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Biomedical subjects

Masanori Terashima

Publications and source records attributed to Masanori Terashima.

At least 19 recordsLinked to original sources

[Diagnostic procedure combination in gastric cancer treatment].

Present status and problems in diagnostic procedure combination (DPC) for treatment of gastric cancer are reviewed in this article. DPC for gastric malignancies are subgrouped by the presence or absence of operation, operative procedures and adjuvant treatment such as intensive care, radiotherapy and chemotherapy. In a comparison between prospective payment and medical cost invested, most investments can be recovered by DPC in patients who underwent mucosal resection or gastrectomy without major complications. However, in patients with postoperative complications who required intensive treatment,considerable investments can not be recovered by DPC. In patients given chemotherapy, most of the investments in conventional chemotherapy can be recovered by current DPC. The clinical pathway appears to be a useful tool to control homogeneously well-qualified investments in DPC.

Antineoplastic Combined Chemotherapy Protocols↗

Phase II study of docetaxel and S-1 combination therapy for advanced or recurrent gastric cancer.

PURPOSE: To evaluate the efficacy and toxicity of docetaxel in combination with a novel oral 5-fluorouracil analogue S-1 for patients with advanced or recurrent gastric cancer. EXPERIMENTAL DESIGN: Patients with advanced or recurrent adenocarcinoma of the stomach and up to one previous chemotherapy regimen were treated with i.v. docetaxel 40 mg/m2 on day 1 and oral S-1 80 mg/m2/d on days 1 to 14 every 3 weeks. RESULTS: Forty-eight patients (median age, 65 years; range, 25-75 years) received a total of 272 treatment cycles (median, 4; range, 1-17). No complete responses and 27 partial responses were observed for an overall response rate of 56.3% [95% confidence interval (95% CI), 38-66%]. Eighteen patients (37.5%) had stable disease and three patients (6.3%) had progressive disease as best response. The tumor control rate (complete response + partial response + stable disease) was 93.8% (95% CI, 83-98%). Median overall survival was 14.3 months (95% CI, 10.7-20.3 months) and median time to tumor progression was 7.3 months (95% CI, 4.3-10.0 months). The most common grade 3 to 4 hematologic toxicities were neutropenia (58.3%), leukopenia (41.7%), febrile neutropenia (8.3%), and anemia (8.3%). The most common grade 3 nonhematologic toxicities included anorexia (14.6%), stomatitis (8.3%), and nausea (6.3%). No grade 4 nonhematologic toxicities were reported and all treatment-related toxicities were resolved. CONCLUSION: Docetaxel/S-1 combination is highly active and well tolerated in advanced or recurrent gastric cancer. Further investigation in randomized studies is warranted.

Adenocarcinoma↗

Molecular cloning and characterization of novel splicing variants of human decay-accelerating factor.

Decay-accelerating factor (DAF) is one of the complement regulatory proteins. Two isoforms of DAF have been identified in humans. In this study, we isolated novel cDNAs encoding five isoforms of DAF from the human lung, which were generated by insertion of new exonic sequences. RT-PCR revealed that all isoforms were expressed in almost all tissues tested, although the expression patterns and levels differed among the tissues. Transfection of isoform vDAF1, 2, and 3 cDNAs into CHO cells showed that these molecules are soluble forms secreted after glycosylation. Isoform vDAF4 and vDAF5 cDNAs included a part of and the entire intron 7 sequence, respectively, and the transfection of vDAF4 cDNA produced a large, glycosylated, membrane-bound form. These results suggest that more than seven isoforms of human DAF are involved in the regulation of complement activation under physiological conditions through their specific structures and localization.

Alternative Splicing↗

Phase II study of a 4-week capecitabine regimen in advanced or recurrent gastric cancer.

Our objective was to evaluate the efficacy and safety of capecitabine in chemotherapy-naive patients with unresectable advanced or metastatic gastric cancer. An open-label multicenter phase II study was conducted for previously untreated patients with advanced or metastatic gastric cancer. Oral capecitabine 828 mg/m2 twice daily was given on days 1-21 every 4 weeks. Baseline characteristics of 60 enrolled patients were: male/female 49/11, median age 64 years (range 28-74), good performance status (ECOG 0-1) in 98% of patients and 27 patients had prior gastrectomy (45%). A median of 4 treatment cycles were administered (range 1-37). Five patients were excluded from the efficacy analysis because they did not meet eligibility criteria. The overall response rate (RR) in the evaluable patient population (n=55) was 26% [95% confidence interval (95% CI) 15-39%] and a further 29% of patients had stable disease. The overall RR in the intent-to-treat population (n=60) was 23% (95% CI 13-36.0%). Median time to progression in the evaluable patient population was 3.4 months (95% CI 1.8-6.1) and overall survival time in the intent-to-treat population was 10.0 months (95% CI 6.4-13.6). The most frequent grade 3/4 drug-related adverse event was hand-foot syndrome (13%), but this was readily managed by treatment interruption and dose reduction. No patients developed grade 3/4 drug-related diarrhea, vomiting, leukopenia or thrombocytopenia. We conclude that this 4-week regimen of capecitabine showed promising activity and was well tolerated as first-line therapy for advanced/metastatic gastric cancer. Further investigation of this regimen is warranted.

Administration, Oral↗

Experimental evaluation of bursting pressure in lymphatic vessels with ultrasonically activated shears.

To evaluate the ability of ultrasonically activated shears (USAS) to occlude lymphatic vessels, we investigated the bursting pressure of lymphatic vessels occluded with USAS and compared with pressures in an artery and a vein. The inguinal lymphatic vessels, testicular arteries, and testicular veins were removed from male pigs. The vessels were occluded by USAS at power level 2. The bursting pressures of the harvested vessels were measured ex vivo. The bursting pressure of the artery (average, 1154 mmHg; range, 1000-1341 mmHg) was significantly greater than that in the vein (average, 747 mmHg; range, 560-973 mmHg; p = 0.0024) or the lymphatic vessel (average, 610 mmHg; range, 491-996 mmHg; p = 0.0003). There was no significant difference of bursting pressure between the vein and lymphatic vessel (p = 0.2226). Although the bursting pressures of the vein and lymphatic vessel were significantly lower than that of the artery, they were much higher than that found in physiologic conditions. USAS is considered to be a powerful tool for lymph node dissection for malignant diseases in open surgery as well as laparoscopic surgery.

Animals↗

A Japanese phase I study of continuous oral capecitabine in patients with malignant solid tumors.

BACKGROUND: This study aimed to evaluate the tolerability and pharmacokinetics of capecitabine, given twice daily for 6 weeks without interruption, and to identify the maximum tolerated dose (MTD) and the suggested phase II schedule. METHODS: The initial dose of capecitabine was 251 mg/m2 twice daily, without interruption, and a dose escalation schedule was planned according to a modified Fibonacci scheme. Patients received oral capecitabine twice daily for at least 6 weeks unless grade 3 or 4 toxicity was observed. Blood and urine samples were collected for pharmocokinetic analysis on days 1 and 15. RESULTS: Sixteen patients with malignant solid tumors (seven breast, seven colorectal, and two gastric) were enrolled, all of whom were evaluable. Among 4 patients treated with capecitabine 1255 mg/m2 twice daily, one experienced grade 4 hemorrhagic gastric ulcer and one experienced grade 3 skin toxicity. Consequently, this dose was defined as the MTD, and gastrointestinal and cutaneous effects were identified as dose-limiting toxicities. There was no grade 3/4 diarrhea at any dose level. There was also no grade 4 hematologic toxicity at doses below the MTD, and there were no treatment-related deaths. Two patients with breast cancer had partial responses, at capecitabine doses of 502 mg/m2 and 1255 mg/m2, twice daily. Pharmacokinetic data show that high concentrations of doxifluridine (5'-DFUR) occur in tumor cells within 2 h after administration of capecitabine. CONCLUSION: The MTD of continuous oral capecitabine over 6 weeks was 1255 mg/m2 twice daily. Because of the higher occurrence of skin disorders reported in this study with a continuous treatment regimen, an intermittent treatment regimen of 828 mg/m2, administered twice daily for 3 weeks, followed by a 1-week rest period, was recommended for phase II studies. This regimen is being evaluated in phase II studies in Japanese patients with gastric, colorectal, and breast cancers.

Administration, Oral↗

Three independent genetic profiles based on mucin expression in early differentiated-type gastric cancers--a new concept of genetic carcinogenesis of early differentiated-type adenocarcinomas.

Recent molecular studies have shown that the genetic profiles of differentiated-type adenocarcinomas of the stomach are associated with distinct cellular mucin phenotypes (gastric- intestinal- and mixed-phenotypes). Therefore, we examined whether these cellular mucin phenotypes reflect specific molecular genetic alterations, and whether the phenotypes can be used to help categorize the intramucosal neoplasias of gastric tumors. We subclassified tumors into four cellular phenotypes using immunohistochemical mucin analysis. In all, 62 early gastric carcinomas (gastric-phenotype, 13; intestinal-phenotype, 17; mixed-phenotype, 31; unclassified-phenotype, 1) were examined using a combination of polymerase chain reaction microsatellite assays and immunohistochemical analysis in order to detect chromosomal allelic losses of multiple cancer-related chromosomal loci (1p, 3p. 4p, 5q, 8p, 9p, 13p, 17p, 18q and 22q), microsatellite instability (MSI), and overexpression of the p53 protein. In addition, we analyzed the relationship between MSI status and hMLH1 promoter hypermethylation, which is thought to be a cause of high MSI status. For gastric phenotype cancers, the frequency of 3p allelic loss was higher than that of other microsatellite markers, whereas 5q allelic loss was frequently found in intestinal phenotype cancers. The genetic profile of mixed phenotype cancers is comprised of two distinct genetic types: LOH and MSI types. In the former, 5q, 3p and 18q allelic losses are seen frequently in intramucosal carcinomas. On the other hand, 17p, 1p and 9p allelic losses are associated with the development of submucosal carcinomas. MSI was observed only in mixed phenotype cancers (six of 31 mixed phenotype cancers). Overexpression of the p53 protein is common in differentiated-type gastric cancers. In addition, the MSI status of the tumor cells was correlated with the extent of hypermethylation of the hMLH1 promoter. We suggest that the cellular mucin phenotypes of the differentiated-type adenocarcinomas result from distinct genetic alterations.

Adaptor Proteins, Signal Transducing↗

A pilot phase II study of capecitabine in advanced or recurrent colorectal cancer.

BACKGROUND: A pilot phase II study was conducted to evaluate the Japanese intermittent regimen of capecitabine in patients with advanced/recurrent colorectal cancer. METHODS: Twenty-two patients received oral capecitabine in a dose of 828 mg/m(2) twice daily for 3 weeks every 4 weeks. RESULTS: In the 20 patients evaluable for efficacy, the overall response rate was 25.0% (95% CI, 8.7-49.1%), rising to 33.0% in the subset of patients previously untreated for metastatic disease (n = 9). A further nine patients had stable disease. The median duration of response was 7.0 months. Five patients (22.7%) experienced grade 3/4 treatment-related adverse events, the most common being a bullous rash observed in two patients (9.1%). CONCLUSIONS: The 3 weeks out of 4 intermittent regimen of capecitabine demonstrated good antitumor activity and tolerability in patients with advanced/refractory colorectal cancer, providing a clear rationale for conducting a larger phase II study in patients with advanced disease.

Administration, Oral↗

[Experimental study for a combination chemo-immunotherapy using dendritic cells].

This study was designed to seek for the optimal anticancer agents for a combination of chemotherapy and specific immunotherapy using dendritic cells (DC) in gastric cancer. We investigated the immuno-suppressive activity of anticancer agents on human peripheral blood mononuclear cells (PBMC), apoptosis inducing activity on gastric cancer cells and expression of Toll-like receptor (TLR)-4 mRNA on immatureDCs (iDCs) by paclitaxel (TXL) and docetaxel (TXT). We further compared the cytotoxicity of cytotixic T lymphocytes (CTLs) induced by DCs pulsed with tumor cell lysate and apoptotic cells induced by TXT. Although most of the anticancer agents demonstrated the suppression activity on proliferation of PBMC in a dose dependent manner, TXT, doxifluridine and irinotecan did not show the suppressive activity on PBMC even in the highest drug concentration. About 60% of gastric cancer cells demonstrated apoptosis after a 24-48 hour treatment with both TXL and TXT. Expression of TLR-4 mRNA in iDCs was up-regulated by TXT, not by TXL, and peaked at 2 hours after the treatment. CTLs induced by DCs pulsed with tumor cell lysate and apoptotic cells showed a similar killing activity to target cells. These results suggest that TXT appears to be an optimal anticancer agent for a combination therapy with chemotherapy and tumor specific immunotherapy using dendritic cells in gastric cancer.

Adult↗

Ideal reconstruction after total gastrectomy by the interposition of a jejunal pouch considered by emptying time.

To establish the ideal form of the pouch for jejunal pouch interposition reconstruction (JPI) after total gastrectomy, the postoperative gastrointestinal function and symptoms were investigated in comparison with jejunal interposition reconstruction (JI). A total of 20 patients who underwent curative surgery for gastric cancer were enrolled in this study. In the JI group (n = 9), an isoperistaltic jejunum about 40 cm in length was interposed between the esophagus and the duodenum. In the JPI group n = 11), a proximal pouch about 15 cm in length with a 10-cm conduit was also interposed between the esophagus and the duodenum. At follow-up 6 months postoperatively, food transit was evaluated using a radiolabeled semisolid test meal. The half-emptying time was 6.9 minutes in the JI group and 46 minutes in the JPI group. The reservoir function influenced the recovery of the patients' body weight and development of the serum total protein in the early postoperative period. An early half-emptying time caused dumping symptoms in JI group. In the JPI group, there were no dumping symptoms; however, extended food clearance of pouch causes postprandial symptoms such as reflux (1 patient), vomiting (2 patients), and discomfort (2 patients). In those patients with symptoms, half-emptying times were longer than 60 minutes. There was a statistically significant correlation between the pouch length and the half-emptying time of the gastric substitute in JPI group (p = 0.0039, r = 0.789). If we estimate that the appropriate half-emptying time is 20 to 60 minutes, correlation of the pouch length and the half-emptying time shows that the ideal pouch length is about 12-15 cm in JPI. In jejunal pouch interposition reconstruction after total gastrectomy, an adequate procedure leads to nutritional advantage and prevents postoperative symptoms.

Adult↗

Intermittent FLDP: 24-h infusion of 5-FU on days 1, 3 and 5 combined with low-dose cisplatin on days 1-5 for gastric cancer, and its pharmacologic and kinetic rationale.

PURPOSE: To improve the therapeutic efficacy and minimize the toxicity of 5-fluorouracil (5-FU), intermittent therapy consisting of alternate 24-h intravenous infusion and based on differences in generation time (T(G)) between normal cells and tumor cells was investigated. METHODS: Two human gastric cancer cell lines MKN-7 and MKN-74 with T(G) of 35 h and 17 h, respectively, were used in an in vitro cytotoxic assay. The drug exposure schedule consisted of a continuous 144-h exposure and alternate 24-h exposures. In a clinical trial, a total of 23 patients with advanced or recurrent gastric cancer were treated with intermittent therapy consisting of 24-h intravenous infusion with 5-FU 700 mg/m(2) per day on days 1, 3 and 5 in combination with low-dose cisplatin (CDDP) at 3.3 mg/m(2) per day on days 1 to 5. One cycle of the combined chemotherapy lasted for four consecutive weeks, followed by withdrawal over 1-2 weeks. Plasma 5-FU concentrations were measured by high-performance liquid chromatography in 15 patients and dihydropyrimidine dehydrogenase (DPD) activity in peripheral blood mononuclear cells (PBMC) was measured in 13 patients. RESULTS: The in vitro study revealed no statistically significant difference in cytotoxicity of 5-FU between the two drug exposure schedules in MKN-7 cells. In MKN-74 cells, however, a statistically significant decrease in cytotoxicity was found with the alternate 24-h exposure. In a clinical trial, plasma 5-FU concentrations showed a trapezoidal pattern. There was a significant correlation between DPD activity in PBMC and total body clearance of 5-FU. There were eight partial responders (8/22, 36%). Toxicities were very mild in severity, with no grade 3 or 4 toxicity. In particular, diarrhea and stomatitis were infrequent (one patient), and none of the patients developed thrombocytopenia. CONCLUSIONS: Toxicities which may be observed in rapidly growing cells such as bone marrow cells and gastrointestinal epithelial cells following continuous intravenous infusion of 5-FU seemed to be reduced by intermittent therapy of 5-FU consisting of alternate 24-h intravenous infusions.

Adult↗

A rapid biosensor chip assay for measuring of telomerase activity using surface plasmon resonance.

Considerable interest has been focused on telomerase because of its potential use in assays for cancer diagnosis, and for anti-telomerase drugs as a strategy for cancer chemotherapy. A number of assays based on the polymerase chain reaction (PCR) have been developed for evaluation of telomerase activity. To overcome the disadvantages of the conventional telomerase assay [telomeric repeat amplification protocol (TRAP)] related to PCR artifacts and troublesome post-PCR procedures, we have developed a telomeric repeat elongation (TRE) assay which directly measures telomerase activity as the telomeric elongation rate by biosensor technology using surface plasmon resonance (SPR). 5'-Biotinylated oligomers containing telomeric repeats were immobilized on streptavidin-pretreated dextran sensor surfaces in situ using the BIACORE apparatus. Subsequently, the oligomers associated with the telomerase extracts were elongated in the BIACORE apparatus. The rate of TRE was calculated by measuring the SPR signals. We examined elongation rates by the TRE assay in 18 cancer and three normal human fibroblast cell lines, and 12 human primary carcinomas and matching normal tissues. The elongation rates increased in a concentration- and time-dependent manner. Those of cancer cells were two to 10 times higher than fibroblast cell lines and normal tissues. Telomerase activities and its inhibitory effects of anti-telomerase agents as measured by both the TRE and TRAP assays showed a good correlation. Our assay allows precise quantitative comparison of a wide range of human cells from somatic cells to carcinoma cells. TRE assay is suitable for practical use in the assessment of telomerase activity in preclinical and clinical trials of telomerase-based therapies, because of its reproducibility, rapidity and simplicity.

Cell Line↗

Prediction of sensitivity to fluoropyrimidines by metabolic and target enzyme activities in gastric cancer.

BACKGROUND: This study was designed to investigate the role of thymidylate synthase (TS), dihydropyrimidine dehydrogenase (DPD), and thymidine phosphorylase (TP) in tumor progression and sensitivity to 5-fluorouracil (5-FU). METHODS: A total of 275 tumor samples from 275 patients with gastric cancer were utilized in this study. TS activity was determined in 130 samples by 5-fluorodeoxyuridine monophosphate binding assay. DPD activity was measured in 140 samples by radioenzymatic assay, and TP protein level was determined in 157 samples by an enzyme-linked immunosorbent assay (ELISA) system. These parameters were compared with several clinicopathologic factors and sensitivity to 5-FU determined by in-vitro ATP assay. The antitumor activities of 5-FU, uracil plus tegafur (UFT), and 1M tegafur--0.4 M 5-chloro-2,4-dihydroxypyridine--1 M potassium oxonate (S-1 [TS-1]) were also compared, using three human gastric cancer xenografts in nude mice. RESULTS: There was no correlation between either TS or TP and sensitivity to 5-FU. However, a weak inverse correlation was found between DPD activity and sensitivity to 5-FU. High DPD activity in tumor resulted in poor prognosis, especially in patients who received 5-FU-based adjuvant chemotherapy. Although TP was significantly correlated with depth of tumor invasion and with lymphatic and venous invasions, TP alone had no impact on survival. On the other hand, TS, as well as peritoneal, hepatic, and lymph node metastases, was selected as an independent prognostic factor in gastric cancer. In the animal model, there was no significant difference in antitumor activities among the drugs in a tumor with low DPD activity. However, S-1 showed superior antitumor activity to 5-FU or UFT in tumors with high DPD activity. CONCLUSION: DPD is considered to be a most important predictive factor of 5-FU sensitivity. The use of DPD inhibitory fluoropyrimidines is strongly recommended for tumors with high DPD activity.

Adult↗

Biweekly administration regimen of docetaxel combined with CPT-11 in patients with inoperable or recurrent gastric cancer.

BACKGROUND: Both docetaxel (TXT) and irinotecan (CPT-11) are active chemotherapeutic agents for gastric cancer. We designed a biweekly administration regimen of TXT combined with CPT-11 for 4 weeks as one cycle in patients with inoperable or recurrent gastric cancer, and conducted a dose-escalation study. METHODS: Patients with histologically confirmed gastric cancer were treated with the regimen. The dosage levels of TXT and CPT-11 were as follows: level 1, 30 mg/m(2) and 50 mg/m(2); level 2, 35 and 50 mg/m(2); level 3, 40 and 50 mg/m(2); level 4, 40 and 60 mg/m(2); and level 5, 50 and 60 mg/m(2). The dose escalation was based on the dose-limiting toxicity (DLT) observed during the first cycle. RESULTS: Grade 4 neutropenia was observed at level 3, but no other DLT was observed at less than level 4 during the first cycle. However, three patients at level 3 could not continue treatment without a decrease in the dosage after the second cycle. Based on these results, level 2 was considered to be the clinically recommended dosages. CONCLUSION: Biweekly TXT and CPT-11 was well tolerated. The recommended dosages of TXT and CPT-11 for a phase II trial are 35 mg/m(2) and 50 mg/m(2), respectively.

Adult↗

Cell-type-specific repression of the maspin gene is disrupted frequently by demethylation at the promoter region in gastric intestinal metaplasia and cancer cells.

Maspin, a serine protease inhibitor, was originally reported as a tumor suppressor gene in breast and prostatic cancers. We examined maspin expression and/or the allele-specific methylation status in four gastric cancer cell lines, as well as normal, metaplastic, and cancerous epithelia obtained from 50 gastric cancer patients. Three gastric cancer cell lines exhibiting maspin overexpression showed hypomethylation at either both alleles or a haploid allele. Only one cell line (GCIY) was maspin-negative but maspin expression was reactivated after treatment with a demethylating agent, 5-aza-2'-deoxycytidine. Dense and diffuse immunoreactivity for maspin was observed in 40 (80%) of 50 gastric cancers and all gastric normal epithelia (GNE) with intestinal metaplasia (IM), but not in GNE without IM. We further analyzed the allele-specific methylation status in 10 of 50 cases subjected to immunohistochemistry by the crypt isolation technique followed by a bisulfite genome sequencing method. The maspin gene promoter region of all GNE without IM was hypermethylated on both alleles whereas those with IM frequently represented the haploid type of hypomethylation status. In six of seven gastric cancers in which crypt isolation was possible, demethylation frequently occurred and extended to both alleles. Maspin mRNA was amplified from GNE with IM and cancerous crypts but not from GNE without IM. These results suggest that demethylation at the maspin gene promoter disrupts the cell-type-specific gene repression in both GNE and gastric cancer.

Blotting, Western↗

Promoter methylation status of DAP-kinase and RUNX3 genes in neoplastic and non-neoplastic gastric epithelia.

Silencing of tumor suppressor and tumor-related genes by hypermethylation at promoter CpG islands is frequently found in human tumors, including gastric cancer. Promoter methylation is not restricted to cancer cells, and is also present in non-neoplastic cells as an age-related tissue-specific phenomenon. To clarify the physiological consequence of DAP-kinase and RUNX3 age-related methylation in gastric epithelia, we investigated the promoter methylation status of these genes in both neoplastic and non-neoplastic gastric epithelia obtained at autopsy and surgery, as well as in 10 gastric cancer cell lines. Methylation of DAP-kinase and RUNX3 was detected in 10% (1/10) and 70% (7/10) of the cell lines, respectively, and was almost concordant with their expression status. Among autopsy samples, methylation of these genes was not seen in non-neoplastic gastric epithelia from persons who were aged 22 years and below (0%; 0/4). DAP-kinase was methylated in 87% (13/15) of non-neoplastic gastric epithelia of persons who were aged 45 years or older, while RUNX3 methylation in non-neoplastic gastric epithelia was restricted to individuals who were aged 77 years or older. Among samples obtained from patients with stomach cancer, methylation was observed in both the neoplastic and the corresponding non-neoplastic gastric epithelia; 43% (40/93) and 73% (68/93) for DAP-kinase, and 45% (42/93) and 8% (7/93) for RUNX3, respectively. Frequencies of DAP-kinase and RUNX3 methylation differed significantly in non-neoplastic gastric epithelia (P < 0.01), although those in gastric cancers were almost the same. RUNX3 methylation is mostly cancer-specific, except for very old individuals, and therefore may be a possible molecular diagnostic marker and malignancy predictor.

Adenocarcinoma↗

A pilot phase II study of capecitabine in advanced or recurrent gastric cancer.

OBJECTIVES: To evaluate the efficacy and safety of capecitabine in patients with advanced or recurrent gastric cancer, we conducted a pilot phase II study in Japan. METHODS: Patients with advanced or recurrent gastric cancer were given oral capecitabine 828 mg/m(2) twice daily for 3 weeks, followed by 1 week of no treatment. Two or more cycles were administered. From July 1996 to December 1997, 32 patients were enrolled in the study. The response to capecitabine was evaluated in 31 patients, excluding 1 found to be ineligible. RESULTS: The overall response rate was 19.4% (6/31, 95% confidence interval: 7.5-37.5%). The median duration of response was 124.5 days, the median time to disease progression 85.0 days, and the median survival time 247.5 days. Drug-related adverse events of grade 3 or higher were infrequent: in 2 patients (6.3%) total bilirubin concentration increased, and 1 patient (3.1%) each had elevation of GOT, anemia, lymphopenia, increased creatinine, and hand-foot syndrome. No patient had gastrointestinal toxicity of grade 3 or higher. CONCLUSION: Capecitabine was suggested to be safe and effective in the treatment of advanced or recurrent gastric cancer. Further phase II studies of capecitabine on a large scale are warranted.

Administration, Oral↗

Analysis of genetic and epigenetic alterations of the PTEN gene in gastric cancer.

The PTEN tumor suppressor gene on 10q23.3, responsible for the Cowden and Bannayan-Zonana syndromes, encodes a dual-specificity phosphatase able to dephosphorylate both tyrosine phosphate and serine/threonine phosphate residues. Mutational inactivation of PTEN has been reported in various malignancies, including endometrial cancers, ovarian cancers, and glioblastomas. In this study, we investigated PTEN gene mutations in 10 gastric cancer cell lines and 58 primary gastric cancers by polymerase chain reaction single strand conformation polymorphism (PCR-SSCP). Hypermethylation of promoter region CpG islands, an alternative mechanism of gene inactivation to coding region mutations, was also evaluated by methylation specific PCR (MSP). Only one (1.7%) of the 58 primary tumors carried a somatic 5-bp deletion in intron 7 of PTEN, which did not alter the mRNA sequence, and no mutations were detected in any of the cell lines. Similar levels of PTEN mRNA expression were observed in all cell lines and primary tumors studied by RT-PCR, and PTEN promoter CpG islands remained unmethylated. Therefore, we conclude that PTEN does not participate in gastric carcinogenesis as a tumor suppressor gene.

Adenocarcinoma↗