By Jill Stein
PARIS, FRANCE -- October 31, 2005 -- The addition of temozolomide to conventional radiotherapy for high-grade glioma prolongs overall survival, according to researchers said here at the 13th Annual Meeting of the European Cancer Conference (ECCO).
Temozolomide is an orally active alkylating agent derived from dacarbazine that has shown a 30% to 40% response rate and a good safety profile.
Mark Beresford, MD, Staff Oncologist, Charing Cross Hospital, London, United Kingdom, and co-workers reviewed the records of 102 patients who underwent radiation therapy for a high-grade glioma during a recent 5-year period.
An earlier randomized trial of combined temozolomide and radiotherapy versus radiotherapy alone involving 573 patients showed a significant increase in median survival of 2.5 months in favor of combined treatment.
"We wanted to see whether the survival advantage could be replicated in standard clinical practice," Dr. Beresford said during a presentation on October 31st.
Radiotherapy was administered to a dose of 60 to 65 Gy in 30 to 37 fractions over 6 weeks. Temozolomide was administered orally at a dose of 75 mg/m2 daily for 6 weeks during radiotherapy, followed by adjuvant temozolomide for six cycles on days 1 through 5 of a 28-day cycle (150 to 200 mg/m2/day).
Of 86 patients with Grade IV gliomas, 57% received combined chemoradiotherapy as the initial treatment, and 43% received radiotherapy alone.
Of the patients treated with adjuvant temozolomide, 17 (35%) completed the six cycles. The median number of treatment cycles was three.
Results showed that the median survival was 13 months in patients who received concomitant temozolomide and radiotherapy versus 8 months in patients treated with radiotherapy alone (P = .029).
Thirty-eight (44%) Grade IV patients received biopsy only, and 48 (56%) underwent maximal debulking procedures. The median survival for patients receiving debulking surgery was 10 months compared with 9.5 months for those receiving biopsy only.
Dr. Beresford cautioned that the study is a retrospective review and thus the choice of radiotherapy alone versus radiotherapy plus temozolomide is open to bias. He emphasized, however, that his group's experience with temozolomide is in line with recently reported data from the European Organisation for Research and Treatment of Cancer and other randomized studies.
The results show that the survival advantage with the addition of temozolomide to standard therapy demonstrated in randomized studies can be repeated in everyday practice, he added.
"We have found temozolomide to be both safe and practical to use in conjunction with radiotherapy for the treatment of glioblastoma multiforme in a UK cancer center, thus giving further support for combined treatment to the standard of care," he said.
[Presentation title: Treatment of Newly-Diagnosed High-Grade Glioma with Concomitant and Adjuvant Temozolomide and Radiotherapy -- UK Experience. Abstract 505]