The role of chemotherapy in the management of gastric cancer

DUSP4 promotes doxorubicin resistance in gastric cancer through epithelial-mesenchymal transition

Chemoresistance limits treatment efficacy in gastric cancer and doxorubicin resistance is common in gastric cancer cells. Dual specificity phosphatase 4 (DUSP4) has been associated with tumor progression. This study aimed to investigate the mechanism of DUSP4 regulating doxorubicin resistance in gastric cancer cells. Cell Counting Kit-8 (CCK-8) and 5-ethynyl-2'-deoxyuridine (EdU) incorporation assay were used to measure cell viability and proliferation in gastric cancer cells treated with doxorubicin. The expression of DUSP4, E-cadherin and Vimentin protein was detected by Western blotting. Overexpression of DUSP4 was more resistant to doxorubicin in gastric cancer cells. Knockdown of DUSP4 increased the sensitivity of gastric cancer cells to doxorubicin. Moreover, up-regulation of DUSP4 promoted the Epithelial-Mesenchymal Transition (EMT) in gastric cancer cells, but blocking the EMT using a Twist siRNA increased the sensitivity of gastric cancer cells to doxorubicin and confirmed the EMT was involved in DUSP4-mediated doxorubicin resistance. These findings demonstrated that DUSP4 could enhance doxorubicin resistance by promoting EMT in gastric cancer cells.

A phase II study of weekly docetaxel and cisplatin plus oral tegafur/uracil and leucovorin as first-line chemotherapy in patients with locally advanced or metastatic gastric cancer

Background:

Docetaxel plus cisplatin and 5-fluorouracil has become a new standard for treating advanced gastric cancer. However, high rates of severe neutropenia limit its application. Modification of the regimen could be the solution to get similar activity but less myelosuppression.

Methods:

Patients with histologically confirmed, locally advanced, or recurrent/metastatic gastric adenocarcinoma without previous chemotherapy were enrolled. This regimen consisted of docetaxel (Tyxan, TTY, Taipei, Taiwan) 30-min infusion at a dose of 36 mg m⁻², followed by cisplatin 30 mg m⁻² infusion over 1 h on days 1 and 8, and oral tegafur/uracil 300 mg m⁻² per day plus leucovorin 90 mg per day on days 1–14, every 3 weeks. Tumour response was evaluated after every 2 cycles of treatment.

Results:

From August 2007 to March 2009, 45 patients were enrolled. The median age was 56 years (range: 22–75). Among the 40 patients evaluable for tumour response, one achieved a complete response, 22 had partial responses and 11 had stable disease. The overall response rates of the evaluable and intent-to-treat (ITT) populations were 58% (95% CI: 41–74%) and 53% (95% CI: 38–68%), respectively. The disease control rates in these populations were 85% (95% CI: 70–94%) and 82% (95% CI: 68–92%), respectively. In the ITT analysis, the median time to progression and overall survival were 6.8 and 13.9 months, respectively. Major grade 3–4 toxicities were neutropenia (51%), anaemia (22%), diarrhoea (16%), and infections (20%). No patient died of treatment-related toxicities.

Conclusion:

Concurrent weekly docetaxel and cisplatin plus oral tegafur/uracil and leucovorin are effective and well tolerated in the treatment of advanced gastric cancer.

Benefits of recurrent colonic stent insertion in a patient with advanced gastric cancer with carcinomatosis causing colonic obstruction

Malignant obstruction develops frequently in advanced gastric cancer. Although it is primarily the gastric outlet that is obstructed, there are occasional reports of colonic obstruction. Treating intestinal obstruction usually requires emergency surgery or stent insertion. There are several kinds of complications with stent insertion, such as bowel perforation, stent migration, bleeding, abdominal pain and reobstruction. Nevertheless, endoscopic stent insertion could be a better treatment than emergency surgery in cases of malignant bowel obstruction in cancer patients with poor performance status. We report a case of advanced gastric cancer with carcinomatosis in which a recurrent colonic stent was inserted at the same site because of cancer growth into the stent. The patient maintained a good condition for chemotherapy, thus improving their chances for survival.

An open, multi-centre, phase II clinical trial to evaluate the efficacy and safety of paclitaxel, UFT, and leucovorin in patients with advanced gastric cancer

The aim of the study was to evaluate the response rate and safety of weekly paclitaxel (Taxol((R))) combination chemotherapy with UFT (tegafur, an oral 5-fluorouracil prodrug, and uracil at a 1 : 4 molar ratio) and leucovorin (LV) in patients with advanced gastric cancer. Patients with histologically confirmed, locally advanced or recurrent/metastatic gastric cancer were studied. Paclitaxel 1-h infusion at a dose of 100 mg m(-2) on days 1 and 8 and oral UFT 300 mg m(-2) day(-1) plus LV 90 mg day(-1) were given starting from day 1 for 14 days, followed by a 7-day period without treatment. Treatment was repeated every 21 days. From February 2003 to October 2004, 55 patients were enrolled. The median age was 62 years (range: 32-82). Among the 48 patients evaluated for tumour response, two achieved a complete response and 22 a partial response, with an overall response rate of 50% (95% confidence interval: 35-65%). All 55 patients were evaluated for survival and toxicities. Median time to progression and overall survival were 4.4 and 9.8 months, respectively. Major grade 3-4 toxicities were neutropenia in 25 patients (45%) and diarrhoea in eight patients (15%). Although treatment was discontinued owing to treatment-related toxicities in nine patients (16%), there was no treatment-related mortality. Weekly paclitaxel plus oral UFT/LV is effective, convenient, and well tolerated in treating patients with advanced gastric cancer.

Phase II study of weekly paclitaxel and 24-hour infusion of high-dose 5-fluorouracil and leucovorin in the treatment of recurrent or metastatic gastric cancer

To investigate the efficacy and safety of combining weekly paclitaxel with weekly 24-hour infusion of high-dose 5-fluorouracil (5-FU) and leucovorin (LV, folinic acid) in the treatment of patients with advanced gastric cancer. Patients with histologically confirmed recurrent or metastatic gastric cancer were studied. Paclitaxel 80 mg/m2 3-hour intravenous infusion was given on days 1, 8, and 15, and high-dose 5-FU 2,600 mg/m2 plus LV 300 mg/m2 24-hour intravenous infusion (HDFL) was given on days 2, 9, and 16, repeated every 4 weeks. Between August 1997 and August 2003, 30 patients were enrolled. The median age was 58 years (range: 37-70). Eighteen patients (60.0%) had recurrent or metastatic disease and 12 patients had de novo metastatic disease. Among the 27 patients evaluable for tumor response, 2 achieved complete response and 9 achieved partial response, with an overall response rate of 40.7% (95% confidence interval, CI: 22-61%). Eleven of the 21 patients without prior exposure to HDFL-containing regimens responded (response rate: 52.4%, 95% CI: 29-74%), while none of the 6 patients who had previously failed HDFL-containing regimens responded (p value = 0.054 by Fisher's exact test). All 30 patients were evaluated for survival and toxicities. Median time to progression and overall survival were 6 and 10 months, respectively. Major grade 3-4 toxicities were neutropenia in 12 patients (40.0%), diarrhea in 10 patients (33.3%), and stomatitis in 3 patients (10.0%). Grade 1-2 and 3-4 paclitaxel-related neuropathy developed in 16 (53.3%) and 2 (6.7%) patients, respectively. None of the patients discontinued protocol treatment because of paclitaxel-related neuropathy or developed HDFL-related hyperammonemic encephalopathy. This paclitaxel-HDFL regimen is effective and well tolerated in the treatment of advanced gastric cancer.

Stomach- and Site-Selective Delivery of 5-Fluorouracil Following Its Application on the Gastric Serosal Surface in Rats

The present study was undertaken to elucidate the stomach- and site-selective delivery of 5-fluorouracil (5-FU) following its application on the gastric serosal surface in rats. An experimental system utilizing a cylindrical diffusion cell attached to the gastric serosal surface was established. To evaluate the gastric distribution of 5-FU, the stomach was separated into the site under the diffusion cell (site 1) and the site not under the diffusion cell (site 2). Furthermore, the mucosal side at site 1 was separated from the serosal side. After intravenous and oral administration of 5-FU, the 5-FU concentrations at sites 1 and 2 until 240 min were similar. After gastric serosal surface application of 5-FU, however, the concentration of 5-FU at site 1 until 240 min was approximately 10-fold higher than that at site 2, and was sustained. Furthermore, the 5-FU concentration on the mucosal side at site 1 and the serosal side at site 1 were comparable after gastric serosal surface application. The blood concentration of 5-FU was low (<4.4 microg/ml) until 240 min after gastric serosal surface application. The maximum blood concentration of 5-FU after gastric serosal surface application was significantly lower than after intravenous administration. Thus, the stomach- and site-selective delivery system following application on the gastric serosal surface could be applied with anticancer drugs for the treatment of gastric cancer.

Phase II study of weekly oxaliplatin and 24-h infusion of high-dose 5-fluorouracil and folinic acid in the treatment of advanced gastric cancer

To investigate the efficacy and safety of combining weekly oxaliplatin with weekly 24-h infusion of high-dose 5-fluorouracil (5-FU) and folinic acid (FA) in treatment of patients with advanced gastric cancer. Patients with histologically confirmed, locally advanced or recurrent/metastatic gastric cancer were studied. Oxaliplatin 65 mg m⁻² 2-h intravenous infusion, and 5-FU 2600 mg m⁻² plus FA 300 mg m⁻² 24-h intravenous infusion, were given on days 1 and 8, repeated every 3 weeks. Between January 2001 through January 2002, 55 patients were enrolled. The median age was 64 years (range: 22–75). In all, 52 patients (94.5%) had recurrent or metastatic disease and three patients had locally advanced disease. Among 50 patients evaluable for tumour response, 28 patients achieved partial response, with an overall response rate of 56% (95% confidence interval (CI): 41.8–70.3%). All 55 patients were evaluated for survival and toxicities. Median time to progression and overall survival were 5.2 and 10.0 months, respectively, during median follow-up time of 24.0 months. Major grades 3–4 toxicities were neutropenia in 23 cycles (7.1%) and thrombocytopenia in 16 cycles (5.0%). Treatment was discontinued for treatment-related toxicities in nine patients (16.4%), of whom eight were due to oxaliplatin-related neurotoxicity. One patient (1.8%) died of neutropenic sepsis. This oxaliplatin-containing regimen is effective in the treatment of advanced gastric cancer. Except for neurotoxicity that often develops after prolonged use of oxaliplatin, the regimen is well tolerated.

Differentially expressed genes in gastric tumors identified by cDNA array

Using cDNA fragments from the FAPESP/lICR Cancer Genome Project, we constructed a cDNA array having 4512 elements and determined gene expression in six normal and six tumor gastric tissues. Using t-statistics, we identified 80 cDNAs whose expression in normal and tumor samples differed more than 3.5 sample standard deviations. Using Self-Organizing Map, the expression profile of these cDNAs allowed perfect separation of malignant and non-malignant samples. Using the supervised learning procedure Support Vector Machine, we identified trios of cDNAs that could be used to classify samples as normal or tumor, based on single-array analysis. Finally, we identified genes with altered linear correlation when their expression in normal and tumor samples were compared. Further investigation concerning the function of these genes could contribute to the understanding of gastric carcinogenesis and may prove useful in molecular diagnostics.

Towards a molecular approach to gastric cancer management

Gastric cancer is a leading cause of cancer death worldwide. Most patients with gastric cancer present with locally advanced and incurable disease, and overall survival is poor. Considerable research efforts towards the epidemiology and pathogenesis of gastric cancer have not been translated into treatment success. We discuss current concepts of the pathogenesis of gastric cancer and how recent research advances, in particular global gene expression strategies, may improve this understanding, and suggest a framework wherein these approaches may be used.

Differentiation therapy of human cancer: basic science and clinical applications

Current cancer therapies are highly toxic and often nonspecific. A potentially less toxic approach to treating this prevalent disease employs agents that modify cancer cell differentiation, termed 'differentiation therapy.' This approach is based on the tacit assumption that many neoplastic cell types exhibit reversible defects in differentiation, which upon appropriate treatment, results in tumor reprogramming and a concomitant loss in proliferative capacity and induction of terminal differentiation or apoptosis (programmed cell death). Laboratory studies that focus on elucidating mechanisms of action are demonstrating the effectiveness of 'differentiation therapy,' which is now beginning to show translational promise in the clinical setting.