PubMed Health⌕ Search

Biomedical subjects

Tetsuichiro Muto

Publications and source records attributed to Tetsuichiro Muto.

At least 19 recordsLinked to original sources
PubMed2007

Prognosis and risk factors of metastasis in colorectal carcinoids: results of a nationwide registry over 15 years.

BACKGROUND: Colorectal carcinoids are often described as low-grade malignant. However, no study has compared the survival between patients with colorectal carcinoids and those with carcinomas, in a large series. In addition, no global consensus has been established on the crucial determinants of metastasis in colorectal carcinoids. AIM: To determine the predictive factors for metastasis in colorectal carcinoids and clarify their prognosis compared with adenocarcinomas. METHODS: Data of all patients diagnosed as having colorectal carcinoids were extracted from a large nationwide database of colorectal tumours, the Multi-Institutional Registry of Large-Bowel Cancer in Japan, for the period from 1984 to 1998. Risk factors for lymph node (LN) metastases and distant metastases were analysed among those who were undergoing surgery, by univariate and multivariate analysis. Cancer-specific survival was also compared between patients with colorectal carcinoids and those with adenocarcinomas registered in the same period. RESULTS: Among the 90 057 cases of colorectal tumours that were diagnosed, a total of 345 cases of carcinoids were identified, including 247 colorectal carcinoids of those undergoing surgery. Risk factors for LN metastasis were tumour size >/=11 mm and lymphatic invasion, whereas those for distant metastasis were tumour size >/=21 mm and venous invasion. Colorectal carcinoids without these risk factors exhibited no LN metastasis or distant metastasis. Cancer-specific survival of patients with colorectal carcinoids without metastasis was better than that of those with adenocarcinomas. However, the survival was similar between carcinoids and adenocarcinomas if the tumours had LN metastasis or distant metastasis. CONCLUSIONS: The presence of metastasis in colorectal carcinoids could lead to survival that is as poor as in adenocarcinomas. Tumours </=10 mm and without lymphatic invasion could be curatively treated by local resection, but others would need radical LN dissection.

Adenocarcinoma↗
PubMed2006

Proposal of a new and simple staging system of colorectal liver metastasis.

AIM: To create a new, simple and useful staging system for colorectal liver metastasis analogous to the Tumor Node Metastasis classification system of International Union Against Cancer. METHODS: A retrospective review was undertaken of 81 consecutive patients who underwent partial hepatectomy for colorectal liver metastases (group 1). Clinical and pathological features of both primary and metastatic liver cancers were entered into a multivariate analysis to determine independent variables helpful in accurately predicting long-term prognosis after hepatectomy. Using selected variables, we created a new staging system like TNM classification. The usefulness of the new staging system was examined in a series of 92 patients from another hospital (group 2). RESULTS: Multivariate analysis showed that 81 patients in group 1 had significant multiple hepatic tumors with the largest tumor being more than 5 cm in diameter, resectable extrahepatic distant metastases, and independent prognostic factors for poor survival after hepatectomy. Using these three variables, we created a new staging system to classify patients with colorectal liver metastases. Finally, our new staging system classified the patients both in group 1 and in group 2. CONCLUSION: Our new staging system of colorectal liver metastasis is simple and useful for staging patients.

Adult↗
PubMed2006

Proposal of criteria to select candidates with colorectal liver metastases for hepatic resection: comparison of our scoring system to the positive number of risk factors.

AIM: To select accurately good candidates of hepatic resection for colorectal liver metastasis. METHODS: Thirteen clinicopathological features, which were recognized only before or during surgery, were selected retrospectively in 81 consecutive patients in one hospital (Group I). These features were entered into a multivariate analysis to determine independent and significant variables affecting long-term prognosis after hepatectomy. Using selected variables, we created a scoring formula to classify patients with colorectal liver metastases to select good candidates for hepatic resection. The usefulness of the new scoring system was examined in a series of 92 patients from another hospital (Group II), comparing the number of selected variables. RESULTS: Among 81 patients of Group I, multivariate analysis, i.e. Cox regression analysis, showed that multiple tumors, the largest tumor greater than 5 cm in diameter, and resectable extrahepatic metastases were significant and independent prognostic factors for poor survival after hepatectomy (P < 0.05). In addition, these three factors: serosa invasion, local lymph node metastases of primary cancers, and post-operative disease free interval less than 1 year including synchronous hepatic metastasis, were not significant, however, they were selected by a stepwise method of Cox regression analysis (0.05 < P < 0.20). Using these six variables, we created a new scoring formula to classify patients with colorectal liver metastases. Finally, our new scoring system not only classified patients in Group I very well, but also that in Group II, according to long-term outcomes after hepatic resection. The positive number of these six variables also classified them well. CONCLUSION: Both, our new scoring system and the positive number of significant prognostic factors are useful to classify patients with colorectal liver metastases in the preoperative selection of good candidates for hepatic resection.

Adult↗
PubMed2006

Distal colorectal cancers with microsatellite instability (MSI) display distinct gene expression profiles that are different from proximal MSI cancers.

Promoter methylation of the mismatch repair gene plays a key role in sporadic microsatellite instability (MSI) colorectal cancers. However, promoter methylation often occurs in proximal colon cancers, and molecular phenotypes underlying MSI cancers in distal colon have not been fully clarified. Our goal was to clarify the difference between MSI and microsatellite stability (MSS) cancers and, furthermore, to determine distinct characteristics of proximal and distal MSI cancers. By DNA microarray analysis of 84 cancers (33 MSI and 51 MSS), we identified discriminating genes (177 probe sets), which predicted MSI status with a high accuracy rate (97.6%). These genes were related to phenotypic characteristics of MSI cancers. Next, we identified 24 probe sets that were differentially expressed in proximal and distal MSI cancers. These genes included promoter methylation-mediated genes, whose expression was significantly down-regulated in proximal MSI cancers. Among discriminating genes between MSI and MSS, nine methylation-mediated genes showed down-regulation in MSI cancers. Of these, 7 (77.8%) showed down-regulation in proximal MSI cancers. Furthermore, methylation-specific PCR confirmed that frequency of hMLH1 promoter methylation was significantly higher in proximal MSI cancers (P = 0.0317). These results suggested that there is a difference between proximal and distal MSI cancers in methylation-mediated influence on gene silencing. In conclusion, using DNA microarray, we could distinguish MSI and MSS cancers. We also showed distinct characteristics of proximal and distal MSI cancers. The inactivation form of hMLH, per se, differed between proximal and distal MSI cancers. These results suggested that distal MSI cancers constitute a distinct subgroup of sporadic MSI cancers.

Adaptor Proteins, Signal Transducing↗
PubMed2006

Characteristics of recurrence and surveillance tools after curative resection for colorectal cancer: a multicenter study.

BACKGROUND: The aim of this study was to clarify the characteristics of recurrence and the effectiveness of surveillance tools after curative resection for colorectal cancer. METHODS: We enrolled 5230 consecutive patients (stage I, 1367; stage II, 1912; stage III, 1951) who underwent curative resection at 14 hospitals from 1991 to 1996. All patients were followed up intensively, and their outcomes were investigated retrospectively. RESULTS: Of the 5230 patients, 906 developed recurrence. The recurrence rates of stage I, II, and III cancers were 3.7%, 13.3%, and 30.8%, respectively (P < .0001). The curves of the cumulative appearance rate of recurrence in stage II and III patients showed a rapid increase for the first 3 years. Recurrence after 5 years was less than 1% in each stage. Clinical visits combined with measurements of tumor markers detected the majority of recurrences except in the case of lung metastasis. In contrast, 43.4% of hepatic recurrences were detected by liver imaging, and 48.4% of pulmonary recurrences were noted by chest x-ray. The 5-year survival rates after primary colorectal surgery in patients who underwent resection for recurrence were better than in those without resection: 55% vs 11% in hepatic recurrence, 68% vs 13% in pulmonary recurrence, and 48% vs 22% in local recurrence (all P < .001). CONCLUSION: It is useful to take these characteristics of recurrence into account in the management of patients after curative resection for colorectal cancer and in the setting of clinical trial for follow-up after curative resection for colorectal cancer.

Aged↗
PubMed2006

Prediction of sensitivity of rectal cancer cells in response to preoperative radiotherapy by DNA microarray analysis of gene expression profiles.

Preoperative radiotherapy has been widely used to improve local control of disease and to improve survival in the treatment of rectal cancer. However, the response to radiotherapy differs among individual tumors. Our objective here was to identify a set of discriminating genes that can be used for characterization and prediction of response to radiotherapy in rectal cancer. Fifty-two rectal cancer patients who underwent preoperative radiotherapy were studied. Biopsy specimens were obtained from rectal cancer before preoperative radiotherapy. Response to radiotherapy was determined by histopathologic examination of surgically resected specimens and classified as responders or nonresponders. By determining gene expression profiles using human U95Av2 Gene Chip, we identified 33 novel discriminating genes of which the expression differed significantly between responders and nonresponders. Using this gene set, we were able to establish a new model to predict response to radiotherapy in rectal cancer with an accuracy of 82.4%. The list of discriminating genes included growth factor, apoptosis, cell proliferation, signal transduction, or cell adhesion-related genes. Among 33 discriminating genes, apoptosis inducers (lumican, thrombospondin 2, and galectin-1) showed higher expression in responders whereas apoptosis inhibitors (cyclophilin 40 and glutathione peroxidase) showed higher expression in nonresponders. The present study suggested the possibility that gene expression profiling may be useful in predicting response to radiotherapy to establish an individualized tailored therapy for rectal cancer. Global expression profiles of responders and nonresponders may provide insights into the development of novel therapeutic targets.

Combined Modality Therapy↗
PubMed2006

Anal canal carcinoma with Pagetoid spread: report of a case.

A 70-year-old man with a history of colon polyps was found to have a semipedunculated polyp in the anal canal. The patient was asymptomatic. The lesion was 14 mm in diameter and located 5 mm from the dentate line. Histological examination of biopsy specimens revealed well-differentiated adenocarcinoma of the anal canal. During transanal local excision of the tumor, an abnormality of the perianal skin was recognized. Although intraoperative frozen section of the perianal skin did not show malignancy, permanent sections of the perineal skin revealed Paget's cells in the epidermis. Pathological examination of the anal canal carcinoma revealed submucosally invasive well-differentiated adenocarcinoma with a positive distal surgical margin. Thus, we performed additional wide local excision of the perianal skin including the distal margin of the previous local excision. Pathological examination revealed continuance within the epidermis between the anal canal adenocarcinoma and Paget's cells in the perianal skin lesion. Scattered Paget's cells also formed some glandular structures. Thus, we concluded that the perianal skin lesion was Pagetoid spread of anal canal adenocarcinoma. This report shows that the perianal skin should be examined carefully in patients with anal canal carcinoma.

Adenocarcinoma↗
PubMed2006

Does a selective cyclooxygenase-2 inhibitor (tiracoxib) induce clinically sufficient suppression of adenomas in patients with familial adenomatous polyposis? A randomized double-blind placebo-controlled clinical trial.

BACKGROUND: There have been few placebo-controlled randomized double-blind studies of the clinical effects of selective cyclooxygenase-2 (COX-2) inhibitors on the regression of colorectal tumors. This study was designed to examine the regressive effect of a selective COX-2 inhibitor, tiracoxib (JTE-522), on colorectal polyps in patients with familial adenomatous polyposis (FAP), and its safety. METHODS: Sixty-one patients with FAP diagnosed by Japanese criteria were assigned randomly to receive placebo or JTE-522, at either 150 mg or 200 mg, once daily orally for 26 weeks. Prior to and at the end of the medication period, endoscopy was performed. Adenomas located near an india-ink tattoo injected at the first colonoscopy were identified and measured. The response variables were the percent changes from the baseline in polyp numbers and in specified polyp diameters. Any adverse events that appeared in at least four persons were taken into consideration and compared between the JTE-522 treatment groups and the placebo group. RESULTS: No change in polyp number (median, 0) was observed in any of the three groups. There were no differences between the placebo group and the two treatment groups in the change in polyp size. JTE-522 was well tolerated. CONCLUSION: Our findings, in keeping with other reports on COX-2 inhibitors, indicated that the inhibition of a COX-2 with a moderate dose of a selective COX-2 inhibitor did not induce clinically sufficient regression of adenomas in patients with FAP in a limited (6-month) medication period.

Adenomatous Polyposis Coli↗
PubMed2006

Indication and benefit of pelvic sidewall dissection for rectal cancer.

PURPOSE: This study was designed to clarify indication and benefit of pelvic sidewall dissection for rectal cancer. METHODS: The retrospective, multicenter study collected the data of rectal cancer patients who underwent surgery between 1991 and 1998 and were prospectively followed. RESULTS: Of 1,977 patients with rectal cancers, 930 underwent pelvic sidewall dissection without adjuvant radiotherapy. Positive lateral lymph nodes were found in 129. Multivariate analysis disclosed a significantly increased incidence of positive lateral lymph nodes in female gender, lower rectal cancers, non-well-differentiated adenocarcinoma, tumor size of > or =4 cm and T3-T4. The five-year survival rate for 1,977 patients was 79.7 percent. The survival of patients with positive lateral lymph nodes was significantly worse than that of Stage III patients with negative lateral lymph nodes (45.8 vs. 71.2 percent, P<0.0001). Multivariate analysis showed significantly worse prognosis in male gender, pelvic sidewall dissection, lower rectal cancers, T3-T4, perirectal lymph node metastasis, and positive lateral lymph nodes. During the median follow-up time of 57 months, recurrence developed in 19.7 percent: 17 percent in negative and 58.1 percent in positive lateral lymph nodes (P<0.0001). Local recurrence was found in 8 percent: 6.8 percent in negative and 25.6 percent in positive lateral lymph nodes (P<0.0001). Multivariate analysis disclosed that lower rectal cancers, non-well-differentiated adenocarcinoma, T3-T4, perirectal lymph node metastasis, and positive lateral lymph nodes were significantly associated with an increased local recurrence. CONCLUSIONS: Positive lateral lymph node was the strongest predictor in both survival and local recurrence. Pelvic sidewall dissection may be indicated for patients with T3-T4 lower rectal cancers because of the greater probability of positive lateral lymph nodes.

Adenocarcinoma↗
PubMed2006

Frequency of immunohistochemical loss of mismatch repair protein in double primary cancers of the colorectum and stomach in Japan.

PURPOSE: Colorectal cancer and gastric cancer are the two most commonly associated malignancies in Japan. We examined mismatch repair deficiency in the tumors of patients with primary colorectal and gastric cancers retrospectively. METHODS: In 103 cases and 102 healthy control subjects, surgical specimens of colorectal and gastric cancer underwent immunohistochemical analysis of mismatch repair proteins (hMLH1 and hMSH2) and microsatellite instability testing. RESULTS: Immunohistochemical and microsatellite instability testing produced similar results. High microsatellite instability in colorectal cancer was found in 23 of 103 cases (23 percent) with colorectal and gastric cancers, and in 8 of 102 healthy control subjects (8 percent). Twelve (12 percent) had mismatch repair deficiency in both colorectal and gastric cancers, and both tumors had loss of the same mismatch repair protein (hMLH1, n = 5; hMSH2, n = 7). They had the first cancer at a younger age, with a higher frequency of familial colorectal cancer than the others. Seventeen had mismatch repair deficiency in either tumor, which showed loss of expression of hMLH1. Multiple cancers and right-sided colon cancers developed more frequently in patients with mismatch repair deficiency. CONCLUSIONS: Patients with both colorectal and gastric cancers are more likely to have phenotypic evidence of hereditary nonpolyposis colorectal cancer than patients with colorectal cancer only. Among patients with double tumors, 12 percent showed a common deficiency in the same mismatch repair protein in both tumors by immunohistochemistry, and they should undergo genetic counseling for germline mutational analysis. Immunohistochemistry was effective in detecting mismatch repair deficiency of colorectal and gastric cancer as well as microsatellite instability testing, and may be more practical to perform phenotypic analysis of tumors because of its cost-effectiveness.

Adaptor Proteins, Signal Transducing↗
PubMed2006

Usefulness of LigaSure for liver resection: analysis by randomized clinical trial.

BACKGROUND: The goal of the present study was to evaluate the efficacy of the novel LigaSure Vessel Sealing System (Valleylab, Boulder, CO) when used for liver resection. METHODS: Sixty patients (n = 30 in each group) with liver pathology from a single center were randomized to undergo liver resection with either the LigaSure system or with conventional clamping methods. Patients were stratified according to tumor size (<5 or >5 cm), type of hepatectomy (minor or major), and liver damage (normal or injured). Estimated blood loss during liver transection was used as the primary end point, whereas liver transection speed and morbidity rate were used as secondary end points. RESULTS: There were no hospital deaths. The median blood loss during liver transection was less in the LigaSure than in the conventional group (200 vs 322 mL; P = .185). The amount of blood loss during minor hepatectomy was significantly less in the LigaSure than in the conventional group (186 vs 412 mL, P = .012). The liver transection speed was significantly faster in the LigaSure than in the conventional group (2.3 vs 1.6 cm(2)/min, P < .001. The number of ties required during liver transection was significantly less in the LigaSure than in the conventional group (6 vs 69 ties, P < .001). The morbidity rate was similar when comparing the 2 groups, indicating that the LigaSure sealing device and conventional methods had comparable efficacy in sealing the bile duct in the portal triad. Postoperative bile leak was observed in 1 patient (3%) in the LigaSure group and in 3 patients (9%) in the conventional group (P = .301). CONCLUSIONS: The LigaSure system is an effective and safe tool for decreasing liver resection time.

Aged↗
PubMed2006

[Cancer board--new medical system in cancer clinic].

To proceed with more patient-oriented cancer medicine, the development of a new medical system is necessary in Japan. In Ariake Hospital of the Japanese Foundation for Cancer Research, a new medical system has been developed, which is composed of a common outpatient clinic and a conference system. The core conference system is called "Cancer Board". The practice of patient-oriented medicine in gastroenterological cancer has been introduced as a sample of the Cancer Board system in our hospital.

Ambulatory Care Facilities↗
PubMed2005

Increase in the frequency of K-ras codon 12 point mutation in colorectal carcinoma in elderly males in Japan: the 1990s compared with the 1960s.

The incidence of colorectal carcinomas has been increasing over the last 50 years in Japan. In order to determine whether adenoma-carcinoma sequence (ACS) or de novo cancer development, generally considered to be two separate genetic pathways, might be responsible, K-ras codon 12 mutations, good markers for ACS, were examined in 59 and 84 cases of advanced colorectal cancer surgically resected in Cancer Institute Hospital of the Japanese Foundation for Cancer Research in 1960-1969 and in 1990-1999, respectively. There was no significant difference of K-ras codon 12 mutation between the 25.4% (15/59) in the 1960s and 36.9% (31/84) in the 1990s (P = 0.148), and the reference of distal colon cancer also showed no significant difference between 24.4% (11/45) and 36.4% (20/55). Yet elderly males showed a significant difference: 27.3% (6/22) in the 1960s and 59.3% (16/27) in the 1990s. The references of males, elderly patients (over 75 years old) and distal colon cancer in the 1990s were significantly more likely to demonstrate mutations than their counterparts in the 1960s. There was no variation with the tumor location. The results suggest that the ACS pathway might have primarily contributed to the increased incidence of colorectal cancer in elderly males in Japan.

Adenocarcinoma↗
PubMed2005

[Gene testing of hereditary cancer on comprehensive gene medical examination support system].

It has been estimated that genetic factors or a combination of genetic and environmental factors play a role in the development of 10-15% of all cancers. A genetic cause of hereditary cancer has been identified in more than 40 diseases till now. For preventing this cancer, gene testing is essential because it has no definite clinical marker as in hereditary non-polyposis colorectal cancer: HNPCC. Much more experience must be accumulated in this testing at the clinical base in order to increase specificity and sensitivity while safeguarding ethical, legal and social issues (ELSI). Recently, the Personal Information Protection Law was enforced. Gene inspection involving hereditary cancer should be carried out under a comprehensive gene medical examination organization. It is important for the family doctor, medical specialist, and gene inspection person in charge to cooperate closely with one another, and this will be a subject of future study.

Adenomatous Polyposis Coli↗
PubMed2004

Reconstruction of hepatic or portal veins by use of newly customized great saphenous vein grafts.

BACKGROUND AND AIMS: Segmental resection of major hepatic veins or the portal vein is sometimes required if one is to secure adequate surgical margins from hepatic or pancreatic malignancies. An external iliac vein is widely sacrificed as a vein graft to replace the defect, but this is associated with postoperative edema of the lower leg. We developed a new method for constructing the great saphenous vein to interpose the hepatic or portal veins. PATIENTS AND METHODS: The great saphenous vein was divided transversely into three sections, which were aligned side-to-side. The three pieces were anastomosed to make a sheet 3 x 2 cm, which was rolled up into a cylindrical form of approximately 1 cm in diameter and 2 cm in length. We applied the finished vein grafts to interpose the major hepatic veins in three patients with metastatic liver tumors and the portal vein in two patients with pancreatic malignancies in cylindrical form and to reconstruct the portal vein in one patient with a pancreas cancer, using a three-row sheet as a patch graft. RESULTS: No patient developed venous thrombosis of the graft or edema of the lower leg. CONCLUSIONS: The newly customized vein graft was safe and useful for the reconstruction of the major hepatic or portal veins.

Aged↗
PubMed2004

Bloodless liver resection using the monopolar floating ball plus ligasure diathermy: preliminary results of 16 liver resections.

Blood loss during liver transection and ischemia-reperfusion injury associated with hepatic inflow occlusion are significant drawbacks during liver surgery. Sixteen patients underwent liver resection using the Monopolar Floating Ball (FB) plus LigaSure (LS) diathermy without occlusion of the hepatoduodenal ligament (group FB-LS). The liver parenchyma was precoagulated using the FB, and the uncovered tiny vessels were sealed using LS. Surgical outcomes were retrospectively compared with 16 well matched patients who underwent liver resection using the conventional clamp crushing method with Pringle's maneuver (group CC). The amount of blood loss during liver transection was significantly less in group FB-LS than in group CC [200 ml (0-990 ml) vs. 480 ml (120-1800 ml); p = 0.006]. The median time it took to complete the liver transection was significantly longer in group FB-LS than in group CC [144 minutes (43-335 minutes) vs. 58 minutes (18-94 minutes); p < 0.0001]. Hepatic inflow occlusion was temporally used in five patients in group FB-LS to achieve hemostasis in hepatic venous tributaries for 6, 10, 19, 26, and 61 minutes, respectively. Using these two electronic devices allows liver resection to be safely performed, with the advantage of minimal blood loss and a reduced inflow occlusion period compared to the conventional method. The major disadvantage may be a slower transection speed. A prospective randomized trial is needed to clarify the clinical benefits of liver resections performed using this novel technique.

Adult↗