Impact of Adjuvant Chemoradiation Therapy on the Postoperative 5-year Survival Rates for Stage-II Gastric Cancer

ABSTRACT

PURPOSE: This study was conducted to evaluate the effectiveness and the role of post-operative adjuvant chemoradiation therapy in a stage-II (UICC,1997) primary gastric cancer. MATERIALS AND METHODS: From September 1994 to December 2004, 954 stage-II gastric-cancer patients were seen, and all of them underwent a curative resection with extensive (D2) lymph-node dissection. The chemotherapy consisted of fluorouracil (400 mg/m2) plus leucovorin (20 mg/m2) for 5 days, followed by 4,500 cGy of radiotherapy for 5 weeks with fluorouracil and leucovorin on the first 4 days and the last 3 days of radiotherapy. Two five-day cycles of chemotherapy were given four weeks after the completion of radiotherapy. The Kaplan-Meier method was used to estimate the survival rates. To assess the importance of potential prognostic factors, we performed univariate and multivariate analyses using a log-rank test and Cox's proportional hazards regression model. A P value <0.05 was considered significant. RESULTS: Univariate analysis revealed that age, tumor size, gross type, surgical method, and postoperative adjuvant therapy had statistical significance. Among these factors, age, surgical method, tumor size, surgical method, and postoperative adjuvant therapy were found to be independent prognostic factors by using a multivariate analysis. The postoperative adjuvant chemotherapy group and the chemoradiation therapy group had survival benefit compared to the surgery-only group. However, the chemoradiation therapy group had no significant survival benefit compared to the chemotherapy group. CONCLUSION: The postoperative adjuvant therapy in stage-II gastric-cancer patients had significant benefit. Therefore, postoperative adjuvant chemoradiation therapy has an acceptable effect. A large-scale, randomized study is needed to evaluate the effectiveness and the role of postoperative radiation therapy.