Central nervous system cancers, version 2.2014. Featured updates to the NCCN Guidelines

Temozolomide in the Era of Precision Medicine

In the January 1, 2017, issue of Cancer Research, Nagel and colleagues demonstrate the value of assays that determine the DNA repair capacity of cancers in predicting response to temozolomide. Using a fluorescence-based multiplex flow cytometric host cell reactivation assay that provides simultaneous readout of DNA repair capacity across multiple pathways, they show that the multivariate drug response models derived from cell line data were applicable to patient-derived xenograft models of glioblastoma. In this commentary, we first outline the mechanism of activity and current clinical application of temozolomide, which, until now, has been largely limited to glioblastoma. Given the challenges of clinical application of functional assays, we argue that functional readouts be approximated by genomic signatures. In this context, a combination of MGMT activity and mismatch repair (MMR) status of the tumor are important parameters that determine sensitivity to temozolomide. More reliable methods are needed to determine MGMT activity as DNA methylation, the current standard, does not accurately reflect the expression of MGMT. Also, genomics for MMR are warranted. Furthermore, based on patterns of MGMT expression across different solid tumors, we make a case for revisiting temozolomide use in a broader spectrum of cancers based on our current understanding of its molecular basis of activity. Cancer Res; 77(4); 823-6. ©2017 AACR.

Predictive factors of early distant brain failure after gamma knife radiosurgery alone in patients with brain metastases of non-small-cell lung cancer

The objective of this study was to elucidate the predictive factors for early distant brain failure in patients with brain metastases of non-small-cell lung cancer (NSCLC) who were treated with gamma knife radiosurgery (GKRS) without previous whole-brain radiotherapy (WBRT) or surgery. We retrospectively reviewed clinical and imaging data of 459 patients with brain metastases of NSCLC who underwent GKRS from June 2008 to December 2013. The primary end-point was early distant brain failure, defined as the detection of newly developed metastatic lesions on magnetic resonance imaging (MRI) 3 months after GKRS. Factors such as tumor pathology subtype, concurrent systemic chemotherapy, epidermal growth factor receptor (EGFR) mutation status, use of EGFR tyrosine kinase inhibitors (TKIs), systemic disease status, presence of a metastatic lesion only in delayed MRI, and volume and number of metastases were analyzed. There were no statistically significant differences with respect to pathologic subtype, concurrent systemic chemotherapy, EGFR mutation, and early distant brain failure. Patients treated with EGFR-TKIs (p = 0.004), with a stable systemic disease status (p = 0.028) and 3 or fewer brain lesions (p = 0.000) experienced a significantly lower incidence of early distant brain failure. This study suggests that GKRS alone could be considered for patients treated with EGFR-TKIs who have a stable systemic disease status and 3 or fewer brain lesions. WBRT should be considered for other patients.

Tumor-targeted nanotherapeutics: overcoming treatment barriers for glioblastoma

Glioblastoma (GBM) is a highly aggressive and lethal form of primary brain cancer. Numerous barriers exist to the effective treatment of GBM including the tightly controlled interface between the bloodstream and central nervous system termed the 'neurovascular unit,' a narrow and tortuous tumor extracellular space containing a dense meshwork of proteins and glycosaminoglycans, and genomic heterogeneity and instability. A major goal of GBM therapy is achieving sustained drug delivery to glioma cells while minimizing toxicity to adjacent neurons and glia. Targeted nanotherapeutics have emerged as promising drug delivery systems with the potential to improve pharmacokinetic profiles and therapeutic efficacy. Some of the key cell surface molecules that have been identified as GBM targets include the transferrin receptor, low-density lipoprotein receptor-related protein, α_v β₃ integrin, glucose transporter(s), glial fibrillary acidic protein, connexin 43, epidermal growth factor receptor (EGFR), EGFR variant III, interleukin-13 receptor α chain variant 2, and fibroblast growth factor-inducible factor 14. However, most targeted therapeutic formulations have yet to demonstrate improved efficacy related to disease progression or survival. Potential limitations to current targeted nanotherapeutics include: (1) adhesive interactions with nontarget structures, (2) low density or prevalence of the target, (3) lack of target specificity, and (4) genetic instability resulting in alterations of either the target itself or its expression level in response to treatment. In this review, we address these potential limitations in the context of the key GBM targets with the goal of advancing the understanding and development of targeted nanotherapeutics for GBM. WIREs Nanomed Nanobiotechnol 2017, 9:e1439. doi: 10.1002/wnan.1439 For further resources related to this article, please visit the WIREs website.

Whole brain radiotherapy in management of non-small-cell lung carcinoma associated leptomeningeal carcinomatosis: evaluation of prognostic factors

To assess the efficacy of whole-brain radiotherapy (WBRT) and prognostic factors in leptomeningeal carcinomatosis (LMC) of non-small-cell lung cancer (NSCLC) patients. WBRT records of 51 LMC patients confined to brain were reviewed. Eligible patients had squamous-cell carcinoma (SCC) or adenocarcinoma, and Eastern Cooperative Oncology Group Performance Status (ECOG PS) 0-3. The WBRT was either 20 or 30 Gray. The primary and secondary objectives were to determine overall survival (OS) and prognostic factors for improved treatment response, respectively. Median age was 53 years (range 39-68), 58.8 % had SCC, 74.5 % had ECOG PS 1-2, and 70.6 % had LMC accompanied by parenchymal brain metastases (BM). The median follow-up was 4.1 months (range 0.7-14.4); all patients died due to disease progression. Median OS was 3.9 months (95 % CI 3.3-4.5) with 6 and 12 month estimates of 19.6 and 5.9 %, respectively. Evaluation of prognostic factors revealed that patients with ECOG 1, longer time to LMC (TT-LMC) from NSCLC diagnosis (>11.3 months), and absence of parenchymal BM had significantly superior OS than those patients with ECOG 2 (p = 0.01) or 3 (p < 0.001), TT-LMC < 11.3 months (p = 0.001), and parenchymal BM (p = 0.012). Median OS of 3.9 months after WBRT appeared to confirm the poor prognosis of LMC. WBRT might be most effective for patients with favorable PS, longer TT-LMC, and no accompanying BM. Therefore, we identified ECOG PS 1, TT-LMC > 11.3 months, and no BM as independent prognosticators for better response to WBRT in NSCLC patients with LMC.

Current Management of Adult Diffuse Infiltrative Low Grade Gliomas

Diffuse infiltrative low grade gliomas (LGG) account for approximately 15 % of all gliomas. The prognosis of LGG differs between high-risk and low-risk patients notwithstanding varying definitions of what constitutes a high-risk patient. Maximal safe resection optimally is the initial treatment. Surgery that achieves a large volume resection improves both progression-free and overall survival. Based on results of three randomized clinical trials (RCT), radiotherapy (RT) may be deferred in patients with low-risk LGG (defined as age <40 years and having undergone a complete resection), although combined chemoradiotherapy has never been prospectively evaluated in the low-risk population. The recent RTOG 9802 RCT established a new standard of care in high-risk patients (defined as age >40 years or incomplete resection) by demonstrating a nearly twofold improvement in overall survival with the addition of PCV (procarbazine, CCNU, vincristine) chemotherapy following RT as compared to RT alone. Chemotherapy alone as a treatment of LGG may result in less toxicity than RT; however, this has only been prospectively studied once (EORTC 22033) in high-risk patients. A challenge remains to define when an aggressive treatment improves survival without impacting quality of life (QoL) or neurocognitive function and when an effective treatment can be delayed in order to preserve QoL without impacting survival. Current WHO histopathological classification is poorly predictive of outcome in patients with LGG. The integration of molecular biomarkers with histology will lead to an improved classification that more accurately reflects underlying tumor biology, prognosis, and hopefully best therapy.

A successful case of an anaplastic meningioma treated with chemotherapy for soft tissue sarcomas

Malignant meningioma has a bad prognosis. Surgery and radiotherapy are the most effective therapeutic options, without an established role for chemotherapy. We report a case of 2-year-old male child with diagnosis of postoperative relapse of a malignant meningioma. Considering the rapid progression, the young age and the lack of effective therapeutic alternatives, the patient underwent multidisciplinary anticancer treatment with a protocol made for soft tissue sarcomas (EpSSG NRSSTS 2005 protocol), with positive outcome. This case represents a successful management of an anaplastic meningioma with a multimodal treatment, including chemotherapy, in a pediatric patient.

The Current and Future Treatment of Brain Metastases

Brain metastases are the most common intracranial malignancy, accounting for significant morbidity and mortality in oncology patients. The current treatment paradigm for brain metastasis depends on the patient’s overall health status, the primary tumor pathology, and the number and location of brain lesions. Herein, we review the modern management options for these tumors, including surgical resection, radiotherapy, and chemotherapy. Recent operative advances, such as fluorescence, confocal microscopy, and brachytherapy, are highlighted. With an increased understanding of the pathophysiology of brain metastasis come increased future therapeutic options. Therapy targeted to specific tumor molecular pathways, such as those involved in blood–brain barrier transgression, cell–cell adhesion, and angiogenesis, are also reviewed. A personalized plan for each patient, based on molecular characterizations of the tumor that are used to better target radiotherapy and chemotherapy, is undoubtedly the future of brain metastasis treatment.

The Largest Known Survival Analysis of Patients with Brain Metastasis from Thyroid Cancer Based on Prognostic Groups

PURPOSE

To analyze the clinical features and prognostic factors associated with the survival of patients with a very rare occurrence of brain metastasis (BM) from differentiated thyroid cancer (DTC).

METHODS AND MATERIALS

A total of 37 patients with DTC who were diagnosed with BM between 1995 and 2014 were included. We reviewed the clinical characteristics, treatment modalities, and image findings of BM. Factors associated with survival were evaluated, and the patients were divided into three prognostic groups (Groups A, B, and C) for comparative analysis.

RESULTS

The median age at BM was 63 years, and the median time from initial thyroid cancer diagnosis to BM was 3.8 years. The median survival and the 1-year actuarial survival rate after BM were 8.8 months and 47%, respectively. According to univariate and multivariate analyses, four good prognostic factors (GPFs) were identified including age ≤ 60 years, PS ≤ ECOG 2, ≤ 3 BM sites, and without extracranial metastasis prior to BM. Three prognostic groups were designed based on age and number of remaining GPFs: patients ≤ 60 years of age with at least 2 GPFs (Group A) had the most favorable prognosis with a median survival of 32.8 months; patients ≤ 60 years of age with fewer than 2 GPFs and those > 60 years of age with at least 2 GPFs (Group B) had an intermediate prognosis with a median survival of 9.4 months; and patients > 60 years of age with fewer than 2 GPFs (Group C) had the least favorable prognosis with a median survival of 1.5 months.

CONCLUSIONS

The survival of patients with BM form DTC differed among the prognostic groups based on the total number of good prognostic factors.

Progressive Low-Grade Glioma: Assessment of Prognostic Importance of Histologic Reassessment and MRI Findings

BACKGROUND

In patients with progressive low-grade glioma (LGG), the presence of new magnetic resonance imaging (MRI) enhancement is commonly used as an indicator of malignant degeneration, but its accuracy in this setting is uncertain.

OBJECTIVE

We characterize the ability of new MRI enhancement to serve as a surrogate for histologic grade in patients with progressive LGG, and to explore the prognostic value of new MRI enhancement, pathologic grade, and extent of resection.

METHODS

Patients at our institution with World Health Organization grade II glioma diagnosed between 1994 and 2010 and who underwent repeat biopsy or resection at progression were retrospectively reviewed (n = 108). The positive predictive value, negative predictive value, sensitivity, and specificity of new MRI enhancement were characterized. A multivariable proportional hazards model was used to test associations with overall survival (OS), and Kaplan-Meier curves were constructed to compare OS between patient subsets.

RESULTS

The positive predictive value, negative predictive value, sensitivity, and specificity of new MRI enhancement were 82%, 77%, 92%, and 57%, respectively. In patients without malignant degeneration, new MRI enhancement was associated with inferior median OS (92.5 months vs. not reached; P = 0.03). In patients with malignant degeneration, gross or near total resection was associated with improved median OS (58.8 vs. 28.8 months; P = 0.02).

CONCLUSION

In patients with progressive LGG, new MRI enhancement and pathologic grade were discordant in greater than 20% of cases. Pathologic confirmation of grade should therefore be attempted, when safe, to dictate management. Beyond functioning as a surrogate for pathologic grade, new MRI enhancement may predict for worse outcomes, a concept that merits prospective investigation.

Novel risk scores for survival and intracranial failure in patients treated with radiosurgery alone to melanoma brain metastases

Purpose

Stereotactic radiosurgery (SRS) alone is an increasingly common treatment strategy for brain metastases. However, existing prognostic tools for overall survival (OS) were developed using cohorts of patients treated predominantly with approaches other than SRS alone. Therefore, we devised novel risk scores for OS and distant brain failure (DF) for melanoma brain metastases (MBM) treated with SRS alone.

Methods and materials

We retrospectively reviewed 86 patients treated with SRS alone for MBM from 2009-2014. OS and DF were estimated using the Kaplan-Meier method. Cox proportional hazards modeling identified clinical risk factors. Risk scores were created based on weighted regression coefficients. OS scores range from 0-10 (0 representing best OS), and DF risk scores range from 0-5 (0 representing lowest risk of DF). Predictive power was evaluated using c-index statistics. Bootstrapping with 200 resamples tested model stability.

Results

The median OS was 8.1 months from SRS, and 54 (70.1 %) patients had DF at a median of 3.3 months. Risk scores for OS were predicated on performance status, extracranial disease (ED) status, number of lesions, and gender. Median OS for the low-risk group (0-3 points) was not reached. For the moderate-risk (4-6 points) and high-risk (6.5-10) groups, median OS was 7.6 months and 2.4 months, respectively (p < .0001). Scores for DF were predicated on performance status, ED status, and number of lesions. Median time to DF for the low-risk group (0 points) was not reached. For the moderate-risk (1-2 points) and high-risk (3-5 points) groups, time to DF was 4.8 and 2.0 months, respectively (p < .0001). The novel scores were more predictive (c-index = 0.72) than melanoma-specific graded prognostic assessment or RTOG recursive partitioning analysis tools (c-index = 0.66 and 0.57, respectively).

Conclusions

We devised novel risk scores for MBM treated with SRS alone. These scores have implications for prognosis and treatment strategy selection (SRS versus whole-brain radiotherapy).