A prognostic model to predict clinical outcome in gastric cancer patients with bone metastasis

Background: The clinicopathological manifestations and treatment outcomes of bone metastasis of gastric cancer are largely unknown. We delineated a prognostic model to identify different risk groups on the basis of clinical parameters. Methods: Patients who had bone metastasis at the time of diagnosis of gastric cancer (synchronous metastasis) or who developed bone metastasis during follow-up (metachronous metastasis) were retrospectively reviewed from January 1998 to May 2008. Results: Bone metastasis was identified in 203 (2.4%) of 8,633 patients: 126 patients (62%) with synchronous metastasis and 77 patients with metachronous metastasis. The median time to event was 16 months (range 4-87). As for treatment, 120 patients (59%) received systemic chemotherapy. The median survival time was 103 days (95% CI 80-126). Poor performance status [Eastern Cooperative Oncology Group 3-4; relative risk (RR) = 1.91, p = 0.011], multiple bone metastasis (RR = 2.593, p = 0.002), and abnormal carcinoembryonic antigen (RR = 1.779, p = 0.004) implied independent factors for survival. For patients who had zero to two of these factors identified, chemotherapy had a beneficial effect (175 vs. 43 days; p < 0.0001). Conclusion: We recommend that the therapeutic approach with bone metastasis be customized to facilitate the risk stratification, so as to consequently provide the most appropriate therapy for each patient.