Phase II trial of procarbazine, lomustine, and vincristine as initial therapy for patients with low-grade oligodendroglioma or oligoastrocytoma: efficacy and associations with chromosomal abnormalities

Low-grade gliomas in adults

Adult patients with a magnetic resonance scan suggestive of a supratentorial low-grade glioma should generally undergo at least a stereotactic biopsy to confirm the diagnosis and rule out an anaplastic glioma or a non-neoplastic lesion. Early tumor treatment should be given to patients with newly diagnosed low-grade gliomas who are over age 50 years, those who have headaches or neurologic deficits other than seizures, or those whose neuroimaging studies show tumor growth or mass effect. For younger patients presenting with seizures and no other neurologic symptoms, it is reasonable to defer therapy until there is clinical or radiographic tumor progression. When it is judged that intervention is necessary, patients should undergo the maximal surgical tumor resection, which preserves or improves neurologic function. For younger (<50 years) astrocytoma patients with a good tumor resection, radiation may be deferred until tumor progression. Early radiation should be given to astrocytoma patients who are older than 50 years of age at diagnosis (regardless of the type of surgery) or to younger patients who are judged to require early intervention but who are not candidates for aggressive surgical resection. The radiation dose for low-grade glioma should be 4500 to 5000 cGy, preferably with three-dimensional conformal ports. The same guidelines for management apply to patients with low-grade oligodendroglioma or oligoastrocytoma, except that chemotherapy is a reasonable alternative to radiation when it is judged that treatment other than surgical resection is required.

Chimiothérapie néoadjuvante dans les astrocytomes fibrillaires de grade II symptomatiques non opérables de l’adulte

We collected 6 case-reports of symptomatric non removable low grade fibrillary astrocytoma of adults treated with a procarbazine-CCNU-vincristine chemotherapy regimen. All patients had drug-resistant epilepsy but brain imaging was stable. Total gross resection was rejected because of Volume or tumor location. After 4 to 7 cycles of chemotherapy, 2 patients had partial response and one minor response on brain MRI. All of them were seizure-free. Progression free survival was not reached at 5 Years. Up-front chemotherapy for low-grade astrocytomas may be useful and has to be prospectively evaluated.

Can chemotherapy replace radiotherapy in low-grade gliomas? Time for randomized studies

For the last three decades surgery and radiotherapy have been the mainstay of treatment for patients with low-grade gliomas, despite a lack of support from randomized controlled trials. Recent developments in our knowledge of low-grade tumor chemosensitivity and the approval of temozolomide for treatment of gliomas have led to increased interest in chemotherapy for treating low-grade gliomas. Despite challenges, including response assessment and appropriate patient selection, several phase II studies investigating chemotherapeutic treatment of low-grade gliomas have yielded promising results. Although most of these phase II studies are of limited sample size, they have shown that chemotherapy might induce clinically relevant responses and disease stabilization in patients with low-grade gliomas. As expected, low-grade oligodendroglioma is sensitive to chemotherapy, but responses were also seen in astrocytic tumors. Randomized, controlled studies should be conducted to determine the clinical significance of responses observed in phase II studies and to assess time to progression. Two randomized, controlled studies are currently investigating chemotherapy in the treatment of low-grade gliomas. Although it will take years before the data are available, these studies will help define the role of chemotherapy in the treatment of low-grade gliomas. Perhaps then we can answer the question, can chemotherapy replace radiotherapy in low-grade gliomas?

Prognostic factors for low-grade gliomas

Low-grade gliomas are a heterogenous group of diseases characterized by relatively slow-growing primary brain tumors of astrocytic and/or oligodendroglial origin. Many patients present with easily controlled seizures and remain stable for years, whereas others progress rapidly to higher-grade tumors. Several studies have retrospectively investigated tumor-, patient-, and treatment-related prognostic factors in this patient population. Tumor histology, grade, location, contrast enhancement, and molecular markers have been identified as prognostic factors for survival. Likewise, patient age, performance status, and seizure history are patient-dependent prognostic factors. However, although patients who undergo surgical resection and receive adjuvant radiotherapy tend to have improved survival, treatment-dependent prognostic factors have yet to be definitively identified. Recursive partitioning and multivariant analyses have identified a class of patients with good prognosis. Younger patients with good performance status, non-contrast-enhancing tumors (<5 cm), and tumors of oligodendroglial or mixed-oligoastrocytic subtype have improved survival. The European Organisation for Research and Treatment of Cancer has recently developed a prognostic score based on identified prognostic factors to assist in the management of low-grade gliomas. For patients with a favorable (low-risk) score, treatment with radiotherapy or chemotherapy treatment should be withheld until tumor progression. For patients with a high-risk score, treatment at diagnosis may be indicated. However, other than surgery, the optimal types and sequence of therapies are not yet established. Improvements in defining prognostic factors will assist in low-grade glioma management.

Phase II study of primary temozolomide chemotherapy in patients with WHO grade II gliomas

BACKGROUND

The aim of this study was to assess the efficacy of temozolomide in patients with World Health Organisation (WHO) grade II gliomas treated with surgery alone using imaging and clinical criteria.

PATIENTS AND METHODS

Thirty patients with histologically verified WHO grade II gliomas (17 astrocytoma, 11 oligodendroglioma, two mixed oligoastrocytoma) following surgery 2-104 months (median 23 months) after initial diagnosis received temozolomide 200 mg/m(2)/day for 5 days, on a 28-day cycle, for a maximum of 12 cycles or until tumour progression. Median age was 40 years (range 25-68 years). Median follow-up from entry into the study was 3 years [range 23-47 months (for patients alive)]. Objective response was assessed by 3-monthly magnetic resonance imaging and monthly health-related quality of life (HQoL) and clinical assessment. Tumour size was measured as the high signal intensity area on fluid attenuated inversion recovery sequences. Responses were assessed using change in the product of two perpendicular diameters as complete response (CR), partial response (PR), minimal response (MR), stable disease (SD) and progressive disease (PD).

RESULTS

Twenty-nine of 30 patients entered into the study were evaluable for response. Three patients had a PR, 14 MR, 11 SD and one PD. Twenty-four patients received 12 cycles of chemotherapy. Of 29 evaluable patients, three discontinued after four, five and six cycles and two after 10 cycles. Nine patients progressed (three during chemotherapy-one PD and two initial SD-and six after completion of chemotherapy); five had evidence of transformation. The 3-year progression-free survival was 66%. Five patients died; the actuarial 3-year survival was 82%. Ninety-six per cent of patients with impaired HQoL had improvement in at least one HQoL domain. There was improvement in 115 of the 207 domains (56%). Fifteen of 28 patients (54%) with epilepsy had reduction in seizure frequency, of whom six became seizure free. Six patients had transient grade III/IV haematological toxicity (11 episodes; 3.5%).

CONCLUSIONS

Temozolomide has single-agent activity in patients with WHO grade II cerebral glioma, with modest improvement in quality of life and improvement in epilepsy control. On present evidence, temozolomide cannot be considered as primary therapy without formal comparison with other treatment modalities.

Temozolomide chemotherapy for progressive low-grade glioma: clinical benefits and radiological response

BACKGROUND

The optimal treatment for low-grade glioma (LGG) is still controversial. Recent data indicate a potential influence of chemotherapy on the natural evolution of these tumors, allowing for the deferral of more aggressive therapies.

PATIENTS AND METHODS

Forty-three patients affected with LGG (29 astrocytoma, four oligodendroglioma and 10 mixed oligo-astrocytoma) were treated with temozolomide (TMZ) at the time of documented clinical and radiological progression. McDonald's response criteria were utilized to evaluate TMZ activity. Thirty patients (69.7%) had previously received radiotherapy; 16 (37.2%) had received prior chemotherapy. Clinical benefit was evaluated measuring seizure control, reduction in steroid dose and modification of Karnofsky performance status and Barthel index. Quality of life was assessed with the QLQ-C30 questionnaire.

RESULTS

We observed a complete response in four patients, 16 partial responses, 17 stable disease (with four minor response) and six progressive disease. Median duration of response was 10 months [95% confidence interval (CI) 8-12], with a 76% rate of progression free survival (PFS) at 6 months, and a 39% rate of PFS at 12 months. A relevant clinical benefit was observed particularly in patients presenting epilepsy.

CONCLUSIONS

The high response rate of 47% (95% CI 31% to 61%) confirms that TMZ chemotherapy is a valid option in the treatment of progressive LGG. The present preliminary results seem interesting and warrant further evaluation of TMZ clinical activity in a larger series of progressive LGG.