Bromodeoxyuridine labeling index in glioblastoma multiforme: Relation to radiation response, age, and survival

Purpose: Various measures of the rate of tumor cell proliferation have been found to predict survival in patients with intracerebral gliomas. We correlated the bromodeoxyuridine labeling index (BrdUrd LI) with the response to radiation therapy, survival, and known prognostic factors in a series of patients with glioblastoma multiforme (GM) to test its utility as a prognostic factor. Methods and Materials: The BrdUrd LI was determined in 200 newly diagnosed intracranial GMs. Age and sex were known for all patients. The response to radiation therapy was determined in 116 patients by comparing neuroimaging studies obtained before and after external beam radiation therapy, Survival was analyzed in 64 patients who were treated according to two consecutive prospective clinical protocols. Results: The median BrdUrd LI was 6.5% (mean, 7.2%; range, 1.1-25.4%). The BrdUrd LI did not correlate significantly with age, sex, radiation response, or survival, Age and Karnofsky performance score were independent prognostic factors in our cohort. Conclusion: The proliferative rate as measured by BrdUrd LI was not a prognostic factor in our GM cohort, The BrdUrd LI did not correlate significantly with known prognostic factors in GM. There was no significant relationship between the BrdUrd LI and radiation response.