Concurrent and adjuvant temozolomide-based chemoradiotherapy schedules for glioblastoma. Hypotheses based on two prospective phase II trials.

AIM

To investigate the impact of nonstandard concomitant temozolomide (TMZ) administration in two prospective phase II studies for glioblastoma (GBM).

PATIENTS AND METHODS

From October 2000 to June 2008, 104 patients were enrolled in two studies: 25 in RT-TMZ-10.00 and 79 in RT-TMZ-01.04. Adjuvant radiotherapy (RT) was used with a total dose of 59.4 Gy (1.8 Gy/day). Patients received concomitant TMZ (75 mg/m(2)/day) from Monday to Friday during the first and last weeks of RT in the RT-TMZ-10.00 study and from Monday to Friday during all weeks of RT in the RT-TMZ-01.04 trial. Adjuvant TMZ (200 mg/m(2)) was administered for 5 days every 28 days.

RESULTS

Median progression-free (PFS) and overall survival (OS) were 9 and 16 months, respectively, with no significant difference between the two groups (p = 0.5 and 0.14, respectively). The 2- and 5-year OS rates were 32 and 3 %, respectively, and similar to those observed with standard treatment regimens.

CONCLUSION

Our data support the hypothesis that adjuvant TMZ is more important than concomitant chemotherapy (CH) and that RT is the more important element of the concomitant treatment schedule.