• IMMUNE NETWORK
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• v.6 no.3
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• pp.154-162
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• 2006

Background: Dendritic cell (DC)-based cancer immunotherapy is studied for several years. However, it is mainly derived from autologous PBMC or leukapheresis from patient, which has limitations about yield and ability of DC production according to individual status. In order to solve these problems, inquiries about allogeneic DCs are performed but there are no preclinical trial answers for effect or toxicity of allogeneic DC to use for clinical trial. In this study, we compared the anti-tumor effect of allogeneic and autologous DCs from mouse bone marrow stem cells in mouse metastatic melanoma model. Methods: B16F10 melanoma cells ($5{\times}10^4$/mouse) were injected intravenously into the C57BL/6 mouse. Therapeutic DCs were differentiated from autologous (C57BL/6: CDC) or allogeneic (B6C3F1: BDC) bone marrow stem cells with GM-CSF, SCF and IL-4 for 13days and pulsed with B16F10 tumor cell lysate (Blys) for 18hrs. DC intra-peritoneal injections began on the 8th day after the tumor cell injection by twice with one week interval. Results: Anti-tumor response was observed by DC treatment without any toxicity especially in allogeneic DC treated mice (tumor burden score: $2.667{\pm}0.184,\;2.500{\pm}0.463,\;2.000{\pm}0.286,\;1.500{\pm}0.286,\;1.667 {\pm}0.297$ for saline, CDC/unpulsed-DC: U-DC, CDC/Blys-DC, BDC/U-DC and BDC/Blys-DC, respectively). IFN-${\gamma}$ secretion was significantly increased in allogeneic DC group stimulated with B16F10 cell lysate ($2,643.3{\pm}5,89.7,\;8,561.5{\pm}2,204.9.\;6,901.2{\pm}141.1pg/1{\times}10^6$ cells for saline, BDC/U-DC and BDC/Blys-DC, respectively) with increased NK cell activity. Conclusion: Conclusively, promising data was obtained that allogeneic DC can be used for DC-based cancer immunotherapy.

• Journal of Gastric Cancer
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• v.9 no.3
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• pp.110-116
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• 2009

Purpose: The aim of this study was to examine the usefulness of positron emission tomography (PET)-computed tomography (CT) in the pre-operative staging of gastric cancer. Materials and Methods: Between February 2006 and August 2008, PET-CT and CT were performed on 70 patients diagnosed with gastric cancer by gastrofiberscopic biopsy. The sensitivities, specificities, Positive predictive value (PPV), and negative predictive value (NPV) of PET-CT and CT imaging for the detection of gastric cancer TNM staging were compared. Results: The detection rates for the primary tumor were as follows: PET-CT, 81.4% (57/70); and CT, 42.9% (30/70). For both early gastric cancer (EGC) and advanced gastric cancer (AGC), PET-CT was more accurate than CT in detecting the lesions. As the size of the tumor exceeded 3 cm, the detection rate increased. The sensitivities, specificities, PPV, and NPV of PET-CT for lymph node staging were 55.6%, 81%, 86.2%, and 45.9%, while the sensitivities, specificities, PPV, and NPV of CT were 40.0%, 85.7%, 85.7% and 40%, respectively. One case of multiple liver metastasis and two cases of dual primary cancer (rectal and pancreatic cancers) were detected by PET-CT. PET-CT also had a higher detection rate for all histologic types of primary tumors. PET-CT was more accurate than CT in detecting primary gastric cancer lesions. The detection of nodal metastasis by PET-CT was similar to CT; small-sized tumors or EGC detection rates were not high. However, PET-CT provided additional information to detect distant metastases and dual primary cancers and reduced unnecessary laparotomies to detect peritoneal seeding or carcinomatosis. Conclusion: It would be useful to make a pre-operative diagnosis of gastric cancer and determine treatment if PET-CT were added to other routine pre-operative studies.

• Journal of Gastric Cancer
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• v.6 no.4
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• pp.263-269
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• 2006

Purpose: The aim of this study was to investigate the causes of under-staging in patients with advanced gastric cancer that was proven to be unresectable after a laparotomy. Materials and Methods: We retrospectively analyzed 25 gastric cancer patients who had undergone a diagnostic laparotomy between 2001 and 2005. For the preoperative evaluation, spiral CT and multidetector-row CT were performed. We analyzed the clinicopathologic features of patients and compared the image findings and the results of surgery. The causes of under-staging were divided into 3 groups; patient factor, CT factor, and interpretation factor. Results: Grossly, there were 12 cases of Borrmann type-III tumors and 13 cases of Borrmann type-IV tumors. The most frequent histologic type was poorly differentiated adenocarcinomas (8 cases) and signet ring cell carcinomas (7 cases). There were 13 cases of adjacent organ invasion, and the pancreas was the most frequently invaded organ (9 cases). There were 17 cases of peritoneal metastasis, and 3 cases of distant lymph node metastasis. For the cause of under-staging, there were four cases of patient factor, 19 cases of interpretation factor, and 9 cases of CT factor. In three cases, the cause of under-staging could not be identified. Conclusion: CT interpretation factor was the most frequent cause of under-staging in the preoperative diagnosis with gastric cancer patients. Therefore, more cautious CT interpretation is necessary to avoid unnecessary laparotomies in gastric cancer patients.

• Journal of Gastric Cancer
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• v.5 no.3 s.19
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• pp.174-179
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• 2005

Purpose: The 5-year survival rate is the most useful parameter for evaluating the effect of management on most malignant tumors. Recurrence after a curative resection for gastric cancer occurs mostly within 3 years of the operation, which caused us to evaluate whether a 3-year disease-free survival (3DFS) can be substituted for a 5-year overall survival (5OS). Materials and Methods: We reviewed the medical records of 656 consecutive patients who had undergone a curative resection for gastric cancer To assess whether 3DFS represents 5OS, we used a simple linear regression with survival probability calculated by using the survival function. Results: Recurrence was found in 175 cases during the follow-up periods. The accumulative frequencies of recurrence at postoperative 1 year, 3 years, and 5 years were 46% (81 cases), 89% (156 cases), and 97% (170 cases), respectively. The correlation coefficient (r) and the coefficient of determination $(r^2)$ between 3DFS and 5OS were 0.87 and 0.76, respectively, and the regression equation was $5OS=0.18+(0.80{\times}3DFS)$. The r and $R^2$ according to the type of recurrence were 0.89 and 0.80 in peritoneal seeding, 0.88 and 0.78 in hematogeneous metastasis, and 0.86 and 0.73 in local recurrence, respectively. The r (0.77) and $r^2$ (0.60) were relatively lower in low stages (stage I and II) compared to r (0.88) and $r^2(0.77)$ in high stages (stage III and IV). Conclusion: The 3DFS is an excellent predictor of 5OS. Therefore, if we use the former as the treatment evaluating method, 2-year time reduction in assessing and reporting treatment results is expected.

• Radiation Oncology Journal
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• v.16 no.1
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• pp.17-25
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• 1998

Purpose : Although local recurrence rates of stomach cancer after radiocal surgery have been reported in the range of $30-70\%$, the role of postoperative adjuvant therapy has not been established. We report the result of radiotherapy in resected stomach cancer with positive surgical margin to elucidate the role of postoperative radiotherapy. Materials and Methods : From June 1991 to August 1996, twenty five patients with positive surgical margins after radical gastrectomy were treated with postoperative radiotherapy and chemotherapy. Median dose of radiation was 55.8Gy and the range was 44.6-59.4Gy. Second cycle of chemotherapy was delivered concurrently with radiation and total number of six cycles were delivered. Twenty three had adenocarcinoma and the other two had leiornyosarcoma. The numbers of patients with stage I B, II, III A, III B, and IV were 1, 2, 11, 10 and 1 respectively. Positive margins at distal end of the stomach were in 17 patients and proximal in 5. The other three patients had positive margin at the sites of adjacent organ invasion Minimum and median follow-up periods were 12 months and 18 months, respectively, Results : Twenty-four of 25 patients received prescribed radiation dose and RTOG grade 3 toxicity of UGI tract was observed in 3, all of which were weight loss more than $15\%$ of their pretreatment weight. But hematemesis. melena, intestinal obstruction or grade 4 toxicity were not found. Locoregional failure within the radiation field was observed in 7 patients, and distant metastasis in 10 patients. Sites of locoregional recurrences involve anastomosis/remnant stomach in 3, tumor bed/duodenal stump in 3, regional lymph node in 1 patient Peritoneal seeding occurred in 6, liver metastases months and median disease free survival time was 26 months. Stages andradiation dose were not significant prognostic factors for locoregional in 2, and distant nodes in 2 patients. Four year disease specificsurvival rate was $40\%$ and disease free survival was $48\%$. Median survival was 35 failures. Conculsion : Although all patients in this study had positive surgical margins, locoregional failure rate was $28\%$, and 4 year disease specific survival rate was $40\%$. Considering small number of patients and relatively short follow-up period, it is not certain that postoperative radiotherapy lowered locoregional recurrences. but we could find a Possibility of the role of postoperative radiotherapy in Patients with high risk factors.