Survival of patients with primary malignant tumors of the central nervous system in the Arkhangelsk region, Russia, 2000-2011: a population-based cohort study

Objective. To analyze survival of patients with primary tumors (PT) of the central nervous system (CNS) in the Arkhangelsk region in 2000-2011 and to study factors associated with the survival using the data from the Arkhangelsk Regional Cancer Registry (ARCR). Materials and methods. Data on all cases of PT CNS with ICD-10 codes C70-C72 were obtained from the ARCR. The database contained data on gender, date of birth, place of residence, data of diagnosis, ICD code, morphological type of tumor, stage, status at the end of the year, date of death, cause of death. Tumor-specific survival was calculated using Kaplan-Maier survival analysis. Differences between survival curves were assessed using log-rank test. Independent effects of the studied factors were assessed using Cox proportional hazard analysis. The study was approved by the ethical committee of the Northern State Medical University. Results. Oneand fiveyears survival and the median survival for the full sample (n=784) were 48.1% (95% Confidence Interval (CI): 44.5-51.6), 31.5% (95% CI: 28.0-35.1) and 10.6 (95% CI: 8.7-14.1) months, respectively. In multivariable Cox regression, age-groups 20-39 years (HR=2.02), 40-49 years (HR=2.82), and 60+ years (HR=5.50) had higher risk of death compared to those aged below 20 years. Men (HR=1.27), rural residence (HR=1.31) and the absence of the morphological confirmation of the tumor (HR=1.22) were also associated with the survival. In the model that included only histologically confirmed gliomas (n=393), stages III-IV (HR=2.44) were associated with shorter survival. The use of surgical treatment (HR=0.21) and radiotherapy (HR=0.24) were significantly associated with survival compared to no treatment. Conclusion. The population of patients with PT CNS in the Arkhangelsk region has similar survival to what has been reported from developed countries.