Time taken for a primary tumor to metastasize to the brain and the overall survival of patients with brain metastasis

Brain metastasis (BM) is one of the main causes of high morbidity and mortality in cancer patients. To evaluate the factors that influenced the survival time of patients with primary cancer and survival time after BM. Ninety patients with BM diagnosed by magnetic resonance imaging (MRI) were included in the study. We retrospectively analyzed the time to brain metastasis (TTB), overall survival time (OS1) and survival time after BM (OS2). The Kaplan-Meier method and Cox regression analysis were used for survival analyses. The median TTB was 12.0 (95% CI : 9.2–14.8 months), the median OS1 was 31.0 (95% CI : 25.8–35.2 months) and the median OS2 was 14.0 (95% CI : 10.9–17.1 months). Surgical excision of the primary tumor was an independent factor for a prolonged TTB (p< 0.000) and prolonged OS1 (p< 0.000). A single intracranial metastatic lesion was an independent protective factor for prolonged OS1 (p= 0.011) and prolonged OS2 (p= 0.050). TTB, OS1 and OS2 were analyzed with Gender (p< 0.000, < 0.000, and = 0.017, respectively). It suggests that TTB can be prolonged by primary tumor resection. Furthermore, women with a prolonged TTB and single intracranial metastasis are associated with high OS. These were helpful for the clinical treatment of BM patients before brain metastasis.