Gastric cancer: advances in adjuvant and adjunct therapy

Effects of stromal interacting molecule 1 gene silencing by short hairpin RNA on the biological behavior of human gastric cancer cells

Gastric cancer is one of the most common types of cancer worldwide. It has been reported that stromal interacting molecule 1 (STIM1) is associated with tumor progression and metastatic spread, including in cervical cancer, breast carcinoma and prostatic cancer. The present study investigated whether STIM1, an endoplasmic reticulum Ca(2+) sensor and activator of store-operated channel entry, contributed to SGC7901 cell progression. The pGPU6-shSTIM1 recombinant plasmid was constructed, and the effects of downregulation of STIM1 on the proliferation, apoptosis, migration and invasion of SGC7901 cells were examined. Western blot analysis revealed that transfection with the pGPU6-shSTIM1 plasmid successfully inhibited the expression of STIM1. STIM1 silencing in the gastric cancer cells significantly inhibited cell proliferation by arresting the cell cycle at the G0/G1 phase, and increasing the apoptotic rate following treatment of the SGC7901 cells with pGPU6-shSTIM1, indicated using an MTT cell viability assay and flow cytometery, respectively. As expected, STIM1 knock down also reduced the migration and invasion of the SGC7901 cells, demonstrated using a Transwell assay. The possible molecular mechanism involved the regulation of several signaling pathways involved in the biological behavior of cell survival, apoptosis, migration and metastasis. Together, these finding suggested that the expression of STIM1 is crucial for the proliferation and invasion of SGC7901 cells, providing a foundation for the development of novel type‑specific diagnostic strategies and treatments for gastric cancer.

Surgical resection of advanced gastric cancer following trastuzumab/oxaliplatin/capecitabine combination therapy

Late-stage gastric adenocarcinoma patients have a poor prognosis because of high recurrence rates. To improve long-term outcomes, perioperative chemotherapies are combined with surgery. Human epidermal growth factor receptor 2 (HER2) overexpression had been noted in gastric cancer; therefore, trastuzumab has been used occasionally in this setting. A 63-year-old male Chinese patient, who was diagnosed with adenocarcinoma in the gastric antrum, as well as lymph node metastases along the left gastric and hepatic artery, and left adrenal area, was admitted to our hospital. HER2 expression was positive, and cluster amplification was detected in a fluorescence in situ hybridization assay. The patient received three cycles of a neoadjuvant trastuzumab/oxaliplatin /capecitabine regimen. He subsequently underwent distal gastrectomy, D2+ lymphadenectomy, left adrenalectomy, cholecystectomy and Billroth II anastomosis. Treatment was continued with another five postoperative cycles of the same medication and trastuzumab application for 1 year. No recurrence has been observed 18 mo after the operation. Trastuzumab as perioperative and adjuvant medication, in combination with oxaliplatin and capecitabine for a HER2-overexpressing advanced gastric adenocarcinoma, led to recurrence-free survival of at least 18 mo after surgery.

The effectiveness of intravenous 5-fluorouracil-containing chemotherapy after curative resection for gastric carcinoma: A systematic review of published randomized controlled trials

This is a review of randomized controlled trials of intravenous 5-flurorouracil (5-FU)-containing chemotherapy after curative resection versus surgery alone in patients with gastric carcinoma to determine the impact on survival rate, safety and economics. Data sources were the Cochrane Library (2006, Issue 2), Pub-Medline and Chinese Biomedical Database. We included 22 randomized controlled trials comparing 4501 patients. Intravenous 5-FU-containing chemotherapy after curative resection had a slightly significant improvement in 3-, 5- and 7-year overall survival rate (OR 1.49, 1.41 and 1.32). No benefit of postoperative disease-free survival rate was induced by 5-FU-containing chemotherapy. Sensitivity analysis was restricted to trials with the highest methodological quality, and the result was similar when the studies with Jadad score less than 3' were excluded. Subgroup analyses found borderline improved overall survival rate in both Western and Eastern countries but the statistical significance was stronger in the Eastern subset. The combinations of 5-FU plus mitomycin C, 5-FU plus cytosine arabinoside and 5-FU plus adriamycin or epidoxorubicin induced potentially more improvement of 3- and 5-year overall survival rates. Severe toxicities were reported in 1629 patients from 15 included trials, and hematological and gastrointestinal toxicities were the most remarkable side effects, around 5%-15% respectively. The chemotherapy-related overall mortality was 1.1%. No trials mentioned cost-effectiveness analysis. Although the results provide some evidence of a beneficial effect of adjuvant chemotherapy with 5-FU-containing regimens, they are inconclusive due to the limitations of methodological quality of including randomized controlled trials. Large scale randomized controlled trials with a positive result are still mandatory before postoperative chemotherapy are recommended.