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S Obi

Publications and source records attributed to S Obi.

At least 19 recordsLinked to original sources
PubMed2006

Absence of PIK3CA hotspot mutations in hepatocellular carcinoma in Japanese patients.

A recent study revealed that the p110alpha (PIK3CA), catalytic subunit of phosphatidylinositol 3-kinase (PI3K), is somatically mutated in many types of cancer. For example, PIK3CA is mutated in an estimated 35.6% of hepatocellular carcinoma (HCC) cases. To measure the frequency of PIK3CA hotspot mutations in Japanese HCC patients, exons 9 and 20 of the PIK3CA gene were sequenced in 47 clinical HCC samples. Contrary to expectations, no hotspot mutations were found any of the HCC samples. In addition, we found abnormally migrating waves near the end of exon 9 in the PCR chromatograms from 13 of the 47 samples. PCR amplification and subsequent cloning and sequencing revealed that these chromatograms contained two distinct sequences, the wild-type p110alpha sequence and a different sequence found on human chromosome 22q11.2, the Cat Eye Syndrome region, which contains a putative pseudogene of PIK3CA. These abnormally migrating waves were also found in noncancerous liver tissue, indicating that this was not a result of HCC-associated mutations. Therefore, it is likely that the percentage of hotspot mutations in the PIK3CA gene of Japanese HCC patients is lower than was previously reported.

Adult↗
PubMed2005

Proposal of a new prognostic model for hepatocellular carcinoma: an analysis of 403 patients.

BACKGROUND: The prognosis of hepatocellular carcinoma (HCC) is highly dependent on tumour extension and liver function. Recently, two new prognostic scoring systems-the CLIP score, developed by Italian investigators and the BCLC score, developed in Barcelona-have been widely used to assess prognosis in patients presenting with hepatocellular carcinoma. Each system has its own relative limitations. AIMS: To create a new prognostic scoring system which is simple, easy to calculate, and suitable for estimating prognosis during radical treatment of early HCC. METHODS: A total of 403 consecutive patients with HCC treated by percutaneous ablation at the Department of Gastroenterology, University of Tokyo Hospital, between 1990 and 1997 were used as the training sample to identify prognostic factors for our patients and used to develop the Tokyo score. As a testing sample, 203 independent patients who underwent hepatectomy at the Department of Hepato-Biliary-Pancreatic Surgery were studied. Prognostic factors were analysed by univariate and multivariate Cox proportional hazard regression. RESULTS: The Tokyo score consists of four factors: serum albumin, bilirubin, and size and number of tumours. Five year survival was 78.7%, 62.1%, 40.0%, 27.7%, and 14.3% for Tokyo scores 0, 1, 2, 3, and 4-6, respectively. The discriminatory ability of the Tokyo score was internally validated by bootstrap methods. The Tokyo score, CLIP score, and BCLC staging were compared by Akaike information criterion and Harrell's c index among training and testing samples. In the testing sample, the predictive ability of the Tokyo score was equal to CLIP and better than BCLC staging. CONCLUSIONS: The Tokyo score is a simple system which provides good prediction of prognosis for Japanese patients with HCC requiring radical therapy.

Adolescent↗
PubMed2002

False positive uptake of metaiodobenzylguanidine in hepatocellular carcinoma.

We present the case of a patient who showed increased accumulation of (123)I-metaiodobenzylguanidine (MIBG) in hepatocellular carcinoma, leading to a false presumptive diagnosis of intrahepatic neuroendocrine tumour. The increase in uptake was not seen on images obtained 4 h after tracer injection but was evident on those taken after 24 h, suggesting slower washout from the liver tumour than from non-tumoural liver parenchyma. Our observations indicate that a non-neuroendocrine malignant tumour may exhibit high accumulation of MIBG associated with prolonged retention.

3-Iodobenzylguanidine↗
PubMed2001

Des-gamma-carboxy prothrombin as a useful predisposing factor for the development of portal venous invasion in patients with hepatocellular carcinoma: a prospective analysis of 227 patients.

BACKGROUND: Portal venous invasion (PVI) in patients with hepatocellular carcinoma (HCC) is an important factor affecting prognosis. The objective of this study was to elucidate predisposing factors for the development of PVI. METHODS: Two hundred twenty-seven patients with HCC who did not show PVI and who received percutaneous ethanol injection therapy and/or microwave coagulation therapy at the time of their first hospital admission were enrolled between 1994 and 1996. After their HCC was treated, the patients were followed for a mean of 19 months. For the detection of HCC recurrence and/or development of PVI, ultrasonography was performed every 3 months, a computed tomography (CT) scan was performed every 6 months, and the biochemical parameters of the patients were measured every month. PVI was defined as protrusion of the tumor into the first and/or second branch or into the main trunk of the portal vein. RESULTS: Of the 227 patients, 24 (11%) later developed PVI. Tabular analysis was performed on these 24 patients and indicated that tumor size, albumin, total bilirubin, prothrombin time, alpha-fetoprotein (AFP) level, and des-gamma-carboxy prothrombin (DCP) level differed significantly between the time of initial admission and the time of PVI development. A univariate analysis performed on the 227 patients indicated that an increase in the numbers of tumors, the histologic tumor grade (differentiation), the AFP level, and the DCP level at the time of initial diagnosis of HCC had a significant correlation with the later development of PVI; and a stepwise, multivariate Cox regression analysis revealed that the DCP level was the strongest predisposing factor (P < 0.0010; risk ratio = 5.65) followed by the histologic grade of tumor differentiation. CONCLUSIONS: The results suggest that the serum DCP level is the most useful predisposing clinical parameter for the development of PVI.

Adult↗
PubMed2001

Hepatocellular carcinoma depicted as hypoattenuation on CT hepatic arteriography (CTA) and hyperattenuation on CT during arterial portography (CTAP).

We report a 68-year-old man with three nodules of hepatocellular carcinoma (HCC) in a cirrhotic liver; the largest nodule was 3.0cm in diameter. The nodules showed hypoattenuation on computed tomography (CT) hepatic arteriography (CTA) and hyperattenuation on CT during arterial portography (CTAP), indicating that the dominant vascularity of the HCC nodules may have been the portal vein. A biopsy specimen obtained from the nodules showed well differentiated HCC (Edmondson-Steiner grade I). The imaging findings of the nodules on both CTA and CTAP are unusual, in spite of the rather large size, so this seemed suggestive of the hemodynamic properties of relatively large nodules of well differentiated HCC.

Aged↗
PubMed2001

Power Doppler signals after percutaneous ethanol injection therapy for hepatocellular carcinoma predict local recurrence of tumors: a prospective study using 199 consecutive patients.

BACKGROUND/AIMS: This study was prospectively conducted to elucidate the relationship between pre-/post-treatment power Doppler signals of hepatocellular carcinoma (HCC) and local recurrence. METHODS: One hundred ninety-nine consecutive patients with 359 HCC lesions receiving percutaneous ethanol injection therapy (PEIT) as a first-line option were enrolled. Arterial power Doppler signals in the tumor were found in 130 nodules, but not detected in 229. After confirmation of complete tumor necrosis on dynamic CT, Doppler signals in nodules were re-evaluated. Patients received periodical examinations to detect HCC recurrence. RESULTS: Local HCC recurrence was observed in 36 lesions; 22%(28/130) of the pretreatment signal positive lesions, in contrast to 3.5% (8/229) of the pretreatment signal negative lesions (P < 0.01). Out of 130 signal positive nodules, signals disappeared in 120 (92%) after PEIT, but were present in ten (8%). During the 25-month follow up, local recurrence was detected in 19 (16%) from the former, in contrast to nine (90%) from the latter (P < 0.001). Uni- and multivariate Cox analysis revealed that the presence of pre-/post-treatment power Doppler signals, histological differentiation and tumor number were independent factors for local recurrence. However, 3-year recurrence rate of new lesions was 51%, but no predictors were identified. CONCLUSIONS: Residual Doppler signals in tumor after PEIT were related to the local HCC recurrence.

Adult↗
PubMed2001

Percutaneous ethanol injection therapy for liver tumors.

Percutaneous ethanol injection therapy (PEIT) has been widely practiced in the treatment of liver tumors, especially of hepatocellular carcinoma (HCC). Histopathologic examinations, findings in imaging modalities and serum tumor marker levels have shown a remarkable anticancer effect of this procedure. In addition, PEIT has achieved considerably high long-term survival rates. For small HCC, PEIT has been generally accepted as an alternative to surgery. Here we will describe PEIT from the viewpoints of patient selection, technique, various evaluation procedures of efficacy, long-term results, side effects and complications, and relationship with other therapies.

Carcinoma, Hepatocellular↗
PubMed2001

Thoracoscopic thermal ablation therapy for hepatocellular carcinoma located beneath the diaphragm.

BACKGROUND AND STUDY AIMS: Percutaneous interstitial thermal ablation therapy effectively treats hepatocellular carcinoma (HCC) that can be visualized on percutaneous ultrasonography. However, when the tumor is located just under the top of the diaphragm, visualization can be difficult with conventional ultrasonographic examination. There are also problems concerning complete tumor ablation. We performed thoracoscopic thermal ablation therapy for HCC located just beneath the diaphragm in nine patients with advanced liver cirrhosis. PATIENTS AND METHODS: Eight patients underwent thoracoscopic microwave coagulation therapy, and one patient underwent thoracoscopic radiofrequency ablation therapy. RESULTS: Despite the poor hepatic reserve, postoperative recovery after thoracoscopic thermal ablation therapy was rapid in all patients, without deterioration of hepatic function. CONCLUSIONS: This preliminary study suggests that the new technique of thoracoscopic thermal ablation therapy is a less invasive optional therapy for HCC located in segments VII or VIII in cirrhotic patients.

Aged↗
PubMed2000

Unique clinical characteristics of patients with hepatocellular carcinoma who present with high plasma des-gamma-carboxy prothrombin and low serum alpha-fetoprotein.

BACKGROUND: Although the importance of alpha-fetoprotein (AFP) and des-gamma-carboxy prothrombin (DCP) in the clinical treatment of hepatocellular carcinoma (HCC) has been studied extensively, the authors examined the clinical picture of HCC with regard to the state of these two tumor markers. METHODS: The authors categorized 237 HCC cases into 4 groups according to levels of AFP and DCP: high levels of AFP with low DCP levels, high DCP levels with low AFP levels, high levels of both tumor markers, and low levels of both tumor markers. Comparisons of survival rates were made among these groups using the Kaplan-Meier product limit method, and for other comparisons of clinical parameters the Fisher PSLD test was used. Prognostic significance was tested with the Cox proportional hazards model. RESULTS: The cutoff values were set at 100 ng/mL for AFP and 0.0625 AU/mL for DCP. Forty-eight patients (20.7%) had high levels of AFP and low levels of DCP, 22 (9.3%) had high DCP levels and low levels of AFP, 12 (4.6%) had high levels of both AFP and DCP, and 155 (65.4%) had low levels of both DCP and AFP. Patients with high levels of DCP but low levels of AFP were predominantly male and had large lesions but few nodules. Patients with high levels of both tumor markers had the most discouraging outcome observed in this study (death within 3 years). CONCLUSIONS: Patients with high levels of DCP and low levels of AFP exhibited the unique clinical characteristic of large HCC nodules that were few in number. In addition, it was observed that measurement of both AFP and DCP can predict the survival of patients.

Adult↗
PubMed2000

Risk factors for recurring hepatocellular carcinoma differ according to infected hepatitis virus-an analysis of 236 consecutive patients with a single lesion.

Patients with hepatocellular carcinoma (HCC) frequently experience intrahepatic HCC recurrence even after complete ablation of primary lesions. Because the oncogenic process may be different for hepatitis B viral (B-viral) and hepatitis C viral (C-viral) HCC, the present study was conducted to elucidate the factors contributing to HCC recurrence with respect to the infected hepatitis virus. Two hundred thirty-six patients with a single HCC lesion who underwent complete ablation of the tumor by PEIT and/or PMCT or surgical resection at Tokyo University and its affiliated hospitals from 1993 to 1997 were enrolled. The patients were classified into 3 groups: the B-viral group, C-viral group, and NBNC group. After complete removal of tumors, the patients were followed for a mean period of 39 months. The factors contributing to HCC recurrence were analyzed by univariate and multivariate analysis using the Cox proportional hazard model. The rate of intrahepatic recurrence in enrolled patients at 1, 3, and 5 years was 19%, 50%, and 64%, respectively. The intrahepatic recurrence rate in C-viral and B-viral HCC was higher than that in the NBNC-related HCC. Fibrosis staging, pathological grading of HCC, and serum AFP levels were significantly linked to intrahepatic recurrence by univariate analysis, and fibrosis staging was strongest in the multivariate analysis for C-viral HCC (P = .004). In contrast, fibrosis staging did not affect the recurrence in B-viral (P = .51) and NBNC-related (P = .77) HCC. Risk factors for HCC recurrence differed according to the infected viral state.

Aged↗
PubMed2000

Early detection of haemobilia associated with percutaneous ethanol injection for hepatocellular carcinoma.

OBJECTIVE: Haemobilia often results from iatrogenic injury caused by therapeutic procedures. The objective of this study was to evaluate the efficacy of early diagnosis of haemobilia based on ultrasonography in patients with hepatocellular carcinoma undergoing percutaneous ethanol injection. PATIENTS AND METHODS: A combination retrospective and prospective study on the early detection of haemobilia caused by percutaneous ethanol injection was conducted on 365 patients in 1995-1996. The retrospective study reviewed the clinical, laboratory and imaging data of 172 patients who had undergone ethanol injection therapy in 1995. The results showed that ultrasonographic changes in the gallbladder, namely the rapid appearance of echogenic material in the gallbladder lumen, are a useful early sign of haemobilia. Based on the results of the retrospective study, a prospective study on the early detection of haemobilia was carried out in 1996. In the prospective study, percutaneous ethanol injection was halted as soon as haemobilia was detected. RESULTS: The incidence of haemobilia in the prospective group (3.6%) was not different from that in the retrospective group (4.7%). However, the mean duration between percutaneous ethanol injection and diagnosis of haemobilia was only 0.3 +/- 0.2 days in the prospective group, compared with 2.8 +/- 2.1 days in the retrospective group (P < 0.001), and the mean duration of jaundice in the prospective group (4.3 days) was significantly shorter than in the retrospective group (40.0 days) (P< 0.05). CONCLUSION: Early diagnosis of haemobilia based on ultrasonographic findings of the gallbladder lumen effectively reduces the severity of haemobilia-related complications due to immediate interruption of the interventional procedure.

Administration, Cutaneous↗
PubMed2000

[Percutaneous tumor ablation therapy for the advanced stage of HCC].

We have performed percutaneous tumor ablation (PTA) including percutaneous ethanol injection therapy (PEIT) for 90% of the patients with hepatocellular carcinoma. Until December 1998, the 793 patients received PTA, 5 years survival rate reached 39.8%. Excluding the patients with Child C whose hepatic function were extremely low, 5 years survival rate reached to the level of 41.2%. Since 5 years survival rate in stage IV-A reached 24.4%, the patients of stage IV-A may be considered to have an indication for PTA. We have confirmed the effectiveness of the local treatment including radiotherapy for advanced hepatocellular carcinoma with portal vein invasion. We are attempting to perform PTA for the extra-hepatic lesions that had no indication of other treatment. However the indication of PTA is limited by the presence of diffuse nodules, exacerbation of the hepatic function, or tumor invasion to portal vein, bile duct, inferior vena cava.

Carcinoma, Hepatocellular↗
PubMed1999

Endoscopic variceal ligation is a sufficient procedure for the treatment of oesophageal varices in patients with hepatitis C liver cirrhosis: comparison with injection sclerotherapy.

AIMS: Endoscopic variceal ligation (EVL) is a recently developed alternative to endoscopic injection sclerotherapy (EIS) for the treatment of oesophageal varices. Endoscopic variceal ligation and EIS were compared in an attempt to clarify the efficacy and safety of EVL for patients with cirrhosis due to hepatitis C. METHODS: Endoscopic variceal ligation was performed in 60 patients and EIS in 30. Varices were eradicated in all patients by EVL and 87% (26 out of 30) by EIS. RESULTS: There was no significant difference between EVL and EIS in relation to the incidence of bleeding and the 5 year survival rate after treatment. There were no severe complications except mild substernal pain after EVL, while pulmonary embolism occurred in one patient receiving EIS. CONCLUSIONS: Endoscopic variceal ligation is a safe and effective technique for eradicating oesophageal varices in patients with hepatitis C cirrhosis.

Esophageal and Gastric Varices↗
PubMed1998

Power Doppler sonography for hepatocellular carcinoma: factors affecting the power Doppler signals of the tumors.

AIMS/BACKGROUND: A recent advancement in Doppler ultrasonography (US) is power Doppler for detecting low-velocity blood flow at the microvascular level with angle independence. The present study was performed to characterize the factors contributing to the power Doppler signals of hepatocellular carcinoma (HCC). METHOD: Correlation of Doppler signals of HCC in 114 patients with 178 HCC nodules was analyzed in relation to the findings of CT and angiography, tumor characteristics (size, echo pattern, and histological differentiation of tumor), viral markers and severity of liver disease. RESULTS: The sensitivity of power Doppler US was superior to that of CT and angiography (each p<0.05; McNemar's test). The detection rate of power Doppler signal was significantly higher in tumors with diameter > or =2 cm (vs <2 cm in diameter), and with low/mixed echo pattern (vs high echo appearance), and with moderately/poorly differentiated HCC (vs well-differentiated HCC). Univariate analysis revealed that echo pattern, tumor size and histological differentiation of HCC in addition to CT and angiographic findings were significant. Multivariate analysis showed that tumor size and differentiation were significant. CONCLUSION: These results indicate that tumor characteristics play an important role in power Doppler signals and that these could be assessed by the presence or absence of power Doppler signals.

Angiography↗
PubMed1998

Percutaneous hepatic infarction therapy for hepatocellular carcinoma.

OBJECTIVE: We percutaneously injected ethanol into small vessels afferent to tumor nodules to induce hepatic infarction in areas of tumor caused by hepatocellular carcinoma. CONCLUSION: Percutaneous hepatic infarction therapy holds promise as a new method of treating large hepatocellular carcinoma.

Carcinoma, Hepatocellular↗