The evaluation of surgical treatment for gastric cancer patients with noncurative resection.

PURPOSE: This study aims to analyze the results of treatment in a series of 233 gastric cancer patients who underwent a noncurative resection. METHODS: We performed a retrospective study of patients with noncurative treatment for advanced gastric cancer who were divided into three treatment groups: total gastrectomy (TG, n=150), distal gastrectomy (DG, n=44), and nonresection (NR, bypass procedure or chemotherapy only, n=39). RESULTS: In multivariate analysis, surgical treatment (TG) and an absence of chemotherapy were significant independent prognostic factors for a poor survival. In the late period, the overall survival rate was significantly lower in the TG group than in the DG group (p=0.005) and was marginally lower than in the NR group (p=0.054). The resection group had a poorer compliance for chemotherapy than the NR group, and the TG group had a poorer compliance than the DG group (p<0.01). The morbidity rate was higher in the TG group than in the DG group (p<0.05). CONCLUSIONS: TG is considered to be inappropriate for the treatment of noncurative gastric cancer because of the poor prognosis, high morbidity rates, and poor compliance for chemotherapy associated with the procedure. However, noncurative DG was acceptable and postoperative chemotherapy should be used in selected patients.

Endoscopic resection of duodenal bulb neuroendocrine tumor larger than 10 mm in diameter.

BACKGROUND: Endoscopic treatment for duodenal bulb neuroendocrine tumor larger than 10 mm is still controversial. This report presents four cases successfully treated with endosonography (EUS)-assisted endoscopic mucosal resection (EMR) procedure for duodenal bulb neuroendocrine tumor larger than 10 mm in diameter. METHODS: The case series of four patients diagnosed with neuroendocrine tumor from 2003 to 2008 were reviewed. EUS demonstrated well-defined hypoechoic tumors confined to the submucosal hyperechoic layer and the underlying hypoechoic muscularis propria was intact in all four patients. EMR were planned and performed for the duodenal bulb neuroendocrine tumors larger than 10 mm. RESULTS: En bloc resections with tumor free lateral and basal margins were accomplished using an endoscopic diathermic snare with forward-viewing instruments without any complications. Neither residual duodenal neuroendocrine tumors nor metastatic lesions were detected during the observation period ranging 19 to 78 months CONCLUSION: Duodenal bulb neuroendocrine, larger than 10 mm in diameter, can be treated by endoscopic procedure, after confirming that the tumor confined to the submucosal layer in EUS examination, and no lymph node involvement by abdominal CT and US.

Optimal period for the prophylactic administration of neutrophil elastase inhibitor for patients with esophageal cancer undergoing esophagectomy.

BACKGROUND: The present study was designed to determine the optimal period for the prophylactic administration of the neutrophil elastase inhibitor, Sivelestat, in patients undergoing transthoracic esophagectomy. Sivelestat is reported to be effective in patients who undergo esophagectomy by providing an increased oxygenation ability and suppressing the serum inflammatory cytokines in the postoperative period. However, the optimal period for the prophylactic administration of Sivelestat remains to be elucidated. METHODS: The 30 patients who underwent esophagectomy for thoracic esophageal cancer were enrolled in one of two groups. The initial 15 patients were assigned to group A and received intravenous infusion of Sivelestat sodium hydrate until postoperative day (POD) 2, and the subsequent 15 patients were assigned to group B and received Sivelestat until POD 5. Historical controls without Sivelestat administration were used. The postoperative courses and serum inflammatory cytokines were evaluated. RESULTS: Sivelestat improved oxygenation in the postoperative period; however, there were no differences between the two groups in terms of duration of mechanical ventilation, intensive care unit stay, systemic inflammatory response syndrome, and postoperative change of oxygenation. In addition, there were no differences in the postoperative changes in the serum interleukin (IL)-6 and high mobility group box chromosomal protein 1. Although the serum IL-8 on POD 3 was lower in group B than in group A, the neutrophil elastase showed no difference between these groups. None of the patients in either group suffered respiratory complications. CONCLUSIONS: The two-day administration of Sivelestat initiated immediately after intrathoracic manipulation was found to be sufficient for prophylactic use to prevent pulmonary complications by suppressing hypercytokinemia after esophagectomy.

[Peptide vaccine therapy with TLR-9 agonist for patients with esophageal squamous cell carcinoma].

Patients with advanced carcinoma are thought to have an impaired immune surveillance system. Therefore, the potent helper action is required for the induction of an antitumor immune response in such patients. We evaluated the efficacy of CpG-ODN, which is TLR-9 agonist, as cancer vaccine adjuvant through in vitro experiments. We also conducted a phase I clinical trial for patients with advanced esophageal squamous cell carcinoma (ESCC) using peptide vaccine in combination with CpG-B. In vitro experiments showed that CpG-ODN caused various immune-modifications, suggesting an efficacy of CpG-ODN as peptide vaccine adjuvant. Moreover, the immune monitoring data in phase I clinical trial suggested that CpG-B augmented the generation of antigen-specific T cell responses and innate immunity. These data indicated that the vaccination with cancer-testis antigen derived peptide in combination with CpG-B may be useful as a new immunotherapy for patients with advanced ESCC.

Vaccination with peptides derived from cancer-testis antigens in combination with CpG-7909 elicits strong specific CD8+ T cell response in patients with metastatic esophageal squamous cell carcinoma.

Potent helper action is necessary for peptide-based vaccines to efficiently induce antitumor immune responses against advanced cancer. A phase I trial for advanced esophageal squamous cell carcinoma was carried out for patients with HLA-A*2402 using epitope peptides derived from novel cancer-testis antigens, LY6K and TTK, in combination with CpG-7909 (NCT00669292). This study investigated the feasibility and the toxicity as well as induction of tumor antigen-specific immune responses. Nine patients were vaccinated on days 1, 8, 15, and 22 of each 28-day treatment cycle with peptide LY6K-177, peptide TTK-567, and CpG-7909 (level-1; 0, level-2; 0.02, level-3; 0.1 mg/kg) and all were tolerated by this treatment. LY6K-specific T cell responses in PBMCs were detected in two of the three patients in each level. In particular, two patients in level-2/3 showed potent LY6K-specific T cell responses. In contrast, only two patients in level-2/3 showed TTK-567-specific T cell responses. The frequency of LY6K-177 or TTK-567-specific CD8+ T cells increased in patients in level-2/3 (with CpG). The vaccination with peptides and CpG-7909 increased and activated both plasmacytoid dendritic cells and natural killer cells, and increased the serum level of α-interferon. There were no complete response (CR) and partial response (PR), however, one of three patients in level-1, and four of six patients in level-2/3 showed stable disease (SD). In conclusion, vaccination with LY6K-177 and TTK-567 in combination with CpG-7909 successfully elicited antigen-specific CD8+ T cell responses and enhanced the innate immunity of patients with advanced esophageal squamous cell carcinoma. This vaccine protocol is therefore recommended to undergo further phase II trials.

High CCR7 mRNA expression of cancer cells is associated with lymph node involvement in patients with esophageal squamous cell carcinoma.

Esophageal squamous cell carcinoma (SCC) is one of the biological malignant tumors. Once a tumor invades the submucosa, an incidence of lymph node (LN) metastases is very high, thus resulting in poor survival. Recently, chemokines have been reported to play an important role in organ-specific metastases in several malignancies. In particular, CCR7 has been reported to be associated with LN metastases by immunohistochemistry. However, there have been no studies of quantitative analyses of CCR7 mRNA expression on cancer cells. In this study, we investigated the clinical significance of the expression of CCR7 in the establishment of LN metastases of esophageal SCC. A series of 78 patients with esophageal SCC who underwent esophagectomy were consecutively selected. The expression of CCR7 mRNA from tumor tissue samples was analyzed by quantitative real-time reverse transcriptase-polymerase chain reaction (qRT-PCR), and that from cancer cell samples collected using laser microdissection system was analyzed by qRT-PCR. Immunohistochemical staining of CCR7 was also performed. Although CCR7 mRNA expression in tumor tissues demonstrated no association with the LN metastases, that in cancer cells correlated with LN metastases (p<0.05) due to the fact that not only cancer cells but also infiltrating lymphocytes expressed CCR7 in tumor tissue. Multivariate logistic regression analysis revealed a high CCR7 expression in cancer cells to be an independent predictive factor for LN metastases. These results suggested that CCR7 expression might play an important role in establishing LN metastases in patients with esophageal SCC.

Evaluation of double tract reconstruction after total gastrectomy in patients with gastric cancer: prospective randomized controlled trial.

BACKGROUND: The double tract (DT) method was compared with the Roux-en-Y (R-Y) method to identify the optimal reconstruction procedure after total gastrectomy for patients with gastric cancer. The DT reconstruction is as simple as the R-Y, and it can be safely performed even after total gastrectomy. However, these have been no studies evaluating the usefulness of DT reconstruction in comparison to R-Y reconstruction. METHODS: A group of 44 patients with gastric cancer were intraoperatively randomized for R-Y (n = 23) or DT reconstruction (n = 21) after total gastrectomy (TG). Body weight, food intake, nutritional conditions, and quality of life (QOL) were determined at 3 and 12 months after the operation. This study is registered with ClinicalTrials.gov, no. NCT00746161. RESULTS: Food intake significantly decreased soon after the operation. No differences were observed between the DT and R-Y groups. The body weight decreased throughout the ensuing period (P < 0.05) and thereafter gradually recovered. However, no differences were observed between the two groups. Among the nutritional laboratory parameters, serum prealbumin, retinol-binding protein, total cholesterol, and triglyceride were decreased soon after the operation. The changes of those parameters were not substantially different between the two groups. The postoperative QOL was evaluated, and no differences were observed between those groups. CONCLUSIONS: There were no particular advantages in the DT method after TG in comparison to the simple R-Y method in terms of body weight, QOL, and nutritional conditions, suggesting that the DT method might not be recommended after TG for patients with gastric cancer.

Analysis of the prognostic factors and evaluation of surgical treatment for synchronous liver metastases from gastric cancer.

BACKGROUND AND AIMS: Whether or not a synchronous resection of liver metastases from gastric cancer provides a survival benefit has been a key issue. We identify the significant prognostic factors and clarify the beneficial effect on the survival of liver surgical treatment. MATERIALS AND METHODS: We reviewed 72 patients who underwent a gastrectomy for gastric cancer with synchronous liver metastases and classified the liver metastases into three grades, such as H1: metastases were limited to one of the lobes, H2: there were a few scattered metastases in both lobes, and H3: there were numerous scattered metastases. RESULTS: H1, 2 metastases, and an absence of peritoneal dissemination (P0) were significantly independent prognostic factors for liver metastases of gastric cancer. In addition, the cumulative 1 and 5-year survival rates of liver surgical treatment (hepatic resection and/or microwave coagulation therapy) were 80.0% and 60.0%, whereas the survival rates for non-hepatic surgical treatment were 36.4% and 0% in 26 patients with H1, 2, and P0. In those patients, the radical operation, the solitary metastatic liver tumor, and no-distant lymph node metastases were independent prognostic determinants of survival. CONCLUSION: The radical operation including the surgical treatment for metastatic liver tumors should be performed to improve the prognosis in gastric cancer patients with synchronous H1, 2, and P0.

Optimal dose of preoperative enteral immunonutrition for patients with esophageal cancer.

PURPOSE: A preoperative immunonutrition pharmaceutics diet (IMPACT) significantly reduced the incidence of postoperative infectious complications, but the optimal regimen still remains unclear. We evaluated the optimal dose of a preoperative IMPACT for patients with esophageal carcinoma and the incidence of postoperative complications based on the dose of IMPACT. METHODS: This study design was a prospective nonrandomized study. Twenty patients with thoracic esophageal carcinoma who underwent a right transthoracic subtotal esophagectomy were divided into two groups. These patients were administered immunonutrition of 500 ml/day (IMP500) or 1000 ml/day (IMP1000) for 7 days before the operation. RESULTS: The incidence of postoperative mortality and morbidity was not different between the IMP500 group and the IMP1000 group. No difference was observed in the perioperative changes in inflammatory, immunological and nutritional variables between the two groups. There were no adverse effects in the IMP500 group, but four patients (40%) had diarrhea and four patients (40%) had appetite loss in the IMP1000 group. In the IMP1000 group, only four patients (40%) could take 1000 ml, but others reduced the quantity of IMPACT because of diarrhea and discomfort. CONCLUSION: This study suggests that 500 ml of IMPACT is recommended as an optimal dose for patients with esophageal cancer.

Tumor vaccine therapy against recrudescent tumor using dendritic cells simultaneously transfected with tumor RNA and granulocyte macrophage colony-stimulating factor RNA.

Recently, dendritic cells (DC) transfected with tumor RNA have been used as a cancer vaccine. The efficacy of a cancer vaccine using DC transfected tumor RNA was examined. Of particular interest was whether a vaccine using DC transfected with recrudescent tumor RNA is effective for the treatment of a regrowing tumor after prior immunotherapy. In addition, the usefulness of co-transfection of granulocyte macrophage colony-stimulating factor (GM-CSF) mRNA to augment the DC vaccine was examined. CT26 tumor-bearing mice were immunized by s.c. injection with DC transfected with CT26 mRNA (DC-CT26). The cytotoxic activity against CT26 in mice immunized with DC-CT26 was significantly higher than that in the control group (P < 0.001) and was augmented by GM-CSF mRNA co-transfection (P < 0.05), resulting in remarkable therapeutic efficacy in CT26 s.c. tumor models. Cytotoxic T lymphocytes induced by the vaccination using DC transfected with mRNA from the recrudescent tumor showed a potent cytotoxicity against the recrudescent CT26 tumor cells, which was significantly higher than the cytotoxicity induced by the vaccination using DC-CT26 (P < 0.05). In addition, in a recrudescent tumor model, this vaccination suppressed the regrowing s.c. tumors, and was augmented by GM-CSF mRNA co-transfection (P < 0.05). These results suggested that vaccination therapy using DC simultaneously transfected with whole tumor RNA and GM-CSF mRNA could generate therapeutic immune responses even against recrudescent tumor after prior vaccination.

Streptococcal preparation OK-432 promotes the capacity of dendritic cells (DCs) to prime carcinoembryonic antigen (CEA)-specific cytotoxic T lymphocyte responses induced with genetically modified DCs that express CEA.

Cancer immunotherapy using dendritic cells (DCs) adenovirally transduced with the whole tumor-associated antigen (TAA) gene is an effective approach. Streptococcal preparation OK-432 is useful for stimulating DCs in terms of maturation. In this study, we established carcinoembryonic antigen (CEA)-specific cytotoxic T lymphocytes (CTLs) using in vitro stimulation with adenovirally modified human DCs that express CEA. We investigated whether OK-432 stimulation could be more effective in inducing CEA-specific CTLs compared with other typical stimuli. DCs adenovirally transduced with the CEA gene were cultured under various conditions with tumor necrosis factor (TNF)-alpha, lipopolysaccharide (LPS), or OK-432. A cytotoxicity assay using peripheral blood mononuclear cell (PBMC)-derived CTLs was performed in a 4 h-51Cr release assay. OK-432 stimulated immature DCs to acquire a mature phenotype and to produce significant amounts of T-helper 1 cytokines. In all groups (immature DCs, TNF-alpha/DCs, LPS/DCs, OK-432/DCs), CEA-specific CTLs were generated. OK-432-stimulated DCs (HLA-A24) induced the most potent cytotoxic activity against CEA-expressing targets (A24) but not against controls. OK-432/DCs were able to induce markedly potent CTLs specific to target cells pulsed with CEA652 peptide (HLA-A24-restricted peptide), although others failed to induce potent CTLs. In conclusion, the CTL induction protocol using adenovirally modified DCs that express CEA after maturation with OK-432 showed a potent antitumor activity against CEA-expressing target cells, and is therefore promising for clinical applications as a cancer vaccine therapy.

An analysis of the factors contributing to a reduction in the incidence of pulmonary complications following an esophagectomy for esophageal cancer.

BACKGROUND: Pulmonary complications occur most frequently following a transthoracic esophagectomy for esophageal cancer and would get to be lethal occasionally. In this study, we sought to determine the effect of respiratory physiotherapy, corticosteroid administration, and the use of the video-assisted thoracoscopic (VATS) esophagectomy with a small thoracotomy incision, on the incidence of pulmonary complications following a transthoracic subtotal esophagectomy. MATERIALS AND METHODS: Approximately 184 patients who had undergone a right transthoracic subtotal esophagectomy for squamous cell carcinoma of the thoracic esophagus were studied. To reduce the incidence of pulmonary complications, we performed clinical trials using respiratory physiotherapy, corticosteroid administration, and the VATS-esophagectomy surgical technique. RESULTS: The independent risk factors for pulmonary complications in the multivariate logistic regression analysis were not administering corticosteroids, blood loss greater than 630 ml, and not providing respiratory physiotherapy. In addition, the use of a small surgical incision, less than 10 cm, for the thoracotomy had no effect on the prevention of pulmonary complications. CONCLUSIONS: We concluded that patients with thoracic esophageal cancer could undergo a three-field dissection in comparative safety if the patients were provided with corticosteroid medication in the perioperative period, if the patients received sufficient respiratory physiotherapy, and if surgical blood loss was reduced.

Multiple early gastric cancer with gastritis cystica profunda showing various histological types.

We report a case of multiple early gastric cancer showing varied histological types associated with gastritis cystica profunda (GCP). A 61-year-old man who had early gastric cancer associated with GCP underwent a distal gastrectomy with lymphadenectomy. Histological examination showed various histological types of cancer -well differentiated, moderately differentiated, poorly differentiated adenocarcinoma, mucinous adenocarcinoma and signet ring cell carcinoma- that had developed independently in the mucosal and submucosal layers of the resected specimen. Furthermore, multiple cysts with a single layer of columnar epithelium were present in the submucosa around the cancerous lesions. However, no neoplastic changes were found in those epithelial cells. Helicobacter pylori was detected in the residual stomach 3 months after surgery. Although the mechanism of the relationship between gastric carcinoma and GCPs is obscure, we speculate that repeated erosion and regeneration induced by chronic inflammation causes multicentric carcinogenesis as well as an aberration of the gastric glands. GCPs may be a risk factor for multiple gastric cancer.

Benefits of gene transduction of granulocyte macrophage colony-stimulating factor in cancer vaccine using genetically modified dendritic cells.

Granulocyte macrophage colony-stimulating factor (GM-CSF) is a key cytokine for the generation and stimulation of dendritic cells (DCs), and it may also play a pivotal role in promoting the survival of DCs. In this study, the feasibility of creating a cancer vaccine using DCs adenovirally transduced with the carcinoembryonic antigen (CEA) gene and the GM-CSF gene was examined. In addition, the effect of the co-transduction of GM-CSF gene on the lifespan of these genetically modified DCs was determined. A cytotoxic assay using peripheral blood mononuclear cell (PBMC)-derived cytotoxic T lymphocytes (CTLs) was performed in a 4-h 51Cr release assay. The apoptosis of DCs was examined by TdT-mediated dUTP-FITC nick end labeling (TUNEL) assay. CEA-specific CTLs were generated from PBMCs stimulated with genetically modified DCs expressing CEA. The cytotoxicity of these CTLs was augmented by co-transduction of DCs with the GM-CSF gene. Co-transduction of the GM-CSF gene into DCs inhibited apoptosis of these DCs themselves via up-regulation of Bcl-x(L) expression, leading to the extension of the lifespan of these DCs. Furthermore, the transduction of the GM-CSF gene into DCs also suppressed the incidence of apoptosis of DCs induced by transforming growth factor-beta1 (TGFbeta-1). Immunotherapy using these genetically modified DCs may therefore be useful with several advantages as follows: i) adenoviral toxicity to DCs can be reduced; ii) the lifespan of vaccinated DCs can be prolonged; and iii) GM-CSF may protect DCs from apoptosis induced by tumor-derived TGFbeta-1 in the regional lymph nodes.

The boosting effect of co-transduction with cytokine genes on cancer vaccine therapy using genetically modified dendritic cells expressing tumor-associated antigen.

The T-helper 1 (Th1) immune reaction is most important in dendritic cell (DC)-based immunotherapy. Interleukin 12 (IL-12) and granulocyte macrophage colony-stimulating factor (GM-CSF) play a pivotal role in inducing Th1 and cytotoxic T lymphocyte (CTL) responses. In this study, DCs expressing the natural tumor antigen gp70 of BALB/c-derived CT26 were adenovirally transduced with the IL-12 gene and/or GM-CSF gene, and it was examined whether vaccinations using these genetically engineered DCs can induce strong therapeutic antitumor immunity. Mice were immunized once by subcutaneous (s.c.) injection with genetically modified DCs. The cytotoxic activity of splenocytes against CT26 was assayed in a 51Cr-release assay 14 days after immunization. The therapeutic efficacy of the vaccination was examined in s.c. tumor models. The cytotoxic activity of CTLs against CT26 in mice immunized with DCs expressing gp70 (DC-AxCAgp70) was significantly augmented by co-transduction with the GM-CSF/IL-12 gene (p<0.0001) and remarkably reduced by the depletion of CD4+ or CD8+ cells (p<0.01). The cytotoxic activity against CT26 of the plain spleen cells in mice immunized with DC-AxCAgp70/GM-CSF/IL-12 was significantly higher than that in mice immunized with DC-AxCAgp70 (p<0.0001), and this activity decreased to almost 50% upon the depletion of NK cells. Vaccinations using DC-AxCAgp70/GM-CSF/IL-12 or DC-AxCAgp70/IL-12 could elicit potent therapeutic immunity in s.c. tumor models; tumor-free mice were observed in these vaccination groups. However, there was no significant difference between these two groups. A vaccination therapy using DCs co-transduced with the TAA gene and Th 1-type cytokine genes, especially the IL-12 gene, is ideal for immunotherapy in terms of the activation of DCs, NK cells, CD4+ T cells and CD8+ T cells, and may be useful in the clinical application of a cancer vaccine therapy.

Individualized adjuvant chemotherapy guided by chemosensitivity test sequential to extended surgery for advanced gastric cancer.

BACKGROUND AND OBJECTIVES: Various adjuvant chemotherapy regimens have been proposed for patients with advanced gastric cancer; however, the majority of these trials failed to show a clear survival benefit over surgery alone. In this study, the feasibility and efficacy of a strategy of extended surgery combined with individualized adjuvant chemotherapy for advanced gastric cancer with serosal invasion and nodal involvement was examined. PATIENTS AND METHODS: Sixty-four patients with advanced gastric cancer underwent gastrectomy with extended lymph node dissection. After surgery, a chemosensitivity test by MTT assay, using highly purified tumor cells, was performed, and the patients received individualized adjuvant chemotherapy on the basis of the results of this chemosensitivity test. RESULTS: Overall survival in the chemosensitivity-guided chemotherapy (CSC) group was significantly better than the standard chemotherapy (SC) and the no-chemotherapy (NC) group (p<0.05). In patients with stage IV disease, the 5-year survival rate was 38.1% in the CSC group and 0% in the SC + NC group, respectively, with a significant difference being observed in the two survival curves (p<0.01). In patients with paraaortic node involvement, survival in the CSC group was significantly better than that in the SC + NC group (p<0.01). On the other hand, in patients without paraaortic node involvement, no survival difference was observed between the two groups. CONCLUSION: The strategy of extended surgery combined with individualized adjuvant chemotherapy offers a favorable survival outcome for advanced gastric cancer patients with serosal invasion and nodal involvement.

Evaluation of chemosensitivity testing with highly purified tumor cells in 435 patients with gastric carcinoma using an MTT assay.

BACKGROUND: We evaluated the results of chemosensitivity testing for gastric cancer using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay in terms of the correlation of chemosensitivity and clinicopathological findings. PATIENTS AND METHODS: We analyzed 435 consecutive patients with gastric cancer treated between January 1991 and January 2002. Highly purified fresh human gastric cancer cells were obtained from 485 lesions including 415 primary tumors and 70 metastatic tumors. RESULTS: CDDP and 5-FU were more potent drugs than MMC, ADR and VP-16. The chemosensitivity of metastatic tumors was lower than that in primary tumors. The chemosensitivity in differentiated cancer was equivalent to that in undifferentiated cancer. The manner of tumor invasion and clinical stage affected chemosensitivity for some drugs. CONCLUSION: Our results suggest that individual chemosensitivity testing is essential to individualize chemotherapy for gastric cancer.

Adenoviral-mediated gene transduction of the hepatocyte growth factor (HGF) antagonist, NK4, suppresses peritoneal metastases of gastric cancer in nude mice.

The competitive inhibitory effects of NK4 (a specific hepatocyte growth factor (HGF)-antagonist) on the interaction between HGF and the c-Met/HGF receptor has been shown in HGF-mediated invasion of some distinct types of human cancer cells. Furthermore, NK4 has inhibitory effects on the angiogenic pathways driven by basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF), as well as by HGF. In this study, to evaluate the therapeutic efficacy of adenoviral-mediated NK4 gene treatment, we employed animal models of peritoneal metastasis using two gastric cancer cell lines, the strongly c-Met expressing MKN45 cell line and the weakly c-Met-expressing cell line, TMK1. In both models, the total number and weight of peritoneal tumours per mouse and ascites treated early with AxCANK4 (administered 3 times 2, 7 and 12 days after the tumour inoculation) were significantly reduced compared with those treated with phosphate-buffered solution (PBS) and AxCALacZ (P < 0.05). In Factor-VIII-related-antigen-stained sections from peritoneal metastatic tumours, the inhibition of intratumour vessels was observed in tissues from tumours of MKN45 and TMK1 treated with AxCANK4. We also compared the therapeutic effect of early AxCANK4 treatment with that of late treatment (at 7, 12 and 17 days). Peritoneal metastases and ascites treated late with AxCANK4 showed less of an improvement than those treated early with AxCANK4 in both models. In addition, the inhibitory effect of cisplatin (CDDP) on peritoneal metastasis was significantly enhanced by AxCANK4, suggesting that the combination of intraperitoneal (i.p.) chemotherapy with NK4 gene therapy might be effective, even in cases of advanced peritoneal metastasis from gastric cancer. To conclude, these results show clearly that NK4 gene therapy inhibits peritoneal metastases from gastric cancer, regardless of the level of c-Met/HGF receptor expression in the tumour cells, and especially in the early stages of peritoneal metastasis.

Preoperative endoscopic analysis of thymidine phosphorylase and dihydropyrimidine dehydrogenase in gastrointestinal cancer.

Thymidine phosphorylase (TP) and dihydropyrimidine dehydrogenase (DPD) are considered to be key enzymes affecting the prognosis for patients with advanced gastrointestinal cancer. Preoperative examination of TP and DPD expression levels and assessment of these enzymes in inoperable cancer patients may contribute to successful treatment. We tried to prove the correlation of TP and DPD expression in preoperative specimens by endoscopy and in surgical specimens. The present study was designed to quantify TP and DPD levels by enzyme-linked immunosorbent assay (ELISA) in tumor tissue obtained from 30 gastrointestinal cancer patients by preoperative endoscopy and surgery, including 15 gastric and 15 colorectal cancers. Successful cases as those in which cancer cells were demonstrated histologically in preoperative specimens by endoscopy were 12 (success rate: 80%) in gastric cancer patients, and 15 (success rate: 100%) in colorectal cancer patients. In successful cases, there were almost significant correlations in all cases, gastric cancer, and colorectal cancer among the expression of TP, DPD, and TP/DPD ratio in each preoperative specimen by endoscopy and surgical specimen, respectively. On the other hand, in the gastric cancer group, 3 unsuccessful cases resulted in a significant departure from ideal equation compared with 12 successful cases. In actual clinical care, physicians should pay attention to and evaluate carefully the data from endoscopical biopsy specimens in which cancer cells may not be demonstrated histologically. Thus, endoscopic analysis of TP and DPD expression in preoperative or inoperable cancer patients may contribute to successful treatment.

Comparative analysis of thymidine phosphorylase and dihydropyrimidine dehydrogenase expression in gastric and colorectal cancers.

Thymidine phosphorylase (TP) and dihydropyrimidine dehydrogenase (DPD) are considered to be key enzymes affecting the prognosis for patients with gastric and colorectal cancers. We tried to prove the correlation of TP and DPD expressions in gastric and colorectal cancers. The present study was designed to quantify TP and DPD levels by an enzyme-linked immunosorbent assay (ELISA) in tumors and normal tissues obtained from 16 gastric and 20 colorectal cancer patients. TP and TP/DPD ratio in the tumor specimens were almost all higher than those in each normal tissue, especially for tumors in the progressive state. In the early stage of the colorectal cancer group, DPD in the normal tissues were higher than those in the tumor specimens. There were no significant differences between TP levels in the tumor specimens of the two groups, whereas in stages III and IV, those of the gastric cancer group tended to be higher than those of colorectal cancer group. In stages I and II, DPD levels in the tumor specimens tended to be higher in the gastric cancer group than in the colorectal cancer group. DPD T/N was higher in the gastric cancer group than in the colorectal cancer group. There were no significant differences between TP/DPD ratios in the tumor specimens of the two groups, whereas those in normal tissue were higher in the gastric cancer group than in the colorectal cancer group. We may be able to achieve the successful effects or reduction of side effects of anticancer chemotherapy for gastric and colorectal cancer using the results of this study.