Masato Abei

Kaohsiung Medical University, Kaohsiung, Kaohsiung, Taiwan

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Publications (30)115.95 Total impact

  • Article: Effects of Dipyridamole Coadministration on the Pharmacokinetics of Ribavirin in Healthy Volunteers.
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    ABSTRACT: Ribavirin (RBV), a guanosine analog for treatment of hepatitis C, is a substrate of a nucleoside transporter, solute carrier family 29 member 1 (SLC29A1). To clarify the impact of SLC29A1 on the pharmacokinetics of RBV, an open-label, crossover study of single-dose RBV (200 mg, po) with and without coadministration of dipyridamole (DP), an inhibitor of SLC29A1, was performed. Plasma and erythrocyte concentrations of RBV in the control phase and DP phase (25 mg, 3 times daily for 4 days) were compared in 10 healthy volunteers. SLC29A1 mRNA expression in peripheral blood mononuclear cells was also determined. In the DP phase, area under the concentration-time curves (AUC) of RBV in plasma and erythrocytes showed reductions of 23% and 17%, respectively (p<0.05), with increases in apparent oral clearance of 18% and 25%, respectively (p<0.05). The reduction rate of the AUC of erythrocyte RBV in the DP phase was associated with SLC29A1 mRNA expression: higher mRNA expression showed greater AUC reduction. The elimination half-life of both plasma and erythrocyte RBV did not differ between the 2 phases. These results suggest that RBV/DP coadministration reduces the concentration of RBV in blood by inhibiting an important role of SLC29A1 in gastrointestinal absorption of RBV.
    Drug Metabolism and Pharmacokinetics 03/2013; · 2.32 Impact Factor
  • Article: Cyclophosphamide enhances antitumor efficacy of oncolytic adenovirus expressing uracil phosphoribosyltransferase (UPRT) in immunocompetent Syrian hamsters.
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    ABSTRACT: Oncolytic viruses (OVs) are novel cancer therapeutics with great promise, but host antiviral immunity represents the hurdle for their efficacy. Immunosuppression by cyclophosphamide (CP) has thus been shown to enhance the oncolytic efficacy of many OVs, but its effects on OVs armed with therapeutic genes remain unknown. We have previously reported on the efficacy of AxE1CAUP, an oncolytic adenovirus (OAd) expressing uracil phosphoribosyltransferase (UPRT), an enzyme that markedly enhanced the toxicity of 5-fluorouracil (5-FU), in immunodeficient, Ad-nonpermissive nude mice. Here we explored the efficacy and safety of intratumoral (i.t.) AxE1CAUP/5-FU therapy and of its combination with CP for syngenic HaP-T1 pancreatic cancers in immunocompetent, Ad-permissive Syrian hamsters. AxE1CAUP infected, replicated, expressed UPRT, and increased the sensitivity to 5-FU in HaP-T1 cells in vitro. I.t. AxE1CAUP/5-FU treatment inhibited the growth of subcutaneous HaP-T1 allografts. The combination with high-dose CP inhibited serum Ad-neutralizing antibody formation, increased intratumoral AxE1CAUP replication and UPRT expression, and resulted in further enhanced therapeutic effects with 5-FU. Neither body weight nor histology of the liver and lung changed during these treatments. A clinically-approved, intermediate-dose CP also enhanced the efficacy of i.t. AxE1CAUP/5-FU treatment in these hamsters, which was not affected by preexisting immunity to the vector. These data demonstrate the excellent antitumor efficacy and safety of an OAd armed with a suicide gene in combination with CP for treating syngenic tumors in immunocompetent, Ad-permissive animals, indicating the efficacy of CP in overcoming the hurdle of antiviral immunity for effective OV-mediated gene therapy. © 2013 Wiley Periodicals, Inc.
    International Journal of Cancer 02/2013; · 5.44 Impact Factor
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    Dataset: Potent in vitro and in vivo antitumor effects of MDM2 inhibitor nutlin-3 in gastric cancer cells
  • Article: Impact of solute carrier family 29 member 1 (SLC29A1) single nucleotide polymorphisms on mRNA expression in peripheral blood mononuclear cells.
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    ABSTRACT: The effects of solute carrier family 29 member 1 (SLC29A1) single nucleotide polymorphism (SNP), rs6932345 and rs747199, on SLC29A1 mRNA expression were examined. The expression levels of SLC29A1 mRNA in peripheral blood mononuclear cells (PBMCs) isolated from 46 healthy subjects (28 males and 18 females) was compared between wild type and mutant carriers. The mRNA levels in the rs6932345 wild-type (AA genotype) was 1.71 times that in the mutation carriers (AC/CC genotype) (p<0.05). Similar results were observed for rs747199, because rs747199 was linked with rs6932345 at a frequency of 84.8%. It was confirmed that wild-type for rs6932345 and rs747199 showed higher SLC29A1 mRNA expression in PBMCs.
    Biological & Pharmaceutical Bulletin 10/2012; · 1.66 Impact Factor
  • Article: Evaluation of liver function after proton beam therapy for hepatocellular carcinoma.
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    ABSTRACT: Our previous results for treatment of hepatocellular carcinoma with proton beam therapy (PBT) revealed excellent local control. In this study, we focused on the impact of PBT on normal liver function. The subjects were 259 patients treated with PBT at the University of Tsukuba between January 2001 and December 2007. We evaluated the Child-Pugh score pretreatment, on the final day of PBT, and 6, 12, and 24 months after treatment with PBT. Patients who had disease progression or who died with tumor progression at each evaluation point were excluded from the analysis to rule out an effect of tumor progression. An increase in the Child-Pugh score of 1 or more was defined as an adverse event. Of the 259 patients, 241 had no disease progression on the final day of PBT, and 91 had no progression within 12 months after PBT. In univariate analysis, the percentage volumes of normal liver receiving at least 0, 10, 20, and 30 GyE in PBT (V0, 10, 20, and 30) were significantly associated with an increase of Child-Pugh score at 12 months after PBT. Of the 91 patients evaluated at 12 months, 66 had no increase of Child-Pugh score, 15 had a 1-point increase, and 10 had an increase of ≥2 points. For the Youden index, the optimal cut-offs for V0, V10, V20, and V30 were 30%, 20%, 26%, and 18%, respectively. Our findings indicate that liver function after PBT is significantly related to the percentage volume of normal liver that is not irradiated. This suggests that further study of the relationship between liver function and PBT is required.
    International journal of radiation oncology, biology, physics 03/2012; 82(3):e529-35. · 4.59 Impact Factor
  • Article: EpCAM- and EGFR-targeted selective gene therapy for biliary cancers using Z33-fiber-modified adenovirus.
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    ABSTRACT: A critical issue in adenovirus (Ad)-based cancer gene therapy is to improve the specificity of gene delivery to cancer cells for better efficacy and safety. We explored methods of retargeting Ad vectors for selective gene therapy of human biliary cancers using the Ad incorporating an IgG Fc-binding motif (Z33) from the Staphylococcus protein A (Ad-FZ33) combined with tumor-specific antibodies. Flow cytometry analysis revealed high-expression levels of epithelial cell adhesion molecule (EpCAM) and epidermal growth factor receptor (EGFR) on human biliary cancer cells. Ad-FZ33 expressing LacZ combined with antibodies against EpCAM or EGFR, followed by β-gal assay, demonstrated highly efficient gene transduction in these biliary cancer cells, compared to the treatment with control antibody or without antibody. Ad-FZ33 expressing uracil phosphoribosyl transferase (UPRT), an enzyme which greatly enhances the toxicity of 5-fluorouracil (FU), combined with antibodies against EpCAM or EGFR, remarkably enhanced the sensitivity of biliary cancer cells to 5-FU. By contrast, the treatment did not affect the 5-FU sensitivity of the cells not expressing EpCAM or EGFR including normal hepatocytes. Finally, treatments with the UPRT-expressing Ad-FZ33 with antibodies against EpCAM or EGFR, followed by 5-FU administration, significantly suppressed the growth of biliary cancer xenografts in nude mice. These results indicate that the gene therapy mediated by the Z33 fiber modified Ad with anti-EpCAM or anti-EGFR antibodies offers a potentially effective therapeutic modality against biliary cancers.
    International Journal of Cancer 09/2011; 129(5):1244-53. · 5.44 Impact Factor
  • Article: Proton beam therapy for hepatocellular carcinoma located adjacent to the alimentary tract.
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    ABSTRACT: To evaluate the safety and effectiveness of proton beam therapy for hepatocellular carcinoma (HCC) located adjacent to the alimentary tract. Forty-seven patients (median age, 69 years; range, 43-82 years) who had HCC located within 2 cm of the alimentary tract underwent proton beam therapy. Liver damage according to the Child-Pugh classification was Class A in 35 patients, Class B in 9, and Class C in 3. Treatment protocols of the early 16 patients and the late 31 patients were 72.6 GyE in 22 fractions and 77 GyE in 35 fractions, respectively. During the median follow-up period of 23 months, 24 patients died; the remaining 23 patients were alive until September 2008. The median overall survival was 33.9 months (95% confidence interval [CI], 10.8-57.0 months). Actuarial overall and local progression-free survival rates at 3 years were 50.0% and 88.1%, respectively. Grade 2 and 3 alimentary tract hemorrhage was observed in 3 (6.4%) and 1 (2.1%) patients, respectively. Our proton beam therapy strategy for HCC located adjacent to the alimentary tract seems to be effective but should be performed with caution.
    International journal of radiation oncology, biology, physics 07/2011; 80(4):992-5. · 4.59 Impact Factor
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    Article: Potent in vitro and in vivo antitumor effects of MDM2 inhibitor nutlin-3 in gastric cancer cells.
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    ABSTRACT: The tumor suppressor gene p53 is the most frequently mutated gene in human cancers. However, its mutation rate is relatively low in gastric cancer compared with other cancers. In this study, we investigated the mechanisms underlying the antitumor effects of nutlin-3, an inhibitor of human homolog of murine double minute 2 (MDM2). MDM2 is a negative regulator of p53. Four gastric cancer cell lines with wild-type p53 (wt p53) and three with mutant-type p53 (mt p53) were analyzed for MDM2 and MDM4 expression by immunoblotting, and for their gene amplification by quantitative real-time PCR. Moreover, the viability of cells exposed to nutlin-3 was examined by WST-8 assay, and the expression of p53 and its downstream genes was analyzed by immunoblotting. Nutlin-3 stabilized p53 and increased the expression of p21(WAF1) and Noxa, and cleaved poly (ADP)-ribose polymerase regardless of the pre-expression levels of MDM2 and MDM4 in gastric cancer cells with wt p53. Flow cytometry revealed that nutlin-3 arrested the cell cycle in G(1) phase and induced apoptosis in the cell lines. These nutlin-3 effects were not observed in the cell lines with mt p53. Nutlin-3 exerted additive or synergistic cytotoxicity in combination with 5-fluorouracil or cisplatin in most cell lines with wt p53. An in vivo antitumor effect of nutlin-3 alone and its additive augmentation by 5-fluorouracil were confirmed in an MDM2 overexpressed xenograft tumor model. Nutlin-3 showed potent antitumor activity against human gastric cancer cells with wt p53 and shows promise as a single agent and in combination with conventional anticancer drugs.
    Cancer Science 03/2011; 102(3):605-13. · 3.33 Impact Factor
  • Article: EpCAM‐ and EGFR‐targeted selective gene therapy for biliary cancers using Z33‐fiber‐modified adenovirus
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    ABSTRACT: A critical issue in adenovirus (Ad)-based cancer gene therapy is to improve the specificity of gene delivery to cancer cells for better efficacy and safety. We explored methods of retargeting Ad vectors for selective gene therapy of human biliary cancers using the Ad incorporating an IgG Fc-binding motif (Z33) from the Staphylococcus protein A (Ad-FZ33) combined with tumor-specific antibodies. Flow cytometry analysis revealed high-expression levels of epithelial cell adhesion molecule (EpCAM) and epidermal growth factor receptor (EGFR) on human biliary cancer cells. Ad-FZ33 expressing LacZ combined with antibodies against EpCAM or EGFR, followed by β-gal assay, demonstrated highly efficient gene transduction in these biliary cancer cells, compared to the treatment with control antibody or without antibody. Ad-FZ33 expressing uracil phosphoribosyl transferase (UPRT), an enzyme which greatly enhances the toxicity of 5-fluorouracil (FU), combined with antibodies against EpCAM or EGFR, remarkably enhanced the sensitivity of biliary cancer cells to 5-FU. By contrast, the treatment did not affect the 5-FU sensitivity of the cells not expressing EpCAM or EGFR including normal hepatocytes. Finally, treatments with the UPRT-expressing Ad-FZ33 with antibodies against EpCAM or EGFR, followed by 5-FU administration, significantly suppressed the growth of biliary cancer xenografts in nude mice. These results indicate that the gene therapy mediated by the Z33 fiber modified Ad with anti-EpCAM or anti-EGFR antibodies offers a potentially effective therapeutic modality against biliary cancers.
    International Journal of Cancer 01/2011; 129(5):1244 - 1253. · 5.44 Impact Factor
  • Article: Investigation of the geometric accuracy of proton beam irradiation in the liver.
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    ABSTRACT: To investigate the geometric accuracy of proton beam irradiation to the liver by measuring the change in Hounsfield units (HUs) after irradiation. We examined 21 patients with liver tumors who were treated with respiratory-gated proton beam therapy (PBT). The radiation dose was 66 GyE in 12 patients and 72.6 GyE in 9 patients. Image registration and reslicing of the computed tomography (CT) results obtained within 1 month before and 3 months after PBT was performed, referring to the planning CT image. The resliced CT images obtained after PBT were subtracted from the images obtained before PBT. We investigated whether the area of the large HU change was consistent with the high-dose distribution area using the location of the largest change in HU around the tumor (peak) on the subtracted CT image and the 90% dose distribution area of the planning CT image. The number of patients (n = 20) whose left-right peaks were within the 90% dose distribution area was significantly larger than the number of patients whose anterior-posterior peaks and superior-inferior peaks were within the 90% dose distribution area (n = 14, n = 13, p = 0.034, and p = 0.02, respectively). Twelve patients exhibited a peak within the 90% dose distribution area in all directions. Nine of the 11 patients with smaller 90% confidence intervals of the percent normalization of the beam cycle (BC; 90% BC) showed a peak within the 90% dose distribution area in six directions, and this percentage was higher than that among the patients with larger 90% BC (3/10, p = 0.03). The geometric accuracy of proton beam irradiation to the liver was higher in the left-right direction than in the other directions. Patients with an irregular respiratory rhythm have a greater risk of a reduced geometric accuracy of PBT in the liver.
    International journal of radiation oncology, biology, physics 01/2011; 82(2):826-33. · 4.59 Impact Factor
  • Article: Proton beam therapy for hepatocellular carcinoma: a comparison of three treatment protocols.
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    ABSTRACT: Our previous results for treatment of hepatocellular carcinoma (HCC) with proton beam therapy revealed excellent local control with low toxicity. Three protocols were used to avoid late complications such as gastrointestinal ulceration and bile duct stenosis. In this study, we examined the efficacy of these protocols. The subjects were 266 patients (273 HCCs) treated by proton beam therapy at the University of Tsukuba between January 2001 and December 2007. Three treatment protocols (A, 66 GyE in 10 fractions; B, 72.6 GyE in 22 fractions; and C, 77 GyE in 35 fractions) were used, depending on the tumor location. Of the 266 patients, 104, 95, and 60 patients were treated with protocols A, B, and C, respectively. Seven patients with double lesions underwent two different protocols. The overall survival rates after 1, 3 and 5 years were 87%, 61%, and 48%, respectively (median survival, 4.2 years). Multivariate analysis showed that better liver function, small clinical target volume, and no prior treatment (outside the irradiated field) were associated with good survival. The local control rates after 1, 3, and 5 years were 98%, 87%, and 81%, respectively. Multivariate analysis did not identify any factors associated with good local control. This study showed that proton beam therapy achieved good local control for HCC using each of three treatment protocols. This suggests that selection of treatment schedules based on tumor location may be used to reduce the risk of late toxicity and maintain good treatment efficacy.
    International journal of radiation oncology, biology, physics 09/2010; 81(4):1039-45. · 4.59 Impact Factor
  • Article: Proton-beam therapy for hepatocellular carcinoma associated with portal vein tumor thrombosis.
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    ABSTRACT: The prognosis of patients with advanced hepatocellular carcinoma (HCC) with portal vein tumor thrombosis (PVTT) is extremely poor, as effective treatment options are limited. The authors performed a retrospective review to evaluate the efficacy of proton-beam therapy (PBT) for patients presenting with PVTT in the setting of HCC. Between February 1991 and September 2005, 35 patients with HCC and tumor thrombi in the main trunk or major branches of the portal vein presented for consideration of PBT. Their tumor sizes ranged from 25 mm to 130 mm (median, 60 mm). A median total dose of 72.6 GyE in 22 fractions was delivered over 31 days to a target volume that encompassed both the primary hepatic lesion and the PVTT. 32 patients were progression-free during a median follow-up period of 21 months (range, 2-88 months) and three patients experienced disease progression. Local progression-free survival rates were 46% at 2 years and 20% at 5 years, and the median local progression-free survival was 21 months. Acute toxicity > or = grade 3 was observed in three patients, and no patient experienced late toxicity > or = grade 3. None of the patients had to discontinue treatment as a result of toxicity. PBT improved local control and significantly prolonged survival in HCC patients with PVTT.
    Strahlentherapie und Onkologie 12/2009; 185(12):782-8. · 3.56 Impact Factor
  • Article: Proton beam therapy for hepatocellular carcinoma
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    ABSTRACT: BACKGROUND:The authors have published a series of studies evaluating the safety and efficacy of proton beam therapy for the treatment of hepatocellular carcinoma in a variety of clinical settings. In the current study, they retrospectively reviewed their entire experience treating hepatocellular carcinoma patients with proton beam therapy at their hospital-based facility at the University of Tsukuba.METHODS:From November 2001 to December 2007, 333 patients with hepatocellular carcinoma were treated with proton beam therapy at the University of Tsukuba. A total of 318 patients were included in this study. Total dose delivered and fractionation scheme were determined by protocols that varied based on location of tumor. Survival rates and prognostic factors were assessed.RESULTS:Overall actuarial survival rates at 1-year, 3-years, and 5-years were 89.5% (95% confidence interval [95% CI], 85.7-93.1%), 64.7% (95% CI, 56.6-72.9%), and 44.6% (95% CI, 29.7-59.5%), respectively. Child-Pugh liver function (hazards ratio [HR], 2.84; P < .01), T stage (HR, 1.94; P < .05), performance status (HR, 2.12; P < .01), and planning target volume (HR, 2.12; P < .05) significantly impacted survival. The 3-year and 5-year survival rates were 69.1% (95% CI, 59.9-78.3%) and 55.9% (95% CI, 41.5-70.3%), respectively, for patients with Child-Pugh A disease and 51.9% (95% CI, 32.3-71.5%) and 44.5% (95% CI, 23.1-65.8%), respectively, for patients with Child-Pugh B disease. The actuarial survival rates of patients with Child-Pugh class A were statistically different between groups of planned target volume ≤125 mL and >125 mL (P < .05).CONCLUSIONS:The authors have shown proton beam therapy to be both safe and effective for the treatment of patients with hepatocellular carcinoma. They strongly recommend the consideration of proton beam therapy in patients for whom other treatment options are risky or contraindicated. Cancer 2009. © 2009 American Cancer Society.
    Cancer 11/2009; 115(23):5499 - 5506. · 4.77 Impact Factor
  • Article: Proton beam therapy for hepatocellular carcinoma: the University of Tsukuba experience.
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    ABSTRACT: The authors have published a series of studies evaluating the safety and efficacy of proton beam therapy for the treatment of hepatocellular carcinoma in a variety of clinical settings. In the current study, they retrospectively reviewed their entire experience treating hepatocellular carcinoma patients with proton beam therapy at their hospital-based facility at the University of Tsukuba. From November 2001 to December 2007, 333 patients with hepatocellular carcinoma were treated with proton beam therapy at the University of Tsukuba. A total of 318 patients were included in this study. Total dose delivered and fractionation scheme were determined by protocols that varied based on location of tumor. Survival rates and prognostic factors were assessed. Overall actuarial survival rates at 1-year, 3-years, and 5-years were 89.5% (95% confidence interval [95% CI], 85.7-93.1%), 64.7% (95% CI, 56.6-72.9%), and 44.6% (95% CI, 29.7-59.5%), respectively. Child-Pugh liver function (hazards ratio [HR], 2.84; P < .01), T stage (HR, 1.94; P < .05), performance status (HR, 2.12; P < .01), and planning target volume (HR, 2.12; P < .05) significantly impacted survival. The 3-year and 5-year survival rates were 69.1% (95% CI, 59.9-78.3%) and 55.9% (95% CI, 41.5-70.3%), respectively, for patients with Child-Pugh A disease and 51.9% (95% CI, 32.3-71.5%) and 44.5% (95% CI, 23.1-65.8%), respectively, for patients with Child-Pugh B disease. The actuarial survival rates of patients with Child-Pugh class A were statistically different between groups of planned target volume <or=125 mL and >125 mL (P < .05). The authors have shown proton beam therapy to be both safe and effective for the treatment of patients with hepatocellular carcinoma. They strongly recommend the consideration of proton beam therapy in patients for whom other treatment options are risky or contraindicated.
    Cancer 07/2009; 115(23):5499-506. · 4.77 Impact Factor
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    Article: Proton beam therapy for large hepatocellular carcinoma.
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    ABSTRACT: To investigate the safety and efficacy of proton beam therapy (PBT) in patients with large hepatocellular carcinoma (HCC). Twenty-two patients with HCC larger than 10 cm were treated with proton beam therapy at our institution between 1985 and 2006. Twenty-one of the 22 patients were not surgical candidates because of advanced HCC, intercurrent disease, or old age. Median tumor size was 11 cm (range, 10-14 cm), and median clinical target volume was 567 cm(3) (range, 335-1,398 cm(3)). Hepatocellular carcinoma was solitary in 18 patients and multifocal in 4 patients. Tumor types were nodular and diffuse in 18 and 4 patients, respectively. Portal vein tumor thrombosis was present in 11 patients. Median total dose delivered was 72.6 GyE in 22 fractions (range, 47.3-89.1 GyE in 10-35 fractions). The median follow-up period was 13.4 months (range, 1.5-85 months). Tumor control rate at 2 years was 87%. One-year overall and progression-free survival rates were 64% and 62%, respectively. Two-year overall and progression-free survival rates were 36% and 24%, respectively. The predominant tumor progression pattern was new hepatic tumor development outside the irradiated field. No late treatment-related toxicity of Grade 3 or higher was observed. The Bragg peak properties of PBT allow for improved conformality of the treatment field. As such, large tumor volumes can be irradiated to high doses without significant dose exposure to surrounding normal tissue. Proton beam therapy therefore represents a promising modality for the treatment of large-volume HCC. Our study shows that PBT is an effective and safe method for the treatment of patients with large HCC.
    International journal of radiation oncology, biology, physics 06/2009; 76(2):460-6. · 4.59 Impact Factor
  • Article: A prospective study of hypofractionated proton beam therapy for patients with hepatocellular carcinoma.
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    ABSTRACT: To evaluate the efficacy and safety of hypofractionated proton beam therapy for patients with hepatocellular carcinoma (HCC). Between September 2001 and August 2004, 51 patients with HCC greater than 2 cm away from the porta hepatis or gastrointestinal tract were treated with proton beam therapy to 66 Gy-equivalents (GyE) in 10 fractions. Overall survival rates were 49.2 and 38.7% at 3 and 5 years after treatment. Local control rates were 94.5 and 87.8% at 3 and 5 years after treatment. Posttreatment serum alpha-fetoprotein values were significantly reduced when compared with pretreatment values (p < 0.0001). Patients experienced only minor acute reactions of Grade 1 or less, and 3 patients experienced late sequelae of Grade 2 or higher. However, there were no treatment-related deaths. Hypofractionated proton beam therapy is safe and well-tolerated by patients with HCC located greater than 2 cm away from the porta hepatis or gastrointestinal tract and may be effective alternative to other modalities.
    International journal of radiation oncology, biology, physics 04/2009; 74(3):831-6. · 4.59 Impact Factor
  • Article: Proton beam therapy for hepatocellular carcinoma adjacent to the porta hepatis.
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    ABSTRACT: To evaluate the efficacy and safety of proton beam therapy (PBT) for patients with hepatocellular carcinoma (HCC) located adjacent to the porta hepatis. Subjects of the study were 53 patients with HCC located within 2 cm of the main portal vein. All patients had tumor confined to the radiation field with no evidence of metastatic disease. All patients had hepatic function levels of a Child-Pugh score of 10 or less, Eastern Cooperative Oncology Group performance status of 2 or less, and no uncontrolled ascites. Patients underwent PBT of 72.6 GyE in 22 fractions from Sept 2001 to Dec 2004. After 3 years, the actuarial survival rate was 45.1% and local control rate was 86.0%. Prognostic factors for survival included Child-Pugh score, number of tumors, and alpha-fetoprotein levels. No late treatment-related toxicity of Grade 2 or higher was observed. The PBT delivering 72.6 GyE in 22 fractions appears to be effective and safe for HCC adjacent to the porta hepatis.
    International Journal of Radiation OncologyBiologyPhysics 07/2008; 71(2):462-7. · 4.11 Impact Factor
  • Article: Proton beam therapy for aged patients with hepatocellular carcinoma.
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    ABSTRACT: To investigate the safety and efficacy of proton beam therapy for aged patients with hepatocellular carcinoma (HCC). Twenty-one patients aged > or =80 years with HCC underwent proton beam therapy. At the time of irradiation, patient age ranged from 80 to 85 years (median, 81 years). Hepatic tumors were solitary in 17 patients and multiple in 4. Tumor size ranged from 10 to 135 mm (median, 40 mm) in maximum diameter. Ten, 5, and 6 patients received proton beam irradiation with total doses of 60 Gy in 10 fractions, 66 Gy in 22 fractions, and 70 Gy in 35 fractions, respectively, according to tumor location. All irradiated tumors were controlled during the follow-up period of 6-49 months (median, 16 months). Five patients showed new hepatic tumors outside the irradiated volume, 2-13 months after treatment, and 1 of them also had lung metastasis. The local progression-free and disease-free rates were 100% and 72% at 3 years, respectively. Of 21 patients, 7 died 6-49 months after treatment; 2 patients each died of trauma and old age, and 1 patient each died of HCC, pneumonia, and arrhythmia. The 3-year overall, cause-specific, and disease-free survival rates were 62%, 88%, and 51%, respectively. No therapy-related toxicity of Grade > or = 3 but thrombocytopenia in 2 patients was observed. Proton beam therapy seems to be tolerable, effective, and safe for aged patients with HCC. It may contribute to prolonged survival due to tumor control.
    International Journal of Radiation OncologyBiologyPhysics 12/2007; 69(3):805-12. · 4.11 Impact Factor
  • Article: E1A, E1B double-restricted adenovirus with RGD-fiber modification exhibits enhanced oncolysis for CAR-deficient biliary cancers.
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    ABSTRACT: Cancers of biliary system represent highly malignant diseases of dismal prognosis. We have previously introduced AxdAdB3, an E1A, E1B double-restricted oncolytic adenovirus, which showed excellent oncolytic efficacy for approximately half of the biliary cancer lines with an enhanced safety to normal cells. The purpose of this study was to evaluate whether RGD-fiber modification (AxdAdB3-F/RGD), which enables integrin-dependent infection, can improve the infectivity and efficacy of AxdAdB3 for biliary cancers. Expressions of adenoviral receptors, coxsackievirus adenovirus receptor (CAR) and integrins (alpha(v)beta(3) and alpha(v)beta(5)), were compared with the level of infectivity of LacZ-expressing replication-defective adenoviruses with wild-type fibers or RGD-modified fibers in a panel of biliary cancer cell lines in vitro. Viral replication and cytotoxicity in vitro of AxdAdB3-F/RGD, a novel E1A, E1B double-restricted replication-selective adenovirus with RGD-modified fibers, were compared with those of its parent virus, AxdAdB3, in various biliary cancer cells and in normal cells. In vivo antitumor effects of these oncolytic viruses were compared in a xenograft tumor model. Expression of CAR significantly correlated with the adenovirus infectivity, whereas integrin alpha(v)beta(5) was abundantly expressed in almost all biliary cancer cells. Whereas AxdAdB3 effectively replicated and lysed only the biliary cancer cells with a preserved expression of CAR, AxdAdB3-F/RGD exhibited efficient replication and potent oncolysis in both CAR-positive and CAR-negative biliary cancer cells. AxdAdB3-F/RGD showed attenuated replication and little cytopathy in human normal cells (i.e., hepatocytes, WI-38 cells) as well as AxdAdB3. Furthermore, in nude mice with s.c. xenografts of CAR-deficient human biliary cancer, i.t. AxdAdB3-F/RGD therapy caused a marked inhibition of tumor growth. The RGD-fiber modification strategy enhanced the infectivity, replication, and oncolytic effects of the E1A, E1B double-restricted oncolytic adenovirus for CAR-deficient biliary cancers. In addition, it preserved the merit of excellent safety of the double-restricted virus for normal cells. These results suggest a potential use of this agent for the treatment of biliary cancers.
    Clinical Cancer Research 06/2007; 13(10):3043-50. · 7.74 Impact Factor
  • Article: Proton beam therapy for hepatocellular carcinoma: a retrospective review of 162 patients.
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    ABSTRACT: We present results of patients with hepatocellular carcinoma (HCC) treated with proton beam therapy. We reviewed 162 patients having 192 HCCs treated from November 1985 to July 1998 by proton beam therapy with or without transarterial embolization and percutaneous ethanol injection. The patients in the present series were considered unsuitable for surgery for various reasons, including hepatic dysfunction, multiple tumors, recurrence after surgical resection, and concomitant illnesses. The median total dose of proton irradiation was 72 Gy in 16 fractions over 29 days. The overall survival rate for all of the 162 patients was 23.5% at 5 years. The local control rate at 5 years was 86.9% for all 192 tumors among the 162 patients. The degree of impairment of hepatic functions attributable to coexisting liver cirrhosis and the number of tumors in the liver significantly affected patient survival. For 50 patients having least impaired hepatic functions and a solitary tumor, the survival rate at 5 years was 53.5%. The patients had very few acute reactions to treatments and a few late sequelae during and after the treatments. Proton beam therapy for patients with HCC is effective, safe, well tolerable, and repeatable. It is the useful treatment mode for either cure or palliation for patients with HCC irrespective of tumor size, tumor location in the liver, insufficient feeding of the tumor with arteries, presence of vascular invasion, impaired hepatic functions, and coexisting intercurrent diseases.
    Clinical Cancer Research 06/2005; 11(10):3799-805. · 7.74 Impact Factor