P-090 Comparison of progression-free survival in gastric cancer patients receiving neoadjuvant chemotherapy alone versus chemotherapy plus concurrent chemoradiotherapy: a randomized, multi-center phase III clinical trial (in progress)

Abstract

Introduction: The incidence of gastric cancer has fallen since 1930, but it is still one of the leading causes of death worldwide. It is the most common cancer in Iran. The high mortality rate of gastric cancer reflects the high prevalence of advanced disease at the time of diagnosis. The 5‐year survival rate for patients with completely resected stage I gastric adenocarcinoma is 70% ‐75% falling to 35% or less for patients with stage II and beyond. These results support the efforts to enhance treatment outcomes using adjuvant or neoadjuvant chemotherapy and radiation. In a large trial (INT0116) conducted in the United States, the benefits of chemoradiotherapy after complete resection of gastric cancer were demonstrated. In contrast to the United States, the standard treatment in many European countries is peri‐operative chemotherapy ( pre‐ and postoperative chemotherapy) based on the results of MAGIC trial. According to NCCN guidelines, for neoadjuvant treatment either chemotherapy or chemoradiation can be used prior to an attempt at curative resection. Combining these two treatments in the neoadjuvant setting with both induction chemotherapy and pre‐operative chemoradiation may enhance tumor response and improve long‐term outcomes, but it can also increase serious side effects. This approach may be appropriate in selected patients, but there is not much randomized evidence to guide treatment decisions on this issue. Regarding the high incidence of gastric cancer in Iran, we attempt to conduct a multi‐center randomized trial to compare progression‐free survival in patients with resectable gastric adenocarcinoma using neoadjuvant therapy with chemotherapy alone or induction chemotherapy plus pre‐operative chemoradiation. Methods: Patients with resectable gastric adenocarcinoma will be entered into this trial. After eligibility assessment and informed consent, all patients (n = 350) will be divided into 2 groups: The control group (n = 175) receives neoadjuvant chemotherapy consisting of 3 courses of Doxorubicin, Oxaliplatin and Capecitabine (DOX) every 28 days, undergoes surgery (3 weeks after their last chemotherapy) and then receives the same post‐operative chemotherapy every 28 days (3 weeks after surgery). The intervention group (n = 175) receives neoadjuvant chemotherapy consisting of 2 courses of DOX every 28 days and 1 course of concurrent radiotherapy with Oxaliplatin and Capecitabine, undergoes surgery and then receives post‐operative chemotherapy regimen consisting of DOX every 28 days (3 weeks after surgery). The main endpoint of this trial will be 2‐year progression‐free survival. Tumor response and overall survival will be compared between the two groups too, in addition to morbidity and mortality. Results: This is a trial in progress. Considering the large number of patients with gastric cancer in Iran and with multi‐center recruitment, we hope to have the preliminary results in the next few years. Conclusion: The results of this trial will shed light on the best neoadjuvant treatment for resectable gastric adenocarcinoma.