COX-2 correlates with F-box protein, Skp2 expression and prognosis in human gastric carcinoma.

The expression of cyclooxygenase (COX)-2 is induced by growth factors, tumor promoters and cytokines, and is correlated with carcinogenesis, tumor progression and inhibition of apoptosis. To clarify the pathological significance of COX-2, we examined the effect of a selective COX-2 inhibitor, NS398, on two human gastric carcinoma cell lines, MKN-45 and KATO-III, and the expression of Skp2, P27/Kip1 and COX-2 protein in human gastric carcinomas. NS398 inhibited cell growth in a time- and dose-dependent manner and exerted cell cycle arrest in the G0/G1 phase without induction of apoptosis in MKN-45, but had no effect in KATO-III. In MKN-45, NS398 induced up-regulation of P27/Kip1 and down-regulation of COX-2, cyclin D1 and Skp2. Immunohistochemistry using 63 surgically resected gastric carcinomas disclosed that COX-2 expression was correlated with Skp2 expression and that P27/Kip1 expression was inversely correlated with COX-2 and Skp2 expression. High levels of COX-2 or Skp2 were significantly correlated with poor survival (P=0.02 and P=0.004). Our results suggested that: a) NS398 induced inhibition of cell proliferation through cell cycle arrest and suppressed the expression of Skp2 in COX-2-expressing gastric carcinoma cells, and b) COX-2 contributes to the expression of Skp2 and poor survival in human gastric carcinomas.

Clinical significance of the loss of KiSS-1 and orphan G-protein-coupled receptor (hOT7T175) gene expression in esophageal squamous cell carcinoma.

PURPOSE: Lymph node metastasis is the most important predictor of prognosis in esophageal squamous cell carcinoma (ESCC). Recently, KiSS-1 was cloned as a human metastasis suppressor gene, and an orphan G-protein-coupled receptor (hOT7T175) was identified as the endogenous receptor of the KiSS-1 product. However, the clinical importance of KiSS-1 and hOT7T175 gene expression in ESCC remains unclear. EXPERIMENTAL DESIGN: In this study, total RNA was extracted from tumors and noncancerous epithelia of 71 patients with ESCC who underwent surgical esophageal resection. The expression levels of KiSS-1, hOT7T175, and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) mRNAs were analyzed quantitatively by real-time reverse transcription-PCR and compared with the clinical findings. RESULTS: The mean KiSS-1:GAPDH and hOT7T175:GAPDH ratios of the tumors were 1.2 and 0.3 and were at the same levels as those in the noncancerous epithelia. The loss of KiSS-1 and hOT7T175 gene expression was detected in 38% and 61% of tumors. Loss of KiSS-1 and/or hOT7T175 gene expression was not correlated with tumor size or degree of tumor invasion but was found to be a significant predictor of lymph node metastasis. CONCLUSIONS: Loss of KiSS-1 or hOT7T175 gene expression may be an important biomarker for detection of lymph node metastasis in ESCC.

Inducible nitric oxide synthase and survivin messenger RNA expression in hepatocellular carcinoma.

PURPOSE: Proliferative activity and suppression of apoptosis of cancer cells are important to tumor progression in hepatocellular carcinoma (HCC). Recently, the expressions of inducible nitric oxide synthase (iNOS) and survivin mRNA have been reported to correlate with suppression of apoptosis in some tumors. However, the clinical importance of expression of these genes in HCC progression remains unclear. In the present study, the correlation between the expression of iNOS and survivin mRNA and the occurrence of spontaneous apoptosis and proliferative activity of cancer cells and prognostic importance of expression of these genes in HCC were investigated. EXPERIMENTAL DESIGN: Tissues were obtained by surgical resection of livers from 61 patients with HCC and 8 without HCC. Expressions of iNOS and survivin mRNA were evaluated using the reverse transcription-PCR in 61 tumors, 61 adjacent histologically noncancerous livers, and 8 normal livers. Apoptotic cancer cells and the proliferative activity of cancer cells were detected by immunohistochemistry. RESULTS: iNOS mRNA expression was detected in 34 of 61 (55.7%) HCCs, 19 of 61 (31.1%) noncancerous liver tissues adjacent to carcinoma, and none of the 8 normal livers. In addition, survivin mRNA was detected in 19 of 61 (31.1%) HCCs, none of 61 noncancerous liver tissues, and none of the 8 normal livers. iNOS mRNA expression did not correlate with the proliferative activity of cancer cells or with the occurrence of apoptosis in HCCs. In contrast, survivin mRNA expression strongly correlated with a high proliferative activity of cancer cells and a low apoptotic index. Disease-specific survivals did not differ between patients with iNOS-positive or -negative HCCs. Although, the disease-specific survival of patients with survivin-positive HCCs was significantly poorer than that of patients with survivin-negative HCCs. CONCLUSIONS: These results indicate that iNOS may not correlate with cancer cell-proliferative activity or apoptosis; survivin, however, may not only suppress apoptosis but also accelerate cancer cell-proliferative activity and play an important role in tumor progression in HCC.

[Clinical significance of micrometastasis in lymph nodes and microinvasion in primary lesion in submucosal gastric cancer].

OBJECTIVE: To clarify the clinicopathologic characteristics of micrometastasis in lymph nodes and microinvasion in primary lesion for the treatment options with regard to submucosal gastric cancer. METHODS: 1945 lymph nodes and 68 primary tumors resected from 79 patients with submucosal gastric cancer were examined. Two consecutive sections were prepared for simultaneous staining with HE and immunostaining with anti-cytokeratin antibody (CAM 5.2), respectively. RESULTS: The incidence of nodal involvement in 79 patients with submucosal gastric cancer was increased from 13% (10/79 patients) by HE staining to 34% (27/79 patients) by cytokeratin immunostaining. Micrometastasis in the lymph nodes were found in 17 of 69 patients (25%) with cancer-free nodes examined by HE staining. Microinvasion to the muscularis properia was found in 11 of 68 patients (16%) who were histologically diagnosed as submucosal gastric cancer. Survival analysis demonstrated a worse 5-year survival in the patients with micrometastasis in lymph nodes (82%) and with microinvasion to muscularis properia (73%). A higher incidence of nodal involvement was found in submucosal cancers of large size (> 2 cm; 43%), a depressed type (48%), lymphatic invasion (73%), and deeper submucosal invasion (submucosal 3; 53%). A higher incidence of microinvasion was found with the diffused-type carcinoma (33%). CONCLUSIONS: Cytokeratin immunostaining is useful for detecting micrometastasis and microinvasion in submucosal gastric cancer. Tumor size, microscopic type, lymphatic invasion, and the depth of submucosal invasion are strongly associated with lymph node involvement. Micrometastasis in lymph nodes and microinvasion in primary lesion indicate an unfavorable outcome of the patients with submucosal gastric cancer.

Expression of Fas and Fas ligand in esophageal tissue mucosa and carcinomas.

The Fas ligand (FasL) and its receptor Fas play a key role in the initiation of an apoptotic pathway. We describe the expression of Fas receptor and ligand pair antigens in surgical samples collected from a cohot of 89 patients compared with 89 squamous cell carcinomas (SCCs), 45 dysplasias and 42 normal mucosae of the esophagus. TUNEL method was performed in 89 SCCs. Evaluation of FasL on normal mucosae displayed a heterogeneous immunoreaction in a minority of specimens, whereas SCCs exhibited a more extended and homogeneous reactivity. Fas-positive carcinoma cells revealed frequent apoptosis. Furthermore, a significantly longer disease-free survival can be observed in patients with Fas-positive tumors than in Fas-negative carcinomas and in patients with FasL-negative tumors than in FasL-positive carcinomas. In conclusion, FasL expression may play an important role in tumor progression. On the other hand, Fas-expressing carcinoma cells were associated with frequent apoptosis. Both FasL and Fas expressions correlate with prognostic significance in esophageal SCCs.

Quantitative reverse transcriptase polymerase chain reaction analysis for KiSS-1 and orphan G-protein-coupled receptor (hOT7T175) gene expression in hepatocellular carcinoma.

PURPOSE: KiSS-1 has been cloned as a human metastasis suppressor gene and an orphan G-protein-coupled receptor (hOT7T175) identified as the endogenous receptor of the KiSS-1 product. In the present study, we evaluated the clinical importance of KiSS-1 and hOT7T175 gene expression in hepatocellular carcinoma (HCC). METHODS: The expression levels of KiSS-1, hOT7T175 and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) messenger RNAs (mRNAs) were analyzed quantitatively by real-time reverse transcriptase polymerase chain reaction (RT-PCR) in 60 surgically resected HCCs. The KiSS-1/GAPDH and hOT7T175/GAPDH ratios of tumors were compared with clinicopathological findings. RESULTS: Loss of KiSS-1 mRNA expression was not detected in HCCs. The mean KiSS-1/GAPDH ratio did not change between non-cancerous cirrhotic livers and carcinomas. On the other hand, the average hOT7T175/GAPDH ratios increased from non-cancerous livers (0.08) to carcinomas (0.48). Overexpression of KiSS-1 and hOT7T175 genes was recognized in 6 tumors, which were in an advanced stage and showed poor survival. CONCLUSION: Overexpression of KiSS-1 and hOT7T175 genes was frequently observed and correlated with HCC progression; thus, the possibility that overexpressed KiSS-1 and hOT7T175 peptides mediate growth signals into cancer cells in HCCs is suggested.

Expression of cyclo-oxygenase-2 is correlated with high intratumoral microvessel density and low apoptotic index in human esophageal squamous cell carcinomas.

Cyclo-oxygenase (COX) is a key enzyme in the conversion of arachidonic acid to prostanoids. COX-2 expression has been found in many malignancies. This study analyzed the correlation between COX-2 expression and angiogenesis or apoptosis in human esophageal carcinomas. The study examined the expression of COX-2 in six esophageal carcinoma cell lines and in 100 esophageal squamous cell carcinomas, comparing intratumoral microvessel density (IMVD) and apoptotic index (AI) by immunohistochemistry and TUNEL methods. COX-2 was variably expressed in all the cell lines examined. COX-2 immunoreactivity was observed mainly in the cytoplasm of carcinoma cells. Significantly higher mean IMVD and lower AI were noted in the 51 strong COX-2 expressing cases than in the 49 weak cases. IMVD and AI were negatively correlated. COX-2 expression was higher in the tumors with lymphatic invasion than in the others. These data indicate that COX-2 expression is associated with increased intratumoral microvessels and suppression of tumor cell apoptosis. Thus COX-2 might play an important role in the angiogenesis and regulation of apoptosis in esophageal squamous cell carcinomas.

The administration of hypotonic intraperitoneal cisplatin during operation as a treatment for the peritoneal dissemination of gastric cancer.

BACKGROUND: Gastric cancers with serosal invasion often spread to the peritoneal surface. Beneficial effects of hypotonic intraperitoneal cisplatin against peritoneal dissemination was noted in experimental models. Prophylactic hypotonic intraperitoneal cisplatin during operation should therefore be examined in human gastric cancer. METHODS: Isotonic intraperitoneal cisplatin was administered immediately after gastrectomy in increasing doses to patients with locally advanced gastric cancer until dose-limiting toxicity (DLT) was observed in 2 or more of 3 patients who were treated at a specific dose level. The osmolarity reduction and dose escalation trial for hypotonic intraperitoneal cisplatin was then performed until DLT was observed in 2 or more of 6 patients. RESULTS: The dose-escalation trial revealed the DLT of isotonic intraperitoneal cisplatin in the form of nausea and vomiting at a dose of 120 mg/m2. Isotonic intraperitoneal cisplatin treatment was recommended at a dose of 100 mg/m2. Because of the possible enhanced toxicity by hypotonic solution, hypotonic intraperitoneal cisplatin at a dose of 70 mg/m2 in one-half normal saline solution was injected, but no serious toxic reaction was observed. Hypotonic intraperitoneal cisplatin at a dose of 70 mg/m2 that had been dissolved in distilled water was then injected. It was accompanied by serious renal toxicity in 2 of 6 patients. Dose escalation was thus terminated, and the trial in an additional 25 patients confirmed that the toxicity of hypotonic intraperitoneal cisplatin at a dose of 70 mg/m2 was tolerable. A pharmacokinetic study to determine the maximum concentration and the area under the curve of concentration versus time of platinum revealed that hypotonic intraperitoneal cisplatin did not appear to increase the maximum concentration or area under the curve of the total and free platinum in the plasma in comparison with the isotonic intraperitoneal cisplatin at the same dose. CONCLUSIONS: Hypotonic intraperitoneal cisplatin treatment with distilled water at the time of a gastric resection is well tolerated. Hypotonic intraperitoneal cisplatin does not increase the plasma level of platinum at a dose of 70 mg/m2. Phase II/III studies are still required to clarify the efficacy of hypotonic intraperitoneal cisplatin for the treatment of the peritoneal dissemination in gastric cancer.

Expression of survivin messenger RNA correlates with poor prognosis in patients with hepatocellular carcinoma.

Suppression of apoptosis is important for carcinogenesis and tumor growth. Recent studies revealed that survivin not only inhibited apoptosis but also accelerated cancer cell proliferative activity. To investigate the prognostic role of expression of the antiapoptosis gene, survivin, in hepatocellular carcinoma (HCC), the authors analyzed the correlation between the expression pattern of survivin messenger RNA (mRNA) and clinicopathologic findings of patients. Tissues were obtained by surgical resection of livers from 51 patients with HCC and 6 patients without HCC. Expression of survivin mRNA was evaluated using reverse transcription-polymerase chain reaction in 51 tumors, 51 adjacent histologically noncancerous livers, and 6 normal livers. Survivin protein expression was evaluated using Western blotting, and apoptotic cancer cells were detected by immunostaining with polyclonal rabbit anti-single-stranded DNA. Survivin mRNA expression was detected in 21 of 51 (41%) tumors, 2 of 51 (4%) noncancerous livers, and none of the 6 normal livers. Survivin mRNA expression did not correlate with tumor size or stage of HCC. Percentage of apoptotic cancer cells of 30 survivin mRNA-negative tumors (5.2 +/- 3.4%) was significantly higher than that of 21 survivin mRNA-positive tumors (2.2 +/- 2.3%, P = 0.0019). The disease-free 5-year survival rate of 21 patients positive for survivin mRNA (19%) was significantly poorer than that of 30 patients negative for survivin mRNA (39%, P = 0.0148). Survivin mRNA was detected in 57% (17/30) patients with HCC recurrence but in only 19% (4/21) of patients without recurrence (P = 0.0072). These results indicated that survivin mRNA expression could be used as an independent prognostic factor for patients with HCC after hepatectomy.

Quantitative analysis of expression levels of bax, bcl-2, and survivin in cancer cells during cisplatin treatment.

Cisplatin (CDDP) exerts significant activity against a wide variety of human malignancies. However, sensitivity to CDDP differs among cancer cells. CDDP induces apoptosis in cancer cells. In the present study, to evaluate good markers of chemo-sensitivity or chemo-resistance of cancer cells, the correlation between occurrence of apoptosis and the changes in expression levels of messenger RNA (mRNA) of three genes (bax, bcl-2, and survivin) in cancer cell lines during CDDP treatment were investigated. Cells (MKN-45, LoVo, and PANC-1) were incubated with CDDP (10 microg/ml). The percentage of cells in sub-G1 fraction was measured by flow cytometry. The changes in expression levels of three genes (bax, bcl-2, and survivin) during CDDP treatment were evaluated by real-time reverse transcriptase-polymerase chain reaction (RT-PCR). The percentage of cells in sub-G1 fraction increased after a shorter incubation with CDDP in LoVo cells and also increased between 12 and 24 h CDDP treatment in MKN-45 cells. On the other hand, even with a 24 h incubation with CDDP, the percentage of cells in sub-G1 fraction did not change in PANC-1 cells. The expression level of bax mRNA significantly increased after 24 h treatment with CDDP in MKN-45 cells and it significantly increased after 12 h treatment with CDDP in LoVo cells. Also, in LoVo cells, the expression level of bcl-2 mRNA decreased after 24 h treatment with CDDP. On the other hand, during CDDP treatment, the expression levels of bcl-2 and survivin mRNA significantly increased in PANC-1 cells. These findings indicate that during chemotherapy, changes in expression levels of bax, bcl-2, and survivin may provide information about chemo-sensitivity or the chemo-resistance of tumors.

Beta-catenin and cyclin D1 expression in human hepatocellular carcinoma.

To understand the nature and roles of mutated beta-catenin in human hepatocellular carcinomas (HCCs), 57 cases of surgically resected HCCs were studied. DNAs extracted from each tumor were examined for somatic mutations of exon 3, and the protein expressions of beta-catenin, cyclin D1, and Ki-67 were observed by immunohistochemical staining. beta-catenin mutations in exon 3 were detected in 10 (17.5%) out of 57 HCCs, including nine missense mutations and one deletion mutation. All of the cases with gene alterations had the anti-HCV antibody, and tested negative for the HBs antigen in the sera. All of the mutations occurred at the serine/threonine phosphorylation sites of glycogen synthase kinase-3beta (GSK-3beta) or their neighboring residues. Significant correlation with intracellular expression (p=0.00055) was shown in the HCCs harboring beta-catenin mutations. The intracellular accumulation of beta-catenin showed significant correlation with the cyclin D1 expression (p=0.00858), and with a higher proliferation index (p=0.00072). In addition, the beta-catenin mutations showed significant association with the cyclin D1 expression (p=0.0424). These results suggest that accumulated beta-catenin proteins may bind to the lymphocyte enhancer binding factor-1 (LEF-1), form the beta-catenin/LEF-1 complex, and stimulate such promoters regulating the cell cycle as the cyclin D1 gene. This is the first report to demonstrate a significant correlation between beta-catenin and the cyclin D1 expression in human HCCs.

Protein and gene expression of tumor-associated antigen RCAS1 in esophageal squamous cell carcinoma.

RCAS1 (receptor-binding cancer antigen expressed on SiSo cells) is expressed on the tumor cell membrane and induces apoptosis on infiltrated immune lymphocytes. RCAS1 has been reported to correlate with the escape of tumor cells from host immune surveillance, and with poor prognosis. However, the clinical importance of RCAS1 protein and gene expression in esophageal squamous cell carcinoma (ESCC) has not been well investigated. In the present study, RCAS1 gene and protein expression levels were evaluated and compared with clinical findings in 67 patients with ESCC. Expression levels of RCAS1 and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) messenger RNAs (mRNAs) from tumors and non-cancerous epithelia were analyzed quantitatively by real-time reverse transcriptase polymerase chain reaction (RT-PCR). RCAS1 protein expression was analyzed by immunohistochemistry. The mean RCAS1/GAPDH ratio of tumors (0.7) was not different from that of non-cancerous epithelia (0.7, p=0.715). RCAS1 immunoreactivity was detected in 19 tumors (28.4%). The mean RCAS1/GAPDH ratio of tumors with RCAS1 protein positive (0.6) did not differ from tumors without RCAS1 expression (0.8, p=0.131). RCAS1 gene and protein expressions did not correlate with tumor size, depth of invasion, lymph node metastasis, or patient prognosis. Thus, RCAS1 gene or protein expression may not correlate with tumor progression in ESCC.

Detection of cancer cells in the peripheral blood of gastric cancer patients.

The existence of occult metastasis in peripheral blood has been reported in various tumors. However, in gastric cancer (GC), this metastasis has not been well analyzed. In the present study, to identify circulating cancer cells in patients with GC, peripheral blood samples from GC patients were investigated. Total RNA was extracted from 1.5 ml peripheral blood from 55 patients with GC, from 34 non-cancer patients, and from 10 healthy volunteers. Carcinoembryonic antigen (CEA), cytokeratin 19 (CK19), and 20 (CK20) messenger RNA (mRNA) were used as probes to detect GC cells in the blood samples using real-time reverse transcriptase polymerase chain reaction (RT-PCR). CEA and CK19 mRNA expression were not detected in the 40 healthy volunteers and non-cancer patients, while 2 of the 40 showed CK20 mRNA expression. In 55 patients with GC, CK19 mRNA was not detected and CEA mRNA was detected in only one case (1.8%) with stage IV. While CK20 mRNA expression was observed in 15 cases (27.3%) and even in stage I, 8 of 24 (33.3%) showed CK20 mRNA expression. Thus, the specificity of CK20 marker may be low. Even though the sensitivity of CEA marker is low, CEA may be a more reliable marker than cytokeratins for detection of cancer cells in GC patient's peripheral blood.

Gene and protein expression of RCAS1 in hepatocellular carcinoma.

BACKGROUND: RCAS1 (receptor-binding cancer antigen expressed on SiSo cells) is expressed on the tumor cell membrane and induces apoptosis in infiltrated lymphocytes. In the present study, the clinical importance of RCAS1 gene and protein expression were analyzed in surgically resected hepatocellular carcinomas (HCCs). PATIENTS AND METHODS: RCAS1 gene and protein expression levels were evaluated and compared with clinical findings in 60 patients with HCC. Expression levels of RCAS1 messenger RNA (mRNA) from tumors was analyzed quantitatively by real-time reverse transcriptase polymerase chain reaction (RT-PCR). RCAS1 protein expression was analyzed by immunohistochemistry and the percentage of RCAS1-positive cancer cells was counted in each case. RESULTS: RCAS1 messenger RNA levels significantly positively correlated with protein expression levels. RCAS1 protein expression was detected in 75% of cases and high RCAS1 immunoreactivity was detected in 19 tumors (31.7%). RCAS1 protein expression did not correlate with tumor differentiation, progression, nor disease-free survival. New tumors developed in the residual livers after resection of primary tumors in 39 patients. Treatment with transcatheter arterial embolization (TAE) from hepatic artery was performed in these patients. Survival periods after TAE treatment in these patients were analyzed. The mean survival period of 13 patients who had primary tumors with high RCAS1 protein expression (41.4 months) was significantly longer than that of 26 patients with low expression (23.5 months, p = 0.024). After TAE treatment, a low expression level of RCAS1 protein in primary tumors was recognized as a poor prognostic factor independently of tumor stage, by multivariate analysis, in patients who had developed new tumors in the residual livers. CONCLUSION: RCAS1 protein expression in primary tumor may be a good marker for the effectiveness of TAE treatment in patients who develop new tumors in the residual livers.

Micrometastasis in lymph nodes of mucosal gastric cancer.

BACKGROUND: Endoscopic mucosal resection is frequently used in the treatment of mucosal gastric cancer. Micrometastasis in the lymph nodes of mucosal gastric cancer remains unclear.METHODS: We examined 2526 lymph nodes from 84 patients with mucosal gastric cancer. Two consecutive sections were prepared, for simultaneous staining with hematoxylin and eosin and immunostaining with CAM 5.2 monoclonal antibody against cytokeratin (CK), respectively. A clinicopathological comparison was made between patients with and without lymph node involvement.RESULTS: Lymph node involvement was detected in 45 of 2526 (1.8%) lymph nodes. The incidence of nodal involvement was significantly increased, from 1.2% (1/84 patients) with hematoxylin and eosin staining, to 19% (16/84 patients) with CK immunostaining. Although no significant difference was found, micrometastasis to lymph nodes was more frequently detected in tumors larger than 1.0 cm (15/72 patients, 21%) than in those less than or equal to 1.0 cm (1/12 patients; 8%, P = 0.307). However, discrete CK-positive cancer cells or clusters of CK-positive cancer cells were detected only in tumors larger than 2 cm.CONCLUSION: Because mucosal gastric cancer of more than 1.0 cm in superficial diameter may indicate a risk of micrometastasis to lymph nodes, endoscopic mucosal resection is not recommended for these patients.

Clinicopathological value of immunohistochemical detection of occult involvement in pT3N0 gastric cancer.

BACKGROUND: In cases of pT3 gastric cancer, even when standard histological staining reveals no evidence of metastases in the regional lymph nodes, patients still may die of postoperative recurrence of the tumor. An attempt was made in the present study to explain the unfavorable outcome of such patients by investigating the presence of occult cancer cells in lymph nodes by immunostaining of cytokeratin.METHODS: We examined 2310 lymph nodes that had been removed from 83 patients with stage II gastric cancer (pT3, N0, M0). Two consecutive sections of 4 &mgr;m thick were prepared for simultaneous staining with hematoxylin and eosin and immunostaining with the CAM 5.2 monoclonal antibody against cytokeratin, respectively.RESULTS: Evidence of occult involvement was found in 299 of 2310 (13%) lymph nodes and in 54 of 83 (65%) patients with pT3 gastric cancer. An analysis of survival demonstrated the limited 5-year survival of patients with occult involvement in their resected lymph nodes, as compared with that of patients without involvement ( P < 0.01). Moreover, the patients in whom group 2 lymph nodes had occult cancer cells had a significantly poorer prognosis than those in whom occult involvement was limited to group 1 lymph nodes ( P < 0.05).CONCLUSIONS: The accuracy of predictions of prognosis of patients with pT3 gastric cancer should be greatly enhanced if cytokeratin-specific immunostaining is performed in conjunction with routine histopathological examination of lymph nodes.

Cyclooxygenase-2 expression in human gastric tubular adenomas and carcinomas; correlation with intratumoral microvessel density and apoptotic index.

BACKGROUND: Cyclooxygenase (COX)-2 plays an important role in carcinogenesis in various human malignancies. This study examined the relationship among COX-2 expression, angiogenesis and apoptosis in human gastric adenoma and carcinoma. MATERIALS AND METHODS: We examined the expression of COX-2 in 30 tubular adenomas and 11 carcinomas, comparing it with intratumoral microvessel density (IMVD) and apoptotic index (AI) by immunohistochemistry and the terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-digoxygenin nick-end labeling (TUNEL) procedure. RESULTS: Immunohistochemistry demonstrated positive expression of COX-2 in 15 (50.0%) adenomas and in 50 (53.1%) carcinomas, respectively. The frequency of COX-2 expression was significantly higher in intestinal-type carcinomas than in diffuse-type, regardless of the tumor stage. The IMVD was significantly higher in the early and advanced carcinomas than in the adenomas and also higher in the COX-2-positive adenomas and carcinomas than in the negative ones. The AI was significantly higher in the adenomas than in the carcinomas and also in the COX-2-negative adenomas and intestinal-type early carcinomas than in their positive counterparts, respectively (p < 0.05). The IMVD and AI showed significant inverse correlation in both the adenomas (p=0.02, r=-0.64) and carcinomas (p=0.04, r=-0.18). CONCLUSION: COX-2 expression might be an early event in gastric tumorigenesis and provide a preferential advantage for tumor cell proliferation because of its vascular-rich microenvironment and escape from tumor cell apoptosis, especially in intestinal-type gastric carcinomas.

Expression of dihydropyrimidine dehydrogenase in cancer cells but not in stromal cells predicts the efficacy of fluorouracil treatment in patients with gastric carcinoma.

BACKGROUND: It is not known whether immunohistochemical quantification of dihydropyrimidine dehydrogenase (DPD) in cancer cells, stromal mononuclear cells and normal glands predicts the efficacy of fluorouracil (FU) derivatives inpatients with T3 gastric adenocarcinoma. MATERIALS AND METHODS: The levels of DPD in cancer cells, stromal cells and normal glands were measured immunohistochemically in 111 patients with T3 gastric carcinoma. Adjuvant chemotherapy with oral UFT (uracil/tegafur[4:1]) was administered to 95 patients for more than 1 year after surgery. RESULTS: Forty-two (37.8%) patients demonstrated high DPD expression in the cytoplasm of their cancer cells. In patients with low DPD expression in cancer cells, the 5-year survival rates were 64.5% in patients given FU and 42.8% in those not given FU (p=0.014). Neither stromal cells nor normal glands affected the efficacy of FU treatment in relation to their DPD expression. CONCLUSION: DPD expression in cancer cells but not in stromal cells could be a predictor of the efficacy of FU chemotherapy in patients with T3 gastric carcinoma.

Immunohistochemical dihydropyrimidine dehydrogenase expression is a good prognostic indicator for patients with Dukes' C colorectal cancer.

BACKGROUND: Dihydropyrimidine dehydrogenase (DPD) is an enzyme that catabolizes 5-fluorouracil (5-FU), which is widely used for chemotherapy in patients with advanced colorectal cancer (CRC). However, the clinical importance of tumor dihydropyrimidine dehydrogenase (DPD) expression in patients with CRC treated with 5-FU remains unclear. MATERIALS AND METHODS: We investigated DPD activities in normal mucosa (N) and tumors (T) by enzyme-linked immunosorbent assay (ELISA) in 64 surgically resected patients with Dukes' C CRC who were treated orally with postoperative adjuvant FU-based chemotherapy. We also immunohistochemically investigated DPD expression in these specimens. The clinicopathological importance of DPD activity and expression was evaluated in the patients. RESULTS: Positive DPD expression was detected in 28 tumors (43.8%) and tumor DPD activity significantly correlated with tumor DPD immunoreactivity (p=0.0121). Further, tumor DPD activity and immunoreactivity also correlated with lymph node metastatic status (p=0.0409). The disease-free survival rate of patients with positive-tumor DPD expression was significantly worse than that of patients with negative-tumor DPD expression (39.3% vs. 72.2%, p=0.0127). However, DPD activity in tumors or normal mucosa did not correlate with patient prognosis. Tumor DPD expression appeared to be an important poor prognostic factor in patients with Dukes' C CRC by multivariate analysis (p=0.013). CONCLUSION: Immunohistochemical DPD expression in tumors is a useful prognostic parameter in patients with Dukes' C CRC treated with postoperative adjuvant FU-based chemotherapy.

Neoangiogenesis in patients with gastric carcinoma in relation to the expression of vascular endothelial growth factor and thymidine phosphorylase.

BACKGROUND: We investigated the prognostic significance of microvessel density and the relationship between the expression of vascular endothelial growth factor (VEGF) and thymidine phosphorylase (TP), and angiogenesis in patients with gastric carcinoma. MATERIALS AND METHODS: The expression of VEGF and TP, and the microvessel density were examined by immunohistochemistry in patients with gastric carcinoma invading the serosa. RESULTS: The prognosis of patients with low microvessel density in the cancerous tissue was significantly better than that of patients with high microvessel density. A multivariate analysis showed that microvessel density, lymph node metastasis and tumor size were independent prognostic indicators. VEGF was expressed in tumor cells and TP was expressed in both tumor cells and infiltrating cells. VEGF expression in tumor cells and TP expression in infiltrating cells significantly correlated with microvessel density. However, microvessel density was not correlated with TP expression in tumor cells. Combined analysis based on VEGF expression in tumor cells and TP expression in infiltrating cells revealed that microvessel density was the highest in VEGF-positive and TP-positive tumors and the lowest in VEGF-negative and TP-negative tumors. Microvessel density is an independent prognostic indicator in patients with gastric carcinoma invading the serosa. CONCLUSION: VEGF expression in tumor cells and TP expression in infiltrating cells may indicate the microvessel density.