Central nervous system metastases after gastrectomy for gastric cancer

Central nervous system (CNS) metastases from gastric cancer are exceedingly rare, occurring in fewer than 1% of patients, but are associated with poor prognosis. As advances in systemic therapies prolong survival, the incidence of CNS metastases appears to be increasing. However, robust real-world evidence remains limited.

We retrospectively reviewed 23,125 patients who underwent gastrectomy for gastric cancer from 1988 to 2019. CNS metastases (brain and/or leptomeningeal) were confirmed radiologically or pathologically. Clinical characteristics, treatments, and survival outcomes were analyzed. Overall survival was estimated using Kaplan-Meier methods, and prognostic factors were assessed using Cox regression models.

CNS metastases were identified in 53 patients (0.23%) at a median interval of 14.8 months after gastrectomy. Sites of involvement included brain-only (n = 36, 67.9%), leptomeningeal-only (n = 11, 20.8%), and both (n = 6, 11.3%). The median overall survival following CNS metastases was 2.4 months. In multivariable analysis, leptomeningeal involvement (hazard ratio [HR], 3.47; 95% confidence interval [CI], 1.50-8.04; P = 0.004) and presence of other systemic metastasis (HR, 2.11; 95% CI, 1.03-4.32; P = 0.041) were independent predictors of poor survival. Conversely, both single-modality (HR, 0.35; 95% CI, 0.13-0.89; P = 0.028) and multimodality treatments (HR, 0.35; 95% CI, 0.12-0.99; P = 0.048) significantly improved survival compared with best supportive care.

CNS metastases from gastric cancer are rare but carry a dismal prognosis. Survival was adversely affected by leptomeningeal involvement and systemic metastatic burden, while active treatment was associated with improved outcomes. Early recognition and multidisciplinary evaluation may identify patients who could benefit from aggressive local or multimodality therapy.