Clinical, pathological and therapeutic aspects of oligodendroglioma

Efficacy and feasibility of standard procarbazine, lomustine, and vincristine chemotherapy in anaplastic oligodendroglioma and oligoastrocytoma recurrent after radiotherapy

BACKGROUND

To the authors' knowledge, there is a scarcity of accurate data regarding the feasibility of standard chemotherapy with procarbazine, lomustine, and vincristine (PCV) in a homogeneous series of patients with primary anaplastic oligodendroglioma (AO) and oligoastrocytoma (AOA) that was recurrent after surgery and standard radiotherapy. The aim of the current study was to evaluate the overall response rate, toxicity, and time to progression (TTP) with the use of standard PCV in this setting.

METHODS

Between November 1994 and September 2000, 37 patients were enrolled in the current study. Of these, 23 had AO (62%) and 14 had AOA (38%). All patients received standard PCV comprised of lomustine (110 mg/m2) on Day 1, procarbazine (60 mg/m2) on Days 8-21, and vincristine (1.4 mg/m2, maximum total 2 mg) on Days 8 and 29. Cycles were repeated every 6 weeks.

RESULTS

There were 11 complete responses (CR; 29.7%) and 11 partial responses (PR; 29.7%) reported and 8 patients had stable disease (SD; 21.6%). The response rate was higher in patients with AO compared with patients with AOA (77.2% vs. 22.7%; P = 0. 02). The median TTP, which was 12.3 months overall, was 30.3 months in patients who achieved a CR, 19.1 months in patients who achieved a PR, and 6.1 months in patients with SD. The median TTP was 18.6 months in AO patients and 6.14 in AOA patients. There were no cases of severe toxicity reported although in 16 patients (43%) who were free of disease progression, PCV was discontinued because of toxicity or inadequate recovery after 2 weeks of delay.

CONCLUSIONS

PCV chemotherapy was reported to achieved a high response rate and TTP but incurred a high risk of persistent toxicity.

Carboplatin and teniposide as third-line chemotherapy in patients with recurrent oligodendroglioma or oligoastrocytoma: a phase II study

BACKGROUND

This study was a phase II study of third-line chemotherapy with carboplatin plus teniposide in patients with recurrent oligodendroglioma.

PATIENTS AND METHODS

Patients with oligodendroglioma progressive or recurrent after surgery, radiotherapy and chemotherapy with PCV (lomustine/procarbazine/vincristine) and temozolomide were treated with 350 mg/m(2) carboplatin on day 1, and 50 mg/m(2) teniposide on days 1-3, every 4 weeks.

RESULTS

Response and toxicity were evaluated in all 23 patients enrolled in the study. Two had partial response [8.6%; 95% confidence interval (CI) 1.8% to 28.6%] and 12 stable disease (52.17%; 95% CI 30% to 73%). Median time to progression was 19 weeks (95% CI 11.4-35.0), and 34.8% of the patients (95% CI 20.0% to 61.0%) had progression-free survival at 6 months. Median survival time was 60.7 weeks (95% CI 39.8 to not achieved) and 51% of the patients (95% CI 33.5% to 79.7%) were alive at 12 months. A total of 103 cycles were administered (on average 4.4 per patient; range 1-9). Toxicity was mild and mainly hematological, with grade 4 neutropenia and grade 4 thrombocytopenia in two (8.6%) and three patients (13%), respectively.

CONCLUSIONS

Although the response rate of combined carboplatin and teniposide chemotherapy in heavily pretreated oligodendroglial tumors is moderate, the toxicity is manageable, and delay of progression in responders or stable patients may still confer a relevant clinical benefit.

Evaluation of gamma knife radiosurgery in the treatment of oligodendrogliomas and mixed oligodendroastrocytomas

Object. Radiosurgery is commonly used for the treatment of patients with glioma. The goal of this study was to evaluate the safety and efficacy of radiosurgery in the management of patients with oligodendrogliomas (ODGs) or mixed oligoastrocytomas (OGAs).

Methods. A retrospective chart review of patients treated between May 1990 and January 2000 identified 18 patients (21 tumors) with either an ODG (10) or a mixed OGA (11) who had undergone radiosurgery. The median patient age was 43 years (range 23–67 years). Sixteen patients had undergone one or more tumor resections before radiosurgery; in two patients biopsy sampling alone had been performed. Tumor grades at the most recent operation were Grade 1 (one), Grade 2 (one), Grade 3 (12), and Grade 4 (seven patients). Seventeen patients had undergone prior radiotherapy; 11 were treated with chemotherapy before radiosurgery, and one had undergone a prior linear accelerator—based radiosurgery treatment. The median tumor volume was 8.2 cm3 (range 1.9–47.7 cm3); the median margin dose was 15 Gy (range 12–20 Gy); and the median maximum dose was 32 Gy (range 24–50 Gy).

In this heterogeneous group, 12 patients died whereas six remain alive. Survival after radiosurgery was 78%, 61%, and 44% at 12, 24, and 48 months, respectively. Factors associated with an improved survival rate included younger age and smaller tumors.

Conclusions. For patients with oligoastroglial tumors that have failed to respond to conventional therapies, radiosurgery may provide some survival benefit. Further study is needed to determine which subpopulation of these patients will have the best chances of enhanced survival from this treatment.

Controversies in the therapy of low-grade glioma: when and how to treat

Treatment of low-grade gliomas is one of the most challenging management dilemmas in neuro-oncology. Young age of onset and low rate of growth theoretically favor minimally invasive treatments. Yet, local recurrence and conversion to malignant glioma are the expected outcome within 4-8 years from diagnosis and impose the use of additional therapies, such as radiotherapy and chemotherapy. Due to low incidence and paucity of randomized trials, the correct timing and dosage of radiotherapy are still controversial, as well as the indications and possible benefits of the administration of cytotoxic drugs. Current concepts and future perspectives in the treatment of low-grade gliomas drawn from recent scientific literature are here summarized and discussed.

Multidisciplinary management of adult anaplastic oligodendrogliomas and anaplastic mixed oligo-astrocytomas

Once thought to be rare, oligodendroglial tumors might actually represent up to 25% of primary glial neoplasms. In recent years, the histologic criteria for the diagnosis of oligodendroglioma have been broadened to include most small cell, monomorphic glial neoplasms. These refinements have led to an increased recognition of oligodendroglial neoplasms, but uniform definitions of pure versus mixed oligodendroglioma as well as the criteria for high-grade (anaplastic) versus low-grade tumors remain elusive. From a prognostic standpoint, the presence of an oligodendroglial component in a malignant glioma predicts longer survivals times for patients treated with surgery, and radiation therapy with or without chemotherapy. High rates of response to PCV (procarbazine, CCNU and Vincristine) chemotherapy also have been noted among patients with anaplastic oligodendroglial neoplasms. Ongoing prospective trials seek to clarify the role of PCV chemotherapy when added to radiation therapy and surgery. In addition, the role of molecular markers as diagnostic aides and guides to therapy and prognosis are being explored for patients with pure and mixed anaplastic oligodendroglial tumors.