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.