Lisa M. DeAngelis

Radiation‐induced dementia in patients cured of brain metastases

When a patient with cancer develops a brain metastasis, death is usually imminent, but aggressive treatment in some patients with limited or no systemic disease yields long-term survival. In such patients, delayed deleterious effects of therapy are particularly tragic. We report 12 patients who developed delayed complications of whole brain radiotherapy (WBRT) given as sole treatment (4 patients) or in combination with surgical resection (8 patients). Within 5 to 36 months (median, 14) all patients developed progressive dementia, ataxia, and urinary incontinence causing severe disability in all and leading to death in 7. No patient had tumor recurrence when neurologic symptoms began. Cortical atrophy and hypodense white matter were identified by CT in all. Contrast-enhancing lesions were seen in 3 patients; 2 of the lesions yielded radionecrosis on biopsy. Autopsies on 2 patients revealed diffuse chronic edema of the hemispheric white matter in the absence of tumor recurrence. Corticosteroids and ventriculoperitoneal shunt offered significant but incomplete improvement in some patients. The total dose of WBRT was only 2,500 to 3,900 cGy, but daily fractions of 300 to 600 cGy were employed. We believe that these fractionation schedules, several of which are used commonly, predispose to delayed neurologic toxicity, and that more protracted schedules should be employed for the safe and efficacious treatment of good-risk patients with brain metastases. The incidence of WBRT-induced dementia was only 1.9 to 5.1% in the 2 populations reviewed here; however, this underestimates the incidence because only severely affected patients could be identified from chart review.

Combination Chemotherapy and Radiotherapy for Primary Central Nervous System Lymphoma: Radiation Therapy Oncology Group Study 93-10

PURPOSE Primary CNS lymphoma (PCNSL) is an aggressive primary brain tumor. Cranial irradiation alone rarely results in long-term disease control or prolonged survival. We prospectively studied the use of combination chemotherapy plus cranial irradiation in newly diagnosed patients with PCNSL. PATIENTS AND METHODS We enrolled 102 newly diagnosed, immunocompetent patients with PCNSL; 98 were assessable. Patients first received five cycles of methotrexate 2.5 g/m(2), vincristine, procarbazine, and intraventricular methotrexate (12 mg). Whole-brain radiotherapy (RT) was administered to a total dose of 45 Gy and all patients received high-dose cytarabine after RT. RESULTS Fifty-eight percent of patients with measurable disease had a complete response to preirradiation chemotherapy and 36% had a partial (> 50%) response, for a 94% response rate. Median progression-free survival was 24.0 months and overall survival was 36.9 months. Age was an important prognostic factor; median survival was 50.4 months in patients younger than 60 and only 21.8 months in those aged 60 or older (P <.001). Fifty-three percent of patients had grade 3 or 4 toxicity during induction chemotherapy, half of which was hematologic. However, 12 patients (15%) experienced severe delayed neurologic toxicity, eight of whom died. CONCLUSION This is the first multicenter trial demonstrating improved survival with the combination of chemotherapy plus RT compared with previous reports of RT alone. A high-dose methotrexate-based regimen produced a high response rate before RT was administered. High-dose methotrexate combined with cranial irradiation is an effective therapeutic approach to PCNSL, but neurotoxicity is a delayed risk of this approach.

Treatment for Primary CNS Lymphoma: The Next Step

PURPOSE The use of preradiotherapy (RT) methotrexate (MTX) has improved disease control and survival in patients with primary CNS lymphoma (PCNSL). The reported protocol was designed to optimize and enhance the chemotherapeutic component of treatment. PATIENTS AND METHODS Fifty-two patients were treated with five cycles of high-dose MTX 3.5 g/m(2), procarbazine 100 mg/m(2)/d, and vincristine 1.4 mg/m(2). Thirty patients received whole-brain RT (45 Gy). Twenty-two older patients deferred RT to diminish the risk of delayed neurotoxicity; these patients are compared with 12 older patients who completed the entire treatment regimen. Most patients (n = 35) received high-dose cytarabine after RT. RESULTS Objective response rate to the induction chemotherapy regimen was 90%; overall median survival is 60 months. Grade 3 or 4 myelosuppression was seen in 30 patients, primarily in association with cytarabine; grade 3 nephrotoxicity due to MTX was seen in two patients. Older patients had similar median survival with or without the addition of RT: 32 versus 33 months, respectively. However, late neurotoxicity was significantly more common in those older patients who received RT (P: =.00004). Patients younger than 60 years who received the complete treatment regimen have not reached median disease-free or overall survival. CONCLUSION Increasing the dose of MTX and adding procarbazine and vincristine improved disease control and overall survival in patients with newly diagnosed PCNSL. Younger patients in particular fared extremely well with this treatment regimen. In older patients, deferring whole-brain RT did not compromise overall survival but did reduce treatment-related toxicity.

Long-term survival in primary CNS lymphoma.

PURPOSE We have previously reported on 31 patients with primary CNS lymphoma (PCNSL) treated between 1986 and 1992 with methotrexate (MTX), cranial radiotherapy (RT), and high-dose cytarabine who remained free of disease longer than historical controls. PATIENTS AND METHODS We performed a follow-up analysis of our original cohort and now report their long-term survival and late treatment-related toxicity. RESULTS The median cause-specific survival was 42 months, with a five-year survival of 22.3% compared with 3% to 4% in historical controls treated with RT alone. Age less than 50 years at diagnosis was a significant prognostic factor for survival (P = .01). Median disease-free survival was 40.3 months; 15 patients relapsed, all but one in the CNS. Late treatment-related toxicity was observed in nearly one third of patients and those more than 60 years of age were at substantially higher risk (P < .0001). CONCLUSION Combined modality therapy for PCNSL has improved survival, but relapse is common and late neurologic toxicity is a significant complication. Although this approach is highly effective for younger patients, efficacious but less neurotoxic regimens need to be developed for older patients.

Combined modality therapy for primary CNS lymphoma.

PURPOSE Primary CNS lymphoma (PCNSL), formerly rare, is being seen with increased frequency among apparently immunocompetent patients. Conventional treatment has consisted of whole-brain radiotherapy (RT) and corticosteroids, with a median survival of 15 to 18 months and a 3% to 4% 5-year survival. Chemotherapy has been useful in the treatment of recurrent PCNSL. In 1985 we began a treatment protocol using chemotherapy and cranial irradiation for the initial therapy of non-AIDS PCNSL. PATIENTS AND METHODS Thirty-one patients (group A) completed the combined modality regimen. All had placement of an Ommaya reservoir and received pre-RT systemic methotrexate, 1 g/m2, plus six doses of intra-Ommaya methotrexate at 12 mg per dose. A full course of cranial RT (4,000-cGy whole-brain RT plus a 1,440-cGy boost) was followed by two cycles of high-dose cytarabine (ara-C), with each course consisting of two doses of 3 g/m2 ara-C separated by 24 hours and infused over 3 hours. During this period, 16 additional patients (group R) were treated with RT alone, either because patients refused chemotherapy or RT was initiated before our consultation; all would have been eligible to participate in the protocol. Follow-up extended through April 1, 1991. RESULTS Group A had a significantly prolonged time to recurrence (median, 41 months) compared with group R (median, 10 months; P = .003). Although median survival was doubled from 21.7 months for group R to 42.5 months for group A, this was not statistically significant because of small sample size. More importantly, group R patients received systemic chemotherapy for recurrent PCNSL, which improved survival. CONCLUSION The addition of chemotherapy to cranial RT for initial treatment of PCNSL significantly improved disease-free survival and contributed to overall survival; all non-AIDS patients with newly diagnosed PCNSL should be considered for combined modality therapy.

Report of an International Workshop to Standardize Baseline Evaluation and Response Criteria for Primary CNS Lymphoma

Standardized guidelines for the baseline evaluation and response assessment of primary CNS lymphoma (PCNSL) are critical to ensure comparability among clinical trials for newly diagnosed patients. The relative rarity of this tumor precludes rapid completion of large-scale phase III trials and, therefore, our reliance on the results of well-designed phase II trials is critical. To formulate this recommendation, an international group of experts representing hematologic oncology, medical oncology, neuro-oncology, neurology, radiation oncology, neurosurgery, and ophthalmology met to review current standards of reporting and to formulate a consensus opinion regarding minimum baseline evaluation and common standards for assessing response to therapy. The response guidelines were based on the results of neuroimaging, corticosteroid use, ophthalmologic examination, and CSF cytology. A critical issue that requires additional study is the optimal method to assess the neurocognitive impact of therapy and address the quality of life of PCNSL survivors. We hope that these guidelines will improve communication among investigators and comparability among clinical trials in a way that will allow us to develop better therapies for patients.

Phase I/II Study of Imatinib Mesylate for Recurrent Malignant Gliomas: North American Brain Tumor Consortium Study 99-08

Purpose: Phase I: To determine the maximum tolerated doses, toxicities, and pharmacokinetics of imatinib mesylate (Gleevec) in patients with malignant gliomas taking enzyme-inducing antiepileptic drugs (EIAED) or not taking EIAED. Phase II: To determine the therapeutic efficacy of imatinib. Experimental Design: Phase I component used an interpatient dose escalation scheme. End points of the phase II component were 6-month progression-free survival and response. Results: Fifty patients enrolled in the phase I component (27 EIAED and 23 non-EIAED). The maximum tolerated dose for non-EIAED patients was 800 mg/d. Dose-limiting toxicities were neutropenia, rash, and elevated alanine aminotransferase. EIAED patients received up to 1,200 mg/d imatinib without developing dose-limiting toxicity. Plasma exposure of imatinib was reduced by ∼68% in EIAED patients compared with non-EIAED patients. Fifty-five non-EIAED patients (34 glioblastoma multiforme and 21 anaplastic glioma) enrolled in the phase II component. Patients initially received 800 mg/d imatinib; 15 anaplastic glioma patients received 600 mg/d after hemorrhages were observed. There were 2 partial response and 6 stable disease among glioblastoma multiforme patients and 0 partial response and 5 stable disease among anaplastic glioma patients. Six-month progression-free survival was 3% for glioblastoma multiforme and 10% for anaplastic glioma patients. Five phase II patients developed intratumoral hemorrhages. Conclusions: Single-agent imatinib has minimal activity in malignant gliomas. CYP3A4 inducers, such as EIAEDs, substantially decreased plasma exposure of imatinib and should be avoided in patients receiving imatinib for chronic myelogenous leukemia and gastrointestinal stromal tumors. The evaluation of the activity of combination regimens incorporating imatinib is under way in phase II trials.

Progression-free survival: An important end point in evaluating therapy for recurrent high-grade gliomas

The North American Brain Tumor Consortium (NABTC) uses 6-month progression-free survival (6moPFS) as the efficacy end point of therapy trials for adult patients with recurrent high-grade gliomas. In this study, we investigated whether progression status at 6 months predicts survival from that time, implying the potential for prolonged survival if progression could be delayed. We also evaluated earlier time points to determine whether the time of progression assessment alters the strength of the prediction. Data were from 596 patient enrollments (159 with grade III gliomas and 437 with grade IV tumors) in NABTC phase II protocols between February 1998 and December 2002. Outcome was assessed statistically using Kaplan-Meier curves and Cox proportional hazards models. Median survivals were 39 and 30 weeks for patients with grade III and grade IV tumors, respectively. Twenty-eight percent of patients with grade III and 16% of patients with grade IV tumors had progression-free survival of >26 weeks. Progression status at 9, 18, and 26 weeks predicted survival from those times for patients with grade III or grade IV tumors (p < 0.001 and hazard ratios < 0.5 in all cases). Including KPS, age, number of prior chemotherapies, and response in a multivariate model did not substantively change the results. Progression status at 6 months is a strong predictor of survival, and 6moPFS is a valid end point for trials of therapy for recurrent malignant glioma. Earlier assessments of progression status also predicted survival and may be incorporated in the design of future clinical trials.

Primary Central Nervous System Lymphoma: The Memorial Sloan-Kettering Cancer Center Prognostic Model

PURPOSE The purpose of this study was to analyze prognostic factors for patients with newly diagnosed primary CNS lymphoma (PCNSL) in order to establish a predictive model that could be applied to the care of patients and the design of prospective clinical trials. PATIENTS AND METHODS Three hundred thirty-eight consecutive patients with newly diagnosed PCNSL seen at Memorial Sloan-Kettering Cancer Center (MSKCC; New York, NY) between 1983 and 2003 were analyzed. Standard univariate and multivariate analyses were performed. In addition, a formal cut point analysis was used to determine the most statistically significant cut point for age. Recursive partitioning analysis (RPA) was used to create independent prognostic classes. An external validation set obtained from three prospective Radiation Therapy Oncology Group (RTOG) PCNSL clinical trials was used to test the RPA classification. RESULTS Age and performance status were the only variables identified on standard multivariate analysis. Cut point analysis of age determined that patients age < or = 50 years had significantly improved outcome compared with older patients. RPA of 282 patients identified three distinct prognostic classes: class 1 (patients < 50 years), class 2 (patients > or =50; Karnofsky performance score [KPS] > or = 70) and class 3 (patients > or = 50; KPS < 70). These three classes significantly distinguished outcome with regard to both overall and failure-free survival. Analysis of the RTOG data set confirmed the validity of this classification. CONCLUSION The MSKCC prognostic score is a simple, statistically powerful model with universal applicability to patients with newly diagnosed PCNSL. We recommend that it be adopted for the management of newly diagnosed patients and incorporated into the design of prospective clinical trials.

Central Nervous System Cancers

Primary and metastatic tumors of the central nervous system are a heterogeneous group of neoplasms with varied outcomes and management strategies. Recently, improved survival observed in 2 randomized clinical trials established combined chemotherapy and radiation as the new standard for treating patients with pure or mixed anaplastic oligodendroglioma harboring the 1p/19q codeletion. For metastatic disease, increasing evidence supports the efficacy of stereotactic radiosurgery in treating patients with multiple metastatic lesions but low overall tumor volume. These guidelines provide recommendations on the diagnosis and management of this group of diseases based on clinical evidence and panel consensus. This version includes expert advice on the management of low-grade infiltrative astrocytomas, oligodendrogliomas, anaplastic gliomas, glioblastomas, medulloblastomas, supratentorial primitive neuroectodermal tumors, and brain metastases. The full online version, available at NCCN. org, contains recommendations on additional subtypes.