E-ISSN: 1019-5157
ISSN: 2651-5024
Research
The Impact of Extended Adjuvant Temozolomide Beyond the Standard Six Cycles in Newly Diagnosed Glioblastoma
Gul Kanyilmaz✉ ,
Pantea Bayatfard ,
Mehmet Koc ,
Gozde Yazici ,
Berrin Yavuz Benli ,
Faruk Zorlu ,
Meryem Aktan
DOI: 10.5137/1019-5149.JTN.50070-25.3
Article in Press
Corresponding Author:
Gul Kanyilmaz (drgulgun@yahoo.com)
Abstract
Aim
The results regarding the use of more than six courses of adjuvant temozolomide (TMZ) in glioblastoma remain controversial. In the current study, we focused on comparing the survival outcomes of patients treated with the standard six courses of adjuvant TMZ and those treated with extended courses of adjuvant TMZ (more than six courses).
Material and Methods
The patients who were treated with a diagnosis of glioblastoma and who received postoperative partial brain radiotherapy with concomitant TMZ and followed by at least six courses of adjuvant TMZ, between 1999 and 2021, were retrospectively evaluated.
Results
Of 350 patients screened, 186 met the inclusion criteria. Among them, 142 (76%) received six cycles of adjuvant TMZ, while 44 (24%) received extended treatment. The median overall survival (OS) was 19.9 months (95% CI, 17.522.3) in the standard group versus 28.4 months (95% CI, 22.234.6) in the extended group (p=0.10). Median progression-free survival (PFS) was 19.5 months (95% CI, 17.221.8) versus 26.3 months (95% CI, 20.232.3), respectively (p=0.18). However, grade 34 hematologic toxicity was significantly more frequent in the extended group (23% vs. 5%, p=0.001).
Conclusion
This study shows that extended adjuvant TMZ administration beyond the standard six cycles was not associated with a statistically significant survival benefit, but was correlated with a substantially higher rate of severe hematologic toxicity (23% vs. 5%, p=0.001).
The results regarding the use of more than six courses of adjuvant temozolomide (TMZ) in glioblastoma remain controversial. In the current study, we focused on comparing the survival outcomes of patients treated with the standard six courses of adjuvant TMZ and those treated with extended courses of adjuvant TMZ (more than six courses).
Material and Methods
The patients who were treated with a diagnosis of glioblastoma and who received postoperative partial brain radiotherapy with concomitant TMZ and followed by at least six courses of adjuvant TMZ, between 1999 and 2021, were retrospectively evaluated.
Results
Of 350 patients screened, 186 met the inclusion criteria. Among them, 142 (76%) received six cycles of adjuvant TMZ, while 44 (24%) received extended treatment. The median overall survival (OS) was 19.9 months (95% CI, 17.522.3) in the standard group versus 28.4 months (95% CI, 22.234.6) in the extended group (p=0.10). Median progression-free survival (PFS) was 19.5 months (95% CI, 17.221.8) versus 26.3 months (95% CI, 20.232.3), respectively (p=0.18). However, grade 34 hematologic toxicity was significantly more frequent in the extended group (23% vs. 5%, p=0.001).
Conclusion
This study shows that extended adjuvant TMZ administration beyond the standard six cycles was not associated with a statistically significant survival benefit, but was correlated with a substantially higher rate of severe hematologic toxicity (23% vs. 5%, p=0.001).
Keywords
Glioblastom
Radiotherapy
Temozolomide
Survival outcomes