Prognostic significance of the expression of vascular endothelial growth factor (VEGF) and VEGF-C in gastric carcinoma.

BACKGROUND AND OBJECTIVES: Angiogenic factors play a major role in tumor growth and metastasis. The purpose of this study was to clarify the prognostic significance of the expression of vascular endothelial growth factor (VEGF) and VEGF-C in gastric carcinoma. METHODS: Formalin-fixed and paraffin embedded sections of tumor tissue were obtained from 76 patients who underwent curative gastrectomy for gastric carcinoma. Immunohistochemical staining for VEGF and VEGF-C was performed. RESULTS: VEGF and VEGF-C were positively expressed in 39 and 45% of the patients, respectively. No correlation existed between VEGF and VEGF-C expressions. VEGF expression was significantly correlated with venous invasion. VEGF-C expression was significantly correlated with lymphatic and venous invasion. Patients with positive staining for VEGF showed a significantly lower survival rate than VEGF negative patients. After subdivision, according to the combination of VEGF and VEGF-C expression, VEGF-C expression had a significant unfavorable impact on prognosis among patients with negative staining for VEGF. The expression of VEGF and/or VEGF-C was independent prognostic determinant by the multivariate survival analysis. CONCLUSIONS: The positive expression for VEGF and/or VEGF-C was an important prognostic determinant after curative gastrectomy for gastric carcinoma. VEGF-C may stimulate the tumor progression in the absence of VEGF.

Interleukin-10 and interferon-gamma levels within the peritoneal cavity of patients with gastric cancer.

BACKGROUND AND OBJECTIVES: Immune status in the peritoneal cavity of patients with gastric cancer remains largely unknown. To clarify the clinical significance of the host immune response within the peritoneal cavity, we examined the levels of interferon-gamma (IFN-gamma), a type 1 cytokine, and interleukin-10 (IL-10), a type 2 cytokine, in peritoneal washings obtained from patients with gastric cancer. METHODS: Both the concentrations of IFN-gamma and of IL-10 in peritoneal washings obtained during surgery from 56 patients with gastric cancer were determined by an enzyme-linked immunosorbent assay. RESULTS: The IFN-gamma level was not correlated with the IL-10 level. The IL-10 level increased in a stage-dependent manner. The high IL-10 level correlated with an unfavorable outcome, whereas there was no relationship between the IFN-gamma level and survival rate. However, among the stage III-IV cancer patients, the high IFN-gamma level correlated with a favorable outcome, while there was no relationship between the IL-10 level and survival rate. CONCLUSION: Although the IL-10 level increases with tumor progression, the outcome of patients with advanced gastric cancer may be affected by the IFN-gamma level, but not by the IL-10 level, in the peritoneal cavity.

Preoperative serum interleukin-18 level as a postoperative prognostic marker in patients with gastric carcinoma.

BACKGROUND: Interleukin-18 (IL-18), a recently described cytokine produced mainly by macrophages, stimulates interferon-gamma (IFN-gamma) production by natural killer cells and T cells. Although it has been reported that serum IL-18 levels are higher in patients with advanced tuberculosis and acute graft-versus-host disease compared with normal controls, the authors found no reports regarding serum IL-18 levels in patients with malignant solid tumors. The purpose of this study was to determine serum IL-18 levels and their clinical significance in patients with gastric carcinoma. METHODS: Peripheral blood samples were obtained from 94 patients with gastric carcinoma who underwent curative surgery and from 50 healthy volunteers. The serum IL-18 level, the IFN-gamma, level, and the Helicobacter pylori (HP) serology status were determined in each sample with an enzyme-linked immunosorbent assay. RESULTS: The mean serum IL-18 level for all patients was significantly higher compared with the mean level in healthy volunteers (P < 0.01). IFN-gamma titers were below the level of detection in all samples tested. When the patients were subdivided into groups, it was found that the serum IL-18 level in patients with Stage II and III disease was significantly higher compared with the level found in healthy volunteers (P < 0.01). The serum IL-18 level decreased after patients underwent surgical resection. However, there was no significant difference in the serum IL-18 level between healthy controls and patients with Stage I or IV disease. Patients with IL-18 levels >or= 310 pg/mL (i.e., equal to or greater than the mean levels +/- 1 standard deviation in the healthy volunteers) experienced a significantly lower survival rate compared with patients who had IL-18 levels < 310 pg/mL after undergoing surgery (P < 0.05) despite a lack of any discernible difference in clinicopathologic factors between the two groups. The serum IL-18 level was identified as an independent postoperative prognostic factor in multivariate survival analysis using a Cox proportional hazards model (hazard ratio, 4.89; P = 0.01). There was no significant correlation between HP serology status and serum IL-18 levels. CONCLUSIONS: The preoperative serum IL-18 level may represent a significant postoperative prognostic determinant in patients with gastric carcinoma. Its function in the host immune system remains to be elucidated.

[Clinical significance of detecting circulating cancer cells in patients with solid malignancies].

There have been several studies attempting to detect the existence of cancer cells in the peripheral blood of patients with solid malignancies. The use of RT-PCR assays for cytokeratin (CK), carcinoembryonic antigen (CEA), alpha-fetoproteins (AFP), prostate specific antigen (PSA) and prostate specific membrane antigen (PMSA) is likely to be practicable in the detection of circulating tumor cells from epithelial-derived malignancies. The positive rates varied widely among the studies attempting to detect circulating cancer cells in peripheral blood, even when the same targets were used, which may be explained by the sensitivity of the RT-PCR assays and the target genes used. Both false negative results and false positive results can be obtained with the RT-PCR assay system. Furthermore, cancer cells may be released from the primary cancer into the circulation intermittently rather than constantly, and the results may vary among the samples obtained at different time points. In this report, we review our recent studies and related studies by other researchers to show the advances and the problems in detecting circulating cancer cells in patients with solid malignancies. The clinical significance of detecting circulating cancer cells in peripheral blood remains to be determined.

Significant correlation between expression of interleukin-1alpha and liver metastasis in gastric carcinoma.

BACKGROUND: Interleukin (IL)-1 has been reported to augment the hematogeneous metastasis of some cancers by inducing the expression of adhesion molecules on vascular endothelial cells and also increasing the expression of proteases from tumor cells in vitro. The purpose of this study was to determine the clinical significance of the IL-1alpha expression in primary tumors of gastric carcinoma. METHODS: Paraffin embedded sections of the tumors obtained from 109 patients who underwent a gastrectomy for gastric carcinoma with subserosal invasion were stained for IL-1alpha by using the streptavidin biotin method. Staining was considered positive when 10% or more of the malignant cells displayed cytoplasmic staining. RESULTS: Sixty (55.0%) tumors expressed IL-1alpha. Positive staining for IL-1alpha was more likely in patients with differentiated tumors than in those with undifferentiated tumors. The expression of IL-1alpha showed a significant correlation with liver metastasis. Of the 84 patients receiving a curative resection, those with tumors expressing IL-1alpha had a significantly higher incidence of liver recurrence than those without. A logistic regression analysis revealed positive staining for IL-1alpha to be the best predictive factor of patients who develop liver recurrence. CONCLUSIONS: The authors' results suggest that the immunohistochemical expression of IL-1alpha is a useful predictor of liver recurrence in patients undergoing a curative resection for gastric carcinoma with subserosal invasion.

Expression of cyclooxygenase-2 in human gastric adenomas and adenocarcinomas.

BACKGROUND AND OBJECTIVES: The increased expression of cyclooxygenase (COX)-2 has been implicated in the development and progression of colorectal cancer. We sought to determine the involvement of COX-2 in human gastric cancer. MATERIALS AND METHODS: COX-2 mRNA was assayed in both gastric cancer cell lines and biopsy specimens from 37 gastric adenocarcinomas, five gastric adenomas, and five hyperplastic polyps by reverse transcription-polymerase chain reaction. RESULTS: COX-2 mRNA was found in four of five gastric cancer cell lines, two from intestinal type and two from diffuse type. COX-2 mRNA was expressed in 19 of 37 (51%) human gastric cancer specimens. The tumor diameter was greater in patients with COX-2 expression than in those without (6.5 +/- 4.6 vs. 3.8 +/- 2.7 cm, P < 0.05). The incidence of COX-2 mRNA expression was significantly higher in patients with pT2-pT4 tumors than in those with pT1 tumors (71 vs. 35%, P < 0.05). Significantly higher expression of COX-2 mRNA was also observed in patients with lymph node involvement than in those without (75 vs. 40%, P < 0.05). COX-2 mRNA was found in one of five adenomas, while it was absent in five hyperplastic polyps. The paired normal gastric musosa did not express COX-2 mRNA in any of the 47 patients. CONCLUSIONS: These results provide clinical evidence that COX-2 may contribute to tumor progression in human gastric adenocarcinoma.

Plasma soluble Fas ligand concentration: decrease in elderly men and increase in patients with gastric carcinoma.

Fas ligand (FasL), which induces apoptosis against Fas-expressing cells, has been found to be expressed on various cell types including cancer cells. Membrane-bound FasL is cleaved to release soluble FasL (sFasL). Although serum or plasma sFasL concentration has been reported to increase in various diseases, sFasL concentration in healthy normal persons has not been fully studied. There have been few reports on sFasL concentrations in patients with carcinomas. We measured plasma sFasL concentrations using an enzyme-linked immunosorbent assay in 155 healthy volunteers (70 males and 85 females with an average age of 41.5+/-15.4) and 112 patients with gastric carcinoma (76 males and 36 females with an average age of 62.3+/-11.5). A significant negative correlation existed between age and plasma sFasL concentration in healthy volunteers. sFasL concentrations in males were significantly lower than those in females. Plasma sFasL levels were significantly higher in patients with gastric carcinoma than in healthy volunteers when male subjects aged 50 or older were analyzed, although no significant difference existed between the groups in the age bracket of 35 to 49. Male patients aged 50 or older with stage 1B or 2 tumors showed significantly higher plasma sFasL concentrations than those with stage 1A tumors or those with stage 3 or 4 tumors. In conclusion, age- and gender-matched controls should be used when plasma sFasL concentration is investigated. The origin and physiological or clinical significance of plasma sFasL in healthy volunteers and gastric cancer patients remain to be clarified.

Intravascular circulation and distribution of human 51Cr-DBBF stroma-free hemoglobin, 51Cr-plasma, 51Cr-saline, 59FE-plasma, and 125I-albumin in the mouse.

Male B6C3HF1 mice were infused with human 51Cr-labeled DBBF (bis 3,5-dibromosalicyl fumarate) crosslinked stroma-free hemoglobin (SFH). In the first hour following SFH infusion, 11.2% of the infused radioactivity was found in the skin, 11.4% in muscle, 9.1% in the skeleton, and 5% in the liver. Twenty-four hours after infusion, 15.4% of the radioactivity was found in the skin, 10.3%, in the muscle, 16.6% in the skeleton, and 6.7% in the liver. The circulation and distribution of 51Cr-labeled DBBF-SFH were compared with levels of 51Cr labeled plasma, 51Cr in saline, 59Fe labeled plasma, and 125I albumin. The radioactivity in the blood was similar for 51Cr-DBBF-SFH, 51Cr-plasma, and 59Fe-plasma. During the 24-hour post-infusion period, extravascular distribution of the 51Cr-saline, 51Cr-plasma, and 125I albumin within the organs was similar to that of 51Cr-DBBF-SFH, with the highest levels being in skin, muscle, skeleton and liver, and no increase in the levels in the lung or spleen. The distribution of 59Fe compared to that of 51Cr-DBBF, 51Cr-plasma, 51Cr-saline, and 125I albumin can be explained by the fact that 59Fe is utilized in the production of new red blood cells.

Urokinase type plasminogen activator and its receptor regulate the invasive potential of gastric cancer cell lines.

To assess the role of urokinase-type plasminogen activator (uPA) and uPA receptor (uPAR) on the invasive potential of cancer cells, in vitro experiments were performed using two human gastric cancer cell lines, NUGC-3 and MKN-28. NUGC-3 cells secreted a higher level of uPA than MKN-28 cells, while the uPAR expression of NUGC-3 cells was lower than that of MKN-28 cells. Both cancer cell lines expressed Met protein and did not express hepatocyte growth factor (HGF). In Matrigel invasion assay, MKN-28 cells demonstrated significantly lower invasion index than NUGC-3 cells. The addition of exogenous uPA significantly increased the invasive activity of MKN-28 cells. The uPA expression in NUGC-3 cells was enhanced by adding conditioned media of fibroblast cells or HGF. These results suggest that uPA promotes the invasive capacity of the uPAR-positive cancer cells, and that stromal cells may play an important role in cancer cell invasion by supplying uPA and/or promoting uPA production.

Cyclooxygenase-2 expression is related to prostaglandin biosynthesis and angiogenesis in human gastric cancer.

Although recent studies have demonstrated that cyclooxygenase (COX)-2 is overexpressed in various cancers including gastric cancer, the mechanisms underlying the contribution of COX-2 to tumorigenesis and tumor promotion still remain unclear. To determine the role of COX-2, we investigated the COX-2 expression, the prostaglandin (PG) levels, and the microvessel density in 42 patients with primary gastric adenocarcinoma. COX-2 protein was over-expressed in 31 (74%) of 42 gastric cancers based on an immunoblot analysis. The intensity of COX-2 expression was found to significantly correlate with lymph node involvement. The COX-2 overexpressed cases showed significantly elevated levels of prostaglandin E2 (PGE2) in cancer tissues in comparison with the normal gastric mucosa by an immunoassay (201 +/- 90 versus 161 +/- 57 ng/mg protein; P < 0.05). However, the COX-2 overexpression was not related to the levels of thromboxane B2 and 6-keto-prostaglandin F1alpha. The density of microvessel immunostained with CD34 was significantly higher in patients demonstrating COX-2 overexpression than in those without such expression (63 +/-21 versus 45 +/- 17/200 x; P < 0.01). Our data thus suggested COX-2 overexpression to be associated with increased PGE2 biosynthesis and angiogenesis in gastric cancer, which indicates that COX-2 may play a role in the development of gastric cancer.

Clinical significance of telomerase activity in biopsy specimens of gastric cancer.

Telomerase has been reported to be activated in most immortal cells and human cancers. The purpose of this study was to assess the clinical significance of telomerase activity in biopsy specimens of gastric cancer. Telomerase activity in endoscopic biopsy specimens obtained preoperatively from 31 patients with gastric cancer was determined semiquantitatively using the telomeric repeat amplification protocol assay, a polymerase chain reaction-based assay. Cancer tissues had significantly higher telomerase activity than adjacent normal tissues (13.9 +/-2.0% vs. 7.0 +/- 0.8%; p < 0.05). The ratio of the telomerase activity in cancer tissues to that in normal tissues (telomerase index) was significantly higher in tumors invading the proper muscle layer or deeper or in tumors with moderate or marked lymphatic invasion than in tumors without these invasive factors (4.7 +/- 1.4 vs. 1.1 +/- 0.1 for depth of invasion and 4.4 +/- 1.3 vs. 1.2 +/- 0.2 for lymphatic invasion; p < 0.05 for both). These results suggest that the analysis of telomerase activity in biopsy specimens might contribute to preoperative assessment of the invasive activity or stage of gastric cancer.

Autonomic nerve plexus involvement and prognosis in patients with rectal cancer.

BACKGROUND: A detailed knowledge of the fundamental basis for cancer involvement of the autonomic nerve plexus and the outcome of patients with such cancer foci is important when considering nerve-preserving surgery for rectal cancer. METHODS: Extrarectal autonomic nerve plexuses were obtained from 61 patients with advanced rectal cancer who were undergoing extended resection of the rectum with the associated nervous system. The specimens were sectioned totally so that any indirect cancer involvement of the extrarectal autonomic nerves and/or the surrounding tissue could be detected. RESULTS: Autonomic nerve plexus involvement was observed in nine patients: none of 25 with Dukes A/B, six of 28 with Dukes C and three of eight with Dukes 'D' lesions. Five of 26 patients with nodal involvement in the pararectal area had such foci, and four of eight patients with nodal involvement further from the primary tumour. Furthermore, of the nine patients with nerve plexus involvement, seven had extranodal cancer deposits in the mesorectum. The 3-year survival rate of patients with nerve plexus involvement was 33 per cent, while it was 83 per cent in those without such disease. CONCLUSION: Nerve plexus involvement was observed in direct proportion to the extent of cancer spread to the mesorectum, and the prognosis of patients with such disease was unfavourable. Further investigation is needed to better identify those patients who would clearly benefit from an en bloc resection of the autonomic nerves.

Induction of apoptosis by JTE-522, a specific cyclooxygenase-2 inhibitor, in human gastric cancer cell lines.

An increased expression of cyclooxygenase (COX)-2 has been observed in various cancers including gastric cancer. Although specific COX-2 inhibitors have a chemopreventive effect on colon cancer, their molecular mechanisms remain unclear. To clarify these mechanisms, we investigated the effects of JTE-522, a newly developed COX-2-specific inhibitor, on gastric cancer cell lines (MKN28 and MKN45). The baseline levels of COX-2 expression were higher in MKN45 than in MKN28. JTE-522 obviously suppressed the levels of COX-2 mRNA, COX-2 protein and PGE2 at a dose of 250 microM in both cancer cells. Apoptosis was induced at 24 hours after treatment with JTE-522 (250 microM) in both cancer cells. To determine the mechanisms of apoptosis induction by JTE-522, the time course of the cell cycle and the apoptosis-related protein levels were examined. An increase in the G1 phase and a decrease in the S phase were observed prior to apoptosis. Moreover, an increase of c-myc protein and a decrease of bcl-2 protein were observed in both cells treated with JTE-522. These findings suggested that JTE-522 could induce apoptosis by blocking the cell cycle, enhancing c-myc expression and diminishing bcl-2 expression. JTE-522 also suppressed proliferation activity in both cell lines. These effects of JTE-522 were more dramatic in MKN45 than in MKN28. Since JTE-522 strongly suppresses cell growth by inducing apoptosis in gastric cancer cell lines, it may therefore serve as a chemopreventive agent.

Detecting circulating cancer cells using reverse transcriptase-polymerase chain reaction for cytokeratin mRNA in peripheral blood from patients with gastric cancer.

BACKGROUND: Cytokeratins (CKs) 19 and 20 have been used as targets for detecting cancer cells. We attempted to detect circulating cancer cells in patients with gastric cancer using a high-sensitivity reverse transcriptase-polymerase chain reaction (RT-PCR) assay for CK transcripts. METHODS: RT-PCR for CK 19 and CK 20 was performed on peripheral blood samples obtained from 52 patients with gastric cancer, from 24 of whom blood samples were collected on three occasions. Fourteen healthy volunteers served as controls. RESULTS: CK 19 and CK 20 were positive in five (9.6%) of 52 patients with gastric cancer. Of these five, four were classified into stage IV and the other stage I, according to the TNM Classification. In gastric cancer patients, three (12.5%) were positive in the 24 cases examined three times and two (7.1%) were positive in 28 cases examined only once. Among the stage IV cancer, positive cases for CK showed significantly lower survival rates than those negative for CK. Between CK 19 and CK 20 in the 24 cases examined three times, CK 19 was found to be more sensitive in detecting cancer cells. CK 20 was detected in one (7.0%) of 14 healthy volunteers, whereas CK 19 was not detected. CONCLUSIONS: We conclude that repeated blood sampling may be desirable to detect circulating cancer cells in peripheral blood, even in patients with advanced gastric cancer; CK 19 may be superior to CK 20 in detecting these cells. The clinical significance of detecting occult cancer in peripheral blood remains to be determined.

A case of primary small cell carcinoma of the cervical esophagus with long-term survival following concurrent chemoradiotherapy: case report and review of the literature.

The authors describe a case of small cell carcinoma of the esophagus that was treated by concurrent chemoradiotherapy. Both the esophageal tumor and the regional lymph node metastases disappeared after this treatment. The patient is alive and disease free after more than five years. Primary small cell carcinoma of the esophagus is a rare and aggressive neoplasm with a very poor prognosis, and the treatment modality is controversial. This case illustrates the possibility of treating this tumor type with concurrent chemoradiotherapy.

Clinicopathological study of intrapelvic cancer spread to the iliac area in lower rectal adenocarcinoma by serial sectioning.

BACKGROUND: The role of iliac lymphadenectomy in surgery for rectal cancer remains unknown. Detailed clinicopathological data on lateral cancer extension may be needed to determine the true role of this procedure. METHODS: Seventy consecutive patients with low rectal cancer who underwent systematic iliac lymphadenectomy between 1991 and 1995 were reviewed. The iliac area was divided into five regions: (1) middle rectal root, (2) internal iliac, (3) obturator, (4) common iliac and (5) external iliac. Iliac lymph nodes that were cancer-free based on conventional pathological examination were serially sectioned at 100-microm intervals and re-examined for occult microscopic involvement. RESULTS: Occult microscopic foci were detected in five (7 per cent) of the 70 patients, and the overall incidence of lateral cancer spread was 24 per cent (17 of 70). Among patients without other sites of distant metastasis or circumferential involvement of the margin, the 5-year survival rate of those with lateral spread was 35 per cent. Although the prognosis of patients with cancer involving multiple iliac regions was poor, three of six patients with metastasis to only a single region were alive without disease at 3 years. CONCLUSION: Surgeons should be aware of the possibility of localized lateral spread, including microscopic metastasis, when determining the optimum procedure for iliac lymphadenectomy in patients with rectal cancer.

A clinical study of the effectiveness of oral glutamine supplementation during total parenteral nutrition: influence on mesenteric mononuclear cells.

Bacterial translocation (BT) is a well-known insult during total parenteral nutrition (TPN) and a high incidence of morbidity has been reported in septic patients receiving TPN. Inflammatory cytokines were shown to play an important role in the pathogenesis of critical complications following sepsis. Previous studies have indicated that supplementation of TPN with glutamine is effective in preventing BT in animals, but its effectiveness in humans is unclear. The aim of this study was to determine the effectiveness of oral glutamine supplementation to patients receiving TPN in suppressing cytokine production of mesenteric blood mononuclear cells (M-MNC). Fifteen colorectal cancer patients were divided into 3 groups according to preoperative nutrition management. (1) TPN group: TPN with conventional glutamine-free amino acid solution. (2) Gln group: TPN with oral glutamine supplementation of 30 g/d. (3) CONTROL GROUP: oral intake of normal food. M-MNC were obtained immediately after laparotomy and tumor necrosis factor-alpha (TNF-alpha) and interleukin-10 (IL-10) production of M-MNC was evaluated with or without lipopolysaccharide (LPS) stimulation. TNF-alpha and IL-10 production by LPS-stimulated M-MNC was increased in the TPN group and suppressed in the Gln group. In conclusion, oral glutamine supplementation to patients with TPN was shown to be effective for the prevention of M-MNC activation to avoid excessive production of cytokines.

Evaluation of the New American Joint Committee on Cancer/International Union against cancer classification of lymph node metastasis from gastric carcinoma in comparison with the Japanese classification.

BACKGROUND: A new system for the classification of gastric carcinoma, based on the number of metastatic lymph nodes, has been adopted by the current American Joint Committee on Cancer/International Union Against Cancer (AJCC/UICC) TNM system (1997). The purpose of this study was to evaluate the rationality of this classification in comparison with the Japanese classification, which is based on the location of positive lymph nodes. METHODS: The authors analyzed 587 patients who underwent clinically curative gastrectomy with D2 lymphadenectomy for gastric carcinoma and each had 15 or more lymph nodes histologically examined from 1982 to 1992. Multivariate analysis with the Cox proportional hazards model was carried out to determine which classification was more effective. RESULTS: Within the pN1 or pN2 category of the new AJCC/UICC system, no significant difference in the survival rates existed between n1 patients and n2 patients of the Japanese classification. On the other hand, the survival rates significantly decreased, in the order of pN1, pN2, and pN3 (from greatest to smallest decrease), within the n1 and n2 categories. In multivariate analysis, lymph node involvement by the AJCC/UICC classification was selected as the most significant prognostic determinant, whereas the Japanese lymph node classification was not significantly prognostic. When survival rates were calculated within the pT1, pT2, and pT3-4 categories, no differences existed between pN0 and pN1. There was some discrepancy between the survival rate for each pT and pN category and the corresponding stage. CONCLUSIONS: The new AJCC/UICC classification for lymph node involvement of gastric carcinoma is basically acceptable and considered superior to the Japanese classification. Further analysis involving a greater number of cases may be necessary to confirm the applicability of this staging system.