Masaharu Yoshihara

Clinicopathological significance of vascular endothelial growth factor (VEGF)‐C in human esophageal squamous cell carcinomas

The purpose of this study was to investigate the expression of vascular endothelial growth factor (VEGF) ‐C in human esophageal squamous cell carcinomas to elucidate its role in lymph node metastasis and tumor progression. The expression of VEGF‐C and flt‐4 genes was examined in 5 esophageal carcinoma cell lines, 12 fresh biopsy specimens and 48 archival surgical specimens of human esophageal carcinoma tissues by RT‐PCR and immunohistochemistry. Immunohistochemistry using antibodies against CD34 (endothelial cell specific) was also carried out and microvessels were quantified by counting vessels in a 200× field in the most vascular area of the tumor. Of the 5 human esophageal carcinoma cell lines, 4 constitutively expressed VEGF‐C mRNA. In 8 (66.7%) of 12 cases, VEGF‐C mRNA was detected in only tumor tissues but not in normal mucosa by RT‐PCR. There was a significant relationship between VEGF‐C and flt‐4 mRNA expression. Out of the 48 surgical specimens of esophageal carcinomas, 19 (39.6%) and 10 (20.8%) exhibited intense VEGF‐C immunoreactivity in the cytoplasm of many cancer cells and the stromal cells, respectively. In contrast, Flt‐4 was mainly expressed on the lymphatic endothelial cells. Normal and dysplastic esophageal squamous epithelium exhibited no or faint cytoplasmic staining of VEGF‐C. VEGF‐C expression correlated with depth of tumor invasion, tumor stage, venous invasion, lymphatic invasion and lymph node metastasis. Vessel count was significantly higher in the VEGF‐C positive tumors than in the negative tumors. These results overall suggest that VEGF‐C may play a role in tumor progression via lymphangiogenesis and angiogenesis in human esophageal carcinoma.

Genetic polymorphisms and esophageal cancer risk.

The aim of this paper is to review and evaluate, in a comprehensive manner, the published data regarding the contribution of genetic polymorphisms to risk of esophageal cancer, including squamous cell carcinoma (SCC) and adenocarcinoma, in humans. All relevant studies available in MEDLINE and published before February 2007 were identified. Studies carried out in humans and that compared esophageal cancer patients with at least 1 standard control group were considered for analysis. One‐hundred studies and 3 meta‐analyses were identified. Eighty (80%) studies were conducted in Asian countries, particularly China including Taiwan (60 (60%) studies). The most intensively examined genes were those encoding carcinogen metabolic enzymes. The most widely studied gene was GSTM1 (15 studies), followed by ALDH2 (11 studies). ALDH2, MTHFR C677T, CYP1A1 Ile/Val, CYP1A1MspI, CYP2E1, GSTP1, GSTM1 and GSTT1 were examined by meta‐analyses and significant relations were found between ALDH2*1*2 and the CYP1A1 Val allele and increased risk of esophageal cancer. In addition, increased risk of esophageal SCC was consistently associated with the ADH2*1*2 and the p53 codon 72 Pro/Pro genotypes. Cohort studies that simultaneously consider multiple genetic and environmental factors possibly involved in esophageal carcinogenesis are needed to ascertain not only the relative contribution of these factors to tumor development but also the contributions of their putative interactions.

Helicobacter pylori eradication therapy improves atrophic gastritis and intestinal metaplasia: a 5-year prospective study of patients with atrophic gastritis.

Aim : To investigate the effect of the eradication of Helicobacter pylori on histological gastritis.

Endoscopic treatment of submucosal invasive colorectal carcinoma with special reference to risk factors for lymph node metastasis

A clinicopathological analysis of the risk factors for lymph node metastasis was performed in 177 patients with submucosal invasive colorectal carcinoma (CRC). The submucosal deepest invasive portion was histologically subclassified as well (W), moderately (M), or poorly (Por) differentiated. M type was further subdivided into moderately-well (Mw) and moderatelypoorly (Mp) differentiated. The pattern of tumor growth was classified as polypoid growth (PG) and non-polypoid growth (NPG). Lymph node metastasis was detected in 21 (12%) of the 177 patients. Macroscopically, type IIc and IIa+IIc lesions showed a significantly higher incidence of lymph node metastasis (44% and 30%) than type IIa and I (4% and 8%). Regarding the histologic subclassification, Por and Mp lesions showed a significantly higher incidence of lymph node metastasis (67% and 37%) than W and Mw lesions (4% and 14%). NPG tumors showed a significantly higher incidence of lymph node metastasis (29%) than PG tumors (7%). The depth of submucosal invastion and lymphatic invasion (ly) were also significantly correlated with incidence of lymph node metastasis (submucosal scanty (sm-s) invasion 4%, massive invasion 20%; ly(+) 23%, ly(−) 5%). None of the lesions with both sm-s invasion and of W or Mw type showed lymph node metastasis. These results indicate that submucosal invasive CRC with both sm-s invasion and of W or Mw type, which shows no ly, is the appropriate indication for endoscopic curative treatment.

Monocyte chemoattractant protein‐1 expression correlates with macrophage infiltration and tumor vascularity in human esophageal squamous cell carcinomas

Tumor angiogenesis requires the production of angiogenic factors by tumor and stromal cells. Macrophages are key effectors of angiogenesis and reported to contribute to tumor angiogenesis in several carcinomas. To investigate interactions between tumor cells and macrophages in angiogenesis, we examined macrophage infiltration, tumor vascularity and expression of monocyte chemoattractant protein (MCP)‐1, CC chemokine receptor 2 (CCR2) and vascular endothelial growth factor (VEGF) in 57 archival specimens from patients with esophageal dysplasia (n = 9) and squamous cell carcinomas (n = 48). Expression of MCP‐1 mRNA was also examined by reverse transcriptase‐polymerase chain reaction (RT‐PCR) in 7 esophageal carcinoma cell lines and fresh biopsy specimens from 14 patients. The number of infiltrating macrophages correlated closely with expression of VEGF by tumor cells and with neovascularization. Of the 7 cell lines, 4 (TE‐1, 3, 5 and 13) constitutively expressed MCP‐1 mRNA. In 9 (64.3%) of the 14 patients, MCP‐1 mRNA was expressed at high levels in tumor tissues as compared to normal mucosa. MCP‐1 immunoreactivity increased with the depth of tumor invasion (Tis 0%, T1 26.3%, T2, T3 42.1%). Moreover, macrophage and vessel counts were significantly higher in MCP‐1‐positive tumors than in MCP‐1‐negative tumors. Normal and dysplastic esophageal squamous epithelium showed no staining or faint cytoplasmic staining of MCP‐1. Expression of CCR2 immunoreactivity was detected in the cytoplasm of mononuclear cells but not of vascular endothelial cells. These results suggest that interactions between cancer cells and macrophages are important for tumor angiogenesis. MCP‐1 may play a role in progression of human esophageal carcinoma through its role in angiogenesis.

Correlation of ratio of serum pepsinogen I and II with prevalence of gastric cancer and adenoma in Japanese subjects

Objective:Gastric cancer (GC) and adenoma (GA) are reported to be related to atrophic gastritis, in which the serum pepsinogen (PG) I level and the PGI/PGII ratio (I/II ratio) are reduced. To verify that the finding of a low PG level increases the risk for GC and GA, we investigated the correlation between low PG levels and the prevalence of GC and GA in individuals.Methods:The 2,039 subjects (734 Japanese men, mean age 68.5 yr, and 1,305 women, mean age 66.7 yr), selected from among 10,996 local residents who underwent health check-ups based on reductions in their serum PG levels, underwent upper gastrointestinal endoscopy.Results:Gastrointestinal endoscopy detected 21 GCs and 15 GAs. The prevalence of GC was higher than that in the residents without low serum PG. The percentage of early stage of GC (90%) was significantly higher than that of GC detected in unscreened residents (56.9%). The prevalence of GC in men was closely and significantly correlated with the I/II ratio (r = 0.935, p= 0.0063), whereas there was less correlation with age (r = 0.842, p= 0.0734). The prevalence of GA was also closely and significantly correlated with the I/II ratio in men (r = 0.881, p= 0.0203), but not with age (r = 0.163, p= 0.7928). In women the prevalence of GC (r 5 0.744, p= 0.090) and GA (r = 0.678, p= 0.1392) did not correlate as strongly with the I/II ratio, although the highest prevalence was seen in the group with the lowest I/II ratio.Conclusion:Our study verified that a low I/II ratio signifies a high risk for GC and GA and that measuring serum PG levels can be used as a screening method for GC and GA.

Interleukin 8 and vascular endothelial growth factor — prognostic factors in human gastric carcinomas?

Gastric carcinoma cells express potent angiogenic factors including vascular endothelial growth factor (VEGF). We previously reported that interleukin-8 (IL-8) acts as an angiogenic factor for human gastric carcinomas. More recently, we found that IL-8 upregulates matrix metalloproteinase-9 (MMP-9) expression and increases invasive activity of gastric carcinoma cells. The purpose of this study was to determine whether the expression of IL-8 and VEGF correlates with clinicopathological parameters in human gastric carcinomas. IL-8 and VEGF expression levels were measured by an enzyme-linked immunosorbent assay (ELISA) in 56 gastric carcinomas and the surrounding normal mucosa. Macroscopic and histopathological tumour findings, presence of metastasis and prognosis were obtained from the patient records and endoscopic, surgical and pathological reports. IL-8 protein levels were higher in most neoplasms than in the corresponding normal mucosal tissue. In contrast, VEGF expression in the tumours was similar to that in normal mucosa. The IL-8 level in the neoplasms correlated significantly with the depth of invasion, venous invasion and lymphatic invasion. VEGF expression in the tumours correlated well with the depth of invasion and lymph node metastasis. No correlation between IL-8 and VEGF expression in the tumours was observed. The survival rates of patients with tumours displaying high IL-8 and VEGF expression levels were significantly lower (P<0.05) than those of patients with tumours displaying low IL-8 and VEGF expression. The results suggest that IL-8 and VEGF may be independent and important prognostic factors in human gastric carcinomas.

Vascular endothelial growth factor-C expression predicts lymph node metastasis of human gastric carcinomas invading the submucosa

We examined the relationship between vascular endothelial growth factor (VEGF)-C expression and lymph node metastases in gastric carcinomas invading the submucosa. Of the six human gastric carcinoma cell lines, two constitutively expressed VEGF-C mRNA. In three of 12 gastric biopsy specimens (25%), VEGF-C mRNA was detected in tumour tissues, but not in corresponding normal mucosa by reverse transcriptase-polymerase chain reaction (RT-PCR). Of the 139 resected gastric carcinomas, 44 (32%) showed intense cytoplasmic VEGF-C immunoreactivity in many cancer cells at the invading edge. VEGF-C immunoreactivity was associated with greater depth of tumour invasion, lymphatic invasion and lymph node metastases. In addition, vessel count was also significantly higher in the VEGF-C immunoreactive tumours than in other tumours. These results suggest that VEGF-C may be involved in the progression of human gastric carcinoma, particularly via lymphangiogenesis. VEGF-C expression at the invading edge of a gastric carcinoma may be a sensitive marker for metastasis to the lymph nodes.

Clinical Significance of Vascular Endothelial Growth Factor C Expression and Angiogenesis at the Deepest Invasive Site of Advanced Colorectal Carcinoma

Aim: Vascular endothelial growth factor C (VEGF-C) is known to be associated with the development of the lymphatic vascular system. The aim of this study was to elucidate the clinical significance of VEGF-C expression and microvessel density (MVD) at the deepest invasive site in advanced colorectal carcinoma (CRC). Methods: 152 patients who had undergone surgical resection for advanced CRC entered this study. VEGF-C expression was examined immunohistochemically with anti-VEGF-C polyclonal antibody C-20. Tumor MVD was determined immunohistochemically with anti-CD34 antibody. VEGF-C expression was defined as positive if distinct staining of the cytoplasm was observed in at least 10% of tumor cells at the deepest invasive site, central portion and superficial part of the tumor. MVD was estimated by averaging the count of three ×400 fields in the most vascular area at the deepest invasive site. Results: VEGF-C expression was detected in 71 of 152 lesions (46.7%) at the deepest invasive site. VEGF-C expression correlated significantly with poorer histologic grade, depth of invasion, lymphatic invasion, lymph node metastasis, venous invasion, liver metastasis and Duke’s stage. At the central portion and superficial part, there were no significant differences between VEGF-C expression and clinicopathological findings. VEGF-C expression at the deepest invasive site also correlated significantly with MVD. In cases with curative surgery, patients with VEGF-C expression at the deepest invasive site had a significantly poorer prognosis than those without VEGF-C expression. Furthermore, prognosis for patients with both VEGF-C expression and high MVD at the deepest invasive site was significantly poorer than that of patients without VEGF-C expression and with low MVD. Multivariate analysis with logistic regression for 5-year survival in patients with curative surgery showed that lymph node metastasis and VEGF-C expression were significant risk factors. Conclusions: VEGF-C expression at the deepest site of tumor invasion can be a useful predictor of poor prognosis in advanced CRC and show a close relation to angiogenesis.

Immunoreactive MUC1 expression at the deepest invasive portion correlates with prognosis of colorectal cancer

This study sought to examine the relationship between MUC1 expression at the deepest invasive portion, invasive/metastatic potential, and prognosis of colorectal cancer in relation to cellular proliferation. MUC1 expression was detected immunohistochemically using KL-6 antibody (anti-MUC1 monoclonal antibody) in 100 surgically resected specimens of advanced colorectal cancer. Distinct staining of the luminal surfaces, defined as positive immunoreactive (IR)-MUC1 expression, was seen in more than 30% of the tumor cells at the deepest invasive portion. The proliferating cell nuclear antigen labeling index (PCNA-LI) was also examined in the same areas. IR-MUC1 expression was detected in 71 (71%) of 100 lesions. Lesions with lymphatic or venous invasion showed a significantly higher incidence of IR-MUC1 expression than those without lymphatic or venous invasion (80 vs. 42% and 82 vs. 61%, respectively). Lesions with lymph node metastasis showed a significantly higher incidence of IR-MUC1 expression than those without lymph node metastasis (88 vs. 53%). Lesions with liver metastasis showed a significantly higher incidence of IR-MUC1 expression than those without liver metastasis (92 vs. 59%). Dukes’ stage was also significantly correlated with IR-MUC1 expression. The incidence of IR-MUC1 expression did not significantly differ with regard to histologic subclassification and depth of invasion. There was no significant correlation between IR-MUC1 expression and the PCNA-LI. IR-MUC1 expression at the deepest invasive portion revealed a significant correlation with prognosis; furthermore, in patients with better differentiated lesions, in those with lesions confined to muscularis propria or subserosa (subadventitial) invasion, in those with Dukes’ B and C, or in those undergoing curative resection, IR-MUC1 expression significantly correlated with prognosis. Patients with high PCNA-LI lesions showed a significantly poorer prognosis than those with low PCNA-LI lesions. Only in patients undergoing curative resection, patients with IR-MUC1-positive and high PCNA-LI lesions showed a significantly poorer prognosis than those with IR-MUC1-negative and low PCNA-LI lesions. The significant risk factors in the order of poorer prognosis in patients undergoing curative resection by the multivariate analysis were the histologic grade (moderately–poorly, poorly or mucinous adenocarcinomas), IR-MUC1 expression, and lymph node metastasis. These results indicate that IR-MUC1 expression is an important predictor of the metastatic potential and the prognosis of colorectal cancer, independent of histologic grade, depth of invasion or cellular proliferative activity. Combined analysis of IR-MUC1 and histologic grade, and combined expression of IR-MUC1 and PCNA at the deepest invasive portion are especially useful in predicting colorectal cancer prognosis.