AIM To test the validity of tumour thickness measurement in distinguishing between the different infiltration depths, especially when the duplication of muscularis mucosae cannot be demarcated clearly. METHODS We re-e...AIM To test the validity of tumour thickness measurement in distinguishing between the different infiltration depths, especially when the duplication of muscularis mucosae cannot be demarcated clearly. METHODS We re-evaluated 100 completely embedded Barrett's adenocarcinomas regarding m-classification, maximum tumour thickness, and muscularis mucosae duplication. For validation, smoothelin staining was performed on a subset of cases. RESULTS The m1-, m2-and m3-classified adenocarcinomasshowed a significant lower tumour thickness compared to the m4-and sm1-classified lesions(P < 0.001). Smoothelin staining determined a clear muscularis mucosae duplication in 64% of the tested samples and enabled the differentiation of the two layers in diffuse and merged splits. CONCLUSION Tumour thickness in early oesophageal adenocarcinoma significantly correlates with the depth of infiltration and demonstrates its worth as an accurate p T classification in non-polypoid lesions. We created a new algorithm, which combines histomorphology with morphometric analyses. It is noteworthy that it facilitates the assessment of mucosal vs submucosal infiltration depth. The smoothelin staining strengthened our results of the tumour thickness evaluation and can be used in cases of doubt.展开更多
AIM： Gene expression profiling provides an unique opportunity to gain insight into the development of different types of gastric cancer. Tumor sample heterogeneity is thought to decrease the sensitivity and tumor spe...AIM： Gene expression profiling provides an unique opportunity to gain insight into the development of different types of gastric cancer. Tumor sample heterogeneity is thought to decrease the sensitivity and tumor specificity of microarray analysis. Thus, microdissection and preamplification of RNA is frequently performed. However, this technique may also induce considerable changes to the expression profile. To assess the effect of gastric tumor heterogeneity on expression profiling results, we measured the variation in gene expression within the same gasbic cancer sample by performing a gene chip analysis with two RNA preparations extracted from the same tumor specimen. METHODS： Tumor samples from six intestinal T2 gastric tumors were dissected under liquid nitrogen and RNA was prepared from two separate tumor fragments. Each extraction was individually processed and hybridized to an Affymetrix U133A gene chip covering approximately 18 000 human gene transcripts. Expression profiles were analyzed using Microarray Suite 5.0 （Affymetrix） and GeneSpring 6.0 （Silicon Genetics）. RESULTS： All gastric cancers showed little variance in expression profiles between different regions of the same tumor sample. In this case, gene chips displayed mean pair wise correlation coefficients of 0.94±0.02 （mean±SD）, compared to values of 0.61±0.1 for different tumor samples. Expression of the variance between the two expression profiles as a percentage of “total change” （Affymetrix） revealed a remarkably low average value of 1.18±0.78 for comparing fragments of the same tumor sample. In contrast, comparison of fragments from different tumors revealed a percentage of 24.4±4.5. CONCLUSION： Our study indicates a low degree of expression profile variability within gastric tumor samples isolated from one patient. These data suggest that tumor tissue heterogeneity is not a dominant source of error for microarray analysis of larger tumor samples, making total RNA extraction an appropriate strategy for performing gene chip expression profiling of gastric cancer.展开更多
文摘AIM To test the validity of tumour thickness measurement in distinguishing between the different infiltration depths, especially when the duplication of muscularis mucosae cannot be demarcated clearly. METHODS We re-evaluated 100 completely embedded Barrett's adenocarcinomas regarding m-classification, maximum tumour thickness, and muscularis mucosae duplication. For validation, smoothelin staining was performed on a subset of cases. RESULTS The m1-, m2-and m3-classified adenocarcinomasshowed a significant lower tumour thickness compared to the m4-and sm1-classified lesions(P < 0.001). Smoothelin staining determined a clear muscularis mucosae duplication in 64% of the tested samples and enabled the differentiation of the two layers in diffuse and merged splits. CONCLUSION Tumour thickness in early oesophageal adenocarcinoma significantly correlates with the depth of infiltration and demonstrates its worth as an accurate p T classification in non-polypoid lesions. We created a new algorithm, which combines histomorphology with morphometric analyses. It is noteworthy that it facilitates the assessment of mucosal vs submucosal infiltration depth. The smoothelin staining strengthened our results of the tumour thickness evaluation and can be used in cases of doubt.
基金Supported by a MeDDrive grant From the University of Dresden 2003by a grant from the Dr. Mildred Scheel Stiftung No. 70-2923
文摘AIM： Gene expression profiling provides an unique opportunity to gain insight into the development of different types of gastric cancer. Tumor sample heterogeneity is thought to decrease the sensitivity and tumor specificity of microarray analysis. Thus, microdissection and preamplification of RNA is frequently performed. However, this technique may also induce considerable changes to the expression profile. To assess the effect of gastric tumor heterogeneity on expression profiling results, we measured the variation in gene expression within the same gasbic cancer sample by performing a gene chip analysis with two RNA preparations extracted from the same tumor specimen. METHODS： Tumor samples from six intestinal T2 gastric tumors were dissected under liquid nitrogen and RNA was prepared from two separate tumor fragments. Each extraction was individually processed and hybridized to an Affymetrix U133A gene chip covering approximately 18 000 human gene transcripts. Expression profiles were analyzed using Microarray Suite 5.0 （Affymetrix） and GeneSpring 6.0 （Silicon Genetics）. RESULTS： All gastric cancers showed little variance in expression profiles between different regions of the same tumor sample. In this case, gene chips displayed mean pair wise correlation coefficients of 0.94±0.02 （mean±SD）, compared to values of 0.61±0.1 for different tumor samples. Expression of the variance between the two expression profiles as a percentage of “total change” （Affymetrix） revealed a remarkably low average value of 1.18±0.78 for comparing fragments of the same tumor sample. In contrast, comparison of fragments from different tumors revealed a percentage of 24.4±4.5. CONCLUSION： Our study indicates a low degree of expression profile variability within gastric tumor samples isolated from one patient. These data suggest that tumor tissue heterogeneity is not a dominant source of error for microarray analysis of larger tumor samples, making total RNA extraction an appropriate strategy for performing gene chip expression profiling of gastric cancer.
