Prognostic scoring system for synchronous brain metastasis at diagnosis of colorectal cancer: A population-based study

BACKGROUND: Brain metastasis (BM) from colorectal cancer (CRC) is rarely encountered clinically, and its prognosis has not been fully evaluated. AIM: To construct a scoring system and accurately predict the survival of patients with synchronous BM at diagnosis of CRC. METHODS: A retrospective study of 371 patients with synchronous BM from CRC was performed, using the data from 2010 to 2014 from the Surveillance, Epidemiology, and End Results database. Survival time and prognostic factors were statistically analyzed by the Kaplan-Meier method and Cox proportional hazards models, respectively. A scoring system was developed using the independent prognostic factors, and was used to measure the survival difference among different patients. RESULTS: For the 371 patients, the median overall survival was 5 mo, survival rates were 27% at 1 year and 11.2% at 2 years. Prognostic analysis showed that age, carcinoembryonic antigen level and extracranial metastasis to the liver, lung or bone were independent prognostic factors. A scoring system based on these three prognostic factors classified the patients into three prognostic subgroups (scores of 0-1, 2-3, and 4). The median survival of patients with scores of 0-1, 2-3 and 4 was 14, 5 and 2 mo, respectively (P < 0.001). Subgroup analysis showed that there were significant differences in prognosis among the groups. Score 2-3 vs 0-1: hazard ratio (HR) = 2.050, 95%CI: 1.363-3.083; P = 0.001; score 4 vs 0-1: HR = 3.721, 95%CI: 2.225-6.225; P < 0.001; score 2-3 vs 4: HR = 0.551, 95%CI: 0.374-0.812; P = 0.003. CONCLUSION: The scoring system effectively distinguishes long-term and short-term survivors with synchronous BM from CRC. These results are helpful in providing a reference for guiding therapy.