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Biomedical subjects

Glenn J Lesser

Publications and source records attributed to Glenn J Lesser.

8 recordsLinked to original sources

Current therapeutic approaches in patients with brain metastases.

The development of brain metastases is often viewed as the end stage of a disease course and engenders skepticism about the efficacy of treatment. Aggressive management of brain metastases is effective in both symptom palliation and the prolongation of life. The majority of patients with controlled intracranial metastases will expire from systemic disease rather than from recurrence of these metastases. Single brain metastases should be treated with surgical resection or stereotactic radiosurgery, though it is unclear at this time if one modality is more effective than the other. Surgical resection is preferred when a pathologic diagnosis is needed, for tumors larger than 3.5 cm, or when immediate tumor mass decompression is required. Stereotactic radiosurgery (SRS) should be applied for single tumors less than 3.5 cm in surgically inaccessible areas and for patients who are not surgical candidates. Small tumors (ie, < 3.5 cm) that cause minimal edema and are surgically accessible may be treated with either surgery or SRS. There is controversy over whether whole brain radiation therapy (WBRT) can be omitted following surgical resection or SRS. Omission of WBRT increases intracranial tumor recurrence; however, this has not been correlated with decreased survival. Clinicians who choose to omit upfront WBRT are obligated to monitor the patient closely for intracranial recurrence, at which time further salvage therapy in the form of surgery, SRS, or WBRT may be considered. Histology is of particular importance when considering WBRT for patients with radioresistant tumors such as melanoma, renal cell carcinoma, or sarcoma. WBRT may be of less clinical benefit in this setting. Chemotherapy has been demonstrated to improve response rates when used as an adjunct to radiation therapy. These improvements in response rates have not been correlated with an improvement in median survival. Noncytotoxic radiosensitizing agents such as motexafin and efaproxiral show promise. Phase III trials to assess the benefit of motexafin in patients with metastatic lung cancer and efaproxiral in patients with metastatic breast cancer are ongoing. Targeted therapies offer promise in achieving therapeutic efficacy while minimizing side effects. Surgical adjuncts such as BCNU (carmustine) wafers and the GliaSite Radiation System (Cytyc Corporation, Marlborough, MA) may be useful in the future in achieving optimal local tumor control.

Antineoplastic Combined Chemotherapy Protocols↗

Esthesioneuroblastoma.

Esthesioneuroblastoma is a rare tumor for which the published literature does not provide an evidence-based consensus treatment approach. Multimodality therapy including a combination of surgery and radiation appears to provide the best disease-free and overall survival. Surgical resection should proceed through a craniofacial approach if possible. The role of chemotherapy in the initial treatment paradigm is less clear. Chemotherapy should not be used as single-modality therapy for initial treatment but may provide additional benefit when used in combination with radiation and surgery, particularly in advanced-stage disease. Combination chemotherapy should be considered as initial therapy for unresectable tumors and metastatic disease, and as salvage therapy in disease recurrence.

Antineoplastic Combined Chemotherapy Protocols↗

Treatment of relapsed central nervous system lymphoma with high-dose methotrexate.

PURPOSE: Over the past decade, high-dose methotrexate has emerged as the single most effective agent in the initial treatment of primary nervous system lymphoma. However, the majority of patients who respond initially to treatment relapse. The optimal management of these patients has not been determined. We performed a multicenter, retrospective study of high-dose methotrexate in patients with relapsed central nervous system lymphoma. EXPERIMENTAL DESIGN: Patients with relapsed disease were eligible if they achieved a complete response to initial treatment with methotrexate-based chemotherapy or received methotrexate after gross total resection or interstitial radiation. All of the patients were retreated with a regimen containing high-dose methotrexate (>/=3 g/m(2)). RESULTS: Twenty-two patients with a median age of 58 years were included in the study. Overall response rates were 91% to first salvage (20 of 22 patients) and 100% to second salvage (4 of 4 patients). Median survival was 61.9 months after first relapse (95% confidence interval, 42.1- infinity ) and 91.9 months overall (95% confidence interval, 47.2- infinity ). Toxicity was primarily hematologic with 10 episodes of grade 3 or 4 toxicity during 566 cycles of chemotherapy. CONCLUSIONS: These results indicate that high-dose methotrexate remains effective for relapsed central nervous system lymphoma in patients who initially respond to methotrexate and raise the possibility of deferring more toxic salvage regimens in this select group of patients.

Adult↗

The management of thromboembolic disease in patients with central nervous system malignancies.

Venous thromboembolic disease (VTE) is a common complication of malignancies affecting the central nervous system (CNS), both in the perioperative period and throughout the disease course. Until recently, the perceived risk of intracranial hemorrhage in patients with CNS malignancies was felt to be a relative contraindication to systemic anticoagulation, and most patients were managed with nonpharmacologic methods in both the prophylactic and treatment setting. However, several studies of the safety and efficacy of anticoagulation in both neurosurgical and cancer patients have challenged the previous dogma, and routine use of unfractionated heparin or low molecular weight heparin (LMWH) for VTE prophylaxis in patients undergoing craniotomy for CNS malignancy is recommended. Likewise, treatment of established VTE in this population with heparins is recommended, at least initially, followed by long-term treatment either with heparin or oral warfarin. Complications of inferior vena cava (IVC) filters, used as an alternative to systemic anticoagulation, appear to be more common in brain tumor patients with VTE, lending further support to treatment with systemic anticoagulation when possible. We advocate a multimodality approach utilizing compression stockings, intermittent compression devices, and heparin in the perioperative setting as the best proven method to reduce the risk of VTE. In the absence of a strict contraindication to systemic anticoagulation, such as previous intracranial hemorrhage or profound thrombocytopenia, LMWH is recommended in brain tumor patients with newly diagnosed VTE, followed by long-term warfarin or LMWH.

Anticoagulants↗

Current controversies in the radiotherapeutic management of adult low-grade glioma.

Over the last decade, the results of four prospective clinical trials of supratentorial low-grade glioma (LGG) in adults have been published. The data from the nearly 1,000 patients treated on these studies are summarized in this presentation, addressing the following three current controversies in the radiotherapeutic management of these patients: (1) optimum timing of radiation therapy (RT); (2) optimum RT dose; and (3) addition of chemotherapy to RT. The 5-year overall survival (OS) and progression-free survival (PFS) rates in these four studies ranged from 58% to 72% and from 37% to 55%, respectively. Significant prognostic factors included extent of surgical resection, histology, tumor size, and age. The European Organization for Research and Treatment of Cancer (EORTC) study 22845 randomized 311 adults to postoperative observation or RT. There was no difference in the 5-year OS rate between the two arms, but the irradiated patients had a significantly improved 5-year PFS rate. EORTC study 22844 randomized 379 adults to low- versus high-dose RT. Similarly, an intergroup study conducted by the North Central Cancer Treatment Group (NCCTG), Radiation Therapy Oncology Group (RTOG), and Eastern Cooperative Group (ECOG) randomized 211 adults to low- versus high-dose RT. There was no difference in the 5-year OS or PFS rates between the two dose groups in either study. A Southwest Oncology Group (SWOG) study randomized 60 adults with incompletely resected LGG to RT alone or RT plus lomustine (CCNU) chemotherapy. There was no difference in outcome between the two treatment arms. Further prospective clinical trials are needed to define the optimal management strategy for adults with supratentorial LGG. The schemata from recently completed and ongoing LGG studies will be presented.

Adult↗

Suramin and radiotherapy in newly diagnosed glioblastoma: phase 2 NABTT CNS Consortium study.

Suramin is a polysulfonated naphthylurea that inhibits the function of growth factors and growth factor receptors implicated in glioma progression, angiogenesis, and radioresistance. The safety and benefits of combining inhibitors of angiogenesis and growth factors with cytotoxic therapies in patients with neoplasms of the central nervous system remain unclear. The objectives of this phase 2 study were to determine the safety of administering suramin with standard cranial radiotherapy (RT) and to estimate survival using this approach in patients with newly diagnosed glioblastoma multiforme (GBM). Fifty-five patients with newly diagnosed GBM (Karnofsky performance status >or= 60) were enrolled in this multicenter phase 2 study. Patients received suramin by a conventional intermittent fixed-dosing regimen for 1 week prior to and during cranial RT (60 Gy in 30 fractions, weeks 2-7). Patients with stable or responsive disease at week 18 received an additional 4 weeks of suramin (weeks 19-22). The median survival for suramin-treated patients was 11.6 months, with 1-year and 18-month survival rates of 49% (95% confidence interval [CI], 36%-62%) and 18% (95% CI, 8%-28%), respectively. Overall, 55% of the patients (30/55) had greater than grade 2 toxicity at least possibly related to suramin therapy. Two patients died of possibly related neurologic events (i.e., stroke, elevated intracranial pressure). Otherwise, toxicities were generally transient and self-limited. Administration of suramin using an intermittent fixed-dosing regimen during cranial RT was generally well tolerated. However, overall survival is not significantly improved when compared with the New Approaches to Brain Tumor Therapy GBM database or other comparable patient populations.

Aged↗

Phase 2 study of weekly irinotecan in adults with recurrent malignant glioma: final report of NABTT 97-11.

The primary objective of this study was to determine the proportion of patients exhibiting a radiographic response in a cohort of patients with recurrent malignant glioma who were treated with irinotecan. Secondary objectives were to determine progression-free survival, overall survival, and toxicity. The trial was terminated after the first 18 patients were enrolled in this multicenter, 2-stage, phase 2 study. Twelve patients received concurrent enzyme-inducing antiepileptic drugs, and 6 did not. Each cycle consisted of a 90-min i.v. infusion of irinotecan every week for 4 consecutive weeks, followed by 2 weeks off. One patient had a complete response, 5 patients had stable disease, 5 patients had radiographic progression, 6 patients were removed from the study because of toxicity, and 1 patient refused further therapy and was removed from the study. The response rate in this study was 6% (1/18), and 28% (5/18) of these patients progressed while receiving irinotecan. Dose-limiting toxicities consisted of diarrhea in 5 patients, neutropenia in 1 patient, infection in 1 patient, and respiratory failure in 1 patient. Irinotecan had minimal efficacy in this cohort of 18 patients with recurrent malignant glioma. Toxicity was significant but similar to that reported in other patient populations.

Adult↗

Malignant spinal cord compression.

Malignant spinal cord compression is one of the most dreaded complications of cancer. If untreated, it can lead to worsening neurologic function culminating in paralysis and sphincter incontinence. The most challenging aspect in the management of this complication is early diagnosis because the single most important factor determining outcome is the level of neurologic function at initiation of therapy. Magnetic resonance imaging is the diagnostic modality of choice. Steroids have a proven role in the treatment. Radiation therapy has been the standard of care, with surgery reserved for special cases. A recent randomized trial has proven that in appropriately selected patients initial surgery, followed by radiation, provides better functional and neurologic outcome compared to radiation alone and will likely become the standard of care in the future. Newer modalities, such as transarterial embolization and extracranial stereotactic radiosurgery, are emerging and may be considered in appropriate cases if available.

Antineoplastic Agents, Hormonal↗