Impact of Extended Adjuvant Temozolamide Beyond 6 Months in the Management of Glioblastoma Patients

Objectives: Our study aimed to assess the benefit of prolonging adjuvant temozolomide (TMZ) therapy beyond 6 cycles in glioblastoma multiform patients. Materials and Methods: The medical records of 329 patients in 2 cancer centers in Egypt were reviewed from January 2008 to December 2018 who were diagnosed with diffuse gliomas. Data were collected on patient demographics, presenting complaints, tumor size, treatment modalities (extent of surgery, radiotherapy dose and technique, concomitant TMZ, and the number of adjuvant TMZ cycles), and reported adverse events. Results: In the studied cohort, 105 patients were treated with adjuvant TMZ, 33 patients received <6 cycles (TMZL), 41 patients received the standard 6 cycles (TMZS), and 31 patients received >6 cycles (TMZE). Our results showed the median overall survival in the TMZL arm was 8.47 months compared with 15.83 months in the TMZS arm and 27.33 months in the TMZE arm (P < 0.001). Furthermore, a median progression-free survival of 6.35 months was reported in the TMZL group versus, 12.7 and 22.90 months in (TMZS) and (TMZE) groups, respectively(P < 0.001). In the multivariate analysis, the extended adjuvant TMZ with a hazard ratio of 3.106 (95% CI: 2.43-14.46; P < 0.001) was statistically significantly associated with a better outcome. Conclusions: Extended adjuvant TMZ therapy beyond 6 cycles may significantly improve the progression-free survival and overall survival in patients with glioblastoma multiform.