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Gastric cancer is not a recognised extra-colonic manifestation of FAP, except in countries with a high prevalence of gastric cancer. Data regarding gastric adenomas in FAP are sparse. The aim of this study was to review the clinical characteristics of gastric tumours occurring within an FAP population from the largest European polyposis registry. All patients that developed a gastric adenoma or carcinoma were identified from a prospectively maintained registry database. The primary outcome measure was the occurrence of gastric adenoma or adenocarcinoma. Secondary outcomes included APC mutation, tumour stage, management and survival. Eight patients developed gastric cancer and 21 an adenoma (median age 52 and 44 years, respectively). Regular oesophagogastroduodenoscopy surveillance was performed in 6/8 patients who developed cancer. Half were advanced T3/4 tumours and 6/8 had nodal or metastatic spread at diagnosis. All cancer cases died within a median of 13.5 months from diagnosis. Gastric adenomas were evenly distributed: 11/21 (52%) in the distal and 10/21 (48%) proximal stomach, whereas 5/8 (63%) cancers were located proximally. An association between gastric tumour and desmoid development was observed; 7/8 (88%) cancer and 11/21 (52%) adenoma cases had a personal or family history of desmoid. It would appear from this small, retrospective study that gastric cancer is not a prominent extra-colonic feature of FAP in the Western world. It seems to present at an advanced stage with a poor prognosis. There may be an association between gastric tumour and desmoid occurrence but a large multicentre cohort is necessary to investigate this further.

A method has been developed for the simultaneous determination of arsenic, antimony, bismuth, selenium and tellurium by generation of their gaseous hydrides and introduction of these hydrides into an inductively coupled plasma source where the atomic line emission from the elements is detected. The effect of different plasma-torch assemblies on the detection limits attainable has been studied and suitable compromise conditions have been established for the simultaneous generation of the hydrides of the analyte elements and their determination by optical ernission spectrometry in t h e plasma source. Dctection limits of 1 ng ml-1 or below for aqueous solutions of the elements studied have been obtained under the conditions employed to allow their determination in samples of interest in geochemistry.Keywovds A rsenic, antimony, bismuth, seleniunz and tellurium detevminat i o n ; geochemical samples ; hydride generatiox. ; inductively coupled plasma etnission spectrometry

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Purpose: Duodenal polyposis and cancer are important causes of morbidity and mortality in familial adenomatous polyposis (FAP) and MUTYH-associated polyposis (MAP). This study aimed to comprehensively characterize somatic genetic changes in FAP and MAP duodenal adenomas to better understand duodenal tumorigenesis in these disorders.Experimental Design: Sixty-nine adenomas were biopsied during endoscopy in 16 FAP and 10 MAP patients with duodenal polyposis. Ten FAP and 10 MAP adenomas and matched blood DNA samples were exome sequenced, 42 further adenomas underwent targeted sequencing, and 47 were studied by array comparative genomic hybridization. Findings in FAP and MAP duodenal adenomas were compared with each other and to the reported mutational landscape in FAP and MAP colorectal adenomas.Results: MAP duodenal adenomas had significantly more protein-changing somatic mutations (P ¼ 0.018), truncating mutations (P ¼ 0.006), and copy number variants (P ¼ 0.005) than FAP duodenal adenomas, even though MAP patients had lower Spigelman stage duodenal polyposis. Fifteen genes were significantly recurrently mutated. Targeted sequencing of APC, KRAS, PTCHD2, and PLCL1 identified further mutations in each of these genes in additional duodenal adenomas. In contrast to MAP and FAP colorectal adenomas, neither exome nor targeted sequencing identified WTX mutations (P ¼ 0.0017).Conclusions: The mutational landscapes in FAP and MAP duodenal adenomas overlapped with, but had significant differences to those reported in colorectal adenomas. The significantly higher burden of somatic mutations in MAP than FAP duodenal adenomas despite lower Spigelman stage disease could increase cancer risk in the context of apparently less severe benign disease.

In the simultaneous determination of arsenic, antimony, bismuth, selenium and tellurium by measurement of the atomic line emission from the elements in an inductively coupled plasma source after their introduction as the gaseous hydrides, two types of possible interferences were investigated. Mutual interferences between the analytes were found to be negligible under the operating conditions used. The presence of certain metal ions in solution resulted in low recoveries of some of the analytes, especially selenium ancl tellurium. However, this could be overcome by prior separation of the analytes by co-precipitation on lanthanum hydroxide.Keywords Arsenic, a n t i m o n y , bismuth, selenium a n d tellurium determination ; geocheniical saiq!des ; hydride generation ; inductively coupled plasma einission spectrometry ; interferences

Chromoendoscopy improved the diagnostic yield of anomas in MAP and FAP 3-fold, and in both MAP and FAP this resulted in a clinically significant upstaging in Spigelman score. Further studies are required to determine the impact of improved adenoma detection on the management and outcome of duodenal polyposis.