Treatment options for brain metastases in patients with non-small cell lung cancer

Chemotherapy in the management of brain metastases: the emerging role of fotemustine for patients with melanoma and NSCLC

INTRODUCTION

An estimated 20 - 40% of cancer patients will develop brain metastases that are the most common intracranial tumors in adults. Patients with cerebral metastases represent a variegate group where selection of the most appropriate treatment depends on many patient- and disease-related factors. The impact of therapeutic option on overall survival is lacking and it is important to consider quality of life (QOL) when treating patients with brain metastases.

AREAS COVERED

A considerable proportion of patients are treated with palliative approaches such as whole-brain radiotherapy. The role of chemotherapy was limited in the past. Recently, several chemotherapeutic agents have been identified as potentially useful. This article examines the pharmacokinetics, efficacy and safety and tolerability of fotemustine (FTM) for the management of patients with cerebral metastasis from melanoma and non-small cell lung cancer (NSCLC).

EXPERT OPINION

FTM is a third-generation nitrosourea that has proved its efficacy on brain metastases of melanoma and showed promising results for the treatment of brain metastasis of NSCLC because of its ability to pass the blood-brain barrier.

Trans-differentiation of neural stem cells: a therapeutic mechanism against the radiation induced brain damage

Radiation therapy is an indispensable therapeutic modality for various brain diseases. Though endogenous neural stem cells (NSCs) would provide regenerative potential, many patients nevertheless suffer from radiation-induced brain damage. Accordingly, we tested beneficial effects of exogenous NSC supplementation using in vivo mouse models that received whole brain irradiation. Systemic supplementation of primarily cultured mouse fetal NSCs inhibited radiation-induced brain atrophy and thereby preserved brain functions such as short-term memory. Transplanted NSCs migrated to the irradiated brain and differentiated into neurons, astrocytes, or oligodendrocytes. In addition, neurotrophic factors such as NGF were significantly increased in the brain by NSCs, indicating that both paracrine and replacement effects could be the therapeutic mechanisms of NSCs. Interestingly, NSCs also differentiated into brain endothelial cells, which was accompanied by the restoration the cerebral blood flow that was reduced from the irradiation. Inhibition of the VEGF signaling reduced the migration and trans-differentiation of NSCs. Therefore, trans-differentiation of NSCs into brain endothelial cells by the VEGF signaling and the consequential restoration of the cerebral blood flow would also be one of the therapeutic mechanisms of NSCs. In summary, our data demonstrate that exogenous NSC supplementation could prevent radiation-induced functional loss of the brain. Therefore, successful combination of brain radiation therapy and NSC supplementation would provide a highly promising therapeutic option for patients with various brain diseases.

Epidermal growth factor receptor tyrosine kinase inhibitors in the treatment of epidermal growth factor receptor-mutant non-small cell lung cancer metastatic to the brain

Brain metastases are a common and devastating consequence of disease progression in patients with non-small cell lung cancer (NSCLC). The epidermal growth factor receptor (EGFR) inhibitors erlotinib and gefitinib have shown efficacy in patients with NSCLC and brain metastases. The cerebrospinal fluid (CSF) exposure to these drugs is a small fraction of the plasma levels achieved with standard doses, but disruption of the blood-brain barrier in the presence of central nervous system metastases is likely to lead to locally increased drug concentration, and dose escalation to boost CSF exposure has documented clinical efficacy. The use of gefitinib and erlotinib in this setting is reviewed here, including evidence from case reports, case series, and single-arm phase II trials. High response rates in the brain are seen in patients with EGFR mutation, or in populations in which this genotype is expected. By contrast, activity in the context of documented wild-type EGFR in disease metastatic to the brain is not common. These drugs may potentiate the effectiveness of radiotherapy to the brain, and their use may also delay development of disease within the brain.

Concomitant or adjuvant temozolomide with whole-brain irradiation for brain metastases: a meta-analysis

The objective of this study was to assess the clinical efficacy and safety of concomitant or adjuvant tomozolomide with whole-brain irradiation (WBI) in patients with brain metastases. MEDLINE, EMBASE, Cochrane Library, Chinese Biomedical Literature Database were searched to identify relevant original published trails, and the references of eligible studies were manually screened. Randomized controlled trails reported in any language, comparing concomitant or adjuvant temozolomide (TMZ) and WBI with WBI alone in patients with brain metastases, were eligible for inclusion. Two investigators independently assessed the quality of included trials and extracted data. The RevMan 5 software was used for statistical analysis. Four trials involving 280 patients were included. The result showed that the group TMZ+WBI was superior to group WBI in partial response, stable disease, progressive disease, and objective response with the pooled risk ratio value and 95% confidence interval, respectively, 1.89 (1.19-3.02), 0.82 (0.45-1.50), 0.29 (0.10-0.78), and 1.72 (1.32-2.24). The incidence of gastrointestinal symptoms and > or =grade 3 myelosuppression presented statistical difference, TMZ+WBI group is higher than WBI group, the pooled risk ratio value and 95% confidence interval were 3.75 (1.04-13.44) and 13 (1.75-96.79), respectively. The currently available evidence showed that the combination of TMZ and WBI may moderately improve the response rate, but accordingly increase the incidence of gastrointestinal symptoms and myelosuppression. Future large-scale, high-quality, placebo-controlled, double-blind trials are needed.

Current Management of Brain Metastases, With a Focus on Systemic Options

Brain metastases are an important sequelae of many types of cancer, most commonly lung cancer. Current treatment options include whole-brain radiation therapy (WBRT), surgical resection, stereotactic radiosurgery, and chemotherapy. Corticosteroids and antiepileptic medications are commonly used for palliation of mass effect and seizures, respectively. The overall median survival is only 4 months after WBRT. Combined-modality strategies of WBRT with either chemotherapy or novel anticancer agents are under clinical investigation. Promising results have been obtained with several experimental agents and confirmatory phase III trials are underway. Although improvement in overall survival has not been seen universally, reduction in death due to progression of brain metastases and prolongation of the time to neurologic and neurocognitive progression have been reported in selected series. On the basis of these findings, it might be possible to identify new agents that may enhance the efficacy of WBRT.

Analysis of long-term outcomes and prognostic factors in patients with non—small cell lung cancer brain metastases treated by gamma knife radiosurgery

Object.The authors conducted a study to evaluate the long-term outcomes and prognostic factors for survival in a large series of patients treated by gamma knife surgery (GKS) for non—small cell lung cancer (NSCLC) brain metastases.

Methods.The study is based on the retrospective analysis of clinical and radiological records obtained during a 10-year period (1993–2003), concerning 836 lesions in 504 patients. The lesions were primary in 86% and recurrent 14% of the cases; they were solitary in 31%, single in 29%, and multiple in 40%. The mean follow-up period was 16 months (range 4–113 months). The most common histological types were adenocarcinoma (51%) and squamous cell carcinoma (27%). Dose planning parameters were as follows: mean target volume 6.2 cm3(range 0.06–22.5 cm3); mean prescription dose 21.4 Gy (range 15.5–28 Gy); and mean number of isocenters 6.7 (range one–18). Progression-free and actuarial survival curves were calculated using the Kaplan—Meier method. The main factors affecting survival were determined by unimultivariate analysis (log-rank test and Cox proportional hazard models).

Analysis of long-term outcomes seemed to confirm that GKS is a primary therapeutic option in these patients. The 1-year local tumor control rate was 94%. The overall median survival was 14.5 months, with extremely rewarding quality of life indices. The recursive partitioning analysis classification was the dominant prognostic factor.

Conclusions.Gamma knife surgery is a useful treatment for brain metastases from NSCLC.

Analysis of long-term outcomes and prognostic factors in patients with non—small cell lung cancer brain metastases treated by gamma knife radiosurgery

Object. The authors conducted a study to evaluate the long-term outcomes and prognostic factors for survival in a large series of patients treated by gamma knife surgery (GKS) for non—small cell lung cancer (NSCLC) brain metastases.

Methods. The study is based on the retrospective analysis of clinical and radiological records obtained during a 10-year period (1993–2003), concerning 836 lesions in 504 patients. The lesions were primary in 86% and recurrent 14% of the cases; they were solitary in 31%, single in 29%, and multiple in 40%. The mean follow-up period was 16 months (range 4–113 months). The most common histological types were adenocarcinoma (51%) and squamous cell carcinoma (27%). Dose planning parameters were as follows: mean target volume 6.2 cm3 (range 0.06–22.5 cm3); mean prescription dose 21.4 Gy (range 15.5–28 Gy); and mean number of isocenters 6.7 (range one–18). Progression-free and actuarial survival curves were calculated using the Kaplan—Meier method. The main factors affecting survival were determined by unimultivariate analysis (log-rank test and Cox proportional hazard models).

Analysis of long-term outcomes seemed to confirm that GKS is a primary therapeutic option in these patients. The 1-year local tumor control rate was 94%. The overall median survival was 14.5 months, with extremely rewarding quality of life indices. The recursive partitioning analysis classification was the dominant prognostic factor.

Conclusions. Gamma knife surgery is a useful treatment for brain metastases from NSCLC.