Purpose: To evaluate toxicity and efficacy of the combination of lomustine, temozolomide (TMZ) and involved-field radiotherapy in patients with newly diagnosed glioblastoma (GBM). Patients and Methods: Thirty-one adult patients (median Karnofsky performance score 90; median age, 51 years) accrued in two centers received involved-field radiotherapy (60 Gy in 2-Gy fractions) and chemotherapy with lomustine 100 mg/m² (day 1) and TMZ 100 mg/m²/d (days 2 to 6) with individual dose adjustments according to hematologic toxicity. Results: A median of five courses (range, one to six courses) were delivered. WHO grade 4 hematotoxicity was observed in five patients (16%) and one of these patients died as a result of septicemia. Nonhematologic toxicity included one patient with WHO grade 4 drug-induced hepatitis (leading to discontinuation of lomustine and TMZ) and one patient with WHO grade 2 lung fibrosis (leading to discontinuation of lomustine). The progression-free survival (PFS) rate at 6 months was 61.3%. The median PFS was 9 months (95% CI, 5.3 to 11.7 months), the median overall survival time (MST) was 22.6 months (95% CI, 12.5 to not assessable), the 2-year survival rate was 44.7%. O⁶-Methylguanine–DNA methyltransferase (MGMT) gene-promoter methylation in the tumor tissue was associated with longer PFS (P = .014, log-rank test) and MST (P = .037). Conclusion: The combination of lomustine, TMZ, and radiotherapy had acceptable toxicity and yielded promising survival data in patients with newly diagnosed GBM. MGMT gene-promoter methylation was a strong predictor of survival.

Objective: This is the final report of a phase III randomized study to evaluate whole-brain radiotherapy (WBRT) in primary therapy of primary CNS lymphoma (PCNSL) after a median follow-up of 81.2 months. Methods: Patients with newly diagnosed PCNSL were randomized to high-dose methotrexate (HDMTX)–based chemotherapy alone or followed by WBRT. We hypothesized that the omission of WBRT would not compromise overall survival (OS; primary endpoint), using a noninferiority design with a margin of 0.9. Results: In the per-protocol population (n = 320), WBRT nonsignificantly prolonged progression-free survival (PFS) (median 18.2 vs 11.9 months, hazard ratio [HR] 0.83 [95% confidence interval (CI) 0.65–1.06], p = 0.14) and significantly PFS from last HDMTX (25.5 vs 12.0 months, HR 0.65 [95% CI 0.5–0.83], p = 0.001), but without OS prolongation (35.6 vs 37.1 months, HR 1.03 [95% CI 0.79–1.35], p = 0.82). In the intent-to-treat population (n = 410), there was a prolongation by WBRT of both PFS (15.4 vs 9.9 months, HR 0.79 [95% CI 0.64–0.98], p = 0.034) and PFS from last HDMTX (19.4 vs 11.9 months, HR 0.72 [95% CI 0.58–0.89], p = 0.003), but not of OS (32.4 vs 36.1 months, HR 0.98 [95% CI 0.79–1.26], p = 0.98). Conclusion: Although the statistical proof of noninferiority regarding OS was not given, our results suggest no worsening of OS without WBRT in primary therapy of PCNSL. Classification of evidence: This study provides Class II evidence that in PCNSL HDMTX-based chemotherapy followed by WBRT does not significantly increase survival compared to chemotherapy alone. The study lacked the precision to exclude an important survival benefit or harm from WBRT.

The DNA repair protein O⁶‐methylguanine‐DNA methyltransferase (MGMT) plays a pivotal role in alkylating drug resistance. Here, we determined MGMT activity in primary and recurrent glioblastomas (GBM, WHO grade IV) of patients who received radiation therapy (RT) or RT plus chemotherapy with alkylating agents (temozolomide, chloroethylnitrosoureas). The mean MGMT activity of untreated GBM was 37 ± 45 (range 0–205) fmol/mg proteins. In the 1st, 2nd and 3rd recurrences, MGMT activity increased from 66 ± 50 (13–194) to 68 ± 44 (14–143) and 182 ± 163 (64–423) fmol/mg protein, respectively. Comparing patients who received RT only with RT plus chemotherapy, a significant increase of MGMT in 1st recurrences was only found after treatment with RT plus chemotherapy, indicating either selection of MGMT expressing cells or induction of the MGMT gene by alkylating agents. The p53 status was not significantly related to the MGMT expression level, although a trend for lower MGMT activity in p53 positively stained tumors was observed. Patients expressing MGMT activity of ≤30 fmol/mg protein in the pretreatment tumor had a significant better therapeutic response than patients expressing MGMT above this level, which was shown by Kaplan‐Meyer curves and the recurrence free interval after primary tumor resection. In patients who received RT only, this correlation was not found. The data revealed a threshold of MGMT expression (30 fmol/mg protein) below which patients respond better to alkylating agents. Therefore, determination of MGMT activity in the primary tumor appears to be useful in predicting the outcome of GBM therapy.