From the Guidelines
The average life expectancy after a grade 4 astrocytoma (glioblastoma) diagnosis is approximately 15 months, with a 2-year survival rate of 27%. This poor prognosis reflects the aggressive nature of this brain tumor, which tends to grow rapidly and invade surrounding brain tissue. The prognosis can be influenced by the methylation status of the MGMT gene, with methylated tumors having a better prognosis than unmethylated tumors, with a median survival of 23 months and a 2-year survival rate of 49% for methylated tumors, compared to 13 months and a 2-year survival rate of 12% for unmethylated tumors 1. Standard treatment typically involves maximal safe surgical resection followed by concurrent radiation therapy and chemotherapy with temozolomide. Despite this multimodal approach, recurrence is common, usually within 6-9 months of initial treatment. Factors that may positively influence survival include younger age, good functional status at diagnosis, more extensive tumor removal, and certain molecular markers like IDH mutations.
Some key points to consider in the management of glioblastoma include:
- The importance of maximal safe surgical resection in improving survival outcomes
- The use of concurrent radiation therapy and chemotherapy with temozolomide as the standard treatment approach
- The potential for molecular markers like MGMT promoter methylation and IDH mutations to influence prognosis and treatment outcomes
- The need for regular follow-up and monitoring for recurrence, which is common in glioblastoma.
It's worth noting that the most recent and highest quality study on this topic is from 2021, which provides updated guidelines for the diagnosis and treatment of diffuse gliomas of adulthood, including glioblastoma 1. However, the study from 2014 provides the most relevant information on the prognosis of glioblastoma, including the median survival and 2-year survival rates for methylated and unmethylated tumors 1.
From the FDA Drug Label
The addition of concomitant and maintenance temozolomide to radiotherapy in the treatment of patients with newly diagnosed GBM showed a statistically significant improvement in overall survival compared to radiotherapy alone ( Figure 1). The hazard ratio (HR) for overall survival was 0.63 (95% CI for HR=0.52 to 0.75) with a log-rank P<0. 0001 in favor of the temozolomide arm. The median survival was increased by 2.5 months in the temozolomide arm.
The median survival for patients with Glioblastoma multiforme (GBM) is increased by 2.5 months with the addition of temozolomide to radiotherapy, but the average life expectancy after diagnosis is not directly stated in the provided text. However, it can be inferred that the median overall survival is around 14.5 months (12 months + 2.5 months) for patients receiving temozolomide and radiotherapy, but this is not explicitly stated as the average life expectancy. 2
From the Research
Average Life Expectancy After Diagnosis of Grade 4 Astrocytoma
The average life expectancy after diagnosis of grade 4 astrocytoma, also known as glioblastoma multiforme, varies depending on several factors, including the treatment approach and patient characteristics.
- According to 3, the maximum average life expectancy following an astrocytoma diagnosis is 18 months.
- A study published in 4 reported a median survival time of 13.3 months for patients with high-grade astrocytomas, including glioblastoma multiforme.
- In contrast, a more recent study 5 found a median overall survival of 31.2 months for patients with IDH-mutant grade 4 astrocytoma.
- Another study 6 compared primary and secondary IDH-mutant grade 4 astrocytomas and found that patients with primary tumors had a significantly longer median overall survival (34.2 months) compared to those with secondary tumors (11.8 months).
- The standard treatment for high-grade gliomas, including glioblastoma multiforme, typically involves surgical resection, radiation therapy, and temozolomide, with a reported median overall survival of 14.6 months 7.
Factors Affecting Life Expectancy
Several factors can influence life expectancy after diagnosis of grade 4 astrocytoma, including:
- Resectability: Patients who undergo subtotal or total resection tend to have a longer median survival compared to those who receive biopsy only 4.
- IDH mutation status: Patients with IDH-mutant grade 4 astrocytoma may have a better prognosis compared to those with IDH-wildtype tumors 5, 6.
- MGMT promoter methylation: Methylation of the MGMT promoter has been associated with improved survival in patients with IDH-mutant grade 4 astrocytoma 5.
- TERT promoter mutation: The presence of a TERT promoter mutation may be associated with poorer survival in patients with IDH-mutant grade 4 astrocytoma 5.