Volume of residual disease as a predictor of outcome in adult patients with recurrent supratentorial glioblastomas multiforme who are undergoing chemotherapy

Object. For patients with recurrent glioblastomas nuiltiforme (GBMs) the prognosis is poor. Although chemotherapy may provide a survival advantage, the role of the extent of tumor resection, or the volume of the residual tumor at the time of recurrence, before instituting chemotherapy, is unclear. This study was designed to assess the response to chemotherapy based on the volume of residual disease (VRD) at the start of treatment in patients with recurrent GBMs. To accomplish this, the authors evaluated a homogeneous group of patients with recurrent GBMs who received the same chemotherapeutic agent. Methods. One hundred nineteen adult patients with recurrent supratentorial GBMs received temozolomide chemotherapy at the time of tumor recurrence. In this cohort the authors analyzed the prognostic significance of volumetrically assessed tumor mass on time to tumor progression (TTP) and survival time (ST). Multivariate analysis demonstrated that the VRD at the beginning of chemotherapy was a statistically significant predictor of both TTP (p < 0.0001) and ST (p < 0.006) when adjusted for the patient's age, performance score, and time from the initial diagnosis. Patients in whom the VRD was less than 10 cm(3) at the start of chemotherapy had a 6-month progression-free survival rate of 32% compared with 8% for patients with a VRD between 10 and 15 cm(3) and 3% for patients with a VRD larger than 15 cm(3). Patients in whom the VRD was smaller than 10 cm(3) had a 1-year survival rate of 37% compared with 9% for patients with a VRD between 10 and 15 cm(3) and 18% for patients with a VRD larger than 15 cm(3). Conclusions. These data indicate that patients with recurrent GBMs who start chemotherapy with a smaller volume (< 10 cm(3)) of residual disease may have a more favorable response to chemotherapy and a more favorable outcome.