DNA image cytometry test for primary screening of esophageal cancer: a population-based multi-center study in high-risk areas in China

Objective： To evaluate the feasibility of DNA image cytometry （DNA-ICM） as a primary screening method for esophageal squamous cell cancer （ESCC）. Methods： A total of 5,382 local residents aged 40-69 years from three high-risk areas in China （Linzhou in Henan province, Feicheng in Shandong province and Cixian in Hebei province） from 2008 to 2011 were recruited in this population-based screening study. And 2,526 subjects declined to receive endoscopic biopsy examination with Lugol＇s iodine staining, while 9 and 815 subjects were excluded from liquid-based cytology and DNA-ICM test respectively due to slide quality. Finally, 2,856, 5,373 and 4,567 subjects were enrolled in the analysis for endoscopic biopsy examination, liquid-based cytology and DNA-ICM test, respectively. Sensitivity （SE）, specificity （SP）, negative predictive values （NPV） and positive predictive values （PPV） as well as their 95% confidence intervals （95% CI） for DNA-ICM, liquid-based cytology and the combination of the two methods were calculated. Receiver operating characteristic （ROC） curves were applied to determine the cutoff point of DNA-ICM for esophageal cancer. Results： DNA-ICM results were significantly correlative with esophageal cancer and precancer lesions （X2= 18.016, P〈0.001）. The cutoff points were 5,802, 5,803 and 8,002 based on dissimilar pathological types of low grade intraepithelial neoplasia （LGIN）, high grade intraepithelial neoplasia （HGIN）, and ESCC, respectively, and 5,803 was chosen in this study considering the SE and SP. The SE, SP, PPV, NPV of DNA-ICM test （cutoff point 5,803） combined with liquid-based cytology [threshold atypical squamous cells of undetermined significance （ASCUS）] were separately 72.1% （95% CI： 70.3%-73.9%）, 43.3% （95% CI. 41.3%-45.3%）, 22.8% （95% CI： 21.1%-24.5%） and 87.0% （95% CI： 85.7%-88.3%） for LGIN, 85.7% （95% CI： 84.3%-87.1%）, 41.3% （95% CI： 39.3%-43.3%）, 4.6% （95% CI： 3.8%-5.4%） and 98.9% （95% CI： 98.5%-99.3%） for HGIN, and 96.0% （95% CI： 95.2%-96.8%）, 40.8% （95% CI： 38.8%-42.8%）, 1.7% （95% CI： 1.2%-2.2%） and 99.9% （95% CI： 99.8%-100.0%） for ESCC. Conclusions： It is possible to use DNA-ICM test as a primary screening method before endoscopic screening for esophageal cancer.

Assessing the Malignancy of Hepataocellular Carcinoma in Cirrhosis Using the Hepatocellular Contrast Agent Gd-EOB-DTPA and Correlation with the Cytometric DNA Index

Aim: Investigation whether the signal intensity of hepatocellular carcinoma (HCC) on dynamic magnetic resonance imaging (MRI) with hepatocellular contrast medium (CM) correlates with the histologic malignancy grade and cytometric DNA index. Material and Methods: MRI at 1.5 T with hepatocellular CM Gd-DTPA-EOB of 63 patients (52 men, 11 women;64.0 ± 8.5 years) with HCC in cirrhosis. SI of the tumor and liver tissue in sequences (T1, T1fs, T2fs, T1fs + CM (arterial, venous, late venous phase) were correlated like the asymmetry coefficient of the SI in the arterial and venous phases respective the native and late venous phases of the tumor with the histologic malignancy grade and DNA index indicating the grade of abnormal DNA steam line respective aneuploid DNA. Results: SI did not significantly correlate with the histologic malignancy grade or DNA index for precontrast or postcontrast images. There is a significant correlation for the asymmetry coefficient of the SI in the arterial and venous phases with the DNA-index (p values of 0.00089 (Pearson) and 0.0082 (Spearman). Conclusion: A highly arterialized hepatocellular carcinoma with rapid washout in the venous phase corresponds to a higher malignant potential. These findings suggest that the MR parameters investigated here may predict the malignant potential and prognosis of HCC before surgery.

Estimation of Nuclear DNA Content in Tannin-rich Medicinal Plant Cornus officinalis by Flow Cytometry

Objective The amount of nuclear DNA（C-value）is a key biodiversity character that provides strong unifying elements in revealing the phylogenetic regularity and relationship between genome size and functional traits for plant resource.The estimation of C-values could primarily extend our knowledge on the genetic background and genome diversity for medicinal plants,and thereby the variation of pharmacological constituents and phylogenetic mechanism of medicinal plant taxa will be revealed.However,a large number of medicinal plants（e.g.Cornus officinalis）typically contain a series of secondary metabolites,especially tannic acid,which would significantly affect the estimation of DNA content by flow cytometry（FCM）.Methodological discussions and improvement need to be made to solve this problem.Methods Two isolation buffers LB01 and Otto 1 were selected to prepare nuclear suspension with additional treatments of pre-soaking and centrifugation combination of gradient centrifugal force and duration.The best isolation and estimation methods were determined by FCM measurement in C.officinalis.Results The dry leaves were pre-soaked in Otto I buffer for 15 min and the Otto I nuclear suspension was centrifugated at 1.0×103 g for 2 min.The results showed that debris and nuclei were better separated and the scatterplots of good quality were obtained with low coefficient of variation（CV）.Contrarily,the nuclear DNA content of C.officinalis could not be accurately estimated for nuclei extracted by LB01 buffer.Finally,2C-value and genome size of C.officinalis were first estimated as 5.92 pg and 2893 Mbp,respectively.Conclusion The new methods proposed here are able to accurately estimate DNA content of C.officinalis,which provides valuable references for the estimation of genome size in other tannin-rich medicinal plants.