1 | Introduction
Glioblastoma multiforme (GBM) ranks as the most prevalent and highly invasive primary malignancy of the central nervous system(CNS) in adults1,2, constituting 57.3% of all gliomas and 48.3% of malignant brain tumors 3,4. As the global population ages, the incidence of GBM increases. Older patients being diagnosed with GBM generally face a less favorable prognosis compared to their younger counterparts 5, experiencing a median overall survival (OS) of 9 months, in contrast to the 15-month OS observed in the general adult population. The management of GBM in older patients can be more complex due to age-related comorbidities and the potential impact of treatment on their quality of life 6. Moreover, gender influences GBM onset, with a male-to-female ratio of 1.6:1 7. Previous studies suggest that females are associated with better outcomes in both adults and children. Although there is some evidence indicating the potential involvement of sex hormones, the exact causes of the observed differences remain unclear8.
According to the World Health Organization (WHO) classification, glioblastoma multiforme (GBM) is categorized into two subtypes based on genetic characteristics, specifically the presence or absence of isocitrate dehydrogenase (IDH) mutations: IDH-mutant and IDH-wild type.9,10. These subtypes are referred to as primary (IDH-wild type) and secondary (IDH-mutant) GBMs. Primary GBMs generally impact older patients, lack precursor lesions, and are associated with a less favorable prognosis. In contrast, secondary GBMs occur in younger individuals, arise from lower-grade gliomas, feature IDH mutations, and show a more extended overall survival (OS)11,12. Furthermore, studies have shown that distinct histopathological subtypes exhibit different treatment responses, resulting in varying survival rates. In addition to patient age and sex, predictive factors include clinical parameters, the extent of surgical resection, and tumor imaging characteristics, including tumor size, location, the presence of necrosis, and surrounding edema 13.
The primary treatment involves comprehensive surgical removal while preserving neurological function and minimizing postoperative complications. Preoperative and intraoperative assessments, encompassing laboratory tests, neuronavigation, intraoperative MRI, and fluorescence-guided surgery, are pivotal for safe and maximal tumor resection14,15. The treatment protocol extends to postoperative care, including radiotherapy and chemotherapy14,15. This often includes using temozolomide (TMZ), an oral chemotherapy agent with methylating properties16,17. The unfavorable prognosis associated with the tumor comes from its tendency to persist even after surgical resection and adjuvant therapies. Tumor complete removal is difficult due to the infiltrative tumor growth into the adjacent brain tissue and the brain’s vulnerability to surgical interventions, which could lead to functional impairment 18,19. Despite advancements in medical care, GBM patients have consistently confronted an unfavorable prognosis in recent years, with a survival rate of less than 7% over five years20, underscoring the persistent challenge of managing this highly aggressive and rapidly progressing malignant tumor. The situation highlights a major challenge in global public health, emphasizing the urgent demand for innovative approaches21,22.
Within the context of the challenging survival rates of GBM, this study investigates the factors impacting survival, explicitly age and gender. The study’s population consists of individuals who sought medical care at educational and medical institutions of Guilan Province, located in northern Iran, from 2014 to 2018. This study followed the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE)23 guidelines.