Long-term survival and prognostic factors in patients with metastatic gastric cancers treated with chemotherapy in the Japan Clinical Oncology Group (JCOG) study

Background: The long-term survival of patients after chemotherapy for advanced gastric cancer remains unclear. The aim of this analysis was to investigate prognostic factors for patients with metastatic gastric cancer treated by chemotherapy, and to identify the characteristics of long-term survivors. Methods: Six hundred and forty three patients were enrolled in four phase 11 studies and one phase III study by the Japan Clinical Oncology Group between January 1985 and April 1997. By adjusting patients' eligibility between the five studies, 497 patients (77%) were selected for the analysis. Univariate and multivariate analyses were performed using log-rank tests and Cox's proportional hazard model, respectively. Results: Of the 497 patients analyzed, 39 (8%) and 11 (2%) patients have survived longer than 2 and 5 years, respectively. By multivariate analysis, better performance status, a small number of metastatic sites and macroscopically non-scirrhous type tumors were significantly associated with better prognosis. Characteristics of the 11 5-year survivors revealed eight with para-aortic node metastases alone. Eight of these patients received gastrectomy; four underwent it before chemotherapy, and the other four patients received it after achieving downstaging with successful chemotherapy. Conclusions: These results demonstrated that better performance status, a small number of metastatic sites and macroscopically non-scirrhous type tumors are independent favorable factors for survival. There were a few 5-year survivors with unresectable gastric cancers, most of whom had only abdominal lymph node metastases and received gastrectomy before or after chemotherapy.