ABSTRACT
There has been limited research exploring how the demographic characteristics of children with pediatric cutaneous mastocytosis (PCM) may influence both the cutaneous and systemic symptoms. In this observational retrospective study of 51 children with PCM, we found a significantly higher rate of gastrointestinal (GI) symptoms in children of Hispanic ethnicity (4/21,19%) compared to non-Hispanics (0/30, 0%, p = 0.024). While this finding may reflect the high proportion of Hispanics in our population, a racial predisposition toward distinct systemic symptoms may be possible. We also found a significantly lower proportion of Hispanic children being diagnosed with PCM under the age of 3 years (47.6%) when compared with non-Hispanic children (76.7%, p = 0.03), suggesting that more data are needed to further assess the role of ethnicity and healthcare disparities in PCM diagnosis. Larger prospective studies are necessary to better evaluate the association between ethnicity, early diagnosis, and systemic symptoms in PCM and to describe its impact on long-term outcomes.
Subject(s)
Ethnicity , Mastocytosis, Cutaneous , Humans , Child , Child, Preschool , Retrospective Studies , Prospective Studies , Hispanic or Latino , Mastocytosis, Cutaneous/diagnosis , Mastocytosis, Cutaneous/epidemiologyABSTRACT
WTX is a tumor suppressor gene expressed during embryonic development and inactivated in 20-30% of cases of Wilms tumor, the most common pediatric kidney cancer. WTX has been implicated in several cellular processes including Wnt signaling, WT1 transcription, NRF2 degradation, and p53 function. Given that WTX is widely expressed during embryonic development and has been recently shown to regulate mesenchymal precursor cells in several organs, we tested for the potential involvement of WTX in a panel of pediatric tumors and adult sarcomas. A total of 353 tumors were screened for WTX deletions by fluorescence in situ hybridization (FISH). Discrete somatic WTX deletions were identified in two cases, one hepatoblastoma and one embryonal rhabdomyosarcoma, and confirmed by array comparative genomic hybridization. Direct sequencing of the full WTX open reading frame in 24 hepatoblastomas and 21 embryonal rhabdomyosarcomas did not identify additional mutations in these tumor types. The presence of WTX mRNA was confirmed in hepatoblastomas and embryonal rhabdomyosarcomas without WTX deletions by RNA-in situ hybridization. Notably, tumors with evidence of WTX inactivation, Wilms tumor, hepatoblastoma and rhabdomyosarcoma, are primitive tumors that resemble undifferentiated precursor cells and are linked to overgrowth syndromes. These results indicate that WTX inactivation occurs in a wider variety of tumor types than previously appreciated and point to shared pathogenic mechanisms between a subset of pediatric malignancies.
Subject(s)
Adaptor Proteins, Signal Transducing/genetics , Hepatoblastoma/genetics , Liver Neoplasms/genetics , Rhabdomyosarcoma, Embryonal/genetics , Tumor Suppressor Proteins/genetics , Wilms Tumor/genetics , Adult , Child, Preschool , Female , Gene Expression Regulation , Humans , Male , Sequence DeletionABSTRACT
PURPOSE: Salivary duct carcinomas (SDC) are a rare and aggressive subtype of salivary gland cancers for which cytotoxic chemotherapy has limited efficacy. We investigated whether genotyping analysis could detect novel tumor-specific mutations that would help direct SDC patient treatment using targeted agents. EXPERIMENTAL DESIGN: We genotyped 27 SDC archival specimens from patients followed at Massachusetts General Hospital and Massachusetts Eye and Ear Infirmary (Boston, MA) between 2000 and 2011. These included the tumors of 8 patients who were tested prospectively. Targeted mutational analysis of 13 clinically relevant cancer genes was conducted using SNaPshot multiplexed genotyping. FISH was conducted to detect HER2 gene amplification. Patient medical records and tumor histopathologic features were retrospectively reviewed. RESULTS: Mutually exclusive genetic aberrations were detected in 15 of 27 (56%) tumors, including 2 (7%) mutations in BRAF, 5 (19%) mutations in PIK3CA, and 8 (30%) cases of HER2 gene amplification. To our knowledge, this is the first time that BRAF and PIK3CA mutations have been reported in this tumor type. Prospective clinical testing of 8 patients with SDC identified actionable genetic alterations in 6 tumors and influenced therapeutic decisions for all 6 patients. CONCLUSION: SNaPshot molecular profiling identified novel genetic changes in SDCs, expanded the therapeutic options for patients with this rare tumor, and is changing SDC management at our institution. These findings highlight the importance of using broad-based genetic profiling to expedite the identification of effective-targeted therapies for patients with rare malignancies.
Subject(s)
Carcinoma, Ductal/genetics , Salivary Gland Neoplasms/genetics , Adult , Aged , Aged, 80 and over , Antineoplastic Agents/therapeutic use , Carcinoma, Ductal/drug therapy , Carcinoma, Ductal/mortality , Carcinoma, Ductal/pathology , Class I Phosphatidylinositol 3-Kinases , Female , Gene Amplification , Gene Expression Profiling , Genotype , Humans , Male , Middle Aged , Mutation , Neoplasm Staging , Phosphatidylinositol 3-Kinases/genetics , Protein Kinase Inhibitors/therapeutic use , Proto-Oncogene Proteins B-raf/genetics , Receptor, ErbB-2/genetics , Salivary Gland Neoplasms/drug therapy , Salivary Gland Neoplasms/mortality , Salivary Gland Neoplasms/pathology , Young AdultABSTRACT
Apocrine-eccrine carcinomas are rare and associated with poor prognosis. Currently there is no uniform treatment guideline. Chemotherapeutic drugs that selectively target cancer-promoting pathways may complement conventional therapeutic approaches. However, studies on genetic alterations and EGFR and Her2 status of apocrine-eccrine carcinomas are few in number. In addition, hormonal studies have not been comprehensive and performed only on certain subsets of apocrine-eccrine carcinomas. To investigate whether apocrine-eccrine carcinomas express hormonal receptors or possess activation of oncogenic pathways that can be targeted by available chemotherapeutic agent we performed immunohistochemistry for AR, PR, ER, EGFR, and HER2 expression; fluorescence in situ hybridization (FISH) for EGFR and ERBB2 gene amplification; and molecular analyses for recurrent mutations in 15 cancer genes including AKT-1, EGFR, PIK3CA, and TP53 on 54 cases of apocrine-eccrine carcinomas. They include 10 apocrine carcinomas, 7 eccrine carcinomas, 9 aggressive digital papillary adenocarcinomas, 10 hidradenocarcinomas, 11 porocarcinomas, 1 adenoid cystic carcinoma, 4 malignant chondroid syringomas, 1 malignant spiradenoma, and 1 malignant cylindroma. AR, ER, PR, EGFR and HER2 expression was seen in 36% (19/53), 27% (14/51), 16% (8/51), 85% (44/52) and 12% (6/52), respectively. Polysomy or trisomy of EGFR was detected by FISH in 30% (14/46). Mutations of AKT-1, PIK3CA, and TP53 were detected in 1, 3, and 7 cases, respectively (11/47, 23%). Additional investigation regarding the potential treatment of rare cases of apocrine-eccrine carcinomas with PI3K/Akt/mTOR pathway inhibitors, currently in clinical testing, may be of clinical interest.
Subject(s)
Apocrine Glands/metabolism , Apocrine Glands/pathology , Carcinoma/metabolism , Carcinoma/pathology , Eccrine Glands/metabolism , Eccrine Glands/pathology , Immunohistochemistry/methods , Adult , Aged , Aged, 80 and over , ErbB Receptors/genetics , ErbB Receptors/metabolism , Female , Humans , In Situ Hybridization, Fluorescence , Male , Middle Aged , Receptor, ErbB-2/genetics , Receptor, ErbB-2/metabolism , Young AdultABSTRACT
PURPOSE: Merkel cell carcinoma (MCC) is an aggressive cutaneous neuroendocrine tumor, often metastatic at presentation, for which current chemotherapeutic regimens are largely ineffective. As its pathogenesis is still unknown, we hypothesized that deregulation of signaling pathways commonly activated in cancer may contribute to MCC tumorigenesis and may provide insights into targeted therapy approaches for this malignancy. EXPERIMENTAL DESIGN: We retrospectively profiled 60 primary MCC samples using a SNaPshot-based tumor genotyping assay to screen for common mutations in 13 cancer genes. RESULTS: We identified mutations in 9 (15%) MCC primary tumors, including mutations in TP53 (3 of 60) and activating mutations in the PIK3CA gene (6 of 60). Sanger sequencing of the primary MCC tumors detected one additional PIK3CA mutation (R19K) that had not been previously described in cancer. Merkel cell polyoma virus (MCPyV) was detected in 38 (66%) MCC cases and patients with MCPyV-positive cancers showed a trend toward better survival. With one exception, the presence of MCPyV and activating mutations in PIK3CA appeared mutually exclusive. We observed that signaling through the PI3K/pAKT pathway was active in one MCPyV-positive and in all MCPyV-negative MCC cell lines, as evidenced by AKT phosphorylation. Importantly, the presence of a PIK3CA-activating mutation was associated with sensitivity to treatment with ZST474, a specific phosphoinositide 3-kinase (PI3K) inhibitor, and to NVP-BEZ235, a dual PI3K/mTOR inhibitor, targeted agents under active clinical development. CONCLUSIONS: PI3K pathway activation may drive tumorigenesis in a subset of MCC and screening these tumors for PIK3CA mutations could help identify patients who may respond to treatment with PI3K pathway inhibitors.
Subject(s)
Carcinoma, Merkel Cell/genetics , Phosphatidylinositol 3-Kinases/genetics , Signal Transduction , Skin Neoplasms/genetics , Adult , Aged , Aged, 80 and over , Base Sequence , Carcinoma, Merkel Cell/metabolism , Carcinoma, Merkel Cell/mortality , Cell Line, Tumor , Class I Phosphatidylinositol 3-Kinases , Enzyme Activation/drug effects , Enzyme Activation/genetics , Female , Genotype , Humans , Male , Middle Aged , Mutation , Neoplasm Staging , Phosphatidylinositol 3-Kinases/metabolism , Phosphoinositide-3 Kinase Inhibitors , Protein Kinase Inhibitors/pharmacology , Signal Transduction/drug effects , Signal Transduction/genetics , Skin Neoplasms/metabolism , Skin Neoplasms/mortalityABSTRACT
One of the major challenges of surgical neuropathology is the distinction of diffuse astrocytoma (World Health Organization grade II) from astrocytosis. The most commonly used ancillary tool to solve this problem is p53 immunohistochemistry (IHC), but this is neither sensitive nor specific. Isocitrate dehydrogenase 1 (IDH1) mutations arecommon in lower-grade gliomas, with most causing a specific amino acid change (R132H) that can be detected with a monoclonal antibody. IDH2 mutations are rare, but they also occur in gliomas. In addition, gains of chromosome 7 are common in gliomas. In this study, we assessed the status of p53, IDH1/2, and chromosome 7 to determine the most useful panel to distinguish astrocytoma from astrocytosis. We studied biopsy specimens from 21 World Health Organization grade II diffuse astrocytomas and 20 reactive conditions. The single most sensitive test to identify astrocytoma is fluorescence in situ hybridization for chromosome 7 gain (76.2%). The combination of p53 and mutant IDH1 IHC provides a higher sensitivity (71.4%) than either test alone (47.8%); this combination offers a practical initial approach for the surgical pathologist. The best overall sensitivity (95%) is achieved when fluorescence in situ hybridization for chromosome 7 gain is added to the p53-mutant IDH1 IHC panel.
Subject(s)
Astrocytoma/diagnosis , Astrocytoma/pathology , Brain Neoplasms/diagnosis , Brain Neoplasms/pathology , Chromosomes, Human, Pair 7/genetics , Gliosis/diagnosis , Gliosis/pathology , Isocitrate Dehydrogenase/genetics , Tumor Suppressor Protein p53/genetics , Diagnosis, Differential , Gene Dosage , Genotype , Humans , Immunohistochemistry , In Situ Hybridization, Fluorescence , Isoenzymes/genetics , Mutation/genetics , Tissue EmbeddingABSTRACT
Lung cancers harboring mutations in the epidermal growth factor receptor (EGFR) respond to EGFR tyrosine kinase inhibitors, but drug resistance invariably emerges. To elucidate mechanisms of acquired drug resistance, we performed systematic genetic and histological analyses of tumor biopsies from 37 patients with drug-resistant non-small cell lung cancers (NSCLCs) carrying EGFR mutations. All drug-resistant tumors retained their original activating EGFR mutations, and some acquired known mechanisms of resistance including the EGFR T790M mutation or MET gene amplification. Some resistant cancers showed unexpected genetic changes including EGFR amplification and mutations in the PIK3CA gene, whereas others underwent a pronounced epithelial-to-mesenchymal transition. Surprisingly, five resistant tumors (14%) transformed from NSCLC into small cell lung cancer (SCLC) and were sensitive to standard SCLC treatments. In three patients, serial biopsies revealed that genetic mechanisms of resistance were lost in the absence of the continued selective pressure of EGFR inhibitor treatment, and such cancers were sensitive to a second round of treatment with EGFR inhibitors. Collectively, these results deepen our understanding of resistance to EGFR inhibitors and underscore the importance of repeatedly assessing cancers throughout the course of the disease.