Primary Malignant Brain Tumor Trends in Southern Iran, 2001- 2017: an alarming increase in glioblastoma

Introduction: Primary Brain tumors which include a 1.7 percent of all cancers among which glioblastomas are the most lethal and the most frequent malignant types. Ionizing radiation and some genetic factors have been reported as the etiology of such cancers. We are reporting the trends in the Brain tumors with a focus on malignant types and its outcome in the South of the Iran for the first time. Methods: We selected all the patients with primary brain tumors who undergone brain surgery at teaching hospitals the Shiraz Medical School between 2001 and 2017. Data was obtained from Fars Population-based Cancer Registry. ICD-O-3 morphology coding system according to WHO 2007 classification of CNS tumors was used for grouping the tumors. Using SPSS, Total Growth Rate (TGR) and Incidence Rate (IR) were calculated to assess the changes overtime. Results: A total number of 2130 (male: 890, 41.8% and female: 1240, 58.2%) brain tumor cases from 2001 to 2017 were included in this study. The highest Incidence Rate (IR) was found in ‘unspecified tumors of the brain’ (2.74 per 100000) between 2011 and 2015 followed by ‘Astrocytoma’ (1.34 per 100000) between 2006 and 2010) and ‘Glioblastoma’ (1.25 per 100000) between years 2011 and 2016. Additionally, the Glioblastoma showed the highest IR in those aged between 30 and 59 of years (0.42 per 100000). Conclusion: An upward trend in the rate of malignant brain tumors in the Fars province could be an alarm sign for more studies to be done especially from the etiology point of view.