Masaru Konishi

National Cancer Center, Japan, Edo, Tōkyō, Japan

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Publications (194)519.42 Total impact

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    ABSTRACT: The patient was a 61-year-old male who was referred to our hospital after dilatation of the main pancreatic duct was detected by screening ultrasonography. Computed tomography revealed a protruding lesion measuring 15 mm in diameter within the main pancreatic duct in the head of the pancreas, and magnetic resonance cholangiopancreatography revealed interruption of the duct at the tumor site. We performed pancreaticoduodenectomy under a suspected diagnosis of invasive ductal carcinoma. Gross examination of the resected specimen showed that the tumor invaginated into the main pancreatic duct, and no mucin was found. Histological examination revealed proliferation of high-grade dysplastic cells in a tubulopapillary growth pattern. Immunohistochemically, cytokeratin 7 expression was detected, but not trypsin expression. Based on these morphological features, we diagnosed the tumor as intraductal tubulopapillary neoplasm (ITPN). We report the case with bibliographic consideration, together with a review of intraductal neoplasms of the pancreas encountered at our institution.
    International surgery. 02/2015; 100(2):281-6.
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    ABSTRACT: To clarify the benefit of energy devices such as ultrasonically activated device and bipolar vessel sealing device in liver surgeries. Several studies have suggested the benefit of energy devices in liver transection, while a randomized trial has found no association between their use and surgical outcomes. Patients scheduled to undergo open liver resection were eligible for this multicenter non-blinded randomized study. They were randomized to receive an energy device (experimental group) or not (control group) during liver transection. The primary endpoint was the proportion of patients with intraoperative blood loss >1,000 mL. The primary aim was to show non-inferiority of hepatectomy with energy device to that without energy device. A total of 212 patients were randomized and 211 (105 and 106 in the respective groups) were analyzed. Intraoperative blood loss >1,000 mL occurred in 15.0 % patients with energy device and 20.2 % patients without energy device. The experimental minus control group difference was -5.2 % (95 % confidence interval -13.8 to 3.3 %; non-inferiority test, p = 0.0248). Hepatectomy with energy device resulted in a shorter median liver transection time (63 vs. 84 min; p < 0.001) and a lower rate of postoperative bile leakage (4 vs. 16 %; p = 0.002). The hypothesis that hepatectomy with energy device is not inferior to that without energy device in terms of blood loss has been demonstrated. The use of energy devices during liver surgery is clinically meaningful as it shortens the liver transection time and reduces the incidence of postoperative bile leakage.
    World journal of surgery. 01/2015;
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    ABSTRACT: Several studies have shown that maintenance of the central venous pressure at a low level during liver surgery is effective for intraoperative management. However, others have suggested that stroke volume variation (SVV) may be a better predictor of fluid responsiveness than central venous pressure. The purpose of this study is to conduct a new type of circulatory management using the FloTrac(TM) system in laparoscopic liver resection and to evaluate specific fluctuations in SVV. Of the laparoscopic liver resections that we performed between March 2012 and December 2013, we used the FloTrac system for intraoperative circulatory management in 21 cases. We analyzed the data, mainly the average value of SVV. The average SVV value during liver transection was 5.2%-24.6% (mean, 17.0%), and 18 cases (86%) exceeded the conventional cut-off value (13%). The average SVV value was 4.3%-18.2% (mean, 9.7%) when pneumoperitoneum was not in effect, whereas it was 7.3% greater on average during liver transection (mean, 17.0%). No perioperative complications developed. The average SVV value during laparoscopic liver transection (mean, 17.0%) exceeded the conventional cut-off value, but in this study, no perioperative complications developed, which enabled safe management. We might be able to manage appropriate fluid control using FloTrac system in patients with laparoscopic liver resection. Therefore, it is necessary to set the target SVV and conduct prospective trials to verify the safety margin for intraoperative management in the future. © 2014 Japan Society for Endoscopic Surgery, Asia Endosurgery Task Force and Wiley Publishing Asia Pty Ltd.
    Asian Journal of Endoscopic Surgery 12/2014;
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    ABSTRACT: Precise risk assessment for postoperative pancreatic fistula (POPF) after pancreaticoduodenectomy (PD) may be facilitated using imaging modalities. Computed tomography perfusion (CTP) of the pancreas may represent histologic findings. This study aimed to evaluate the utility of CTP data for the risk of POPF after PD, in relation to histologic findings. Twenty patients who underwent preoperative pancreatic CTP measurement using 320-detector row CT before PD were investigated. Clinicopathologic findings, including CTP data, were analyzed to assess the occurrence of POPF. In addition, the correlation between CTP data and histologic findings was evaluated. POPF occurred in 11 cases (grade A, 6; grade B, 5; and grade C, 0). In CTP data, both high arterial flow (AF) and short mean transit time (MTT) were related to POPF occurrence (P = 0.001, P = 0.001). AF was negatively correlated with fibrosis in the pancreatic parenchyma (r = -0.680), whereas MTT was positively correlated with fibrosis (r = 0.725). AF >80 mL/min/100 mL and MTT <16 s showed high sensitivity, specificity, positive predictive value, and negative predictive value (80.0%, 100.0%, 100.0%, and 83.3%, respectively) for the occurrence of POPF. CTP data for the pancreas were found to be correlated with the occurrence of POPF after PD. Alterations in the blood flow to the remnant pancreas may reflect histological changes, including fibrosis in the pancreatic stump, and influence the outcome after PD. CTP may thus facilitate objective and quantitative risk assessment of POPF after PD. Copyright © 2014 Elsevier Inc. All rights reserved.
    Journal of Surgical Research 11/2014; · 2.12 Impact Factor
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    ABSTRACT: Although pancreatic consistency is a factor known to have an impact on the occurrence of postoperative pancreatic fistula (POPF) after pancreaticoduodenectomy (PD), it usually is assessed subjectively by the surgeon. Measurement of the elastic modulus (EM), a parameter characterizing the elasticity of a material, may be one approach for achieving objective and quantitative assessment of pancreatic consistency. This study was conducted to investigate the utility of determining the EM of the pancreas. Fifty-nine patients who underwent PD and measurement of the EM of the ex vivo pancreas were investigated. Data for EM were compared with the tactile evaluation made by surgeons, histologic findings, and the occurrence of POPF. The EM of the pancreas was correlated with the tactile evaluation made by the surgeon (soft pancreas, 1.4 ± 2.1 kPa vs hard pancreas, 4.4 ± 5.1 kPa; P < .001). An EM of >3.0 kPa was correlated with histologic findings including increased ratios of azan-Mallory positivity (P = .003) and α-smooth muscle actin positivity (P = .006), a decreased lobular ratio (P = .021), and an increased vessel density (P < .001). Patients with a pancreatic EM of <3.0 kPa had an increased risk of POPF (hazard ratio, 9.333; P = .002). Assessment of the EM of the resected pancreas reflects the tactile evaluation made by the surgeon and histological degree of pancreatic fibrosis, and is correlated with the occurrence of POPF after PD. Copyright © 2014 Elsevier Inc. All rights reserved.
    Surgery 11/2014; 156(5):1204-11. · 3.11 Impact Factor
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    ABSTRACT: The international consensus guidelines for the management of intraductal papillary mucinous neoplasm (IPMN) of the pancreas were revised in 2012 Tanaka (Pancreatology 12(3):183-197, 2012), making the indications for operation less aggressive. Therefore, the number of branch duct-type IPMN (BD-IPMN) patients requiring follow-up care is expected to increase in the future.
    World Journal of Surgery 10/2014; · 2.35 Impact Factor
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    ABSTRACT: The treatment strategy for adenocarcinoma of the esophagogastric junction (AEG) remains controversial. In the present study, the recurrence pattern of AEGs according to Siewert's classification after radical resection was reviewed, and predictive factors of recurrence were examined.
    Anticancer research 08/2014; 34(8):4391-7. · 1.87 Impact Factor
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    ABSTRACT: The prognostic significance of bile duct tumor thrombus (BDTT) in hepatocellular carcinoma (HCC) is unclear and the usefulness of resection for HCC with BDTT is still controversial. The aim of the present study was to evaluate the impact of BDTT on prognosis in HCC and to determine whether resection of HCC with BDTT was useful.
    Anticancer research 08/2014; 34(8):4367-72. · 1.87 Impact Factor
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    ABSTRACT: Neural invasion is a characteristic pattern of invasion and an important prognostic factor for invasive ductal carcinoma (IDC) of the pancreas. M2 macrophages have reportedly been associated with poor prognosis in various cancers. The aim of the present study was to investigate the prognostic impact of M2 macrophages at extrapancreatic nerve plexus invasion (plx-inv) of pancreatic IDC.
    European journal of cancer (Oxford, England: 1990) 05/2014; · 4.12 Impact Factor
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    ABSTRACT: Duodenal cancer excluding Vater's papilla cancer is a relatively rare disease entity; therefore, the most appropriate operative methods depending on the tumor condition, such as the tumor site and/or depth of invasion, still remain unclear. The aim of this study is to determine an appropriate operative method and an appropriate extent of lymph node dissection depending on tumor site or tumor invasion depth. Data of a total of 35 patients with duodenal cancer who underwent resectional surgery with curative intent were reviewed retrospectively, and the clinicopathological factors and survival outcomes were investigated. Overall 5-year survival rates of all resected cases were 63.0% (median survival: 9.1 years). Multivariate analysis identified histological G3/4 (P = 0.002) and presence of lymph node metastasis (P = 0.004) as independent adverse prognostic factors. Of the 35 patients, 11 (31.4%) had lymph node metastasis. In all patients with the tumor invasion depth within limited to the mucosa or submucosa (T1a or T1b), lymph node metastasis was absent (0/15 patients). T2/3/4 tumor (P < 0.001) and G3/4 (P = 0.021) were identified as predictors of the presence of lymph node metastasis. Four (11.4%) of the 35 patients had metastasis in the infrapyloric node. Limited resection is sufficient for patients with T1a tumor. In the case of T1b tumor, limited resection or pancreatoduodenectomy may be selected after performing pancreaticoduodenal node biopsy as sentinel lymph node biopsy. For patients with T2-4 tumor, pancreatoduodenectomy or substomach preserving pancreatoduodenectomy (excepting Pylorus-preserving pancreatoduodenectomy) with regional lymph node dissection should be performed.
    Japanese Journal of Clinical Oncology 01/2014; · 1.75 Impact Factor
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    ABSTRACT: Background Neural invasion is a characteristic pattern of invasion and an important prognostic factor for invasive ductal carcinoma (IDC) of the pancreas. M2 macrophages have reportedly been associated with poor prognosis in various cancers. The aim of the present study was to investigate the prognostic impact of M2 macrophages at extrapancreatic nerve plexus invasion (plx-inv) of pancreatic IDC. Methods Participants comprised 170 patients who underwent curative pancreaticoduodenectomy for pancreatic IDC. Immunohistochemical examination of surgical specimens was performed by using CD204 as an M2 macrophage marker, and the area of immunopositive cells was calculated automatically. Prognostic analyses of clinicopathological factors including CD204-positive cells at plx-inv were performed. Results Plx-inv was observed in 91 patients (53.5%). Forty-eight patients showed a high percentage of CD204-positive cell area at plx-inv (plx-inv CD204%high). Plx-inv CD204%high was an independent predictor of poor outcomes for overall survival (OS) (P < 0.001) and disease-free survival (DFS) (P < 0.001). Patients with plx-inv CD204%high showed a shorter time to peritoneal dissemination (P < 0.001) and locoregonal recurrence (P < 0.001). In patients who underwent adjuvant chemotherapy, plx-inv CD204%high was correlated with shorter OS (P = 0.011) and DFS (P = 0.038) in multivariate analysis. Conclusions Plx-inv CD204%high was associated with shortened OS and DFS and early recurrence in the peritoneal cavity and locoregional space. The prognostic value of plx-inv CD204%high was also applicable to patients who received adjuvant chemotherapy. High accumulation of M2 macrophages at plx-inv represents an important predictor of poor prognosis.
    European Journal of Cancer. 01/2014;
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    ABSTRACT: Postoperative pancreatic fistula (POPF) remains a serious complication after pancreaticoduodenectomy (PD). Preoperative risk assessment of POPF is desirable in careful preparation for operation. The aim of this study was to assess simple and accurate risk factors for clinically relevant POPF based on a schematic understanding of the pancreatic configuration using preoperative multidetector computed tomography. Three hundred and eighteen consecutive patients who underwent PD in the National Cancer Center Hospital East between November 2006 and March 2013 were investigated. Pre-, intra-, and postoperative clinicopathological findings as well as pancreatic configuration data were analyzed for the risk of clinically relevant POPF. POPF was defined according to the International Study Group of Pancreatic Fistula classification. POPF grade A occurred in 52 patients (16.4 %), grade B in 84 (26.4 %), and grade C in 6 (1.9 %). Independent risk factors for POPF grade B/C included main pancreatic duct diameter (MPDd) < 2 mm (P = 0.001), parenchymal thickness ≥ 8 mm (P = 0.018), not performing portal vein/superior mesenteric vein resection (P = 0.004), and amylase level of drainage fluid on postoperative day 3 ≥ 375 IU/L (P < 0.001). Pancreatic configuration data including MPDd and parenchymal thickness were good indicators of clinically relevant POPF.
    Journal of Gastrointestinal Surgery 08/2013; · 2.36 Impact Factor
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    ABSTRACT: Detection of early remnant gastric cancer (ERGC) is increasing as a result of the development of endoscopic technology and a surveillance program. The aim of this study was to evaluate the results of limited subtotal gastrectomy (SG) surgery for ERGC compared to total gastrectomy (TG). We retrospectively reviewed a database of 72 consecutive patients with remnant gastric cancer who underwent laparotomy at the National Cancer Center Hospital East between January 1993 and December 2008. Thirty-five patients with a preoperative diagnosis of ERGC underwent curative resection: 13 SG and 22 conventional TG. Patients and tumor characteristics, operative results, and postoperative assessments 1 year after surgery were compared between the two groups. Operating time, blood transfusion, and hospital stay were similar in the two groups. In the SG group, blood loss and postoperative recovery of body weight tended to be better than in the TG group. There was no dumping syndrome in the SG group, while this occurred in three patients in the TG group. The levels of hemoglobin and total protein were higher 1 year after remnant gastrectomy in the SG group than in the TG group. No recurrence of gastric cancer was detected in the SG group during median follow-up of 99.2 months. In comparison to TG, limited SG surgery for ERGC improved the postoperative course, with no recurrence of cancer. Therefore, SG is a safe and effective treatment for ERGC.
    Gastric Cancer 07/2013; · 4.83 Impact Factor
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    ABSTRACT: Laparoscopic distal gastrectomy for gastric cancer has been firmly established in recent decades but still is a difficult procedure, especially for obese patients, as with open surgery. This study aimed to evaluate the perioperative outcome of total laparoscopic distal gastrectomy (TLDG) for early gastric cancer patients with a body mass index (BMI) exceeding 25 kg/m(2) and to consider countermeasures to this. Perioperative outcomes were compared between 42 patients with a BMI exceeding 25 kg/m(2) [overweight or obese group (OWG)] and 174 patients with a BMI lower than 25 kg/m(2) [normal or underweight group (NWG)] who underwent TLDG between September 2010 and December 2012. The BMI was 26.0 ± 1.4 kg/m(2) in the OWG group and 22.0 ± 2.1 kg/m(2) in the NWG group (P < 0.001). The groups did not differ in terms of age, sex, American Society of Anesthesiologists score, presence of diabetes, number of retrieved lymph nodes, number of metastatic lymph nodes, or metastatic lymph node ratio. The two groups did not differ significantly with respect to the extent of lymph node dissection [OWG: D1 (11.9 %), D1+ (66.7 %), D2 (21.4 %) vs NWG: D1 (5.2 %), D1+ (51.7 %), D2 (43.1 %); P = 0.020] or tumor size (OWG: 25.5 ± 20.2 mm vs NWG: 33.0 ± 17.2 mm; P = 0.037). Differences in operation time (OWG: 212 ± 31 min vs NWG: 200 ± 35 min; P = 0.005) and estimated blood loss (OWG: 15 ± 22 ml vs NWG: 10 ± 34 ml; P = 0.013) seemed to have a minimal impact clinically. Postoperative complications including infectious complications and recovery after surgery did not differ between the two groups. For overweight and obese patients, TLDG was managed safely. The procedure was considered to be difficult but sufficiently feasible.
    Surgical Endoscopy 06/2013; · 3.31 Impact Factor
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    ABSTRACT: Background/Aims: Effectiveness of infection control for prevention of pancreatic fistula (PF) after pancreaticoduodenectomy (PD) is not clear. We analyzed the impact of infection on the development of PF and examined the effect of enhanced infection control to prevent PF. Methodology: Amylase level (D-amylase) and bacterial culture (D-culture) of drainage fluid were evaluated on POD 1, 3, 5 and 7, in 90 consecutive patients with soft pancreas who underwent PD. The study period was divided into two periods. The relationship between D-amylase and D-culture was examined, and the clinicopathological factors predicting PF were analyzed in the first period. Then, anti-infection measures were introduced in the second period, and the effect of enhanced infection control was examined. Results: Twenty-nine out of 58 patients (50.0%) developed PF in the first period. D-amylase were higher in patients with D-culture infection than in those without it (p<0.05). D-amylase above 10,000IU/L on POD1 and D-culture infection on POD3 were independent predictive factors for PF by multivariate analysis (p<0.01). After introduction of enhanced infection control in the second period, four out of 32 patients (12.5%) developed PF. The rates of PF and D-culture infection were significantly reduced (p<0.05). Conclusions: Infection of drainage fluid is related to an increased level of amylase, resulting in PF. Enhanced infection control can effectively prevent PF after PD in soft pancreas.
    Hepato-gastroenterology 06/2013; 60(124):876-82. · 0.91 Impact Factor
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    ABSTRACT: BACKGROUND: Postoperative pancreatic fistula (POPF) is a major, intractable complication after distal pancreatectomy (DP). Risk factor evaluation and prevention of this complication are important tasks for pancreatic surgeons. METHODS: One hundred and six patients who underwent DP using a stapler for pancreatic division were retrospectively investigated. The relationship between clinicopathological factors and the incidence of POPF was statistically analyzed. RESULTS: Clinically relevant, Grade B or C POPF by International Study Group of Pancreatic Fistula criteria occurred in 52 patients (49.1 %). Age, American Society of Anesthesiologists score, body mass index, and concomitant gastrointestinal tract resection did not influence the incidence of POPF. Use of a double-row stapler and a thick pancreatic stump were significant risk factors for POPF in multivariate analysis. Compression index was also shown to be an important factor in cases in which the pancreas was divided by a stapler. CONCLUSIONS: The most important risk factor for POPF after DP was suggested to be the thickness of the pancreatic stump, reflecting the volume of remnant pancreas. A triple-row stapler seemed to be superior to a double-row stapler in preventing POPF. However, triple-row stapler use in a thick pancreas is considered to be a future problem to be solved.
    Journal of hepato-biliary-pancreatic sciences. 02/2013;
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    ABSTRACT: BACKGROUND: The optimal surgical strategy for resectable synchronous colorectal liver metastases (SCLM), whether simultaneous or staged resections, still remains obscure. The aim of this study was to assess the efficacy of the predicted operation time (POT) strategy, which recommends staged resections in case of POT ≥6 h, otherwise selecting simultaneous resection. METHODS: This was a prospective, nonrandomized, single-institution study. Fifty-nine patients with SCLM underwent tumor resection according to the POT strategy, with patients with a longer POT (≥6 h) undergoing staged resection. Morbidity, overall hospitalization, tumor resection rates, and survival were compared with that of 86 patients who underwent simultaneous resection for SCLM irrespective of POT from 1992 to 2004. RESULTS: The former simultaneous and the latter POT strategy groups were similar in terms of patient and tumor demographics as well as surgical procedures. Of the 59 POT group patients, 26 patients (44 %) experienced 40 postoperative complications. Comparing the surgical results of simultaneous resection from 1992 to 2004 and those of resection according to the POT strategy, morbidity (64 vs. 44 %, p = 0.02), frequency of anastomotic leakage (21 vs. 5 %, p < 0.01), and length of hospital stay (27 vs. 18 days, p < 0.01) were significantly lower in the latter group, while tumor resection rates (85 vs. 87 %, p = 0.77) were not different. CONCLUSIONS: The POT strategy is effective in reducing the morbidity in SCLM patients by selecting staged resections in the high-morbidity-risk group without adverse effects on oncologic outcome.
    Journal of Gastrointestinal Surgery 02/2013; · 2.36 Impact Factor
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    ABSTRACT: BACKGROUND: Early recurrence correlates with poor survival following various cancer surgeries and puts considerable stress on patients both physically and mentally. This retrospective study investigated the predictive factors for early recurrence after surgical resection for initially unresectable colorectal liver metastasis to elucidate indications for conversion strategies. METHODS: We retrospectively studied 46 patients who underwent hepatectomy after chemotherapy for initially unresectable colorectal liver metastasis from 1997 to 2010. RESULTS: Recurrences occurred within 6 months after hepatectomy in 13 patients (37 %). The median survival time of 21.2 months and the 5-year survival rate of 0 % after hepatectomy in patients with recurrence within 6 months were significantly worse than those in patients with recurrence more than 6 months after hepatectomy. Recurrence in less than 6 months was significantly correlated with impossibility of anticancer therapy for recurrence after hepatectomy (p = 0.01). Eight or more hepatic tumors after chemotherapy were the only predictor of recurrence within 6 months (p = 0.01; odds ratio 9.6; 95 % confidence interval 1.5-60.6). CONCLUSION: Recurrence within 6 months was significantly correlated with a poorer outcome following surgery for initially unresectable colorectal liver metastasis. Surgical indication for initially unresectable colorectal liver metastasis with eight or more hepatic tumors after chemotherapy should be considered carefully in the light of mental and physical status, co-morbidity, and alternative treatment plans.
    Journal of Gastrointestinal Surgery 02/2013; · 2.36 Impact Factor
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    ABSTRACT: Metastatic pancreatic malignant melanoma is considered to be a highly aggressive neoplasm, and only few metastasectomies for lesions originating from the skin or the ocular region have been reported. We report a case of resection of pancreatic metastasis of malignant melanoma originating from the nasal cavity. An isolated pancreatic tumor was detected in a 46-year-old man who had undergone proton-beam therapy for nasal melanoma 12 months earlier. He underwent distal pancreatectomy with splenectomy and the pathological diagnosis was metastatic malignant melanoma. We review cases of malignant melanoma metastatic to the pancreas and further discuss their incidence, therapeutic strategy, and outcome of mucosal melanoma of the head and neck.
    Anticancer research 02/2013; 33(2):567-73. · 1.87 Impact Factor
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    ABSTRACT: A global consensus on how to treat recurrent pancreatic cancer after adjuvant chemotherapy with gemcitabine (ADJ-GEM) does not exist. We retrospectively reviewed the clinical data of 41 patients with recurrences who were subsequently treated with chemotherapy. The patients were divided into two groups according to the time until recurrence after the completion of ADJ-GEM (ADJ-Rec): patients with an ADJ-Rec < 6 months (n = 25) and those with an ADJ-Rec ≥ 6 months (n = 16). The disease control rate, the progression-free survival after treatment for recurrence and the overall survival after recurrence for these two groups were 68 and 94% (P = 0.066), 5.5 and 8.2 months (P = 0.186), and 13.7 and 19.8 months (P = 0.009), respectively. Furthermore, we divided the patients with an ADJ-Rec < 6 months into two groups: patients treated with gemcitabine (n = 6) and those treated with alternative regimens including fluoropyrimidine-containing regimens (n = 19) for recurrent disease. Patients treated with the alternative regimens had a better outcome than those treated with gemcitabine. Fluoropyrimidine-containing regimens may be a reasonable strategy for recurrent disease after ADJ-GEM and an ADJ-Rec < 6 months.
    Pancreatology 09/2012; 12(5):428-33. · 2.50 Impact Factor

Publication Stats

3k Citations
519.42 Total Impact Points


  • 1999–2014
    • National Cancer Center, Japan
      • Center for Cancer Control and Information Services
      Edo, Tōkyō, Japan
  • 1995–2014
    • Chiba-East National Hospital
      Tiba, Chiba, Japan
  • 2001–2002
    • National Cancer Research Institute
      Londinium, England, United Kingdom
  • 2000
    • Tokyo Medical and Dental University
      Edo, Tōkyō, Japan
  • 1997
    • Jichi Medical University
      • Department of Pathology
      Totigi, Tochigi, Japan
  • 1992–1996
    • Tokyo Metropolitan Institute of Medical Science
      Edo, Tōkyō, Japan
  • 1994
    • Tokyo Metropolitan Komagome Hospital
      Edo, Tōkyō, Japan