Chemotherapy of high-grade gliomas: beginning of a new era or the end of the old?

Validation of neuroradiologic response assessment in gliomas: measurement by RECIST, two-dimensional, computer-assisted tumor area, and computer-assisted tumor volume methods

Significant limitations are associated with the use of standard radiographic measurements as indicators of response in glioma therapy trials. The Response Evaluation Criteria in Solid Tumors (RECIST) were recently introduced in an attempt to standardize and simplify assessment of response to treatment in cancer clinical trials. However, their applicability in gliomas has been assessed in only a very small number of patients. Our aim was to validate radiographic response assessment in newly diagnosed glioma patients. Sixty-seven newly diagnosed glioma patients participating in nine North Central Cancer Treatment Group glioma trials were included; 565 MRI scans were analyzed. All scans were performed with the same technique. Kappa statistics were calculated to determine agreement between assessment methods. Cox proportional hazards analyses and time-dependent Cox models were used to assess the association between different measurement methods and overall survival. Results showed agreement between the one-dimensional (1D) and two-dimensional (2D) measurements both for T2 images and for gadolinium-enhanced images. Comparison of duration of response and time to progression as assessed by eight different methods showed similarity in response assessments by 1D, 2D, area, and volume gadolinium measurements. In contrast, time to progression was significantly shorter when assessed by 1D-T2 or 2D-T2 images as compared to area-T2 or volume-T2 images. This set of data indicates that RECIST could be used instead of 2D imaging for response assessment in newly diagnosed glioma trials. Overall, responses as determined by any tumor measurement method did not correlate with patient survival for either enhancing or nonenhancing tumors, although the small number of responders limits definitive conclusions. Time-dependent Cox models demonstrated that, in contrast to the case of nonenhancing tumors, progression as determined by 1D, 2D, area, and volume measurements in gadolinium-enhanced images was predictive of survival of patients with enhancing tumors.

Neoadjuvant phase II multicentre study of new agents in patients with malignant glioma after minimal surgery. Report of a cohort of 187 patients treated with temozolomide

BACKGROUND

The aim of this study was to assess the efficacy of new agents in patients with malignant glioma in a neoadjuvant setting not confounded by surgery. The first study of neoadjuvant temozolomide aimed to provide a benchmark for future evaluation of new treatments.

PATIENTS AND METHODS

This was a multicentre phase II study of chemotherapy in patients with histologically verified glioblastoma multiforme (GBM) and anaplastic astrocytoma (AA) who had undergone biopsy alone. Patients were planned to receive two cycles of temozolomide at 200 mg/m(2) orally daily for 5 days at a 28-day interval prior to radiotherapy. Response was assessed by two central observers on pre- and post-chemotherapy enhanced scans using bi-dimensional criteria and as progression-free survival (PFS) at the time of second assessment prior to radiotherapy. Withdrawal from the study due to worsening clinical condition was, in the absence of second imaging, assessed as progressive disease. Survival and quality of life (QOL) were secondary endpoints.

RESULTS

Between August 1999 and June 2002, 188 patients from 15 UK and two Italian centres were entered into the study and 187 were analysed. Overall, 162 patients were assessable for response; seven had partial and 25 had minimal response. The objective response rate was 20% [95% confidence interval (CI) 14-26%] and PFS prior to commencing radiotherapy was 64% (95% CI 57-72%). The median survival was 10 months, and 1-year survival 41%. The median survival of responders was 16 months compared to 3 months in patients with progressive disease (P <0.001 on multivariate analysis).

CONCLUSION

The phase II study design of primary chemotherapy in patients with malignant glioma following biopsy alone is feasible and provides as objective a method of assessment of efficacy as is currently available. The baseline data on temozolomide provide a benchmark for assessment of efficacy of other agents and combinations.

Review of microdialysis in brain tumors, from concept to application: first annual Carolyn Frye-Halloran symposium

In individuals with brain tumors, pharmacodynamic and pharmacokinetic studies of therapeutic agents have historically used analyses of drug concentrations in serum or cerebrospinal fluid, which unfortunately do not necessarily reflect concentrations within the tumor and adjacent brain. This review article introduces to neurological and medical oncologists, as well as pharmacologists, the application of microdialysis in monitoring drug metabolism and delivery within the fluid of the interstitial space of brain tumor and its surroundings. Microdialysis samples soluble molecules from the extracellular fluid via a semipermeable membrane at the tip of a probe. In the past decade, it has been used predominantly in neurointensive care in the setting of brain trauma, vasospasm, epilepsy,and intracerebral hemorrhage. At the first Carolyn Frye-Halloran Symposium held at Massachusetts General Hospital in March 2002, the concept of microdialysis was extended to specifically address its possible use in treating brain tumor patients. In doing so we provide a rationale for the use of this technology by a National Cancer Institute consortium, New Approaches to Brain Tumor Therapy, to measure levels of drugs in brain tissue as part of phase 1 trials.

Second-line chemotherapy with dacarbazine and fotemustine in nitrosourea-pretreated patients with recurrent glioblastoma multiforme

The aim of this study was to assess the efficacy and toxicity of a combination of dacarbazine (D) and fotemustine (F) administered to a homogenous group of patients with recurrent or progressive glioblastoma multiforme (GBM). Thirty-one patients with computed tomography or magnetic resonance imaging scan evidence of recurrent or progressive GBM after first-line chemotherapy with nitrosoureas as well as radiation therapy were given a combination of D (200 mg/m2) and F (100 mg/m2). At 30 min after termination of D administration, F was given over 60 min. Treatment was performed in an outpatient setting every 21 days. A total of 140 cycles (range 1-12 cycles; median 4 cycles) was administered. One partial response (3%) lasting for 11 weeks was observed. Sixteen (52%) patients reached stable disease lasting between 7 and 94 weeks. Median survival from start of the D/F combination was 45 (range 10-150) weeks. Median time to progression was 17 (3-101) weeks for all patients. Major toxicity was myelosuppression resulting in exclusion from study in seven (23%) patients [due to thrombocytopenia common toxicity criteria (CTC) grade 2 persisting longer than 3 weeks in three patients, due to thrombocytopenia CTC grade >/=3 in three and due to leukopenia CTC grade 3 in one patient]. No other toxicity than alopecia occurred. We conclude that the D/F combination is a well-tolerated second-line regimen and can be administered in a complete outpatient setting. D/F shows efficacy even in nitrosourea-pretreated patients and justifies further investigation.

A retrospective analysis of postradiation chemotherapy in 133 patients with glioblastoma multiforme

The impact on survival of postradiation nitrosourea-containing chemotherapy (CHT) in patients with glioblastoma multiforme (GM) was analyzed retrospectively in 133 patients who completed the planned radiotherapy out of 173 observed cases. Thirty-five patients were < 50 years old, 89 were males, 20 had performance status (PS) < 70 and 72 > or = 70. Surgery was followed by radiotherapy in all cases (50-60 Gy in 95 patients, 61-70 Gy in 38 patients). At the end of radiotherapy, 43 patients received CHT, whereas 90 patients did not receive further therapy. At univariate analysis, age < 50 years, feminine gender, subtotal or total resection, radiotherapy doses > 60 Gy, and CHT had an independent prognostic value. Our results suggest that chemotherapy improves 2-year survival rates from 12% to 28% in GM. The sequence of treatment, new drugs, and combinations should be further explored.

Carboplatin and etoposide for recurrent malignant glioma following surgical and radiotherapy failure: A clinical study conducted at the Northern Israel Oncology Center

BACKGROUND AND OBJECTIVES

We conducted a phase II study using carboplatin and etoposide on patients with recurrent malignant glioma to investigate tumor response.

METHODS

From January 1995 to March 1997, 21 patients with recurrent malignant glioma were treated with a carboplatin (300 mg/m(2), day 1)/etoposide (100 mg/m(2), days 1-3) regimen every 3-4 weeks. The following radiologic parameters were evaluated: tumor size, central lucency, degree of contrast enhancement, and mass effect. No patient had received chemotherapy previously. Dose escalation corresponded to hematologic tolerance and to general and neurologic performance status. Most patients were treated postoperatively with involved field radiotherapy followed by a boost to the tumor area, as defined on the presurgery computed tomography scan or on magnetic resonance imaging. Mean interval to introduction of chemotherapy was 8.8 months (range, 7-36 months). Patients received a mean of four cycles [range, 2-8 cycles].

RESULTS

Only 2 patients showed moderate radiological response, while 12 patients died of progressive disease. Mean time to progression following discontinuation of chemotherapy was 5.8 months (range, 1-11 months). The other patients survived with persistent disease and are being treated palliatively. Toxicity was manageable (1, neutropenic sepsis; 1, thrombocytopenia (45,000/mm(3)); 2, temporarily elevated transaminase level; 2, steroid-induced erosive gastritis).

CONCLUSIONS

This phase II regimen proved to be ineffective in recurrent malignant glioma. Further studies incorporating innovative drug regimens and schedules are warranted. J. Surg. Oncol., 1999;71:167-170.

Gossypol treatment of recurrent adult malignant gliomas

Gossypol, a polyphenolic compound which depletes cellular energy by inhibition of several intracellular dehydrogenases, has been shown to have antiproliferative activity against human glial tumor cell lines in vitro and in nude mouse xenografts. Human trials of gossypol as a male contraceptive have demonstrated safety of long-term administration. We studied the activity of Gossypol 10 mg PO bid in 27 patients with pathologically confirmed glial tumors which had recurred after radiation therapy. Fifteen patients had glioblastoma, 11 patients anaplastic astrocytoma, 1 patient relapsed low grade glioma. Response was assessed every 8 weeks using CT/MRI scan and clinical criteria including decadron requirement. Treatment was continued until disease progression. Two patients had partial response (PR); 4 had stable disease for 8 weeks or more. One patient maintained a PR with improved KPS for 78 weeks. The other had a PR lasting 8 weeks. Toxicity was mild: 2 heavily pretreated patients had mild thrombocytopenia, 5 patients developed hypokalemia, 3 patients developed grade 2 hepatic toxicity and peripheral edema. Gossypol levels measured by HPLC did not correlate with response or toxicity in this study. We conclude that gossypol is well tolerated and has a low, but measurable, response rate in a heavily pretreated, poor-prognosis group of patients with recurrent glioma. The presumed novel mechanism of action, lack of significant myelosuppression, and activity in patients with advance glioma support further study of gossypol as an antineoplastic agent.

Thallium-201 SPECT as response parameter for PCV chemotherapy in recurrent glioma

Combination chemotherapy with procarbazine, CCNU and vincristine (PCV) may be effective in patients with recurrent glioma. Response monitoring is mandatory, but radiological response evaluation is often difficult. We evaluated Thallium-201 (201Tl) SPECT as a response parameter in ten patients treated with intensive PCV chemotherapy for recurrent glioma. 201Tl-SPECT studies showed early changes (decreasing volume and intensity) in nine patients and these changes were more pronounced than radiological findings. 201Tl-SPECT results after completion of chemotherapy seemed to correlate with clininal findings during follow up. We conclude that 201Tl-SPECT may contribute to the assessment of response in patients treated with PCV chemotherapy for recurrent glioma.