What is the difference between diffuse and non-diffuse glioma?

From the Guidelines

Diffuse gliomas are distinct from non-diffuse gliomas in terms of their infiltrative growth patterns, molecular characteristics, and prognosis, with diffuse gliomas being more aggressive and having poorer outcomes, as noted in the EANO guidelines on the diagnosis and treatment of diffuse gliomas of adulthood 1. The key differences between diffuse and non-diffuse gliomas lie in their growth patterns and molecular characteristics.

• Diffuse gliomas, such as astrocytomas, oligodendrogliomas, and glioblastomas, infiltrate widely throughout brain tissue, making complete surgical removal challenging, and are often associated with IDH mutations and chromosome 1p/19q codeletions 1.
• Non-diffuse gliomas, including pilocytic astrocytoma, pleomorphic xanthoastrocytoma, and subependymal giant cell astrocytoma, grow as discrete masses with well-defined borders, allowing for more successful surgical resection, and typically have BRAF alterations rather than IDH mutations. The treatment approaches for these two categories of gliomas also differ significantly, with diffuse gliomas often requiring aggressive multimodal therapy, including radiation and chemotherapy following surgery, as outlined in the guidelines for the treatment of diffuse gliomas 1. In contrast, non-diffuse gliomas may be effectively treated with surgery alone in many cases, highlighting the importance of accurate diagnosis and classification of gliomas to guide treatment planning and improve patient outcomes.
• The prognosis for diffuse gliomas is generally poorer due to their aggressive nature and the challenges associated with their treatment, whereas non-diffuse gliomas tend to have better outcomes due to their more localized growth pattern and greater surgical accessibility 1.

From the Research

Difference between Diffuse and Non-Diffuse Glioma

• The key difference between diffuse and non-diffuse glioma lies in their growth patterns and ability to infiltrate surrounding brain tissue.
• Diffuse gliomas, such as glioblastoma multiforme, are characterized by their infiltrative growth into surrounding brain tissue, making them difficult to completely surgically remove 2.
• Non-diffuse gliomas, on the other hand, tend to have a more circumscribed growth pattern, which can make them easier to treat surgically.
• The treatment approaches for diffuse and non-diffuse gliomas also differ, with diffuse gliomas often requiring a combination of surgery, radiation, and chemotherapy, such as temozolomide and bevacizumab 3, 4.
• The use of bevacizumab in combination with temozolomide has been shown to improve progression-free survival in patients with recurrent glioma, although its effectiveness in non-diffuse gliomas is less clear 5.
• Overall, the distinction between diffuse and non-diffuse glioma is important for determining the most effective treatment approach and predicting patient outcomes.

Characteristics of Diffuse Glioma

• Diffuse gliomas are characterized by their ability to infiltrate surrounding brain tissue, making them difficult to completely remove surgically.
• They often have a poor prognosis, with a high rate of recurrence and limited survival time 2.
• The most common type of diffuse glioma is glioblastoma multiforme, which is a highly aggressive and malignant tumor.
• Diffuse gliomas are often treated with a combination of surgery, radiation, and chemotherapy, such as temozolomide and bevacizumab 3, 4.

Characteristics of Non-Diffuse Glioma

• Non-diffuse gliomas tend to have a more circumscribed growth pattern, which can make them easier to treat surgically.
• They often have a better prognosis than diffuse gliomas, with a lower rate of recurrence and longer survival time.
• Non-diffuse gliomas can be treated with surgery alone, or in combination with radiation and chemotherapy, depending on the specific type and grade of the tumor.
• The use of bevacizumab in combination with temozolomide has been shown to be effective in some cases of non-diffuse glioma, although its effectiveness can vary depending on the specific type and grade of the tumor 5.