Brain intertwined with glowing vines, symbolizing hope and caution in glioma treatment.

Navigating Glioma Treatment: What Korean Research Reveals About Survival

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Nico Varela in Health & Wellness August 2025 • 4 min read.

"A new Korean study sheds light on effective treatment strategies for WHO grade II gliomas, offering crucial insights for patients and oncologists."


Low-grade gliomas (LGGs) present a unique challenge in oncology. Unlike more aggressive brain tumors, LGGs, classified as grade I and II by the World Health Organization (WHO), often allow for longer survival, sometimes up to 7 years. However, the optimal treatment approach remains a topic of debate among experts.

Surgery, particularly Gross Total Resection (GTR), where more than 99% of the tumor is removed, is generally considered the first line of treatment. Adjuvant therapies, such as radiotherapy (RT) and chemotherapy, are used to manage any remaining tumor cells and prevent recurrence. The role and timing of these adjuvant treatments, however, are less clear.

To better understand the effectiveness of different treatment strategies, a large intergroup study was conducted in Korea, involving 555 patients diagnosed with WHO grade II LGGs. The study, known as KNOG 15-02 and KROG 16-04, analyzed patient outcomes over a significant follow-up period, providing valuable insights into the impact of various treatment modalities on survival.

Key Findings: Surgery, Chemotherapy, and Radiotherapy

Brain intertwined with glowing vines, symbolizing hope and caution in glioma treatment.

The Korean study, published in the Journal of Neuro-Oncology, meticulously reviewed the medical records of 555 patients diagnosed with WHO grade II LGG between 2000 and 2010. These patients, treated across 14 institutions, were followed for a median of 83.4 months.

The study revealed several key findings related to patient and tumor characteristics that significantly impacted survival:

  • Gender and Age: Male patients and older patients generally experienced poorer survival rates.
  • Performance Status: Patients with poorer performance status at the time of diagnosis had reduced survival outcomes.
  • Tumor Location: Tumors involving multiple lobes of the brain were associated with poorer survival compared to those confined to a single lobe.
  • Histology: Astrocytoma histology was linked to poorer survival outcomes compared to other LGG subtypes like oligodendroglioma and oligoastrocytoma.
Among the treatment factors, Gross Total Resection (GTR) emerged as a critical element for improved survival. Patients who underwent GTR experienced better progression-free survival (PFS) and overall survival (OS). In contrast, adjuvant radiotherapy (RT) did not improve PFS and was associated with poorer OS in initial analysis. However, after propensity score matching (PSM) to balance patient characteristics, adjuvant RT showed a potential impact on improving PFS. Adjuvant chemotherapy was found to improve PFS, irrespective of the extent of surgery.

Clinical Implications and Future Directions

This Korean study underscores the importance of GTR in the management of LGGs. It also suggests that adjuvant chemotherapy may enhance PFS, while the role of adjuvant RT requires careful consideration due to potential confounding factors. The study highlights the need for personalized treatment strategies based on individual patient and tumor characteristics. As molecular diagnostics become more integrated into glioma classification, future clinical trials should focus on tailoring treatments based on molecular biomarkers to optimize outcomes for LGG patients.

About this Article -

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Everything You Need To Know

1

What are low-grade gliomas?

Low-grade gliomas (LGGs) are a type of brain tumor classified as grade I and II by the World Health Organization (WHO). They are distinct from more aggressive brain tumors due to their slower growth and potential for longer survival, sometimes extending up to 7 years. However, managing LGGs presents a challenge, and the optimal treatment approach can vary.

2

What is Gross Total Resection (GTR), and why is it important in treating gliomas?

Gross Total Resection (GTR) is a surgical procedure that aims to remove more than 99% of the tumor. It is considered a critical element for improved survival. When GTR is successfully performed, patients generally experience better progression-free survival (PFS) and overall survival (OS).

3

What is adjuvant radiotherapy, and what does the research say about its effectiveness?

Adjuvant radiotherapy (RT) is a treatment used after the initial surgery to target any remaining tumor cells and prevent recurrence. However, its role in treating LGGs is complex. Initial findings suggested that adjuvant RT did not improve PFS and might be associated with poorer OS. After further analysis to balance patient characteristics, adjuvant RT showed a potential impact on improving PFS. This indicates that the effectiveness of RT may depend on specific patient factors.

4

What is adjuvant chemotherapy, and how does it impact the treatment of LGGs?

Adjuvant chemotherapy involves using drugs to kill cancer cells after the initial surgery. The research indicates that adjuvant chemotherapy improves progression-free survival (PFS) regardless of how much of the tumor was removed during surgery. This suggests that chemotherapy can be a valuable tool in managing LGGs and preventing their recurrence.

5

What factors can affect survival rates for people diagnosed with WHO grade II gliomas?

Several factors can influence survival rates in individuals with WHO grade II gliomas. Male patients and older patients tend to experience poorer survival rates. Also, patients with poorer performance status at the time of diagnosis have reduced survival outcomes. Tumors involving multiple lobes of the brain are associated with poorer survival compared to those confined to a single lobe, and Astrocytoma histology is linked to poorer survival outcomes compared to other LGG subtypes like oligodendroglioma and oligoastrocytoma.

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