Wang, Meihua

2008b Background: Anaplastic oligodendrogliomas, pure (AO) and mixed (AOA), are chemosensitive tumors, especially if co-deleted for chromosomes 1p and 19q, but whether addition of CT to RT prolongs overall survival (OS), is unknown. Methods: In the RTOG 9402 Phase III trial, patients (pts) with AO/AOA were randomly assigned to PCV [procarbazine, CCNU (lomustine) and vincristine] followed by immediate RT vs. immediate RT alone. Early analysis showed no OS benefit for the PCV+RT group but combined therapy was associated with a longer progression-free survival (PFS). It also showed that the finding of 1p/19q co-deletion was associated with a longer OS independent of treatment. The current analysis has a median follow up of 11.3 years (yrs). Results: Two hundred ninety-one patients were randomized, 148 to PCV+RT and 143 to RT. PCV+RT was associated with longer PFS [2.5 vs. 1.7 yrs, hazard ratio (HR) 0.68, 95% confidence interval (CI) (0.53, 0.88), P = 0.003] and the 1p/19q co-deletion with a longer Median Survival Time (MST) [8.7 vs. 2.7 yrs, HR 0.41, 95% CI (0.30, 0.55), P < 0.001]. For the entire cohort, there was no difference in MST by treatment [4.6 yrs for PCV+RT vs. 4.7 yrs for RT, HR 0.79, 95% CI (0.60, 1.04), P = 0.1]. However, patients with 1p/19q co-deleted tumors lived much longer after PCV+RT (n = 59) than after RT (n = 67) [14.7 vs. 7.3 yrs, HR 0.59, 95% CI (0.37, 0.95), P = 0.03]. There was no difference in MST by treatment in pts without the 1p/19q co-deletion [n=137; 2.6 vs. 2.7 yrs, HR 0.85, 95% CI (0.58, 1.23), P = 0.39]. Re-operation rates upon progression were similar between treatment arms in co-deleted pts (43%, PCV+RT vs. 54%, RT) but salvage CT rates were higher in the RT arm [57% vs. 81% (P = 0.04)]. Conclusions: PCV followed by immediate RT was a highly effective therapy for patients with 1p/19q co-deleted AO/AOA. In this setting, 1p/19q co-deletion was both prognostic and predictive, and the early PFS benefit in co-deleted cases was a harbinger of their longer OS. [This work was supported by RTOG grants U10 CA21661 and U10 CA32115, NCCTG grant U10 CA25224, ECOG grants CA17145 and CA21115, SWOG grant CA32102, and CCOP grant U10 CA37422 from the National Cancer Institute (NCI)]

Purpose Patients with 1p/19q codeleted anaplastic oligodendroglial tumors who participated in RTOG (Radiation Therapy Oncology Group) 9402 lived much longer after chemoradiotherapy (CRT) than radiation therapy (RT) alone. However, some patients with noncodeleted tumors also benefited from CRT; survival curves separated after the median had been reached, and significantly more patients lived ≥ 10 years after CRT than RT. Thus, 1p/19q status may not identify all responders to CRT. Patients and Methods Using trial data, we inquired whether an IDH mutation or germ-line polymorphism associated with IDH-mutant gliomas identified the patients in RTOG 9402 who benefited from CRT. Results IDH status was evaluable in 210 of 291 patients; 156 (74%) had mutations. rs55705857 was evaluable in 245 patients; 76 (31%) carried the G risk allele. Both were associated with longer progression-free survival after CRT, and mutant IDH was associated with longer overall survival (9.4 v 5.7 years; hazard ratio [HR], 0.59; 95% CI, 0.40 to 0.86; P = .006). For those with wild-type tumors, CRT did not prolong median survival (1.3 v 1.8 years; HR, 1.14; 95% CI, 0.63 to 2.04; P = .67) or 10-year survival rate (CRT, 6% v RT, 4%). Patients with codeleted mutated tumors (14.7 v 6.8 years; HR, 0.49; 95% CI, 0.28 to 0.85; P = .01) and noncodeleted mutated tumors (5.5 v 3.3 years; HR, 0.56; 95% CI, 0.32 to 0.99; P < .05) lived longer after CRT than RT. Conclusion IDH mutational status identified patients with oligodendroglial tumors who did (and did not) benefit from alkylating-agent chemotherapy with RT. Although patients with codeleted tumors lived longest, patients with noncodeleted IDH-mutated tumors also lived longer after CRT.

Purpose Radiotherapy with concomitant and adjuvant temozolomide is the standard of care for newly diagnosed glioblastoma (GBM). O 6 -methylguanine-DNA methyltransferase (MGMT) methylation status may be an important determinant of treatment response. Dose-dense (DD) temozolomide results in prolonged depletion of MGMT in blood mononuclear cells and possibly in tumor. This trial tested whether DD temozolomide improves overall survival (OS) or progression-free survival (PFS) in patients with newly diagnosed GBM. Patients and Methods This phase III trial enrolled patients older than age 18 years with a Karnofsky performance score of ≥ 60 with adequate tissue. Stratification included clinical factors and tumor MGMT methylation status. Patients were randomly assigned to standard temozolomide (arm 1) or DD temozolomide (arm 2) for 6 to 12 cycles. The primary end point was OS. Secondary analyses evaluated the impact of MGMT status. Results A total of 833 patients were randomly assigned to either arm 1 or arm 2 (1,173 registered). No statistically significant difference was observed between arms for median OS (16.6 v 14.9 months, respectively; hazard ratio [HR], 1.03; P = .63) or median PFS (5.5 v 6.7 months; HR, 0.87; P = .06). Efficacy did not differ by methylation status. MGMT methylation was associated with improved OS (21.2 v 14 months; HR, 1.74; P < .001), PFS (8.7 v 5.7 months; HR, 1.63; P < .001), and response (P = .012). There was increased grade ≥ 3 toxicity in arm 2 (34% v 53%; P < .001), mostly lymphopenia and fatigue. Conclusion This study did not demonstrate improved efficacy for DD temozolomide for newly diagnosed GBM, regardless of methylation status. However, it did confirm the prognostic significance of MGMT methylation. Feasibility of large-scale accrual, prospective tumor collection, and molecular stratification was demonstrated.

Purpose Anaplastic oligodendrogliomas, pure (AO) and mixed (anaplastic oligoastrocytoma [AOA]), are chemosensitive, especially if codeleted for 1p/19q, but whether patients live longer after chemoradiotherapy is unknown. Patients and Methods Eligible patients with AO/AOA were randomly assigned to procarbazine, lomustine, and vincristine (PCV) plus radiotherapy (RT) versus RT alone. The primary end point was overall survival (OS). Results Two hundred ninety-one eligible patients were randomly assigned: 148 to PCV plus RT and 143 to RT. For the entire cohort, there was no difference in median survival by treatment (4.6 years for PCV plus RT v 4.7 years for RT; hazard ratio [HR] = 0.79; 95% CI, 0.60 to 1.04; P = .1). Patients with codeleted tumors lived longer than those with noncodeleted tumors (PCV plus RT: 14.7 v 2.6 years, HR = 0.36, 95% CI, 0.23 to 0.57, P < .001; RT: 7.3 v 2.7 years, HR = 0.40, 95% CI, 0.27 to 0.60, P < .001), and the median survival of those with codeleted tumors treated with PCV plus RT was twice that of patients receiving RT (14.7 v 7.3 years; HR = 0.59; 95% CI, 0.37 to 0.95; P = .03). For those with noncodeleted tumors, there was no difference in median survival by treatment arm (2.6 v 2.7 years; HR = 0.85; 95% CI, 0.58 to 1.23; P = .39). In Cox models that included codeletion status, the adjusted OS for all patients was prolonged by PCV plus RT (HR = 0.67; 95% CI, 0.50 to 0.91; P = .01). Conclusion For the subset of patients with 1p/19q codeleted AO/AOA, PCV plus RT may be an especially effective treatment, although this observation was derived from an unplanned analysis.

Purpose A prior Radiation Therapy Oncology Group (RTOG) clinical trial in anaplastic oligodendroglioma suggested a progression-free survival benefit for procarbazine, lomustine, and vincristine (PCV) chemotherapy in addition to radiation therapy (RT), as have smaller trials in low-grade glioma (LGG). Patients and Methods Eligibility criteria included supratentorial WHO grade 2 LGG, age 18 to 39 years with subtotal resection/biopsy, or age ≥ 40 years with any extent resection. Patients were randomly assigned to RT alone or RT followed by six cycles of PCV. Survival was compared by using the modified Wilcoxon and log-rank tests. Results In all, 251 patients were accrued from 1998 to 2002. Median overall survival (OS) time and 5-year OS rates for RT versus RT + PCV were 7.5 years versus not reached and 63% versus 72%, respectively (hazard ratio [HR]; 0.72; 95% CI, 0.47 to 1.10; P = .33; log-rank P = .13). Median progression-free survival (PFS) time and 5-year PFS rates for RT versus RT + PCV were 4.4 years versus not reached and 46% versus 63%, respectively (HR, 0.6; 95% CI, 0.41 to 0.86; P = .06; log-rank P = .005). OS and PFS were similar for all patients between years 0 and 2. After 2 years, OS and PFS curves separated significantly, favoring RT + PCV. For 2-year survivors (n = 211), the probability of OS for an additional 5 years was 74% with RT + PCV versus 59% with RT alone (HR, 0.52; 95% CI, 0.30 to 0.90; log-rank P = .02). Conclusion PFS but not OS was improved for adult patients with LGG receiving RT + PCV versus RT alone. On post hoc analysis, for 2-year survivors, the addition of PCV to RT conferred a survival advantage, suggesting a delayed benefit for chemotherapy.