Search

Tumor-associated macrophages of the M2 phenotype promote tumor proliferation and are associated with a poor prognosis in patients with various malignancies, including gastric cancer with peritoneal dissemination. The present study assessed whether paclitaxel (PTX) suppresses M2 macrophages, by acting as a Toll-like receptor 4 (TLR4) agonist. Macrophages derived from the THP-1 monocytic cell line and peripheral blood mononuclear cell (PBMC)-derived macrophages were cultured with gastric cancer cells in medium containing PTX, at a concentration that did not affect cell proliferation. The effects of PTX on macrophage expression of CD204, a marker of M2 macrophages and NOS2, a marker of M1 macrophages, was evaluated by western blotting. The ability of PTX to stimulate intranuclear translocation of NF-κB was determined by evaluating the expression of the p65 subunit of NF-κB. In THP-1 macrophages, low-dose PTX (1 and 5 nM) inhibited the expression of CD204, enhanced the expression of NOS2, and significantly suppressed the phosphorylation of Stat3, which is essential for the M2 phenotype. Low-dose PTX also inhibited CD204 expression in primary macrophages derived from PBMCs. PTX treatment of THP-1 macrophages for 1 h induced marked intranuclear translocation of NF-κB p65. Low-dose PTX inhibited the M2 phenotype and induced the M1 phenotype via TLR4 signaling, suggesting that low-dose PTX can alter the macrophage phenotype, whereas clinical doses can kill cancer cells. These results suggest that the anticancer effects of PTX are due both to its cytotoxic and immunomodulatory activities.

Peritoneal carcinomatosis (PC) is the most frequent metastatic pattern of gastric cancer and its prognosis is extremely poor. PC is characterized by rich fibrosis and the development of obstructive disorders such as ileus, jaundice and hydronephrosis. Epithelial-mesenchymal transition (EMT) is one of the major causes of tissue fibrosis and transforming growth factor β (TGF-β) has a pivotal function in the progression of EMT. Protein-bound polysaccharide K (PSK) is a biological response modifier that can modulate the TGF-β/Smad signaling pathway in vitro. In the present study, we established a fibrotic tumor model using human peritoneal mesothelial cells (HPMCs) and a human gastric cancer cell line to evaluate whether PSK attenuates tumor fibrosis. HPMCs exposed to PSK did not undergo the morphological change from a cobblestone-like pattern to a spindle-shape pattern normally induced by treatment with TGF-β. Immunofluorescence further demonstrated that PSK suppressed TGF-β-induced overexpression of α-SMA in the HPMCs. We further showed that HPMCs contributed to the proliferation of tumor fibrosis by using a mouse xenograft model. Additionally, PSK treatment of these mice significantly reduced the area of observable tumor fibrosis. These results suggest that seeded cancer cells transformed HPMCs into myofibroblast-like cells through their release of TGF-β in the microenvironment, facilitating the development of fibrous tumors in organs covered with HPMCs. Therefore, our study indicates that PSK has potential utility as an anti-fibrotic agent in the treatment of gastric cancer patients with PC.

Intraperitoneal (i.p.) chemotherapy with paclitaxel (PTX) has been shown to be a promising treatment strategy for peritoneal metastasis. The present study focused on the comparative evaluation of the therapeutic efficacy of nanoparticle albumin-bound PTX (Nab-PTX) and i.p. administration of the conventional solvent-based PTX (Sb-PTX). We also investigated the difference in antitumor activity depending on the route of administration in the Nab-PTX treatment. Nab-PTX was administered i.p. or intravenously (i.v.) and Sb-PTX was administered i.p. at equitoxic and equal doses to nude mice bearing gastric cancer OCUM-2MD3 cell subcutaneous and peritoneal xenografts. Therapeutic efficacy of Sb-PTX and Nab-PTX was evaluated as inhibition of tumor growth using a peritoneal metastatic model with subcutaneous xenografts. The survival rate was also investigated using mouse peritoneal models. For assessment of subcutaneous tumors, the change in tumor volume was measured, and for assessment of peritoneal tumors, the weight of ascitic fluid and the total peritoneal tumor burden were measured for each individual mouse. At equitoxic doses, treatment with Nab-PTX resulted in a greater reduction in the size of subcutaneous tumors and the weight of ascites and peritoneal burden as compared with i.p. Sb-PTX (p

Residual mucosa in the gastric stump after pylorus-preserving gastrectomy (PPG) is considered a risk factor for the development of gastric stump carcinoma (GSC). Duodenogastric reflux (DGR) and Helicobacter pylori (H. pylori) infection are suspected to contribute to the development of GSC. The aim of this study was to investigate the prevalence of H. pylori in the residual stomach after PPG for gastric cancer and to assess factors associated with the presence of H. pylori. We investigated 72 patients who had undergone PPG at least 1 year prior to the study and were confirmed to be positive for H. pylori infection on presurgical endoscopic biopsy. The extent of DGR, the prevalence of H. pylori infection based on H. pylori stool antigen (HpSA) tests and the severity of gastritis were analyzed in these post-PPG patients. None of the patients had DGR, as shown by (99m)Tc-PMT. Of the 72 post-PPG patients, 33 (46%) were positive for HpSA. The prevalence of H. pylori infection was significantly lower after surgery than before surgery. The endoscopic severity of remnant gastritis, as well as histological inflammation and activity, were higher in H. pylori-positive patients than in H. pylori-negative patients. In conclusion, some patients who undergo PPG and are negative for DGR experience spontaneous clearance of H. pylori infection.

Cancer stem cells (CSCs) have self-renewal and pluripotency capabilities and contribute to cancer progression and chemoresistance. It has been proposed that the treatment resistance and heterogeneity of CSCs are deeply involved in the prognosis of patients with esophageal squamous cell carcinoma (ESCC). The objective of this study was to identify the influence of the expression status of the CSC markers CD44 and CD133 on chemotherapeutic efficacy and prognosis in ESCC patients who underwent radical esophagectomy after neoadjuvant chemotherapy (NAC). Endoscopically biopsied specimens taken before NAC and surgically resected specimens after NAC were immunohistochemically assessed for CD44 and CD133 expression for 47 ESCC patients who underwent NAC followed by radical esophagectomy. The correlation between CD44 and CD133 expression status and clinicopathological findings and the prognosis of ESCC patients after NAC followed by esophagectomy were analyzed. The percentages of CD44-positive cells and CD133-positive cells in specimens were increased after NAC. CD44 and CD133 expression status before NAC did not correlate with the degree of tumor progression and had no impact on the chemotherapeutic effect. However, strong expression of CD44 or CD133 and a high proportion of CD133-expressing cells before NAC were significantly associated with poorer esophageal cancer-specific survival. Patients with strong expression of CD44 or CD133 and those with a high ratio of CD133-positive tumor cells showed significantly poor prognosis regardless of the effect of chemotherapy. Multivariate analysis showed that simultaneous strong expression of CD44 and CD133 before NAC, a high rate of CD133-positive tumor cells before NAC, and primary tumor remission assessed by preoperative endoscopy were significant independent prognostic factors for ESCC. Our data indicate that CD44 and CD133 expression status prior to treatment dictates the malignant potential of ESCC and may be a novel predictor of recurrence and prognosis of ESCC patients after treatment.

Platelets are crucial components of the tumor microenvironment that function to promote tumor progression and metastasis. In the circulation, the interaction between tumor cells and platelets increases invasiveness, protects tumor cells from shear stress and immune surveillance, and facilitates tumor cell extravasation to distant sites. However, the role and presence of platelets in the primary tumor have not been fully determined. Here, we investigated the presence of platelets around breast cancer primary tumor cells and the associations between these cells. We further investigated the associations among platelets, tumor cells, chemoresistance, and epithelial-mesenchymal transition (EMT). We retrospectively analyzed data from 74 patients with human epidermal growth factor receptor 2 (HER2)‑negative breast cancer who underwent biopsies before treatment and subsequent neo-adjuvant chemotherapy. In biopsy specimens, we evaluated the expression of platelet-specific markers and EMT markers using immunohistochemistry. The associations among the expression of platelet‑specific markers in biopsy specimens, EMT, response to neo‑adjuvant chemotherapy, and survival were analyzed. The presence of platelets was observed in 44 out of 74 (59%) primary breast cancer biopsy specimens. Platelet‑positive tumor cells showed EMT‑like morphological changes and EMT marker expression. Primary tumor cells associated with platelets were less responsive to neo‑adjuvant chemotherapy (pCR rate: 10 vs. 50%, respectively; p=0.0001). Platelets were an independent predictor of the response to chemotherapy upon multivariable analysis (p

金沢大学医薬保健研究域医学系, Several recent studies have reported that selectins are produced during ischemia-reperfusion injury, and that selectin ligands play an important role in cell binding to the endothelium and in liver metastasis. Portal clamping during pancreaticoduodenectomy with vessel resection for pancreatic head cancer causes hepatic ischemia-reperfusion injury, which might promote liver metastasis. We investigated the liver colonization of pancreatic cancer cells under hepatic ischemia-reperfusion and examined the involvement of E-selectin and its ligands. A human pancreatic cancer cell line (Capan-1) was injected into the spleen of mice after hepatic ischemia-reperfusion (I/R group). In addition, to investigate the effect of an anti-E-selectin antibody on liver colonization in the IR group, mice received an intraperitoneal injection of the anti-E-selectin antibody following hepatic ischemia-reperfusion and tumor inoculation (IR+Ab group). Four weeks later, mice were sacrificed and the number of tumor nodules on the liver was compared to mice without hepatic ischemia-reperfusion (control group). The incidence of liver metastasis in the I/R group was significantly higher (16 of 20, 80%) than that in the control group (6 of 20, 30%) (P, Embargo Period 6 months

We examined the effects of the preferential cyclooxygenase-2 (COX-2) inhibitor celecoxib on tumorigenesis, angiogenesis, apoptosis, vascular endothelial growth factor (VEGF) protein expression and metastasis in HT-29 human colorectal carcinoma cell xenografts in nude mouse rectum. COX-2 mRNA expression was examined in the xenograft and metastatic sites. The antitumor effect of celecoxib in the xenografts was evaluated by measuring the weight of the peri-ano-rectal tumor. The anti-metastatic effect of celecoxib was assessed by quantification of lymph node and lung metastases by amplification of a cancer-related human DNA by TaqMan PCR. The effects of celecoxib on angiogenesis, apoptosis, prostaglandin E2 (PGE2) production and VEGF protein expression in the xenografts were evaluated by means of microvessel density (MVD) counting, terminal deoxynucleotidyl transferase-mediated nick end labeling assay, quantitative enzyme-linked immunosorbent assay and western blotting, respectively. The rectal xenograft model showed lymph node and lung metastases with enhanced expression of COX-2 mRNA in each organ. Celecoxib inhibited rectal xenograft growth in a dose-dependent manner as follows: 150 ppm, 33.0% (p=0.000220); 750 ppm, 46.4% (p=0.0000292); 1500 ppm, 63.4% (p=0.0000109). Celecoxib inhibited lymph node metastasis in a dose-dependent manner as follows: 150 ppm, 86.7% (p=0.0263); 750 ppm, 90.3% (p=0.00638); 1500 ppm, 96.0% (p=0.000894). Celecoxib also inhibited lung metastasis as follows: 750 ppm, 53.3% (p=0.0107); 1500 ppm, 78.3% (p=0.00022). Celecoxib (1500 ppm) significantly inhibited PGE2 production by 68.4% (p=0.000157) and MVD counting by 48.2% (p=1.3x10-12) and induced apoptosis 2.5-fold (p=3.0x10-14) in the rectal xenograft. Celecoxib suppressed VEGF protein expression in the rectal xenograft. These studies demonstrate that celecoxib reduces the growth and metastatic potential of colorectal carcinoma in mice through COX-2 inhibition, anti-angiogenesis and apoptosis induction. The studies using HT-29 human colorectal carcinoma cell xenografts in nude mouse rectum also provide important information that supports that the COX-2 inhibitor celecoxib has a high potential for use as a clinical agent for inhibition of hematological and lymphatic metastases of colorectal cancer.

Radiation therapy is one of the most promising therapeutic strategies in unresectable esophageal squamous cell carcinoma (ESCC). The histone deacetylase (HDAC) inhibitor has been shown to enhance radiosensitivity. Valproic acid (VPA) is a well-known drug used to treat seizure disorders and epilepsy, and has been shown to inhibit HDACs. We recently reported that a clinically safe dose of VPA enhances radiation‑induced cytotoxicity in human ESCC cells. However, the mechanism of radiosensitizing effect of VPA has not yet been confirmed. The present study examined the effect of VPA on DNA double-strand break (DSB) repair after radiation in the human ESCC cell lines KES, TE9 and TE11 by examining H2AX phosphorylation (γH2AX) levels as a marker of radiation‑induced DSBs. The present study also examined whether VPA inhibited radiation-induced DNA DSB repair by suppressing non-homologous end joining (NHEJ), focusing particularly on the acetylation of Ku70. VPA was shown to prolong γH2AX levels after irradiation in all three ESCC cell lines. Moreover, prolonged γH2AX foci formation after irradiation was also observed by immunocytochemistry following VPA pretreatment in KES and TE9 cells. VPA was shown to induce Ku70 acetylation after irradiation in all three ESCC cell lines. Our results suggest that VPA prolonged radiation‑induced DSBs by inhibiting NHEJ in DSB repair pathways in ESCC. VPA could therefore be used as an effective radiosensitizer in ESCC radiotherapy.

For rapid intraoperative diagnosis of lymph node micrometastasis, we refined the rapid immunohistochemistry method by combining anti-cytokeratin antibody-labeled nanocrystal beads with rapid hematoxylin and eosin (HE) staining on the same section, referred to as the rapid double staining (RDS) technique. Two frozen-section slices each were obtained from 372 lymph nodes of 100 breast cancer patients. We performed RDS for 1 slide and rapid HE staining for the other. The results were compared with the corresponding final pathological data obtained from the permanent specimens. For specimens from patients with pN1(mi) as determined by final pathological examination, the false‑negative rate was 33.3% for rapid HE staining and 16.7% for RDS. For specimens from patients with pN0(i+) as determined by final pathological examination, the false‑negative rate was 80% for rapid HE staining and 0% for RDS. These results indicate that RDS is superior to conventional rapid HE staining for intraoperative diagnosis of nodal micrometastasis and isolated tumor cells.

The eligibility criteria of liver transplantation (LT) for hepatocellular carcinoma (HCC) must clearly confirm the prognosis not only from pathological diagnosis but also from pre-operative imaging diagnosis. In the present study, we evaluated published eligibility criteria for LT based on both pre-operative imaging diagnosis and pathological diagnosis using living donor liver transplantation (LDLT) recipients at our hospital by α-smooth muscle actin (SMA)-positive cancer-associated fibroblasts (CAFs) in HCC. The Up-to-seven (Up-to-7), Asan and Tokyo criteria were evaluated, in both overall survival and HCC disease-free survival, to be statistically significantly beneficial criteria to define post-LDLT prognosis. Recipients only within Up-to-7 criteria based on both pre-operative imaging diagnosis and pathological diagnosis survived without HCC recurrence. Recipients with proliferation of α-SMA-positive CAFs in HCC had significantly poorer prognosis. All survival recipients without HCC recurrence, who were above the Up-to-7 criteria in pathological diagnosis, had no proliferation of α-SMA-positive CAFs. As a result of multivariate analysis, the significant independent factors defining prognosis of recipients after LDLT for HCC were Up-to-7 criteria and proliferation of α-SMA-positive CAFs. The ideal eligibility criteria for LDLT with HCC is Up-to-7 criteria and α-SMA-positive CAFs was considered to be an important factor in HCC recurrence. LDLT should be limited to recipients within Up-to-7 criteria or without proliferation of α-SMA-positive CAFs.

We investigated the expression of VLA-2 in gastric cancers by immunohistochemistry using anti-integrin alpha 2 and beta 1 antibodies and the data were compared with the pathological findings of each gastric cancer. The specimens were stained with an immunohistological technique for integrin alpha 2 and beta 1 subunits. Tumors, simultaneously expressing both integrin alpha 2 and beta 1 subunits were defined as positive for VLA-2. Tumors expressing either subunits of integrin alpha 2 or beta 1 or those showing reduced expression of both subunits were defined as VLA-2 negative tumors. In the 77 primary tumors, 55 (71%) were VLA-2 positive. 38 (90%) of 42 tumors showing differentiated type including tubular adenocarcinoma and papillary adenocarcinoma expressed VLA-2, whereas 19 (55%) out of 35 undifferentiated type of cancers including poorly differentiated adenocarcinoma, mucinous carcinoma and signet ring cell carcinoma stained for VLA-2. In the undifferentiated type of cancers, VLA-2 negative tumors had a significantly higher incidence of vessel invasion than VLA-2 positive ones (p

E-cadherin has an important role in the cell-cell adhesion and is known as an invasion suppressor gene. The c-met, which is a receptor of hepatocyte growth factor receptor, is involved in the proliferative and motile activity in cancer cells. The invasive and metastatic capacities of gastric cancer were studied from the immunohistochemically examined expression of MET and E-cadherin. Among 127 primary gastric cancers, 47 (34%) tumors were found to have preserved E-cadherin expression and the other 84 tumors showed reduced E-cadherin expression. MET expression was found in 55 (43%) tumors. A strong correlation was found between reduced E-cadherin expression and a larger tumor, positive serosal invasion, lymph node metastases or poor prognosis. Tumors with MET expression have the tendencies to invade deeply, to metastasize in more remote lymph nodes or peritoneum and to run a poor prognosis. MET over-expression and reduced E-cadherin expression were strongly associated with lymph node metastasis, peritoneal dissemination and poor prognosis. This group of patients with simultaneously abnormal expressions of these genes had a sixfold relative risk of death, as compared with patients with tumors showing MET negative or preserved E-cadherin expression. These results indicate that immunohistochemical combined analyses of MET and E-cadherin expression may be a powerful tool for the evaluation of invasive capacity and the prognosis of gastric cancer patients.

The immunological response in the regional lymph nodes (LN) of gastric cancer patients who had metastasis was studied by investigating both the degree of metastasis and the maturation status of dendritic cells (DCs). A total of 732 LNs was obtained from 29 gastric cancer patients, including 25 patients whose LNs were pathological metastasis-negative and 4 patients with metastasis-positive LNs. Micrometastasis (MM) in the LNs was analyzed by immunohistochemical staining of cytokeratin (CK) (IHC-MM) and by amplifying CEA and CK19 mRNA by quantitative real-time RT-PCR (PCR-MM). Distribution and density of mature DCs were evaluated in 119 LNs from pathological metastasis-positive cases by examining CD83 expression immunohistochemically. Then, following the examination of PCR-MM, immunological responses were analyzed by amplifying CD83, CD86, CD1a and IFNγ mRNA by quantitative real-time RT-PCR in 613 LNs from 25 pathological metastasis-negative cases. Among 119 LNs from 4 patients with LN metastasis, 20 LNs had histological metastasis and 6 histological metastasis-negative LNs had IHC-MM. The distribution and density of mature DCs were identical in the LNs regardless of metastasis status. Among 613 LNs from 25 patients without histological LN metastasis, 15 LNs (2.45%) from 6 cases (24%) were PCR-MM positive. The expression levels of CD83 and CD86 mRNA were significantly higher in the 15 PCR-MM-positive LNs than in the 598 PCR-MM-negative LNs. The expression levels of CD83 and CD86 mRNA in 136 PCR-MM-negative LNs from 6 PCR-MM-positive cases were also higher than those in 462 LNs from 19 PCR-MM-negative cases. In gastric cancer patients, activation of the immune response by maturation of DCs is wide-spread in regional lymph nodes at a stage before metastasis is detected histologically, including detection by IHC-MM.

The Japanese randomized trial comparing standard D2 with D2 plus additional para-aortic lymph node (PAN) dissection for advanced gastric cancer (JCOG study 9501) did not demonstrate any difference in survival between the two groups. It is unknown whether there is any prognostic benefit in dissection for subgroups of PAN. Non-inferiority in survival of the patients with PAN metastasis to the patients having n2 metastasis was examined according to the subgroup of PANs and the tumor location. The survival curve of n2 patients (n=131) were retrospectively compared with that of patients with PAN metastasis (n=55) and also compared with that of patients with metastasis to subgroup of PANs by the location of primary tumor (regions U, M and L). Expectedly, the prognosis of the n2 patients is significantly better than that of the patients with PAN metastasis, but there was no difference in the survival times between the n2 (+) group and the a2-lat (+) or the b1-int (+) group, suggesting that the a2-lat or the b1-int dissection matched the D2 dissection. Furthermore, the importance in dissection of the a2-lat and the b1-int was investigated according to the primary tumor location. The patients with metastasis to a2-lat in the region U, a2-lat and b1-int in the region M and b1-int in the region L demonstrated prognostic non-inferiority to the patients having n2 metastasis. Selective lymphadenectomy of subgroups of PANs in which metastases are highly suspected according to the tumor location is one of treatment strategies to advanced gastric cancer.

This study evaluated the feasibility and pharmacology of intraperitoneal docetaxel (IP docetaxel) when administered weekly for 3 consecutive weeks, followed by 1 week without treatment. A total of 24 patients with peritoneal carcinomatosis of gastric cancer (10 preoperative, 7 postoperative and 7 recurrent) were enrolled in this study. Docetaxel was dissolved in an isotonic saline to a final 1 liter solution and was administered in a 1 h dosage of 25, 35, 45 and 60 mg/m(2) to determine the maximum tolerated dose (MTD). To measure the docetaxel concentration, blood and peritoneal fluid samples were collected 0.5, 1, 2, 3, 6 and 24 h after administering the drug to 15 patients. A total of 109 chemotherapy cycles were administered, with a median of four cycles per patient (range 2-9). The MTD of the weekly IP docetaxel was defined at 60 mg/m(2). At a docetaxel dosage of 60 mg/m(2) per week, the dose-limiting events of grade 3 abdominal pain and grade 3 diarrhea, which may be associated with local toxicity, occurred. Peak concentrations of peritoneal fluid ranged from 24.5 to 68.7 microg/ml. The mean ratio of the area under concentration (AUC) in the peritoneal fluid to the plasma concentration was 515. Furthermore, the mean of plasma AUC by IP docetaxel was 5.63 microg h/ml versus that of IV docetaxel at a dose of 60 mg/m(2). The response rate of the preoperative IP docetaxel was 80% (4 CR, 4 PR, 1 NC and 1 PD), which was judged with laparoscopy and peritoneal lavage cytology. Gastrectomy, with D2 lymph node dissection, was performed on all of the patients evaluated as CR. The weekly IP docetaxel demonstrated a low toxicity and high efficacy for peritoneal carcinomatosis with dual anti-cancer effects via the peritoneal surface and capillary blood supply due to its unique pharmacokinetic property.

the present study was performed to examine the sequential process of the development of Barrett's oesophagus (BE) and oesophageal adenocarcinoma (ADC) induced by duodeno-oesophageal reflux (DER) in rats. Total gastrectomy was performed in male Wistar rats weighing approximately 250 g followed by reconstruction with oesophago-jejunostomy, which causes unavoidable DER without exposure to exogenous carcinogens. Animals were selected at random and sacrificed every 10 weeks after surgery until 50 weeks. Severe squamous oesophagitis with erosion, regenerative thickening (RT), and basal cell hyperplasia (BCH) were observed on the 10th week after surgery. On the 20th week, glandular structures that stained positively with Galactose oxidase-Schiff (foveolar metaplasia) were observed in the basal layer of the oesophageal squamous epithelium. On the 30th week, the glands developed and formed cysts that stained positively with concanavalin A (pyloric glandular metaplasia) and/or high-iron diamine and Alcian blue (intestinal metaplasia). From the 40th week after surgery, ADC cells surrounded by columnar-lined epithelium were found. Persistent stimulation with DER can alter the stem cells in the squamous epithelial basal layer leading to the formation of columnar-lined cells and subsequent ADC. Foveolar metaplasia was observed as part of the sequence of events leading to the development of columnar-lined epithelium (CLE), followed by the appearance of pyloric glandular metaplasia and intestinal metaplasia, completing the histogenesis of BE.

Recently, sentinel lymph node (SN) concept has been validated for gastrointestinal and breast cancers. Our previous study has shown that the No. 13 posterior pancreaticoduodenal lymph node group constitutes the major regional drainage site from primary tumors in the pancreatic head, and that the status of these nodes predicts that of the No. 16 abdominal paraaortic lymph node group. Based on these results, we have developed SN navigation surgery for pancreatic cancer, in the search for more curable and less invasive surgery. In brief, 2% patent blue dye is injected into the peritumoral area. Approximately 5 min later, one or more blue-stained nodes within the area of the No. 13 lymph node group are identified and excised for intraoperative frozen section examination. The subsequent surgical decision-tree is as follows: i) if No. 13 SNs are negative, an extended No. 16 lymph node dissection is not performed to reduce morbidity, and ii) when cancer is found, the No. 16 lymph nodes are dissected completely. Since July 1997, nine of 21 patients scheduled to undergo an extended curative surgery underwent SN biopsy. SNs within the area of the No. 13 lymph node group were identified in 8 (89%) patients. An extended No. 16 lymph node dissection was avoided in 4 SN-negative patients. The overall 3-year survival rate of the 21 patients was 36%, and 4 patients (three SN-negative and one SN-positive patients) with stage IVa disease were alive 3 years after surgery. Three SN-negative patients underwent an extended curative pylorus-preserving pancreaticoduodenectomy (PpPD) with combined portal vein resection, but without an extended No. 16 dissection. In conclusion, SN biopsy and curative PpPD can increase curability, reduce morbidity, and provide long-term survival in patients with locally advanced pancreatic head cancer as an alternative to routine extended No. 16 lymph node dissection.

Recently, sentinel lymph node (SN) concept has been validated for gastrointestinal and breast cancers. Our previous study has shown that the No. 13 posterior pancreaticoduodenal lymph node group constitutes the major regional drainage site from primary tumors in the pancreatic head, and that the status of these nodes predicts that of the No. 16 abdominal paraaortic lymph node group. Based on these results, we have developed SN navigation surgery for pancreatic cancer, in the search for more curable and less invasive surgery. In brief, 2% patent blue dye is injected into the peritumoral area. Approximately 5 min later, one or more blue-stained nodes within the area of the No. 13 lymph node group are identified and excised for intraoperative frozen section examination. The subsequent surgical decision-tree is as follows: i) if No. 13 SNs are negative, an extended No. 16 lymph node dissection is not performed to reduce morbidity, and ii) when cancer is found, the No. 16 lymph nodes are dissected completely. Since July 1997, nine of 21 patients scheduled to undergo an extended curative surgery underwent SN biopsy. SNs within the area of the No. 13 lymph node group were identified in 8 (89%) patients. An extended No. 16 lymph node dissection was avoided in 4 SN-negative patients. The overall 3-year survival rate of the 21 patients was 36%, and 4 patients (three SN-negative and one SN-positive patients) with stage IVa disease were alive 3 years after surgery. Three SN-negative patients underwent an extended curative pylorus-preserving pancreaticoduodenectomy (PpPD) with combined portal vein resection, but without an extended No. 16 dissection. In conclusion, SN biopsy and curative PpPD can increase curability, reduce morbidity, and provide long-term survival in patients with locally advanced pancreatic head cancer as an alternative to routine extended No. 16 lymph node dissection.

Thymidine phosphorylase (TP) converts 5'-deoxy-5-fluorouridine (5'-DFUR, doxifluridine), an intermediate metabolite of capecitabine, to 5-fluorouracil (5-FU). While dihydropyrimidine dehydrogenase (DPD) catalyzes 5-FU to inactive molecules. We investigated TP and DPD levels in tumor tissue to assess their clinical significance as indicators for selecting colorectal cancer patients for 5'-DFUR adjuvant chemotherapy. A total of 88 colorectal cancer patients were classified into Dukes' B and C groups and treated for 2 years with oral 5'-DFUR (800 mg/ body/day). During the follow-up period, 20 of the 88 patients developed a recurrence. All the patients were examined retrospectively for primary tumor TP and DPD levels and clinical response to 5'-DFUR. Results showed that: a) median levels of TP and DPD in the primary tumor, measured by enzyme-linked immunosorbent assay (ELISA), were, respectively, 43.6 and 32.3 U/mg protein. Primary tumor TP levels of the 20 patients who had a recurrence were lower than those of the 68 patients with no recurrence (p=0.07); b) although there were no significant differences in clinicopathologic features between high and low median TP level groups, disease-free survival was better in the high TP than in the low TP group (89% vs. 64%, at year 4); and c) of patients classified into 4 groups such as high TP/DPD, high TP but low DPD, low TP but high DPD, and low TP/DPD, patients with high TP but low DPD had the best disease-free survival, whereas the low TP but high DPD group had the worst survival. These results suggest that TP and DPD levels in primary colorectal tumors may be a useful indicator for selecting patients likely to respond to 5'-DFUR adjuvant chemotherapy and probably capecitabine, a prodrug of 5'-DFUR.

Treatment for peritonitis carcinomatosa in gastrointestinal cancer remains to be established though it is one of the commonest causes of cancer death. Subtotal peritonectomy (SP) with chemohyperthermic peritoneal perfusion (CHPP) was developed for the new therapeutic strategy for peritoneal dissemination in gastrointestinal cancer in our department. SP includes resection of stomach, colon, small bowel, spleen, gall bladder, and parietal peritoneum. CHPP was carried out by heated saline containing 25 mg/l cisplatin, 10 mg/l mitomycin C, and 20 mg/l etoposide. Intraperitoneal temperature was maintained at 42 degrees C for 60 min. Fifteen gastric cancer and three colon cancer patients with severe peritoneal dissemination underwent these procedures. The averages of operating time, intraoperative bleeding volume, and total perioperative transfused blood volume were 9 h, 4400 ml, and 5600 ml, respectively. The patients estimated as complete resection and residual disease by histopathological study numbered 11 and 7. There was no treatment-related deaths though bleeding occurred in 5 patients; perforation in 2 patients; and abscesses in 2 patients. The 1-year survival rate (1ysr) and the 2-year survival rate (2-ysr) of all the patients were 57% and 21%, respectively. The 1-ysr and the 2-ysr of the patients who underwent complete resection were 67% and 40% significantly greater than the 43% and 0% of the patients who had residual tumors (p=0.02). The combination therapy of SP and CHPP is feasible in spite of its morbidity and has great possibilities in complete resection of peritoneal dissemination and prolongation of patient's survival.

Matrix metalloproteinase (MMP) expression is associated with advanced-stage cancer and contributes to tumor progression, invasion, and metastasis. Membrane type matrix metalloproteinase (MT-MMP) has a potential transmembrane domain at the C terminus and activates pro-MMP-2, which is mainly produced from interstitial fibroblasts. Its expression on the membrane of invasive tumor cells results in the pericellular space degradation at cell-matrix contact sites and renders cancer cells more invasive at the migration front. To elucidate the relationship between MT-MMP expression and metastasis and prognosis in gastric cancer patients, MT-MMP expression was analyzed immunohistochemically in 127 primary tumors and results were correlated with several prognostic parameters and patient's survival. MT-MMP immunoreactivity was stained on the cell membrane of cancer cells and fibroblasts in the invasion front. MT-MMP was detected in 72 tumors (57%) (MT-MMP-positive). MT-MMP expression was closely associated with macroscopically invasive type, nodal involvement, lymphatic invasion, vessel invasion, and peritoneal dissemination. Patients with MT-MMP-positive tumor had a significantly worse prognosis than those with MT-MMP-negative tumor (p

The object of this study was to evaluate cellular markers which included tumor cell p53 expression, cell proliferation antigens and DNA ploidy in both primary and locally recurrent rectal cancer. The study included 16 locally recurrent rectal cancer and 24 non-recurrent primary rectal cancer. Levels of p53 and Ki-67 expression were quantified and the DNA ploidy analyzed. In the locally recurrent group, labelling index of p53 was significantly higher in the short disease-free interval (DFI) (2 years) group than the long DFI (or = 2 years) group (p0.05). It was immunohistochemically proved that DNA aneuploidy was reflected by accumulation of mutated p53 in both primary rectal cancer and locally recurrent tumors. The early local recurrence after curative operation for rectal cancer was associated with the number of p53 positive cells.

To clarify the interrelationship between urokinase-type plasminogen activator receptor (uPAR) and the progression of gastric cancer, uPAR expression in gastric cancer was studied by the reverse transcription (RT)-PCR and immunohistochemistry. uPAR mRNA was expressed in 44 of 46 primary gastric cancers and uPAR immunoreactivity was found in 21 (14%) of 155 tumors. uPAR immunoreactivity was also observed in the fibroblast-like cells and the inflammatory cells including macrophages. The intensity of uPAR immunoreactivity of these cells was weaker than that of cancer cells. uPAR expression detected by RT-PCR may be from cancer cells and/or non-cancerous stromal cells. uPAR immunoreactivity in cancer cells was closely associated with histologic type, nodal status, and macroscopic type. The uPAR positive tumors were closely associated with the macroscopically infiltrating type, undifferentiated type and stage IV disease. Poorly differentiated carcinomas with rich intestitial fibrosis (scirrhous carcinoma) expressed uPAR with a significantly higher incidence than the other histologic types of carcinoma. Growth of scirrhous carcinoma may be a result of a concerted action of the players in the plasminogen activator system, consisting of cancer cells and stromal elements. Furthermore, there was an intimate relationship between the grade of lymph node metastasis and uPAR tissue status. Patients with a uPAR positive tumor had a significantly poorer prognosis than those with uPAR negative tumor. These results indicate that the immunohistochemical diagnosis of uPAR tissue status on the primary tumor of gastric cancer may be a good predictor for the prognosis of patients with gastric cancer.

To clarify the interrelationship between alpha 3 integrin, subunit/E-cadherin expression and peritoneal dissemination in gastric cancer, alpha 3 integrin subunit and E-cadherin expression gas were immunohistochemically examined and were correlated with clinicopathologic parameters. Among 150 primary gastric cancers, alpha 3 integrin subunit and E-cadherin were strongly expressed in 96 (65%) and 88 (59%) tumors, respectively. Integrin alpha 3 expression was closely associated with peritoneal dissemiantion, but there was no relationship between integrin alpha 3 expression and histologic type, nodal status, macroscopic type or wall invasion. Furthermore, 22 (84%) of 26 tumors which recurred in peritoneum overexpressed integrin alpha 3 expression in primary tumors. All seven peritoneal foci obtained from peritoneal dissemination expressed integrin alpha 3 expression despite no integrin alpha 3 expression in two of these 7 primary tumors. Reduced E-cadherin expression in primary tumors was intimately associated with large tumor size (>6 cm), nodal involvement, peritoneal dissemination and positive serosal invasion. Peritoneal dissemination was most frequently found in the tumors with positive integrin alpha 3 expression and reduced E-cadherin expression. Patients with these type of tumor [E-cadherin expression (-), and integrin alpha 3 subunit (+)] showed the poorest prognosis as compared with the other groups of patients. These results indicate that upregulation of integrin alpha 3 expression and down regulation of E-cadherin might have an important role in the formation of peritoneal dissemination. These tumors have characteristics of easy detachment from the serosal surface via downregulation of E-cadherin and strong adhesion capacity to the peritoneum via up-regulation of integrin alpha 3 expression. The immunohisto-chemical combination analysis of E-cadherin and integrin alpha 3 expression on the primary gastric cancer may be a good screening method to predict peritoneal recurrence.

Cytoreductive resection (RST), chemohyperthermic peritoneal perfusion (CHPP) and/or intra-aortic chemotherapy (IA-chemo) were performed for peritoneal dissemination in gastric cancer. Ninety-six patients with peritoneal dissemination were grouped into tubercular (TB), 40; nodular (ND), 31; diffuse (DF) type, 19; and others, 6, respectively, by the gross findings. Sixty-three patients underwent RST. Fifty-nine patients received CHPP by 10-liter heated saline. Thirty patients underwent intra-aortic catheterization for the IA-chemo. The 1-year and 2-year survival rate (1-ysr and 2-ysr) of the RST(+) group were 47% and 10% significantly greater than the 9% and 0% of the RST(-) group (p

Tissue inhibitor of metalloproteinase-3 (TIMP-3) has an inhibitory effect on tumor development, growth and metastasis due to its interaction with matrix metalloproteinases (MMPs). We investigated the prognostic significance of TIMP-3 gene promoter methylation in esophageal squamous cell carcinoma (ESCC). TIMP-3 methylation was analyzed by MethyLight, a quantitative and methylation-specific PCR method. Hypermethylation was found in 9/51 (18%) surgically resected ESCC samples and was associated with reduced disease-free (p=0.0039) and overall survival (p=0.0047). Upon multivariate analysis, it was found to be an independent prognostic parameter for poor survival and was associated with earlier recurrence after surgery (p=0.0238), especially via pleural dissemination (p=0.001). Expression levels for TIMP-3 protein and for several MMPs were analyzed by Western blot analysis in 20 pairs of ESCC and adjacent normal tissue. The expression of MMP-2, -7 and -9 proteins in tumor tissue was significantly higher than in corresponding normal mucosa (p=0.0051, 0.0064 and 0.0004, respectively). In contrast, the expression of TIMP-3 protein in tumor tissue was significantly lower than in matched normal mucosa (p=0.0152). Tumors with TIMP-3 hypermethylation expressed lower levels of TIMP-3 protein compared to those without hypermethylation (p=0.0357). These results demonstrate that TIMP-3 hypermethylation is associated with lower TIMP-3 protein expression in ESCC and with poor patient survival due to a high frequency of recurrence by pleural dissemination.

Gastric stump carcinoma is now widely recognized to be due to special conditions in the gastric remnant. To examine whether the mechanism of carcinogenesis is different in gastric stump carcinoma from other gastric carcinoma, we analyzed ras mutation in 62 gastric carcinomas. The ras mutation frequency was 4/17 (23.5%) in stump carcinomas, 2/25 (8.0%) in other remnant carcinomas and 1/20 (5.0%) in proximal carcinomas. The mutation frequency in stump carcinomas was much higher than that in other gastric carcinomas. These results suggest that the mechanism of carcinogenesis in gastric stump carcinomas may be different from other gastric carcinomas.