Adjuvant immunochemotherapy with protein-bound polysaccharide K for colon cancer in relation to oncogenic beta-catenin activation.

PURPOSE: Protein-bound polysaccharide K is an immunotherapeutic agent that promotes apoptosis by inhibiting nuclear factor-kappaB activation in cancer cells. We previously showed that oncogenic beta-catenin activates nuclear factor-kappaB and inhibits apoptosis by up-regulating beta-transducin repeat-containing protein. We investigated whether the activation state of beta-catenin in the primary tumor is associated with differences in survival rates of patients with colon cancer undergoing immunochemotherapy with 5-fluorouracil plus polysaccharide K vs. chemotherapy with 5-fluorouracil alone. METHODS: We assessed the activation states of beta-catenin and nuclear factor-kappaB in the primary tumors of 202 colon cancer patients, and analyzed the data in terms of the clinicopathologic characteristics and survival of patients undergoing the two forms of adjuvant therapy. RESULTS: We found two distinct patterns of nuclear accumulation of activated beta-catenin in the tumor cells: diffuse nuclear accumulation in 89 cases (44 percent) and selective nuclear accumulation at the tumor invasion front in 18 cases (9 percent). Nuclear factor-kappaB activation was found in 64 cases (32 percent). In patients with diffuse nuclear accumulation-type beta-catenin activation, immunochemotherapy significantly improved recurrence-free survival, cancer death survival, and overall survival rates compared with patients receiving chemotherapy alone. No survival benefit was found in cases with nuclear accumulation at the tumor invasion front-type beta-catenin activation or no activation. Similarly, immunochemotherapy favored the survival of patients with nuclear factor-kappaB activation. Multivariate analysis established the TNM stage and administration of polysaccharide K as independent prognostic factors in the patients with diffuse nuclear accumulation-type beta-catenin activation. CONCLUSIONS: The presence of diffuse nuclear accumulation-type beta-catenin activation identifies patients with colon cancer who respond better to immunotherapy with polysaccharide K.

Meningeal carcinomatosis preceded by a rapid increase in serum CA19-9 levels in a patient with breast cancer.

We report a patient with breast cancer who developed meningeal carcinomatosis that was preceded by a rapid increase in the serum level of carbohydrate antigen (CA) 19-9. A 60-year-old woman was admitted for primary breast cancer with multiple metastases to the vertebrae. She received cyclophosphamide 400 mg/m(2), epirubicin 40 mg/m(2), and 5-fluorouracil (5-FU) 400 mg/m(2) (CEF) chemotherapy every 3 weeks. Upon admission, her serum concentrations of carcinoembryonic antigen (CEA) and CA19-9 were 28.6 ng/ml and 99.2 U/ml, respectively. After three cycles of CEF therapy, her serum CEA decreased, and metastases to the vertebrae were attenuated. Her serum CA19-9 rapidly increased, however. A modified radical mastectomy was performed, but her serum CA19-9 levels still remained high (>500 U/ml). After four cycles of CEF therapy, she experienced headaches and vomiting due to an increase in cerebrospinal pressure, and she was diagnosed with meningeal carcinomatosis. At the time of this diagnosis, the concentration of CA19-9 in her cerebrospinal fluid was greater than 500 U/ml, and immunohistochemical examination revealed that carcinoma cells in the cerebrospinal fluid overexpressed CA19-9. To our knowledge, this is the first report of the development of meningeal carcinomatosis from CA19-9-producing breast cancer cells, showing thatCA19-9 expression was associated with breast tumor progression.

Deregulated GSK3beta activity in colorectal cancer: its association with tumor cell survival and proliferation.

Glycogen synthase kinase 3beta (GSK3beta) reportedly has opposing roles, repressing Wnt/beta-catenin signaling on the one hand but maintaining cell survival and proliferation through the NF-kappaB pathway on the other. The present investigation was undertaken to clarify the roles of GSK3beta in human cancer. In colon cancer cell lines and colorectal cancer patients, levels of GSK3beta expression and amounts of its active form were higher in tumor cells than in their normal counterparts; these findings were independent of nuclear accumulation of beta-catenin oncoprotein in the tumor cells. Inhibition of GSK3beta activity by phosphorylation was defective in colorectal cancers but preserved in non-neoplastic cells and tissues. Strikingly, inhibition of GSK3beta activity by chemical inhibitors and its expression by RNA interference targeting GSK3beta induced apoptosis and attenuated proliferation of colon cancer cells in vitro. Our findings demonstrate an unrecognized role of GSK3beta in tumor cell survival and proliferation other than its predicted role as a tumor suppressor, and warrant proposing this kinase as a potential therapeutic target in colorectal cancer.

Chemotherapy under cachectic conditions and the possibility of cachexia-controlled chemotherapy.

We studied the role of chemotherapy in cancer cachexia, which is well known to lower QOL and responsiveness to chemotherapy. In BALB/c mice we used two clones derived from the murine colon 26 adenocarcinoma cell line; clone 5, a non-cachexigenic tumor and clone 20, a cachexigenic tumor, in which IL-6 mRNA was selectively detected. While maximum tolerated dose (MTD) of CPM and CPT-11 showed significantly smaller tumor weight and higher survival than 1/2 MTD in both drug groups with clone 5, the results were reversed with clone 20. The tumor weights with MTD of CPM or CPT-11 in combination with anti-IL-6 antibody treatment, which decreases serum IL-6 level and improves cachexia status, were significantly smaller than those in the MTD treatment-alone group with clone 20, but not with clone 5. From these results, we suggest that lower dose chemotherapy or cachexia-controlled chemotherapy, such as some chemotherapeutic agents with neutralizing cachexia-related cytokine effects, elicit anti-tumor effects in cachectic individuals that are superior to conventional MTD chemotherapy.

Preoperative CEA and PPD values as prognostic factors for immunochemotherapy using PSK and 5-FU.

PURPOSE: Immunochemotherapy using PSK used as postoperative adjuvant chemotherapy for colorectal cancer in Japan, is a treatment that depends on the immunocompetence of the host. Therefore, we analyzed the data of Hokuriku district conducted by the CIP study group to compare the long-term survival for preoperative CEA level and PPD reaction. PATIENTS AND METHODS: Between February 1991 and March 1993, 87 patients with primary colon cancer and macroscopic lymph node metastasis (macroscopic Dukes' C) underwent macroscopic curative resection. The patients were randomly allocated to receive 5-FU/PSK therapy or 5-FU alone. The 7-year disease-free survival (DFS), 7-year overall survival (OS) and 7-year cancer death survival (CDS) were compared using the preoperative CEA levels and PPD values. RESULTS: In cases with preoperative CEA level > or =3.0 ng/mL, the 7-year DFS, 7-year OS and 7-year CDS were significantly better in the PSK group (85.7, 90.5, 90.5%) than in the control group (52.4, 52.4, 57 1%; p=0.019, 0.007, 0.014,). In cases with preoperative PPD level <19.0 mm, the 7-year DFS, 7-year OS and 7-year CDS were significantly better in the PSK group (85.7, 85.7, 89.3%) than in the control group (56.7, 60.0, 63.3%; p=0.018, 0.036, 0.028). Recurrence was significantly less in the PSK group. The DFS tended to be superior in the PSK group (87.4%) compared to the control group (69.9%) for hematogenous metastasis. CONCLUSION: The present study demonstrated that preoperative CEA and PPD, that can be measured easily in the clinical setting, may be effective indicators of postoperative adjuvant immunochemotherapy using PSK.

A pilot study of individualized maximum repeatable dose (iMRD), a new dose finding system, of weekly gemcitabine for patients with metastatic pancreas cancer.

OBJECTIVES: We developed and established a new dose-finding system, the individualized maximum repeatable dose (iMRD), suitable to induce prolonged TTP rather than tumor shrinkage. METHODS: We applied this system in weekly gemcitabine therapy for 18 metastatic pancreas cancer patients. We determined the iMRD at the 5th week, after weekly dose adjustments. We started at 500 mg/m2 (1/2 maximum tolerated dose) of gemcitabine and repeated the treatment with an increase or a decrease of 100 mg/m each week, if toxicity was 0 or more than grade 1, respectively. RESULTS: The iMRD of weekly gemcitabine was 300 mg/m2 in 2 patients, 400 mg/m2 in 3 patients, 500 mg/m2 in 5 patients, 600 mg/m2 in 6 patients, and 700 mg/m2 in 2 patients, demonstrating significant differences among individual patients. Grade 3 marrow depression occurred in only 1 patient (5.6%). Of these 18 patients, 3 (16.7%), 13 (72.2%) and 2 (11.1%) patients showed partial response, stable disease, and progressive disease, respectively. The median of times to progressive disease and survival were 4.5 and 9.5 months, respectively. There were no significant differences in 1-year survival time and more than 50% reduction rate of serum CA19-9, a tumor marker for pancreatic cancer, between patients with lower (500 mg/m2 or less) and higher (600 mg/m2 or more) iMRD. CONCLUSION: These results suggest that iMRD is a simple method to determine an individual's tailored dose for chemotherapy and could be the optimal dose for patients with noncurable cancers such as metastatic pancreas cancer.

[A randomized phase II clinical trial of tailored CPT-11 + TS-1 vs TS-1 in patients with advanced or recurrent gastric carcinoma as the first-line chemotherapy (JFMC31-0301)].

The Japanese Foundation for Multidisciplinary Treatment of Cancer (JFMC) has designed and initiated a randomized Phase II clinical trial planned as a first-line of chemotherapy for advanced or recurrent gastric cancer. The trial focuses on two groups and selecting the better of two regimens. The first group was given tailored CPT-11, adjusting individual optimal dosage using toxicity-based grading as an index in combination with TS-1, and the second group was given standard TS-1 treatment. The aim of this tailored dosage regimen for each individual patient is to continue chemotherapy as long as possible, and eventually, to prolong survival. In this trial, subsidiary pharmacokinetics analysis for the tailored arm is also proposed. We would like to introduce the significance and theory of tailored dosage chemotherapy in this paper.

Oral administration of uracil-tegafur (UFT) inhibits liver micrometastasis of human colon cancer in an orthotopic nude mouse model and its early detection system.

PURPOSE: To evaluate the effect of UFT (an oral antineoplastic drug combining uracil and tegafur) as an adjuvant chemotherapy. METHODS: We examined whether UFT inhibits micrometastasis of the liver from colon cancer implanted into the cecum of nude mice in an orthotopic model. Moreover, we studied whether our early detection system using a polymerase chain reaction (PCR) of the human beta-globin gene would be useful in this model. RESULTS: The administration of 20 mg/kg UFT p.o., which is a relatively small dose compared with 65 mg/kg of the maximum tolerated dose of this drug in mice, inhibited liver metastasis completely when started immediately after a cecectomy (micrometastasis present at this time), but did not inhibit liver metastasis significantly when started at 4 weeks after a cecectomy (gross tumor present at this time). There were no severe toxicities at this dose. In our PCR study, all livers in 10 mice to which therapy was given immediately after a cecectomy and without liver metastasis showed no PCR-amplified fragment, while 7 of 10 livers in the nontreatment group in which gross liver metastases were not observed demonstrated this fragment. CONCLUSIONS: These findings indicate that UFT is useful for either adjuvant chemotherapy or the inhibition of micrometastasis, and our system to detect micrometastasis by examining the human beta-globin gene is useful for the early evaluation of the efficacy of these drugs.

Associations among beta-TrCP, an E3 ubiquitin ligase receptor, beta-catenin, and NF-kappaB in colorectal cancer.

BACKGROUND: The ubiquitin-proteasome pathway is important in regulating protein signaling pathways that are involved in tumorigenesis. beta-transducin repeat-containing proteins (beta-TrCP) are components of the ubiquitin ligase complex targeting beta-catenin and IkappaBalpha for proteasomal degradation and are thus a negative regulator of Wnt/beta-catenin signaling and a positive regulator of NF-kappaB signaling. We analyzed expression of beta-TrCP in colorectal cancers and its association with types of beta-catenin subcellular localization, an indirect measure of activation. METHODS: Levels of beta-TrCP1 mRNA and protein were measured by quantitative reverse transcription-polymerase chain reaction and immunoblotting, respectively, in samples of tumor and normal tissues from 45 patients with colorectal cancer. Types of beta-catenin activation (diffuse or invasion edge) and NF-kappaB activation were examined by immunohistochemistry. Apoptosis was determined by the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick-end labeling (TUNEL) assay. All statistical tests were two-sided. RESULTS: Compared with the beta-TrCP1 levels in normal tissues, 25 (56%) of 45 tumors had increased beta-TrCP1 mRNA and protein levels. Of the 22 (49%) tumors with beta-catenin activation, 12 had the diffuse type (i.e., nuclear accumulation throughout the tumor) and 10 had the invasion edge type (i.e., nuclear accumulation predominantly in the tumor cells that formed the invasion edge). Increased beta-TrCP1 levels were statistically significantly associated with beta-catenin activation (P =.023) and decreased apoptosis (P =.035). beta-TrCP accumulated in the nuclei of tumor cells that contained increased levels of beta-TrCP1 mRNA and the active form of NF-kappaB. Higher levels of beta-TrCP1 mRNA were detected in primary tumors of patients who had metastases (0.960 arbitrary units, 95% confidence interval = 0.878 to 1.042) than in the tumors of patients who did not (0.722 arbitrary units, 95% confidence interval = 0.600 to 0.844; P =.016). CONCLUSION: In colorectal cancer, increased expression of beta-TrCP1 is associated with activation of both beta-catenin and NF-kappaB, suggesting that the integration of these signaling pathways by increased beta-TrCP expression may contribute to an inhibition of apoptosis and tumor metastasis.

A randomized phase II clinical trial of tailored CPT-11 + S-1 vs S-1 in patients with advanced or recurrent gastric carcinoma as the first line chemotherapy.

A randomized phase II clinical trial has been designed and started in the Japanese Foundation for Multidisciplinary Treatment of Cancer (JFMC) to select the better regimen between tailored CPT-11 + S-1 and the standard S-1 treatment for advanced or recurrent gastric cancer as the first line chemotherapy. Selection of the better treatment for general clinical practice in this clinical trial will lead to a more precise assignment of a promising regimen for a future phase III randomized trial, placing continuous 5-FU infusion as the reference arm. In this trial, subsidiary pharmacokinetic analysis for the tailored dose arm is also proposed. In order to continue chemotherapy for a long time and to obtain longer survival, our study design for the tailored therapy could be exploited, especially in the field of general clinical practice.

Pilot study of low-dose, divided maximum tolerated dose of CPT-11 in 21 consecutive patients with metastatic colorectal or gastric cancer.

PURPOSE: We devised a new treatment regimen, delivering a frequent low dose of CPT-11, calculated by dividing the maximum tolerated dose (MTD) to reduce its toxicity without impairing its efficacy. METHODS: CPI-11, 25 mg/m2, determined by dividing the MTD dose per month by 12, was given on days 1, 2, and 3 of every week, to 21 consecutive patients; 12 with metastatic colon cancer and 9 with metastatic gastric cancers. RESULTS: The total delivered dose of CPI-11 per patient was more than 1,000 mg in 17 (80.1%) of the 21 patients. Grade 3 marrow depression developed in 3 (14.3%) patients, and although nausea, vomiting, alopecia, and diarrhea developed in some patients, these side effects were all categorized as grade 2 or milder. The antitumor effect was evaluated in 18 patients with measurable lesions, who had received CPI-11 according to our regimen for at least 3 weeks. Of these 18 patients, 10, 7, and 1, respectively, had a found to have partial response, no change, or progression of disease, demonstrating a 55.6% efficacy rate [colon 6/10 (60.0%) and stomach 4/8 (50.0%)]. Moreover, time to progression (TTP) was greater than 90 days in 12 (75.0%) of these 18 patients. CONCLUSION: These results show that our low-dose, divided MTD of CPI-11 regimen is a promising method of reducing toxicity and strengthening the antitumor effect, justifying further large-scale comparative clinical studies to verify this potential.

Angiogenesis of AFP producing gastric carcinoma: correlation with frequent liver metastasis and its inhibition by anti-AFP antibody.

We studied roles of angiogenesis in patients with alpha-fetoprotein (AFP)-producing gastric carcinoma (APGC), which is well known to have a poor prognosis and frequent liver metastases. Immunohistochemical analyses were conducted using antibodies against alpha-fetoprotein, factor VIII (endothelial cells) and vascular endothelial growth factor (VEGF). Archival specimens of APGC (n=25) and non-APGC (n=68) were studied. Expressions of vessel density and VEGF were significantly higher in APGC than those in non-APGC (p<0.001). There is a correlation among the AFP expression, the vessel density and the VEGF expression in APGC (p<0.001). Next, we studied the effects of anti-AFP antibody on APGC xenotransplanted in nude mice. There is significant inhibition of tumor growth in the treatment groups compared to the control groups in 2 APGC lines (p<0.01). There were also significant differences in serum AFP and VEGF levels between treatment groups and non-treatment groups in 2 APGC lines, but not in a non-APGC line. Moreover, vessel densities of the treatment groups were significantly lower than those of the control groups in the two lines. These findings thus suggest that the biological behavior of APGC is angiogenesis-dependent. Down-regulation of angiogenesis by anti-AFP antibody suggest that AFP itself may up-regulate angiogenesis, and the treatment by antibody could have anti-angiogenic effects, inhibiting metastasis, especially liver metastasis in APGC.

Long-term effect of 5-fluorouracil enhanced by intermittent administration of polysaccharide K after curative resection of colon cancer. A randomized controlled trial for 7-year follow-up.

BACKGROUND AND AIMS: The efficacy of a biological response modifier polysaccharide K in adjuvant immunochemotherapy was evaluated in primary colon cancer patients with macroscopic Dukes' C after curative resection. PATIENTS AND METHODS: Employing the minimization method using three factors (lymph node metastases, preoperative serum CEA level, and institution), 446 patients were allocated into groups P and C. Group P received immunochemotherapy, oral PSK (3 g per day) followed by oral 5-FU (200 mg/body per day), while group C received only intermittent chemotherapy, oral 5-FU (200 mg per day) followed by 4-week rest. Both groups received ten courses. RESULTS: Survival for cancer death was significantly higher in group P than in group C, but there was no difference in 7-year disease-free survival or overall survival had. CONCLUSION: Repeated alternating administration with PSK followed by 5-FU can improve survival for cancer death.

The usefulness of CEA and/or CA19-9 in monitoring for recurrence in gastric cancer patients: a prospective clinical study.

BACKGROUND: Many studies on postoperative carcinoembryonic antigen (CEA) and/or carbohydrate antigen (CA)19-9 monitoring after operation for gastric cancer have been reported, but most have been retrospective. METHODS: A nationwide observational study was implemented in 135 leading institutions in Japan to evaluate the significance of CEA and/or CA19-9 in postoperative monitoring for recurrence in patients with advanced gastric cancer. Three hundred and twenty-one patients examined in this analysis underwent radical gastrectomy at one of Japan's leading institutions between November 1993 and March 1996 and had been followed up for at least 5 years. Serum levels of CEA and CA19-9 were examined preoperatively and every 3 months postoperatively, with diagnostic imagings, such as chest X-ray, computed tomography (CT), and ultrasonography also being performed every 3 months. RESULTS: Recurrence was observed in 120 patients (peritoneum, 48; liver 16; lymph node, 16; multiple sites, 25; and others, 12). Sensitivities of CEA and either CEA or CA19-9, or both, for recurrence were 65.8% and 85.0%, respectively, both of which values were significantly higher than the preoperative positivities (28.3% and 45.0%, respectively). In most patients with high preoperative levels CEA and/or CA19-9, these tumor markers increased again at recurrence. Recurrent diseases were detected between 5 months after detection by diagnostic imagings and 12 months before detection by diagnostic imagings (mean of 3.1 +/- 3.6 months before detection by diagnostic imagings) and between 10 months after detection by diagnostic imagings and 13 months before detection by diagnostic imagings (mean of 2.2 +/- 3.9 months before detection by diagnostic imagings) by CEA and CA19-9 monitorings, respectively. CONCLUSION: These results suggest that CEA and/or CA19-9 monitoring after operation was useful to predict the recurrence of gastric cancer, especially in almost all the patients with high preoperative levels of these markers.

Irinotecan enhances IL-12 production by OK-432-activated murine macrophages.

BACKGROUND: Our previous study showed that the combination of irinotecan (CPT-11) and OK-432 had an additive antitumor effect. The purpose of this study was to analyze the mechanism by which this combined treatment had an effect on immunity. MATERIALS AND METHODS: To investigate the immune effects of murine splenocytes stimulated by SN-38 (the active form of CPT-11) and OK-432, endogenous interleukin (IL)-12 p70 production was assayed by ELISA and flow cytometry. RESULTS: Endogenous IL-12 production was increased by SN-38 stimulation of cultures of OK-432-activated splenocytes from C57BL/6, C3H and Balb/c mice, which was not observed with LPS-activated splenocytes. IL-12 production by splenocytes was higher at an early stage after tumor inoculation. SN-38 and OK-432 stimulated IL-12 production in cultures of peritoneal exudate macrophages (PEM), and T cell cooperation was essential in cultured splenocytes. CONCLUSION: These results suggest that the interaction of SN-38 and OK-432 may support a type 1 T helper (Th1)-dominant state through increasing endogenous IL-12 production, mainly by macrophages.

beta-Catenin and ras oncogenes detect most human colorectal cancer.

UNLABELLED: PURPOSE AND STUDY DESIGN: Recent studies have shown that beta-catenin translocated into the cell nucleus functions like an oncogene. Accumulating evidence suggests that activation of the beta-catenin oncogenic signaling cascade along with its twin, the K-ras cascade, may exert syngeneic or synergistic effects on tumor development and progression. In the study reported here, we analyzed oncogenic beta-catenin activation on the basis of its nuclear accumulation (NA) and compared the results with those of mutational activation of K-ras in 74 patients with colorectal cancer to determine whether the two oncogene-mediated signaling cascades interact. RESULTS: We found two distinct patterns of beta-catenin activation, i.e., diffuse NA in 20 cases (27%) and selective NA at the tumor invasion front (NAinv) in 19 cases (26%). The presence of the NAinv pattern was significantly correlated with advanced Dukes' stage tumor (P = 0.0005) and the presence of distant metastases (P = 0.0064). K-ras proto-oncogene was mutated in the tumors of 31 cases (42%). Activated beta-catenin or K-ras was detected in most (78%) colorectal cancers analyzed, although a weak inverse correlation was found between the activities of the two oncogenes in the tumors. Importantly, most (7 of 8) patients with tumor showing both K-ras activation and the NAinv pattern of beta-catenin activation were in Dukes' stage C at surgery, and half of them developed distant metastases to the liver and lungs. CONCLUSION: The results suggest that although oncogenic activation of beta-catenin and K-ras is independent in the process of clinical cancer development, combined analysis of the two major oncogenes can detect most colorectal cancers and identify a subset of patients with poorer outcomes. Consequently, activation of either or both of these oncogenes may serve as a genetic marker for molecular diagnosis.

Thymidylate synthase expression as a predictor of the prognosis of curatively resected colon carcinoma in patients registered in an adjuvant immunochemotherapy clinical trial.

The expression levels of thymidylate synthase (TS) affect the sensitivity of tumor cells to fluorinated pyrimidine cytotoxic agents and determine the response of patients with colorectal cancer to fluorinated-pyrimidine-based chemotherapy. The correlation between the expression of TS and the prognosis of patients with colorectal cancer was examined in a prospective study. Evaluation of biomarkers including TS expression was performed using tumor specimens from 229 colorectal cancer patients. Immunohistochemical analysis of TS expression was performed using an antibody raised against a C-terminal epitope (D186-V313) of the human TS. The intensity of TS staining and the expression of other biomarkers were blindly scored. The five-year survival rates were 63.4% and 85.6% among patients with high and low intratumoral TS expressions, respectively (p=0.0007). Similarly, the disease-free survival (DFS) rate was 51.2% and 80.3% in the high and low TS expression groups, respectively (p=0.0004). In a subset analysis of Dukes' stage C patients, the survival and DFS rates were 44.0% and 40.0% in the high TS expression group, and 73.5% and 67.4% in the low TS expression group, respectively. Significant differences were observed in both survival (p=0.0048) and DFS (p=0.0054) rates. No significant correlation was observed between the expression of other biomarkers and prognosis. Significantly poorer prognosis of curatively resected colon cancer in patients with high TS expression levels in tumor tissue was confirmed by a double-blind prospective study conducted on samples obtained from patients enrolled in an adjuvant immunochemotherapy randomized clinical trial.

Abnormal expression of E-cadherin, beta-catenin, and c-erbB-2 in advanced gastric cancer: its association with liver metastasis.

BACKGROUND AND AIMS: We investigated expression of E-cadherin, beta-catenin, and c-erbB-2 in gastric cancer to identify molecular factor(s) relevant to development of liver metastasis, which is a frequent cause of mortality in gastric cancer patients. PATIENTS AND METHODS: We analyzed by immunohistochemistry and compared expression patterns of E-cadherin, beta-catenin, and c-erbB-2 in the tumor between 40 cases of gastric cancer (GC) without (GC-H(-)) and 16 with concurrent liver metastasis (GC-H(+)). RESULTS: Loss of E-cadherin expression in the primary tumor was found in 18% of GC-H(-) and in 19% of GC-H(+). Oncogenic beta-catenin activation, represented by its nuclear translocation, was detected in 13% of GC-H(-) and in 31% of GC-H(+). There was no statistical difference in incidence of alteration in these molecules between the two groups of patients. c-erbB-2 overexpression was more frequently observed in GC-H(+) (10/16, 63%) than in GC-H(-) (5/40, 13%) while the distribution of histological types of the tumors was similar in the two groups of patients. This overexpression was also detected in metastatic liver tumors and biopsy specimens in the ten of the former group of patients. CONCLUSION: Our results strongly suggest a role of activated c-erbB-2 in the process of liver metastasis, and an importance of detection of this overexpression in biopsy specimens to identify GC patients who are at high risk of developing liver metastasis.

The angiogenic switch of human colon cancer occurs simultaneous to initiation of invasion.

We previously reported that vessel count, vascular endothelial growth factor (VEGF) and platelet derived endothelial cell growth factor (PD-ECGF) expression are associated with metastasis formation in human colon cancer. This study was done to determine a stage of colon cancer progression where induction of these factors occurred (i.e. the angiogenic switch). We examined vessel count, VEGF, and matrix metalloproteinase (MMP)-7 expression in cancer cells and PD-ECGF expression in infiltrating cells in 25 adenomas, 35 mucosal cancers (Tis), 29 submucosal invasive cancers (T1) and 33 muscularis propria invasive cancers (T2) by immunostaining. The intensity of staining of VEGF and MMP-7 was evaluated blindly at the invasive edge and was confirmed by image analysis. Intensity of staining for these factors was graded on a scale of 0 to 3+, with 0 representing no detectable stain and 3+ representing the strongest stain. Intensites of PD-ECGF-positive infiltrating cells were similar on a scale 0 to 3+, as previous studies from our laboratory have demonstrated that PD-ECGF is expressed primarily in tumor infiltrating cells. The vessel density was 12.7+/-2.2 (SE) in adenoma, 11.8+/-1.7 in Tis, 35.0+/-6.5 in T1, and 35.2+/-5.3 in T2. There were significant differences in vessel densities between Tis and T1 (p<0.001). The intensities of VEGF expression were 0.6+/-0.1, 0.9+/-0.2, 1.7+/-0.3, and 1.8+/-0.3 for adenoma, Tis, T1 and T2, respectively, with significant differences between in Tis and T1 (p<0.001). There were also significant differences in the intensities of the expression of MMP-7 and PD-ECGF between Tis and T1. These results suggest that angiogenic switch may occur between Tis and T1, i.e. simultaneous to initiation of invasion, in the early development of colon cancer.