Yasuo Ohkura

Japanese Society for Cancer of the Colon and Rectum (JSCCR) guidelines 2010 for the treatment of colorectal cancer

Colorectal cancer is a major cause of death in Japan, where it accounts for the largest number of deaths from malignant neoplasms among women and the third largest number among men. Many new methods of treatment have been developed during recent decades. The Japanese Society for Cancer of the Colon and Rectum Guidelines 2014 for treatment of colorectal cancer (JSCCR Guidelines 2014) have been prepared as standard treatment strategies for colorectal cancer, to eliminate treatment disparities among institutions, to eliminate unnecessary treatment and insufficient treatment, and to deepen mutual understanding among health-care professionals and patients by making these guidelines available to the general public. These guidelines have been prepared as a result of consensuses reached by the JSCCR Guideline Committee on the basis of careful review of evidence retrieved by literature searches and taking into consideration the medical health insurance system and actual clinical practice in Japan. They can, therefore, be used as a guide for treating colorectal cancer in clinical practice. More specifically, they can be used as a guide to obtaining informed consent from patients and choosing the method of treatment for each patient. As a result of the discussions of the Guideline Committee, controversial issues were selected as clinical questions, and recommendations were made. Each recommendation is accompanied by a classification of the evidence and a classification of recommendation categories, on the basis of consensus reached by Guideline Committee members. Here we present the English version of the JSCCR Guidelines 2014.

Correlations between lymph node metastasis and depth of submucosal invasion in submucosal invasive colorectal carcinoma: a Japanese collaborative study.

BackgroundDepth of submucosal invasion (SM depth) in submucosal invasive colorectal carcinoma (SICC) is considered an important predictive factor for lymph node metastasis. However, no nationwide reports have clarified the relationship between SM depth and rate of lymph node metastasis. Our aim was to investigate the correlations between lymph node metastasis and SM depth in SICC.MethodsSM depth was measured for 865 SICCs that were surgically resected at six institutions throughout Japan. For pedunculated SICC, the level 2 line according to Haggitt’s classification was used as baseline and the SM depth was measured from this baseline to the deepest portion in the submucosa. When the deepest portion of invasion was limited to above the baseline, the case was defined as a head invasion. For nonpedunculated SICC, when the muscularis mucosae could be identified, the muscularis mucosae was used as baseline and the vertical distance from this line to the deepest portion of invasion represented SM depth. When the muscularis mucosae could not be identified due to carcinomatous invasion, the superficial aspect of the SICC was used as baseline, and the vertical distance from this line to the deepest portion was determined.ResultsFor pedunculated SICC, rate of lymph node metastasis was 0% in head invasion cases and stalk invasion cases with SM depth <3000 µm if lymphatic invasion was negative. For nonpedunculated SICC, rate of lymph node metastasis was also 0% if SM depth was <1000 µm.ConclusionsThese results clarified rates of lymph node metastasis in SICC according to SM depth, and may contribute to defining therapeutic strategies for SICC.

Estrogen receptor β is expressed in human stomach adenocarcinoma

AbstractPurpose. In stomach adenocarcinoma, the role of the hormonal receptor, estrogen receptor (ER), has been controversial. Recently, a new estrogen receptor, called estrogen receptor β (ERβ), was found to be expressed in various tissues including normal gastrointestinal tract. In this paper, the expression of ERβ in stomach adenocarcinomas has been investigated for the first time, specifically in signet ring cell adenocarcinomas, together with surrounding non-cancerous tissues. Methods. By immunohistochemistry the expression of ERα and β was studied in 29 stomach adenocarcinomas, ten signet ring cell adenocarcinomas, and 19 other adenocarcinomas. Western blotting was performed to examine the immunohistochemical result. Statistical studies (Students t test and χ2-test) explored the relation between the immunohistochemical result and clinicopathological characteristics. Results. All 29 adenocarcinomas, including the signet ring cell ones, demonstrated clear ERβ nucleus staining. Lymphocytes, venous endothelial cells, smooth muscle, and non-cancerous stomach glands also showed strong ERβ staining, while no staining was observed in the immunohistochemistry of ERα. Western blotting showed equivalent ERβ protein levels in cancerous and non-cancerous tissues, which was consistent with the results of immunohistochemical staining. Among signet ring cell adenocarcinomas of the stomach, cytoplasm were stained in addition to nuclei, specifically in patients under the age of 40 years. Conclusions. Our results imply that the effects of estrogen in stomach cancer, as well as those in normal stomach, may be mediated by ERβ, and that the role of ERβ may differ by the subtype of stomach adenocarcinoma – specifically signet ring cell adenocarcinomas and other ones – although large scale samples are needed to confirm these findings.

Tumor Budding as an Index to Identify High-Risk Patients with Stage II Colon Cancer

PurposeHigh-risk patients with Stage II colon cancer may benefit from adjuvant chemotherapy, but they are difficult to identify. We assessed the value of tumor budding, defined as small clusters of undifferentiated cancer cells at invasive margins, as a predictor of outcomes in patients with Stage II colon cancer.MethodsWe studied a total of 200 patients with Stage II colon cancer who underwent curative surgery. With hematoxylin and eosin-stained specimens, the degree of tumor budding was classified as low-grade or high-grade. The survival rate of patients who had Stage II disease with low-grade or high-grade tumor budding was compared with that of 226 patients who had Stage III colon cancer.ResultsUnivariate analysis revealed that serosal surface involvement (P = 0.04) and tumor budding (P < 0.001) were significantly related to survival. Cumulative five- and ten-year survival rates differed significantly between patients with low-grade tumor budding (93.9 and 90.6 percent, respectively) and those with high-grade (73.9 and 67.8 percent, respectively). Survival rates did not differ significantly between patients with Stage II disease who had high-grade tumor budding and patients with Stage III disease. Cox’s regression analysis demonstrated that tumor budding (hazard ratio, 4.89; P < 0.001) and serosal surface involvement (hazard ratio, 2.561; P = 0.023) were independent prognostic factors. Liver (P < 0.001) and peritoneal (P = 0.003) metastases were more frequent in the patients with high-grade tumor budding than in those with low-grade.ConclusionsTumor budding is useful for prognosis and identifying patients with Stage II colon cancer who have a high risk of disease recurrence after curative surgery.

Pulmonary tumor thrombotic microangiopathy caused by a gastric carcinoma expressing vascular endothelial growth factor and tissue factor

Pulmonary tumor thrombotic microangiopathy (PTTM) is a rare clinicopathological entity causing severe pulmonary hypertension. Its histological features include widespread tumor emboli along with fibrocellular intimal proliferation and thrombus formation in the small arteries and arterioles of the lungs. The result is occlusion or stenosis of the pulmonary vasculature, but the detailed pathogenesis has yet to be clarified in spite of the serious clinical manifestations. Herein is described the case of a 62‐year‐old man with a gastric adenocarcinoma who died of sudden cardiopulmonary arrest. The autopsy revealed advanced cancer disease as well as findings of PTTM, which seemed to be the cause of his unexpected death. The carcinoma cells were immunohistochemically positive for vascular endothelial growth factor (VEGF) and also for tissue factor (TF). There is another report suggesting that TF might play an important role in the pathogenesis of PTTM. Also, VEGF has been reported to be involved in a variety of forms of pulmonary hypertension and to be upregulated by TF. These findings suggest that VEGF and TF may be involved in the pathogenesis of PTTM. The present PTTM case, in which the tumor cells demonstrate the coexpression of VEGF and TF, is important in facilitating understanding of the lethal disorder in the future.

Development of colonic neoplasia in p53 deficient mice with experimental colitis induced by dextran sulphate sodium

Background: Several animal models for human ulcerative colitis (UC) associated neoplasia have been reported. However, most neoplasias developed in these models have morphological and genetic characteristics different from UC associated neoplasia. Aims: To establish a new colitis associated neoplasia model in p53 deficient mice by treatment with dextran sulphate sodium (DSS). Methods: DSS colitis was induced in homozygous p53 deficient mice (p53−/−-DSS), heterozygous p53 deficient mice (p53+/−-DSS) and wild-type mice (p53+/+-DSS) by treatment with 4% DSS. Numbers of developed neoplasias were compared among the experimental groups, and macroscopic and microscopic features of the neoplasias were analysed. Furthermore, K-ras mutation and beta-catenin expression were assessed. Results: p53−/−-DSS mice showed 100% incidence of neoplasias whereas the incidences in p53+/−-DSS and p53+/+-DSS mice were 46.2% and 13.3%, respectively. No neoplasias were observed in the control groups. The mean numbers of total neoplasias per mouse were 5.0 (p53−/−-DSS), 0.62 (p53+/−-DSS), and 0.2 (p53+/+-DSS). The number of neoplasias per mouse in the p53−/−-DSS group was significantly higher than that in the other DSS groups. The incidences of superficial type neoplasias were 91.7% in p53−/−-DSS mice, 75.0% in p53+/−-DSS mice, and 33.3% in p53+/+-DSS mice. The K-ras mutation was not detected in any of the neoplasias tested. Translocation of beta-catenin from the cell membrane to the cytoplasm or nucleus was observed in 19 of 23 (82.6%) neoplasias. Conclusions: The p53−/−-DSS mice is an excellent animal model of UC associated neoplasia because the morphological features and molecular genetics are similar to those of UC associated neoplasia. Therefore, this model will contribute to the analysis of tumorigenesis related to human UC associated neoplasia and the development of chemopreventive agents.

Methylation of the oestrogen receptor gene in non-neoplastic epithelium as a marker of colorectal neoplasia risk in longstanding and extensive ulcerative colitis

Background: Surveillance colonoscopy is widely recommended in patients with longstanding and extensive ulcerative colitis (UC) in order to detect colorectal neoplasia at an early stage. However, it still remains questionable whether surveillance colonoscopy effectively enables early detection of UC associated neoplasia. There is a great need for sensitive markers to identify individuals at increased risk of neoplasia. The oestrogen receptor (OR) gene shows age related methylation in the colorectal epithelium and is methylated frequently in sporadic colorectal neoplasia, suggesting that OR methylation may predispose to colorectal neoplasia. Aim: To clarify whether analysis of methylation of the OR gene in non-neoplastic epithelium can contribute to prediction of increased neoplasia risk in UC patients. Materials and methods: A total of 165 non-neoplastic colorectal epithelia from 30 patients with longstanding and extensive UC, including 13 UC patients with neoplasia and 17 patients without, were evaluated. Methylation specific polymerase chain reaction was performed to determine the methylation status of the OR gene. Results: Methylation of the OR gene was detected in 54 of 70 (77.1%) non-neoplastic colorectal epithelia in UC with neoplasia but in only 23 of 95 (24.2%) without neoplasia. Methylation of the OR gene was significantly more frequent in non-neoplastic epithelium from UC with neoplasia than in chronic colitic epithelium from UC without neoplasia. Furthermore, in UC with neoplasia, the OR gene was extensively methylated in non-neoplastic epithelia throughout the colorectum compared with those in UC without neoplasia. Conclusion: These results suggest that analysis of OR gene methylation may have potential as a useful marker for identifying individuals at increased risk of neoplasia among those with longstanding and extensive UC.

Identification of genes differentially expressed in a newly isolated human metastasizing esophageal cancer cell line, T.Tn-AT1, by cDNA microarray

We isolated a metastasizing human esophageal squamous cell carcinoma (SCC) cell line, T.Tn‐AT1, from a parental non‐metastasizing cell line, T.Tn, by in vitro selection and by use of a nude mouse orthotopic inoculation model. Then, we compared the expression profiles of 9206 genes in T.Tn‐AT1 and T.Tn by cDNA microarray analysis. The gene expression profiles of T.Tn and T.Tn‐AT1 were very similar, and only 34 genes showed more than 3‐fold differential expression. Among the 34 genes, 29 genes were down‐regulated and only 5 genes were up‐regulated in T.Tn‐AT1 cells. Subsequently, we confirmed the expression levels of 14 of the 34 genes in T.Tn and T.Tn‐AT1 cells by means of reverse transcription‐polymerase chain reaction. The expression of 8 genes (KAL1, HPGD, NDN, REG1A, CXCR4, SPOCK, DIAPH2 and AIF1) was down‐regulated and that of one gene (VNN2) was up‐regulated in T.Tn‐AT1 cells. These 9 genes encoded proteins associated with metastatic processes, such as adhesion, migration, inflammation, proliferation, and differentiation. Thus, these genes might regulate the metastasis of esophageal SCC, and could be predictive markers for lymph node metastasis of esophageal SCC.

Optimal Colorectal Cancer Staging Criteria in TNM Classification

PURPOSE Histologic components of the TNM classification system have been repeatedly revised since the fifth edition (TNM5). TNM classification revisions provide different criteria for categorizing tumor nodules without residual lymph node structure (ND). However, there are few systematic evaluations regarding the effectiveness of these revisions. PATIENTS AND METHODS A multicenter pathologic review for ND in colorectal cancer (CRC) was performed. Tumor staging defined by TNM5, sixth edition (TNM6), and seventh edition (TNM7) were compared on the basis of Akaike information criterion (AIC) and Harrells concordance index (c-index). Moreover, TNM7s prognostic value was compared between the original ND and modified criteria, which considered all regional NDs as lymph node metastasis (LNM) irrespective of the original structure. RESULTS In 1,716 treated patients with CRC (1994 to 1998), tumor stages (I/II/III) exhibited better prognoses in TNM7 (AIC, 3055.1; c-index, 0.7215) than in TNM6 (AIC, 3063.7; c-index, 0.7149), but not better than in TNM5 (AIC, 3051.6; c-index, 0.7240). Comparing the original TNM7 and modified criteria, 4.2% of patients were classified in different N stages (N0/N1/N2a/N2b); both AIC and the c-index were superior in the modified criteria (AIC, 3029.40; c-index, 0.7271) compared with the original criteria (AIC, 3040.58; c-index, 0.7230). Modified criteria were also associated with improved prognostic power of tumor stages (I/IIA/IIB/IIC/IIIA/IIIB/IIIC). These results were similar in another cohort of 2,242 treated patients with CRC (1999 to 2003). CONCLUSION The prognostic value of TNM7 is better than that of TNM6; however, improvement over TNM5 is insignificant. By considering all regional NDs as LNM irrespective of their morphology, TNM classification can be simplified and its prognostic value improved.

Analyses of the APC and TGF-β type II receptor genes, and microsatellite instability in mucosal colorectal carcinomas

APC and transforming growth factor‐β type II receptor (TGF‐β RII) gene mutations, and microsatcllitc instability have been found in sporadic colorectal carcinomas. To clarify further the early alterations in colorectal carcinogenesis, we investigated these genetic changes in 23 protruding‐ and 24 superficial‐type mucosal colorectal carcinomas. TGF‐β RII gene mutations and microsatellite instability were rarely found in these lesions. Nevertheless, APC was mutated in 16 of the 47 (34.0%) mucosal colorectal carcinomas and was significantly more frequently mutated in protruding‐ (I) and superficial elevated‐type (Ila) (14/32,43.8%) than in other superficial‐type (IIa+IIc, IIb, IIc, and IIc+IIa) (2/ 15,13.3%) mucosal colorectal carcinomas (P<0.04). These results indicate that the APC gene may be involved from the beginning in the tumorigenesis of many early colorectal carcinomas, particularly of the protruding and superficial elevated types. However, there might be a distinct pathway for other superficial‐type colorectal carcinomas, possibly not involving APC as an initial step of tumorigenesis.