Extent of tumor vascularization correlates with prognosis and hematogenous metastasis in gastric carcinomas.

To determine whether tumor angiogenesis correlates with prognosis and metastasis of patients with gastric carcinoma, we counted the microvessels within the primary carcinoma and compared their numbers with the patient's prognosis and mode of metastasis. Tumor specimens from 110 patients with gastric carcinoma, who had undergone curative resection more than 24 months before, were investigated. Intratumoral microvessels were stained with anti-CD34 and anti-von Willebrand factor monoclonal antibodies before being quantitated by light microscopy (x200). The antibody against von Willebrand factor often showed variability and stromal background staining, providing misleading low vessel counts. The data from three patients who died from nongastric carcinoma within 24 months after surgery were deleted. A total of 107 patients took part in the analysis examining the association between intratumoral microvessels and clinical outcomes. Vessel counts derived from CD34 expression were significantly higher in patients who experienced hematogenous or peritoneal metastasis after surgery than in patients with nonmetastatic tumors. No correlation between vessel counts and lymph node metastasis was found. The prevalence of hematogenous metastasis. but not peritoneal metastasis, increased as the vessel counts increased. Multivariate logistic regression and Cox hazards model analyses showed that the vessel counts obtained with CD34 staining correlated with the development of hematogenous recurrence but not peritoneal recurrence. It was the most important factor for predicting overall survival. These findings support the hypothesis that tumor angiogenesis is closely related to the development of hematogenous metastasis in human gastric carcinomas. Assessment of tumor vascularization may, therefore, prove valuable in identifying patients with gastric carcinoma at high risk for recurrence who would benefit from adjuvant therapy.

Correlation between expression of vascular endothelial growth factor and tumor vascularity, and patient outcome in human gastric carcinoma.

PURPOSE: The relationship between the expression of vascular endothelial growth factor (VEGF) and its receptor, KDR, in human gastric carcinoma tissues and tumor angiogenesis, as well as patient outcome, were investigated. MATERIALS AND METHODS: One hundred sixty-three primary tumor specimens were investigated by immunohistochemical studies with anti-VEGF, anti-KDR, and anti-CD34 antibodies and by monitoring patients for at least 2 years after surgery. RESULTS: For intensity of VEGF staining, 48 tumors were graded as 0, 36 as 1+, 63 as 2+, and 16 as 3+. Tumors with strong VEGF staining, assessed as 2+ and 3+, had significantly higher vascularity than those with weak VEGF. Eighty-eight tumors (54%) were positive for KDR. There was no association between KDR expression and tumor vascularity. No close correlation was found between VEGF and KDR expressions. The Cox proportional hazards model identified intratumoral vessel count as the most significant and independent prognostic factor among various clinicopathologic factors. In contrast, overall survival rates for 84 patients with weak VEGF staining tumors and 79 with strong VEGF staining tumors were not significantly different. Patients with tumors of either localized Borrmann types or well-differentiated histologies, which are found more frequently in tumors with strong VEGF staining, survived significantly longer than those with tumors of either infiltrative Borrmann types or poorly differentiated histologies. CONCLUSION: We suggest that expression of VEGF is more frequently found in tumors with well-differentiated histology and plays a role in the promotion of angiogenesis in human gastric carcinomas.

In vitro growth ability and chemosensitivity of gastric and colorectal cancer cells assessed with the human tumour clonogenic assay and the thymidine incorporation assay.

A human tumour cloning assay (HTCA) has been performed on 191 samples of gastric and 152 samples of colorectal cancers, and a thymidine incorporation assay (TIA) on 178 samples of gastric and 109 samples of colorectal cancers. The rate of evaluable assays was significantly higher in the TIA than in the HTCA (P less than 0.01). In terms of in vitro growth potential in the two assays, gastric cancer cells were less active than the colorectal cancer cells (P less than 0.05). In frequency of in vitro sensitivity to drugs, gastric cancer was more chemosensitive than colorectal cancer in both assays. The in vitro/in vivo correlations of high resistance-predictive ratios and low sensitivity-predictive ratios were similar in both assays. The results indicate that the TIA is more applicable than the HTCA to screening of active agents against fresh gastrointestinal cancers.

Association of vascular endothelial growth factor expression with tumor angiogenesis, survival and thymidine phosphorylase/platelet-derived endothelial cell growth factor expression in human colorectal cancer.

To examine the association of vascular endothelial growth factor (VEGF) expression with tumor angiogenesis, survival and thymidine phosphorylase/platelet-derived endothelial cell growth factor (dThdPase/PD-ECGF) expression in human colorectal cancer, immunohistochemical studies were performed on 136 cases of resected colorectal cancer specimens using antibodies for VEGF, KDR, CD34 and dThdPase/PD-ECGF. Fifty-nine cases (43%) were evaluated as positive for VEGF staining and 71 cases (52%) were evaluated as positive for dThdPase/PD-ECGF staining. The expression of VEGF correlated significantly with vessel counts and the expression of dThdPase/PD-ECGF (P = 0.01 and 0.01, respectively). Cox proportional hazards model analysis showed that vessel counts and VEGF expression were significant and independent prognostic factors, but that KDR expression was not.

Platelet-derived endothelial cell growth factor/thymidine phosphorylase expression correlated with tumor angiogenesis and macrophage infiltration in colorectal cancer.

To clarify whether platelet-derived endothelial cell growth factor/thymidine phosphorylase (PD-ECGF/TP) expression in both tumor cells and stromal cells has independent or synergistic effects on tumor angiogenesis and progression and to explore a possible regulator for PD-ECGF/TP expression, immunohistochemical staining was conducted on 148 specimens of colorectal cancer. The microvessel count was significantly correlated with the extent of PD-ECGF/TP expression. Macrophage infiltration in tumors with positive TP was significantly higher than in tumors with negative TP (P < 0.001). The Cox model showed that PD-ECGF/TP expression was an independent prognostic factor, although the microvessel count had a stronger value in determining the patient prognosis.

Tumor angiogenesis and expression of thymidine phosphorylase/platelet derived endothelial cell growth factor in human gastric carcinoma.

To investigate the relationship between tumor angiogenesis and the expression of platelet-derived endothelial cell growth factor/thymidine phosphorylase (PD-ECGF/dThdPase) and between patients' survival and the expression of PD-ECGF/ dThdPase in human gastric carcinoma tissues, we performed immunohistochemical studies with anti-PD-ECGF/dThdPase and anti-CD34 monoclonal antibodies. Out of 154 gastric carcinoma tissue samples, 61 (40%) were evaluated as PD-ECGF/ dThdPase-positive. The expression of PD-ECGF/dThdPase was significantly associated with the intratumoral microvessel counts (P < 0.0001) and the incidence of hematogenous metastasis (P < 0.05). Intratumoral vessel counts were significantly correlated with overall survival of 154 patients (P < 0.000001). Cox proportional hazards model showed that tumor vasculature was an independent and strong prognostic variable. However, the prevalence of the expression of PD-ECGF did not associate the overall survival. We suggest that expression of PD-ECGF/dThdPase plays a role in the promotion of angiogenesis in human gastric carcinomas, without any definite influence on patient's survival.

Detection of P-glycoprotein in solid tumors by flow cytometry.

P-glycoprotein (P-gp) detection by FCM (flow cytometry) was correlated with P-gp detection by immunohistochemical staining or Western blotting in K562 cell lines variably resistant to doxorubicin (DOX). A strong correlation was noted between the flow cytometric data and the degree of resistance assessed by thymidine incorporation assay (TIA). Of the human carcinomas tested, 37.5% were P-gp positive by flow cytometry. The flow cytometry data correlated strongly with the immunohistochemical staining (p < 0.001). Thirteen of the 15 P-gp positive tumors were resistant to DOX and vincristine (VCR) on TIA. Thus, P-gp detection by FCM correlates strongly with tumor sensitivity to DOX and VCR (p < 0.001).

Laparoscopically assisted pylorus-preserving gastrectomy.

BACKGROUND: The aim of this study was to describe the procedure of laparoscopically assisted pylorus-preserving gastrectomy (LAPPG), and to evaluate intra- and postoperative conditions of the patients. METHODS: We performed pylorus-preserving gastrectomy under laparoscopic observation, including regional lymph node dissection in early gastric cancer of the lower body. Seven patients were treated (two women and five men) using this procedure between April 1996 and April 1999. RESULTS: All the patients showed good postoperative recovery, and no signs of recurrence were recognized. There were no intraoperative or postoperative complications. Less pain, a rapid recovery, and good cosmetic results were noted. The patients exhibited little weight loss after surgery, and none demonstrated the dumping syndrome. Endoscopic examinations performed postoperatively did not indicate the presence of reflux gastritis or esophagitis. CONCLUSIONS: Our procedure of LAPPG may be useful for early gastric cancer, especially intramucosal cancer.

[Potential and limitation of scintillation assay (TIA) for clinical chemotherapy].

The clinical significance of the scintillation assay (thymidine incorporation assay) which we developed was summarized as follows; 1)thymidine uptake by tumor cells which can be evaluated in each assay functioned as a significant predictor of prognosis of patients with gastric or colorectal cancer, 2)the tumor cell compartment in this assay system significantly increased more than did those in other culture systems, 3)evaluable rates were increased to more than 80% by introduction of the preculture system with collagen coated flasks, and 4)it can be considered that chemosensitivity testings may benefit for some types of human tumor, but not for all.

Laparoscopic excision of an omental cyst.

An omental cyst is a rare intra-abdominal tumor. The authors describe a case of omental cyst that was diagnosed correctly with abdominal magnetic resonance imaging (MRI) and successfully resected completely by use of minimal-access surgical techniques. A sagittal or coronal MRI view may precisely reveal the tumor position. The authors consider MRI to be very useful in the diagnosis of abdominal cystic masses. Laparoscopic surgical techniques are replacing or complementing open abdominal surgical procedures.

Retroperitoneoscopic excision of a mesenteric cyst.

Mesenteric cysts are rare intra-abdominal lesions. We present a case of a mesenteric cyst that was discovered by abdominal computed tomography (CT) and excised by retroperitoneoscopic surgery. There have been 10 reports of excision of mesenteric cysts by laparoscopy in the literature, but retroperitoneoscopic resection of such cysts has not been reported. This case suggests that when a mesenteric cyst arises from the ascending or descending colon, the retroperitoneal approach has a lower risk of traumatizing the bowel than does the laparoscopic intra-abdominal approach, and it does not have to compress other intra-abdominal organs.

[In vitro chemosensitivity assay using a double-layer-agar system: human tumor cloning assay and thymidine incorporation assay].

Human tumor cloning assay (HTCA) and thymidine incorporation assay (TIA) were both performed using a double-layer-agar system with continuous exposure of cells to standard anticancer drugs. The rate of evaluable assays was 44% (280 of 638 tumor samples) in HTCA and 48% (216 of 452) in TIA. When the tumor samples were restricted to the gastric and colorectal cancers, it was significantly higher in TIA than HTCA (p < 0.01). HTCA was 95% reliable for predicting in vivo resistance and 52% reliable for in vivo sensitivity, whereas TIA was 88% reliable for in vivo resistance and 44% for in vivo sensitivity. These results seem to suggest that it is unnecessary to select just clonogenic tumor cells among whole tumor cell population in assessing chemosensitivity of human tumors. The current study also indicates that chemotherapy with in vitro sensitive drugs assessed by TIA produced longer survival of the patients with stage III or IV gastric cancer. Most of clinical correlation trials including this study, however, have been performed retrospectively. The prospective study is necessary to determine whether drug selection by in vitro assays is superior to that by an experienced oncologist. In addition, further studies on pharmacokinetics of anticancer drugs are required to solve some other problems inherent to the current chemosensitivity assays.

[Prediction of prognosis of patients with gastrointestinal cancer based on thymidine uptake].

In 173 patients with operable gastric cancer and in 127 patients with colorectal cancer, the relations between thymidine uptake by cancer cells in semi-solid media, their clinico-pathologic features and survival times, were studied. Multivariate analysis using Cox proportional hazard model showed that thymidine uptake is one of the variables most highly correlated with the probability of patient death. Thus, the availability of thymidine uptake information in the perioperative period may be useful for selecting patients who would benefit from more intensive therapy. Thymidine kinase (TK) is the only enzyme by which thymidine is introduced into the DNA metabolism. In 64 specimens, including gastric and colorectal cancers, TK levels in the serum and tumors were measured accordingly. However, there was no correlation between thymidine uptake and the TK levels, suggesting the necessity of measuring thymidine phosphorylase activity as well.

[A case of head metastases of breast cancer successfully treated with radiation therapy and docetaxel].

A 68-year-old female underwent radical mastectomy for left breast cancer in April, 1995. She was treated with conventional combination chemotherapy (CEF) before and after surgery as an adjuvant therapy. She was treated with oral tamoxifen (TAM) and/or medroxyprogesterone (MPA) and doxifluridine daily after surgery. In May, 1998, she was found to have developed a subcutaneous tumor of the head and skull-bone, and a meningeal metastasis. We treated her with 80 mg docetaxel (TXT) one time with radiation (total dose 50 Gy), and with 70 mg two times. After the combination therapy, she achieved partial remissions of the metastases and a decrease in serum CEA. Adverse reactions to TXT were grade 3 alopecia, grade 3 to 4 neutropenia, grade 2 to 3 stomatitis, and grade 2 diarrhea. All were tolerable and reversible. The combination therapy of radiation and TXT may be a good strategy for recurrent breast cancer.

[An in vitro drug screening assay, scintillation assay, and its clinical application].

We have developed an in vitro drug screening test by scintillation assay with which we can assess the chemosensitivity of solid human tumors during the 5 days following tumor resection. We are able to evaluate 62% (271/439) of the human tumors' chemosensitivity results. Seventy-seven of these cases were examined for in vitro-in vivo correlations. In 14 of 33 in vitro sensitivity cases (42%) we found clinical responses. And, in 41 of 44 in vitro resistance cases (95%) we found progressive disease. These in vitro-in vivo correlations with the scintillation assay were similar to those in other reports with different types of chemosensitivity assay. The true-positive accuracy of these tests averaged 50%, while the true-negative accuracy averaged 90%. We think that tumor cell heterogeneity is one of the main reasons for low true positive accuracy in the drug screening assays. In some studies we implanted human tumors into nude mice. The resulting xenografts demonstrated that fresh human tumors are composed of heterogeneous subpopulations of cells with varying chemosensitivities and varying DNA indexes. This heterogeneic nature of human tumor cells means that a single biopsy specimen may not comprehensively define the chemosensitivity of a patient disease.

[Clinical significance of P-glycoprotein expression and multidrug resistance assessed by in vitro thymidine incorporation assay in patients with gastric carcinoma].

Drug resistance in chemotherapy is a significant problem in the treatment of gastric carcinomas as well as other malignant tumors. Multidrug resistant cells frequently overexpress the 170 kDa P-glycoprotein (P-gp). Twenty-four fresh tumor specimens of gastric carcinoma were assessed by flow cytometric detection of P-gp using monoclonal antibody C219. Eight patients were P-gp positive. Differentiated gastric carcinomas contained significantly higher concentrations of P-gp positive. Incidence of P-gp positive case was high in advanced stage. Sixteen cases received in vitro chemosensitivity test assessed by thymidine incorporation assay (TIA). Seven of 9 multidrug resistant cases by TIA were P-gp positive, and all of 7 non-multidrug resistance were negative. Expression of P-gp and multidrug resistance were closely correlated (p < 0.01). Also, in 89 patients with operable gastric carcinoma, the relationship between multidrug resistance by TIA and their clinicopathologic features as well as their survival lengths were examined. Thirty-one of 89 specimens from gastric carcinoma patients were multidrug resistant by TIA. Patients with multidrug resistant group had a significantly poorer cumulative survival rate than non-multidrug resistant cases (p < 0.01). The multivariated analyses showed that multidrug resistance analyzed is useful indicator for prognosis (p < 0.1). We suggest that multidrug resistance cases or P-gp-positive cases of gastric carcinoma are highly malignant, and these determinations are clinically useful.

Laparoscopic splenectomy for treatment of patients with idiopathic thrombocytopenic purpura. Comparison with open splenectomy.

BACKGROUND: Laparoscopic splenectomy (LS) is one of the advanced laparoscopic procedures that benefit most from minimally invasive surgery. This study was undertaken to compare the operating time, blood loss, length of hospital stay, and platelet count response for patients with idiopathic thrombocytopenic purpura (ITP) undergoing open splenectomy (OS) versus LS. METHODS: We performed OS in 20 cases before 1992 and LS in 14 cases after 1993 for the treatment of ITP. RESULTS: The operating time was significantly shorter for OS than for LS (126 +/- 52 min versus 203 +/- 83 min, p < 0.01). Blood loss was less for OS than for LS (321 +/- 264 ml versus 524 +/- 648 ml, p = 0.287). None of the patients who underwent LS were converted to open surgery. Accessory spleens were found in four OS patients (20.0%) and four LS patients (28.6%). The postoperative hospital stay was significantly longer for OS patients than for LS patients (15.2 +/- 5.8 days versus 8.9 +/- 2.9 days, p < 0.0005). No significant difference was noted in the long-term results of splenectomy. CONCLUSIONS: Compared with OS, LS required more operating time, had the potential to cause greater blood loss, had a comparable incidence of accessory spleen and response rate, and appeared to shorten the postoperative stay.

Proliferative activity of human tumors: assessment using bromodeoxyuridine and flow cytometry.

Cell kinetics of human carcinoma xenografts and human solid tumors were evaluated by means of two-color flow cytometry using single sampling at appropriate time intervals after bromodeoxyuridine (BrdU) labeling. The tumors were resected several hours after the administration of BrdU, and flow cytometry was used to measure the DNA content and BrdU incorporation. Once the BrdU labeling index (LI) and DNA synthesis time (Ts) were obtained, the potential doubling time (Tpot) was calculated from these values. In 11 xenografts, the cell kinetic data were compared with the actual tumor doubling time (Td), and a good correlation between Tpot and Td was obtained (r = 0.91, P less than 0.005). In a clinical study, 33 patients with gastric cancer, colorectal cancer, lung cancer, or other solid tumors were analyzed. Aneuploid tumors had a significantly higher LI value (P less than 0.01) and a shorter Tpot than diploid tumors. The cell loss rate of human tumors ranged from 40% to 80%. These cell kinetic parameters therefore accurately indicated the level of proliferative activity of human tumors.

Association of tumour vasculature with tumour progression and overall survival of patients with non-early gastric carcinomas.

In order to investigate the relationship between intratumoral vasculature and progression of gastric carcinomas and between vessel counts and survival of patients with non-early gastric carcinoma, we counted the intratumoral microvessels and compared their numbers with clinicopathological parameters, as well as with the patients' survival. Microvessels were stained with anti-CD34 monoclonal antibody before counting by microscopy (x200). In a group of 181 patients who had undergone tumour resection and were followed for more than 24 months the vessel counts for 83 patients with stage IV disease were significantly higher than those for patients with any other stage of disease. Among various clinicopathological variables, haematogenous metastasis, lymph node metastasis, peritoneal metastasis, stage IV disease and non-curative resection were more frequent in the patients with highly vascularized tumours (intratumoral vessel count > 155) than in those with less vascularized tumours. As a classification of stage IV disease such as haematogenous or peritoneal metastasis generally indicates non-curative resection, it can be considered that the development of stage IV disease is associated with the increase in tumour angiogenesis. Both univariate and multivariate analyses showed that the intratumoral vessel count was significantly predictive of overall survival, when tested as either a continuous or dichotomous variable. Cox hazards model analysis showed that the vessel count was one of the significant and independent prognostic variables. Patients with highly vascularized tumours were significantly more likely to die than those with less vascularized tumours. Assessment of tumour vasculature may therefore be important, not only for its prognostic value, but also as it may help to predict responses to angiogenesis-inhibiting agents.