Observational Study of Perioperative Chemotherapy in Gastric Cancer (PRECISO)

• rate of downstaging [ Time Frame: 3 months ] [ Designated as safety issue: No ]
  To determine the rate of downstaging of locally advanced cT3-4 and/or N+ gastric carcinomas after 3 cycles of preoperative chemotherapy with ECX
  
  

• To evaluate the rates of adverse events of ECX administered preoperatively [ Time Frame: 3 months ] [ Designated as safety issue: No ]
  
• To evaluate clinical response after three cycles of preoperative ECX [ Time Frame: 3 months ] [ Designated as safety issue: No ]
  
• To evaluate the surgical morbidity and mortality after three cycles of preoperative CT [ Time Frame: 5 months ] [ Designated as safety issue: No ]
  
• progression free survival [ Time Frame: 3 years ] [ Designated as safety issue: No ]
  To evaluate the 3 year progression free survival
  
  
• overall survival [ Time Frame: 5 years ] [ Designated as safety issue: No ]
  To evaluate the 5 year overall survival (OS) of patients treated with perioperative CT
  
  
• compliance with the planned postoperative therapy [ Time Frame: 7 months ] [ Designated as safety issue: No ]
  
• quality of life [ Time Frame: 5 years ] [ Designated as safety issue: No ]
  To evaluate quality of life and patient reported specific symptoms of the patients treated with perioperative CT
  
  
• HER 2 expression [ Time Frame: 5 months ] [ Designated as safety issue: No ]
  To determine the number of patients with HER2 overexpressing gastric cancers
  
  

Chile belongs to the countries with a high mortality rate due to gastric cancer, and this disease is the most frequent cause of cancer death in Chile. Despite of adequate surgery, survival rates are disappointing, with less than 60% of patients for all stages achieving to be alive at 5 years. This is due to the fact that frequently gastric cancer is diagnosed at an advanced stage. For locally advanced gastric cancer a multimodality treatment is recommended, with the alternatives of surgery followed by chemotherapy (asian approach), surgery followed by chemoradiation (US approach) and perioperative chemotherapy (european approach). These three strategies are valid standard treatment options and have shown to improve overall survival in stage IB to IVA gastric cancer.

Perioperative chemotherapy administered pre- and postoperatively, has shown to downstage the tumor, increase curative resection, progression free and overall survival.

For patients with potentially resectable gastric cancer staged T2 or higher or cN+, NCCN Guidelines recommend perioperative chemotherapy (category1). Chilean guidelines for gastric cancer state the alternative of perioperative chemotherapy, however this approach has not been used widely in public hospitals because lack of financial support.

Some gastric cancers overexpress HER2, and this subset of patients benefit from targeted therapy at an advanced stage. The proportions of patients with these molecular characteristics vary widely depending of the geographic area. The chilean population has been investigated in small series, but the incidence of HER2 positive gastric cancer is not known. We therefore plan to measure HER2 expression in all participating patients.