13 research outputs found

    Alterations in PTEN and PIK3CA in colorectal cancers in the EPIC Norfolk study: associations with clinicopathological and dietary factors.

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    BACKGROUND: The PTEN tumour suppressor gene and PIK3CA proto-oncogene encode proteins which contribute to regulation and propagation of signal transduction through the PI3K/AKT signalling pathway. This study investigates the prevalence of loss of PTEN expression and mutations in both PTEN and PIK3CA in colorectal cancers (CRC) and their associations with tumour clinicopathological features, lifestyle factors and dietary consumptions. METHODS: 186 adenocarcinomas and 16 adenomas from the EPIC Norfolk study were tested for PTEN and PIK3CA mutations by DNA sequencing and PTEN expression changes by immunohistochemistry. Dietary and lifestyle data were collected prospectively using seven day food diaries and lifestyle questionnaires. RESULTS: Mutations in exons 7 and 8 of PTEN were observed in 2.2% of CRC and PTEN loss of expression was identified in 34.9% CRC. Negative PTEN expression was associated with lower blood low-density lipoprotein concentrations (p = 0.05). PIK3CA mutations were observed in 7% of cancers and were more frequent in CRCs in females (p = 0.04). Analysis of dietary intakes demonstrated no link between PTEN expression status and any specific dietary factor. PTEN expression negative, proximal CRC were of more advanced Dukes' stage (p = 0.02) and poor differentiation (p < 0.01). Testing of the prevalence of PIK3CA mutations and loss of PTEN expression demonstrated that these two events were independent (p = 0.55). CONCLUSION: These data demonstrated the frequent occurrence (34.9%) of PTEN loss of expression in colorectal cancers, for which gene mutations do not appear to be the main cause. Furthermore, dietary factors are not associated with loss of PTEN expression. PTEN expression negative CRC were not homogenous, as proximal cancers were associated with a more advanced Dukes' stage and poor differentiation, whereas distal cancers were associated with earlier Dukes' stage.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are

    Translating In Vivo Metabolomic Analysis of Succinate Dehydrogenase–Deficient Tumors Into Clinical Utility

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    Purpose Mutations in the mitochondrial enzyme succinate dehydrogenase (SDH) subunit genes are associated with a wide spectrum of tumors, including pheochromocytomas and paragangliomas, GI stromal tumors, renal cell carcinomas, and pituitary adenomas. SDH-related tumorigenesis is believed to be secondary to accumulation of the oncometabolite succinate. Our aim was to investigate the potential clinical applications of proton-1 magnetic resonance spectroscopy (1H-MRS) in a range of suspected SDH-related tumors. Patients and Methods Fifteen patients were recruited to this study. Respiratory-gated single-voxel 1H-MRS was performed at 3T to quantify the content of succinate at 2.4 ppm and choline at 3.22 ppm. Results A succinate peak was seen in six patients, all of whom had germ line SDHx mutations or loss of SDHB by immunohistochemistry. Succinate peaks were also detected in two patients with metastatic wild-type GI stromal tumors and no detectable germ line SDHx mutations but with somatic epimutations in SDHC. Three patients without tumor succinate peaks retained SDHB expression, consistent with SDH functionality. In six patients with borderline or absent peaks, technical difficulties such as motion artifact rendered 1H-MRS difficult to interpret. Sequential imaging in a patient with a metastatic abdominal paraganglioma demonstrated loss of the succinate peak after four cycles of [177Lu]DOTATATE, with a corresponding biochemical response in normetanephrine. Conclusion This study has demonstrated the translation into clinical practice of in vivo metabolomic analysis using 1H-MRS in patients with SDH-deficient tumors. Potential applications include noninvasive diagnosis and disease stratification, as well as monitoring of tumor response to targeted treatments. </jats:sec

    Familial ACC in Lynch Syndrome

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    CONTEXT: Adrenocortical carcinoma (ACC) is a rare endocrine malignancy with a poor prognosis. Although the majority of childhood ACC arises in the context of inherited cancer susceptibility syndromes, it remains less clear whether a hereditary tumor predisposition exists for the development of ACC in adults. Here, we report the first occurrence of familial ACC in a kindred with Lynch syndrome resulting from a pathogenic germline MSH2 mutation. CASE: A 54-year-old female with a history of ovarian and colorectal malignancy was found to have an ACC. A detailed family history revealed her mother had died of ACC and her sister had previously been diagnosed with endometrial and colorectal cancers. A unifying diagnosis of Lynch syndrome was considered, and immunohistochemical analyses demonstrated loss of MSH2 and MSH6 expression in both AACs (proband and her mother) and in the endometrial carcinoma of her sister. Subsequent genetic screening confirmed the presence of a germline MSH2 mutation (resulting in deletions of exons 1-3) in the proband and her sister. CONCLUSION: Our findings provide strong support for the recent proposal that ACC should be considered a Lynch syndrome-associated tumor and included in the Amsterdam II clinical diagnostic criteria. We also suggest that screening for ACC should be considered in cancer surveillance strategies directed at individuals with germline mutations in DNA mismatch repair genes.ASP, OK and MG are supported by the National Institutes for Health Research Cambridge Biomedical Research Centre. SNZ is a Wellcome Trust Intermediate Clinical Fellow (WT100183MA). We are grateful to Dr Joan Patterson for clinical advice and Dr Erik Schoenmakers for assistance with illustrations.This is the author accepted manuscript. The final version is available from the Endocrine Society via http://dx.doi.org/10.1210/jc.2016-146

    Pregnancy, Primary Aldosteronism, and Adrenal CTNNB1 Mutations.

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    This is a metadata record relating to an article that cannot be shared due to publisher copyright.Recent discoveries of somatic mutations permit the recognition of subtypes of aldosterone-producing adenomas with distinct clinical presentations and pathological features. Here we describe three women with hyperaldosteronism, two who presented in pregnancy and one who presented after menopause. Their aldosterone-producing adenomas harbored activating mutations of CTNNB1, encoding β-catenin in the Wnt cell-differentiation pathway, and expressed LHCGR and GNRHR, encoding gonadal receptors, at levels that were more than 100 times as high as the levels in other aldosterone-producing adenomas. The mutations stimulate Wnt activation and cause adrenocortical cells to de-differentiate toward their common adrenal-gonadal precursor cell type. (Funded by grants from the National Institute for Health Research Cambridge Biomedical Research Centre and others.).AEDT is supported by Agency for Science, Technology and Research (A*STAR) Singapore and the Wellcome Trust (085686/Z/08/A); SG and LHS are supported by the British Heart Foundation (FS/14/75/31134; FS/11/35/28871); EABA was supported by the Tunku Abdul Rahman Centenary Fund (St Catharine's College, Cambridge, UK) and the Austin Doyle Award (Servier Australia). JZ was supported by the Cambridge Overseas Trust Scholarship. MG is supported by the NIHR Cambridge Biomedical Research Centre (Metabolic), and MB is supported by the MRC (U105192713). The work was funded by the NIHR Cambridge Biomedical Research Centre (Cardiovascular) and an NIHR Senior Investigator award (NF-SI-0512-10052) to MJB

    Multilocus Inherited Neoplasia Alleles Syndrome: A Case Series and Review.

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    Mendelian causes of inherited cancer susceptibility are mostly rare and characterized by variable expression and incomplete penetrance. Phenotypic variability may result from a range of causes including locus heterogeneity, allelic heterogeneity, genetic and environmental modifier effects, or chance. Another potential cause is the presence of 2 or more inherited cancer predisposition alleles in the same individual. Although the frequency of such occurrences might be predicted to be low, such cases have probably been underascertained because standard clinical practice has been to test candidate inherited cancer genes sequentially until a pathogenic mutation is detected. However, recent advances in next-generation sequencing technologies now provide the opportunity to perform simultaneous parallel testing of large numbers of inherited cancer genes. Herein we provide examples of patients who harbor pathogenic mutations in multiple inherited cancer genes and review previously published examples to illustrate the complex genotype-phenotype relationships in these cases. We suggest that clinicians should proactively consider the likelihood of this phenomenon (referred to herein as multilocus inherited neoplasia alleles syndrome [MINAS]) in patients with unusual inherited cancer syndrome phenotypes. To facilitate the clinical management of novel cases of MINAS, we have established a database to collect information on what is likely to be an increasingly recognized cohort of such individuals.J Whitworth is supported by the Cambridge Biomedical Research Campus. E Maher is supported by the Cambridge Biomedical Research Campus and a European Research Council researcher award.This is a metadata record relating to an article that cannot be shared due to publisher copyright
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