Hiroshi Iino

High-b Value Diffusion-Weighted MRI for Detecting Pancreatic Adenocarcinoma: Preliminary Results

OBJECTIVE The objective of our study was to evaluate the usefulness of high-b value diffusion-weighted MRI (DWI) in the detection of pancreatic adenocarcinoma. SUBJECTS AND METHODS Twenty-six patients with pancreatic adenocarcinoma were included in the study. Twenty-three other patients who were being followed up due to pancreatic diseases other than adenocarcinoma were included as control subjects. All patients and subjects underwent DWI, and the images were evaluated by three blinded radiologists. RESULTS Receiver operating characteristic (ROC) curve analysis yielded A(z) values (i.e., area under the ROC curve) of 0.998, 0.998, and 0.995 for the three radiologists. The mean sensitivity and specificity for the detection of pancreatic adenocarcinoma were 96.2% and 98.6%, respectively. The kappa values indicating interobserver agreement between different pairs of radiologists were in the category of excellent. CONCLUSION High-b value DWI allows the detection of pancreatic adenocarcinoma with a high sensitivity and specificity.

High-B-value diffusion-weighted MRI in colorectal cancer.

OBJECTIVE The purpose of this article is to evaluate the usefulness of high-b-value diffusion-weighted MRI (DW-MRI) in the detection of colorectal adenocarcinoma. CONCLUSION High-b-value DW-MRI allows detection of colorectal adenocarcinoma with a high sensitivity and specificity.

Protein overexpression and gene amplification of HER-2 and EGFR in colorectal cancers: an immunohistochemical and fluorescent in situ hybridization study

Overexpression of HER-2 and the epidermal growth factor receptor (EGFR) has been observed in many cancers, sometimes accompanied by gene amplification. To assess whether novel chemotherapies targeting these overexpressed proteins may be effective for the treatment of colorectal cancers, we examined the exact frequency of HER-2 and EGFR overexpression, the relationship between gene amplification and protein expression, and the heterogeneity of gene amplification within and between primary and metastatic tumors. We evaluated 244 colorectal cancers immunohistochemically. All tumors found to overexpress HER-2 or EGFR were further analyzed for gene amplification by fluorescent in situ DNA hybridization. Overexpression of HER-2 and EGFR was found in 8 (3%) and 19 (8%) of the 244 colorectal carcinomas, respectively. Gene amplification was observed in 100 and 58% of the tumors exhibiting HER-2 and EGFR overexpression, respectively. HER-2 amplification in cancer cells was characterized by clusters of hybridization signals, suggesting amplicons in homogeneously staining regions that were predominant in most primary and metastatic tumors. EGFR amplification, observed as scattered signals reminiscent of amplicons in double minute chromosomes, or coamplification of EGFR with the centromeric regions was observed as a minor population within primary tumors, and found in variety of populations in metastatic tumors. Overexpression of HER-2 and EGFR were observed in only a small fraction of colorectal carcinomas, but were frequently accompanied by gene amplification.

Diagnosis of colorectal hepatic metastases: Comparison of contrast‐enhanced CT, contrast‐enhanced US, superparamagnetic iron oxide‐enhanced MRI, and gadoxetic acid‐enhanced MRI

To compare the diagnostic accuracy of contrast‐enhanced computed tomography (CE‐CT), contrast‐enhanced ultrasonography (CE‐US), superparamagnetic iron oxide‐enhanced magnetic resonance imaging (SPIO‐MRI), and gadoxetic acid‐enhanced MRI (Gd‐EOB‐MRI) in the evaluation of colorectal hepatic metastases.

Global histone modification of histone H3 in colorectal cancer and its precursor lesions

Chromatin remodeling through histone modification is an important mechanism of epigenetic gene dysregulation in human cancers. However, little is known about global alteration of histone status during tumorigenesis and cancer progression. Histone H3 status was examined in benign and malignant colorectal tumors by immunohistochemistry and Western blotting. For immunohistochemical evaluation, 4 anti-histone H3 antibodies, specific to dimethylation at lysine 4 (H3K4me2), acetylation at lysine 9 (H3K9ac), dimethylation at lysine 9 (H3K9me2), and trimethylation at lysine 27 (H3K27me3), were used. On immunohistochemistry, H3K4me2, H3K9ac, and H3K27me3 showed no significant changes between normal and colorectal tumors. On the other hand, the global level of H3K9me2 was distinctly higher in neoplastic cells (adenoma and adenocarcinoma) than in normal glandular cells. In addition, it was significantly higher in adenocarcinoma than in adenoma. Correspondingly, Western blotting confirmed that H3K9me2 expression was significantly higher in adenocarcinomas than in normal colorectal mucosa. No alteration of H3K9me2 was observed with tumor differentiation and with the histological subtypes of colorectal cancers. These results suggest that aberration of the global H3K9me2 level is an important epigenetic event in colorectal tumorigenesis and carcinogenesis involved with gene regulation in neoplastic cells through chromatin remodeling.

Imaging of small hepatic metastases of colorectal carcinoma: how to use superparamagnetic iron oxide-enhanced magnetic resonance imaging in the multidetector-row computed tomography age?

Purpose: To compare the accuracy of dynamic contrast-enhanced multidetector-row computed tomography (CT) and superparamagnetic iron oxide-enhanced magnetic resonance imaging (MRI) in the evaluation of small hepatic metastases of colorectal carcinoma. Materials and Methods: Of 94 patients with colorectal carcinoma analyzed, 76 hepatic metastases (<2 cm) were diagnosed in 17 patients. Superparamagnetic iron oxide (SPIO)-magnetic resonance (precontrast and postcontrast MRI) and dynamic contrast-enhanced multidetector-row CT (dynamic CT [precontrast, arterial, portal-venous, and delayed phase]) were evaluated. The alternative free-response receiver operating characteristic analysis was performed, and the sensitivities and positive predictive values were analyzed. Results: The Az values and sensitivities of portal-venous phase CT, dynamic CT, and SPIO-MRI (0.62/59%, 0.69/61%, and 0.67/61%) were identical. The mean positive predictive value of dynamic CT (82%) was inferior to that of SPIO-MRI (91%). Conclusions: The diagnostic ability of dynamic CT is identical to that of SPIO-MRI in Az value and sensitivity. Superparamagnetic iron oxide-MRI should be recommended only if an equivocal lesion is detected by dynamic CT.

Diagnosis of colorectal hepatic metastases: Contrast-enhanced ultrasonography versus contrast-enhanced computed tomography versus superparamagnetic iron oxide-enhanced magnetic resonance imaging with diffusion-weighted imaging

To compare the diagnostic accuracy of contrast‐enhanced ultrasonography (CE‐US), contrast‐enhanced CT (CE‐CT), and superparamagnetic iron oxide‐enhanced MRI (SPIO‐MRI) with diffusion‐weighted imaging (DWI) in the evaluation of colorectal hepatic metastases.

Clinical Impact of Histological Heterogeneity in the Metastatic Lymph Nodes of Patients with Colorectal Cancer

Aim: The purpose of this study was to evaluate the clinical impact of histological heterogeneity in patients with node-positive colorectal cancer (CRC). Patients and Methods: One hundred and twenty-nine patients who underwent curative surgical resection for histological node-positive CRC were enrolled. Patients were divided according to the histological heterogeneity in the primary lesion into p-hetero and p-homo groups. The p-hetero group was further divided according to histological heterogeneity in the metastatic lymph nodes into n-hetero and n-homo groups. Results: There were no significant differences between p-homo and p-hetero groups and between n-homo and n-hetero groups in prognosis. However, the recurrence-free survival rate of the n-homo group was significantly lower than that of the n-hetero group in the N2 category. Conclusion: Histological heterogeneity in metastatic lymph nodes may be useful for predicting prognosis, and prognosis in those with histological heterogeneity in a metastatic lymph node is not necessarily poor, even in those of the N2 category.