Abstract 354P
Background
Maximum safe surgical resection followed by adjuvant chemoradiation and temozolomide chemotherapy is the current standard of care in the management of newly diagnosed high-grade glioma. However, there are controversies about the optimal number of adjuvant temozolomide cycles. This study aimed to compare the survival benefits of 12 cycles against 6 cycles of adjuvant temozolomide adults with newly diagnosed high grade gliomas.
Methods
Adult patients with newly diagnosed high-grade gliomas, and a Karnofsky performance status >60%, were randomized to receive either 6 cycles or 12 cycles of adjuvant temozolomide. Patients were followed-up for assessment of overall survival (OS) and disease-free survival (DFS) by brain MRI every 3 months within the first year after treatment and thereafter every six months.
Results
A total of 100 patients (6 cycles, 50; 12 cycles, 50) were entered (Table). Table: 354P
The demographic characteristics of the patients at baseline
| Variable | 6-cycle group n (%) | 12-cycle group n (%) | p-value |
| Headache | 35 (76.1) | 33 (67.3) | .345 |
| Seizure | 16 (34.8) | 14 (28.6) | .515 |
| Paresthesia | 10 (21.7) | 18 (36.7) | .213 |
| Focal neurologic deficit | 16 (34.8) | 18 (36.7) | .834 |
| Midline shift | 29 (63) | 31 (63.3) | .982 |
| Type of surgery | |||
| Gross total resection | 8 (17.4) | 9 (18.4) | .436 |
| Subtotal resection | 28 (60.9) | 24 (49) | |
| Biopsy only | 10 (21.7) | 16 (32.7) | |
| Histology | |||
| Glioblastoma multiform | 37 (80.4) | 40 (81.6) | .882 |
| Anaplastic astrocytoma | 9 (19.6) | 9 (18.4) | |
| CTV (cc, median) | 244.7 | 263 | .461 |
The rate of treatment completion in 6 cycles and 12 cycles group were 91.3% and 55.1%, respectively. With a median follow-up of 16.5 months, the 12-, 24-, and 36-month OS rates in 6 cycles and 12 cycles groups were 82.6% vs 78.8%, 55.5% vs 63.5%, and 44.4% vs 54.4%, respectively (p=.976). The 12-, 24-, and 36-month DFS rates in 6 cycles and 12 cycles groups were 72.1% vs 57.7%, 42.6% and 34.3, and 39.6% vs 30.8%, respectively (p=.276).
Conclusions
Patients with newly diagnosed high-grade gliomas treated with the adjuvant temozolomide after maximum safe surgical resection and adjuvant chemoradiation do not benefit from increasing the number of cycles of adjuvant temozolomide beyond 6 cycles.
Clinical trial identification
IRCT20160706028815N3.
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Mashhad University of Medical Sciences.
Disclosure
All authors have declared no conflicts of interest.