Ki-67: a prognostic factor for low-grade glioma?

Area of Science:

• Neuro-oncology
• Cancer research
• Molecular pathology

Background:

• Low-grade gliomas (LGGs) are primary brain tumors with variable prognosis.
• Identifying reliable prognostic markers is crucial for guiding treatment decisions in LGG patients.
• Ki-67, a marker of cellular proliferation, is frequently assessed in tumor tissues.

Purpose of the Study:

• To investigate the prognostic significance of Ki-67 expression in predicting survival and recurrence in 180 low-grade glioma patients.
• To determine if Ki-67 is an independent prognostic factor for cause-specific survival (CSS) and progression-free survival (PFS).

Main Methods:

• Retrospective analysis of 180 low-grade glioma tumor specimens using immunohistochemistry to assess Ki-67 expression.
• Evaluation of both maximal and averaged Ki-67 indexes using semiautomated computer analysis.
• Correlation of Ki-67 levels with clinical outcomes, including CSS and PFS, in relation to age, radiotherapy (RT), and other prognostic factors.

Main Results:

• An average Ki-67 index of >=5% was associated with reduced CSS (p=0.05), and >=10% with poor survival (p=0.009).
• Ki-67 positivity correlated with age, but was not an independent predictor of CSS in multivariate analysis.
• In pediatric patients, Ki-67 negativity predicted 100% 5-year CSS and PFS, while any positivity significantly reduced these outcomes.

Conclusions:

• Ki-67 is a useful predictor of cause-specific survival in low-grade gliomas, particularly in pediatric cases.
• Its prognostic value is not independent and is influenced by factors such as age.
• Ki-67 may aid in selecting pediatric patients for radiotherapy and identifying high-risk patients for clinical trials.