is not specific to dermatofibrosarcoma protuberans. Its principal use as an immunohistochemical adjunct lies in its utility in differentiating superficial acral fibromyxoma from dermatofibrosarcoma protuberans. Although strong positive staining of Apo D in a markedly atypical fibrohistiocytic lesion is suggestive of atypical fibroxanthoma and/or malignant fibrous histiocytoma, further studies with the inclusion of other atypical spindled cell neoplasms are required to conclusively prove the same.

Genetic alterations of E-cadherin and beta-catenin in germinoma and teratoma: Report of two central nervous system cases

The genetic basis as well as mechanisms of development of germ cell tumors of the CNS are still unexplained. In the present article changes of Ecadherin (CDH1) and beta-catenin (CTNNB1) genes in two CNS germ cell tumors are reported. Both gene products are components of adherens junctions, but are also involved in the Wnt signaling pathway. A case of germinoma of the central nervous system and a case of spinal channel teratoma were tested for loss of heterozygosity (LOH) of E-cadherin gene by PCR amplification of tetranucleotide polymorphism (D16S752). Changes of beta-catenin were tested by heteroduplex method. Both germ cell tumors analyzed demonstrated LOH of the CDH1 gene. Analysis of exon 3 of the CTNNB1 gene showed additional band in the germinoma, suggesting that this sample harbors mutation in the beta-catenin gene. Immunostaining showed that LOHs in our samples were accompanied with the absence of E-cadherin protein. We also investigated E-cadherin expression in four other germinomas, of which three were negative and one was mildly positive. Our findings may contribute to better understanding of the genetic profile of germ cell tumors.

Revolutionizing oncology patient enrollment in clinical trials: Just-in-time approach

6577 Background: In the US, adult oncology patient enrollment in clinical trials is estimated at 4% (Cancer 2006; 106(2):426–33). This is a major bottleneck in the development of new cancer treatments, especially for rare indications, like stage IV pancreatic cancer in treatment-naive patients. To overcome the challenge of low enrollment in clinical trials, Pharmatech developed the Just-In-Time (JIT) approach. JIT expands the potential patient population and allows research sites to pre-identify patients using standard of care information prior to site activation. This differs from a traditional approach where sites are activated prior to screening for patients. We postulated the JIT approach would impact patient accrual. Methods: With the JIT approach, a central IRB-approved protocol was presented to 38 research-ready sites but only 8 sites with a potential patient obtained IRB-site approval over a 6 month period. Within 5–10 business days after identifying a potential patient, sites obtained IRB approval, investigators at the site were trained, received study materials, and dosed the first patient. We compared traditional site activation conducted by the sponsor to JIT approach in this study. Results: Traditional approach vs JIT approach: No.of patients enrolled: 42 vs 18; No.of months open: 19 vs 6; No. of sites open: 13 vs 8; No. of non-enrolling sites: 2 vs 0; Patient accrual rate (pts/mo/site): 0.17 vs 0.38. Sites participating in the JIT approach accrued subjects at &gt;2x the rate of traditionally activated sites. The JIT approach eliminated non-enrolling sites, increasing sites’ and sponsor's satisfaction with enrollment. JIT also enhanced patient options by providing access to a novel treatment alternative for this rare indication even at smaller research sites. Conclusions: With JIT, patient accrual rate, enrollment success and trial-related cost in a pancreatic cancer study were markedly better than with the traditional approach. Expanding JIT to other rare indications and to trials requiring specific genetic tumor-profiles will show whether these results are reproducible and whether JIT is a viable approach for trials with challenging eligibility criteria. No significant financial relationships to disclose.