Brain neoplasms: epidemiology, diagnosis, and prospects for cost-effective imaging

Re-thinking therapeutic development for CNS metastatic disease

There has been unprecedented progress in the development of systemic therapies for patients with metastatic melanoma over the last decade. There is now tremendous potential and momentum to further and markedly reduce the impact of this disease. However, developing more effective treatments for metastases to the CNS remains a critical challenge for patients with melanoma. Melanoma patients with active CNS metastases have largely been excluded from both early-phase and registration trials for all currently approved targeted and immune therapies for this disease. While this exclusion has generally been justified in clinical research due to concerns about poor prognosis, lack of CNS penetration of agents and/or risk of toxicities, recent post-approval trials have shown the feasibility, safety and clinical benefit of clinical investigation in these patients. These trials have also identified key areas for which more effective strategies are needed. In parallel, recent translational and preclinical research has provided insights into novel immune, molecular and metabolic features of melanoma brain metastases that may mediate the aggressive biology and therapeutic resistance of these tumors. Together, these advances suggest the need for new paradigms for therapeutic development for melanoma patients with CNS metastasis.

Treatment of multiple intracranial metastases in radiation oncology: a contemporary review of available technologies

The use of stereotactic radiosurgery to treat multiple intracranial metastases, frequently concurrently, has become increasingly common. The ability to accurately and safely deliver stereotactic radiosurgery treatment to multiple intracranial metastases (MIM) relies heavily on the technology available for targeting, planning, and delivering the dose. A number of platforms are currently marketed for such applications, each with intrinsic capabilities and limitations. These can be broadly categorised as cobalt-based, linac-based, and robotic. This review describes the most common representative technologies for each type along with their advantages and current limitations as they pertain to the treatment of multiple intracranial metastases. Each technology was used to plan five clinical cases selected to represent the clinical breadth of multiple metastases cases. The reviewers discuss the different strengths and limitations attributed to each technology in the case of MIM as well as the impact of disease-specific characteristics (such as total number of intracranial metastases, their size and relative proximity) on plan and treatment quality.

Epidemiology of Brain Metastases

Brain metastasis continues to be a devastating complication of systemic malignancy, affecting approximately 20% of all patients suffering from cancer. Despite being a major source of morbidity and mortality for this patient population, a nationwide, systematic mechanism for reporting of brain metastases does not exist. Better understanding the epidemiology of brain metastases will help identify individuals who are at greatest risk of developing them and guide clinicians in selecting patients who are most likely to benefit from brain metastasis surveillance and prophylaxis.

Bioengineered microfluidic blood-brain barrier models in oncology research

Metastasis is the major reason for most brain tumors with up to a 50% chance of occurrence in patients with other types of malignancies. Brain metastasis occurs if cancer cells succeed to cross the 'blood-brain barrier' (BBB). Moreover, changes in the structure and function of BBB can lead to the onset and progression of diseases including neurological disorders and brain-metastases. Generating BBB models with structural and functional features of intact BBB is highly important to better understand the molecular mechanism of such ailments and finding novel therapeutic agents targeting them. Hence, researchers are developing novel in vitro BBB platforms that can recapitulate the structural and functional characteristics of BBB. Brain endothelial cells-based in vitro BBB models have thus been developed to investigate the mechanism of brain metastasis through BBB and facilitate the testing of brain targeted anticancer drugs. Bioengineered constructs integrated with microfluidic platforms are vital tools for recapitulating the features of BBB in vitro closely as possible. In this review, we outline the fundamentals of BBB biology, recent developments in the microfluidic BBB platforms, and provide a concise discussion of diverse types of bioengineered BBB models with an emphasis on the application of them in brain metastasis and cancer research in general. We also provide insights into the challenges and prospects of the current bioengineered microfluidic platforms in cancer research.

Multidisciplinary patient-centered management of brain metastases and future directions

The incidence of brain metastasis is increasing as improvements in systemic therapy lead to increased survival. This provides new and challenging clinical decisions for patients who are trying to balance the risk of recurrence or progression with treatment-related side effects, and it requires appropriate management strategies from multidisciplinary teams. Improvements in prognostic assessment and systemic therapy with increasing activity in the brain allow for individualized care to better guide the use of local therapies and/or systemic therapy. Here, we review the current landscape of brain-directed therapy for the treatment of brain metastasis in the context of recent improved systemic treatment options. We also discuss emerging treatment strategies including targeted therapies for patients with actionable mutations, immunotherapy, modern whole-brain radiation therapy, radiosurgery, surgery, and clinical trials.

Optimal Timing and Sequence of Immunotherapy When Combined with Stereotactic Radiosurgery in the Treatment of Brain Metastases

Checkpoint immunotherapy (CIT) is an emerging and exciting treatment modality for the treatment of cancer. Much excitement has ensued in the potential of CIT to revolutionize the treatment and prognosis of brain metastases. The combination of stereotactic radiosurgery (SRS) and CIT has also been studied and showed promise compared with either treatment modality alone. However, several questions have arisen, in particular, the timing at which SRS and CIT should be administered relative to each other. We reviewed the reported data and attempted to offer a potential answer to this question.

The Hidden Morbidity of Cancer: Burden in Caregivers of Patients with Brain Metastases

Caregiving is a highly individualized experience. Although numerous articles have been published on caregiver burden from a variety of diagnoses and conditions, this article presents the unique features of caregiving in patients with brain metastases. Improved long-term survival, concerns about disease recurrence or progression, the cancer experience (initial diagnosis, treatment, survivorship, recurrence, progression, and end of life), and the increasing complexity of cancer treatments add to the demands placed on the caregivers of patients with brain metastases. Health care professionals must identify caregiver burden and administer the appropriate interventions, which must be as unique and individualized as the caregivers' experiences.

Profile of Primary Pediatric Brain and Spinal Cord Tumors from North India

BACKGROUND AND OBJECTIVE

The study was carried out to find the profile of pediatric brain and spinal cord tumors during 2006-2015 in a tertiary referral center of North India.

MATERIALS AND METHODS

It was a retrospective medical record-based observational study. All children <18 years of age with confirmed histopathological diagnosis of cancer were included in the study.

RESULTS

Central nervous system (CNS) tumors constituted 5.6% of all pediatric solid malignancies in our hospital. A total of 54 brain tumors and 13 spinal cord tumors were studied. Medulloblastoma was the most common brain tumor (20.3%) followed by pilocytic astrocytoma (16.6%) and glioblastoma multiforme (9.2%). The most common spinal cord tumor was Ewing's sarcoma/primitive neuroectodermal tumor (30.7%) followed by ependymoma (23%). Mean age was 10.5 years and 12.1 years for brain and spinal cord tumors, respectively. There was male predominance in brain tumors while the sex ratio was almost equal in spinal cord tumors. Histomorphologically, necrosis and angiogenesis were associated with higher grades of tumor. Approximately 35% children were alive after a mean follow-up of 36 ± 6 months.

CONCLUSION

Compared with most international studies, we found a higher percentage of medulloblastoma in the brain, thus stressing the role of regional and ethnic influences in the pathogenesis of CNS tumors.

Cognitive dysfunction in patients with brain metastases: influences on caregiver resilience and coping

PURPOSE

Neurologic deficits that may be manifested as cognitive impairment contribute to the challenges faced by caregivers of patients with brain metastases. To better address their needs, we examined how caregivers respond to these challenges and explore the relationship between the patient's cognitive impairment and caregiver resilience and coping.

METHODS

We conducted a descriptive, cross-sectional study using self-reported data from 56 caregivers of patients with brain metastases. Study participants from a comprehensive cancer center were asked to complete a series of instruments that measured their perception of the patient's cognitive dysfunction (revised memory and behavior problems checklist, RMBC), their own personal resilience (Resilience Scale, RS), and their utilization of a broad range of coping responses (COPE inventory and Emotional-Approach Coping scale).

RESULTS

Caregivers reported that memory-related problems occurred more frequently in the patients they cared for compared to depression and disruptive behavior (mean scores 3.52 vs 2.34 vs. 1.32, respectively). Coping strategies most frequently used by caregivers were acceptance (3.28), planning (3.08), and positive reinterpretation and growth (2.95). Most caregivers scored moderate to high on the RS (77%). The coping strategy acceptance correlated significantly with the memory and disruptive behavior subscales of the RMBC.

CONCLUSIONS

Given the protective effect of problem-focused coping and the high rate of caregivers utilizing less effective coping strategies in instances of worsening cognitive dysfunction, healthcare professionals need to systematically assess the coping strategies of caregivers and deliver a more personalized approach to enhance effective coping among caregivers of patients with brain metastases.

Evaluation of matrix metalloproteinase type IV-collagenases in serum of patients with tumors of the central nervous system

The basement membrane collagen IV-degrading matrix metalloproteinases -2 and -9 (MMPs) are most often linked to the malignant phenotype of tumor cells by playing a critical role in invasion, metastasis, angiogenesis, and vasculogenesis. We verified the activity of these two MMPs in the sera of patients affected by brain tumors (20 gliomas, 28 meningiomas and 20 metastasis) by zymography. The sera of 25 healthy volunteers with no concomitant illnesses were used for controls. Zymography showed four dominant gelatinolytic bands of 240, 130, 92 (MMP-9) and 72 (MMP-2) kDa. No statistically significant variations of MMP-2 proteolytic activity between patients and healthy individuals were observed. On the contrary, MMP-9 (both monomeric and multimeric forms) lytic activities were significantly higher in tumors specimens compared to healthy controls (p < 0.001). Moreover, MMP-9 immunohistochemistry revealed: (1) a strong reactivity in neoplastic vessels of high-grade gliomas showing an inverse correlation with serum multimeric gelatinolytic activity; (2) a cytoplasmatic reactivity in meningiomas with a significantly increase in atypical meningioma compared with low-grade ones (p = 0.036); (3) a positive correlation between MMP-9 and Ki-67 (Sperman Rho coefficient r = 0.418 and p = 0.034). Our results suggest that serum and tissue MMP-9 might provide clinicians additional objective information in intracranial neoplasms. Finally, it should be possible to use MMP-9 as a target for new forms of therapy. Nevertheless, due to the small number of patients included in the study, the conclusion may not be transferable to the general population and therefore further evaluations are needed.

CNS Anticancer Drug Discovery and Development Conference White Paper

Following the first CNS Anticancer Drug Discovery and Development Conference, the speakers from the first 4 sessions and organizers of the conference created this White Paper hoping to stimulate more and better CNS anticancer drug discovery and development. The first part of the White Paper reviews, comments, and, in some cases, expands on the 4 session areas critical to new drug development: pharmacological challenges, recent drug approaches, drug targets and discovery, and clinical paths. Following this concise review of the science and clinical aspects of new CNS anticancer drug discovery and development, we discuss, under the rubric "Accelerating Drug Discovery and Development for Brain Tumors," further reasons why the pharmaceutical industry and academia have failed to develop new anticancer drugs for CNS malignancies and what it will take to change the current status quo and develop the drugs so desperately needed by our patients with malignant CNS tumors. While this White Paper is not a formal roadmap to that end, it should be an educational guide to clinicians and scientists to help move a stagnant field forward.

Multimodality Brain Tumor Imaging: MR Imaging, PET, and PET/MR Imaging

Standard MR imaging and CT are routinely used for anatomic diagnosis in brain tumors. Pretherapy planning and posttreatment response assessments rely heavily on gadolinium-enhanced MR imaging. Advanced MR imaging techniques and PET imaging offer physiologic, metabolic, or functional information about tumor biology that goes beyond the diagnostic yield of standard anatomic imaging. With the advent of combined PET/MR imaging scanners, we are entering an era wherein the relationships among different elements of tumor metabolism can be simultaneously explored through multimodality MR imaging and PET imaging. The purpose of this review is to provide a practical and clinically relevant overview of current anatomic and physiologic imaging of brain tumors as a foundation for further investigations, with a primary focus on MR imaging and PET techniques that have demonstrated utility in the current care of brain tumor patients.

Long-term outcome of gamma knife radiosurgery for metastatic brain tumors originating from lung cancer

Background:

Gamma knife radiosurgery (GKRS) has emerged as an important treatment option for metastasis brain tumors (MBTs). However, the long-term outcome of GKRS on MBTs originating from lung carcinoma is not well understood. The treatment of MBTs derived from lung cancer with GKRS at our institution is reviewed.

Methods:

We performed a retrospective review (2000-2013) of 173 patients with MBTs from lung cancer who received GKRS. Out of 173 patients, 38 patients had recurrent tumors after microsurgical resection and whole brain radiotherapy (WBT).

Results:

GKRS in MBTs metastasized from lung carcinoma showed significant variations in tumor growth control (decreased in 79 [45.7%] patients, arrested growth in 54 [31.2%] patients, and increased tumor size in 40 [23.1%] patients). The median survival in the study population was 14 months. Overall survival after 3 years was 25%, whereas progression-free survival after 3 years was 45%. The predictive factors for improving survival in the patients with MBTs were recursive partitioning analysis (RPA) class I (P = 0.005), absence of hydrocephalus (P = 0.001), Karnofsky performance scale (KPS) >70 (P = 0.007), age ≤65 (P = 0.041), tumor size ≤3 cm (P = 0.023), controlled primary tumor (P = 0.049), and single number of MBTS (P = 0.044).

Conclusion:

Long-term follow-up revealed that GKRS offers a high rate of tumor control and good overall survival period in both new and recurrent patients with MBTs originating from lung carcinoma. Thus, GKRS is an effective treatment option for new patients with MBTs from lung cancer, as well as an adjuvant therapy in patients with recurrent MBTs derived from lung cancer.

Long term outcome of Gamma Knife radiosurgery for metastatic brain tumors

Gamma Knife radiosurgery (GKRS; Elekta AB, Stockholm, Sweden) has emerged as an important treatment option for metastatic brain tumors (MBT). However, the long term outcome of GKRS on MBT is not well understood. We reviewed the treatment of MBT with GKRS at our institution. We performed a retrospective review (2000-2013) of 298 patients with MBT who received GKRS. The study population was monitored clinically and radiographically after GKRS treatment. Survival benefits and predictive factors of the outcome were analyzed using the Kaplan-Meier test and Cox regression model, respectively. GKRS in MBT showed significant variation in tumor growth control (decreased in 135 [45%] patients, arrested growth in 91 [37%] patients and increased tumor size in 72 [24%] patients). The median survival in the study population was 17 months. Overall and progression free survival after 3 years were 25% and 45%, respectively. The predictive factors for improving survival in the patients with MBT were recursive partitioning analysis class I (p<0.0001), absence of hydrocephalus (p<0.0001), Karnofsky Performance Status (KPS) >80 (p=0.007) and absence of recurrent MBT (p=0.01). Forty (12%), 15 (4.3%) and two (0.6%) patients required GKRS, resection and whole brain radiation, respectively, after initial GKRS due to tumor progression and worsening of signs and symptoms. Our findings revealed that GKRS offers a high rate of tumor control and good survival benefits in both new and recurrent patients with MBT. Thus, GKRS is an effective treatment option for new patients with MBT, as well as an adjuvant therapy in patients with recurrent MBT.

Identifying better surgical candidates among recursive partitioning analysis class 2 patients who underwent surgery for intracranial metastases

OBJECTIVE

The management of patients with brain metastases is typically dependent on their prognosis. Recursive partitioning analysis (RPA) is the most commonly used method for prognosticating survival, but has limitations for patients in the intermediate class. The aims of this study were to ascertain preoperative risk factors associated with survival, develop a preoperative prognostic grading system, and evaluate the utility of this system in predicting survival for RPA class 2 patients.

METHODS

Adult patient who underwent intracranial metastatic tumor surgery at an academic tertiary care institution from 1997 to 2011 were retrospectively reviewed. Multivariate proportional hazards regression analysis was used to identify preoperative factors associated with survival. The identified associations were then used to develop a grading system. Survival as a function of time was plotted using the Kaplan-Meier method, and survival rates were compared using log-rank analyses.

RESULTS

A total of 421 (59%) of 708 patients were RPA class 2. The preoperative factors found to be associated with poorer survival were: male gender (P < 0.0001), motor deficit (P = 0.0007), cognitive deficit (P = 0.0004), nonsolitary metastases (P = 0.002), and tumor size >2 cm (P = 0.003). Patients having 0-1, 2, and 3-5 of these variables were assigned a preoperative grade of A, B, and C, respectively. Patients with a preoperative grade of A, B, and C had a median survival of 17.0, 10.3, and 7.3 months, respectively. These grades had distinct survival times (P < 0.05).

CONCLUSIONS

The present study devised a preoperative grading system that may provide prognostic information for RPA class 2 patients, which may also guide medical and surgical therapies before any intervention is pursued.

Brain tumor classification using AFM in combination with data mining techniques

Although classification of astrocytic tumors is standardized by the WHO grading system, which is mainly based on microscopy-derived, histomorphological features, there is great interobserver variability. The main causes are thought to be the complexity of morphological details varying from tumor to tumor and from patient to patient, variations in the technical histopathological procedures like staining protocols, and finally the individual experience of the diagnosing pathologist. Thus, to raise astrocytoma grading to a more objective standard, this paper proposes a methodology based on atomic force microscopy (AFM) derived images made from histopathological samples in combination with data mining techniques. By comparing AFM images with corresponding light microscopy images of the same area, the progressive formation of cavities due to cell necrosis was identified as a typical morphological marker for a computer-assisted analysis. Using genetic programming as a tool for feature analysis, a best model was created that achieved 94.74% classification accuracy in distinguishing grade II tumors from grade IV ones. While utilizing modern image analysis techniques, AFM may become an important tool in astrocytic tumor diagnosis. By this way patients suffering from grade II tumors are identified unambiguously, having a less risk for malignant transformation. They would benefit from early adjuvant therapies.

The Louisiana State University Experience in the Management of Single Small Cerebellar Metastasis

BACKGROUND:

Cerebellar metastasis is often believed to be a more immediately life-threatening complication than brain metastasis in other locations. It is considered a negative prognostic factor in patients with systemic cancers. Despite its clinical importance and technological advances, the survival outcomes of patients with single small cerebellar metastases are rarely studied.

OBJECTIVE:

To retrospectively evaluate our experience in the management of patients with single small cerebellar metastasis and compare the treatment modalities.

MATERIAL AND METHODS:

A total of 35 patients with single small cerebellar metastasis were included in this retrospective analysis. Of the 35 patients, 24 had surgery followed by whole-brain radiation therapy and 11 had Gamma Knife radiosurgery alone.

RESULTS:

The median survival for the whole cohort was 5.6 months after the intervention. No significant differences were noted in median survival between the surgery plus whole-brain radiation therapy and the Gamma Knife radiosurgery alone groups (6.3 months: 95% confidence interval [CI], 4.0-8.6; vs 5.0 months: 95% CI, 1.9-8.1; P = .9). There was no difference in the median time to local progression, distance progression, and overall progression between the 2 groups. Patients with hydrocephalus had a significantly lower survival rate (median, 3.3 months; 95% CI, 0.0-6.6) compared with those without hydrocephalus (median, 6.9 months; 95% CI, 4.4-9.8; P = .02). In the Cox regression model, the significant predictor of survival was hydrocephalus (P = .01; hazard ratio, 3.5; 95% CI, 1.3-9.1) after propensity score adjustment.

CONCLUSION:

Treatment with Gamma Knife radiosurgery alone and surgery plus whole-brain radiation therapy were both efficacious in patients with single small cerebellar metastasis. Overall survival was nearly identical in both treatment groups.

Carmustine and methotrexate in combination after whole brain radiation therapy in breast cancer patients presenting with brain metastases: a retrospective study

Background

Since 1999, patients presenting with brain metastases (BM) from breast cancer (BC) are treated in our institution with a carmustine (BCNU) - methotrexate (MTX) combination. We report here our clinical experience regarding this combination.

Patients and Methods

Patients were treated by a combination of BCNU 100 mg/m² on day 1 and MTX 600 mg/m² on day 1 and 15 of a 28 day cycle. Treatment was continued until progression or unacceptable toxicity.

Results

50 patients were treated between 1999 and 2007. 94% of the patients presented with concomitant extra-cerebral disease. Median number of previous metastatic setting chemotherapy regimens was 2 (0-5). Median number of cycles was 3 (1-20). There were 11 objective responses (23% [95%CI 12-37]) among 48 evaluable patients. Median progression-free survival and overall survival (OS) were 4.2 (95%CI: 2.8-5.3) and 6.9 (4.2-10.7) months respectively, with a one-year OS rate of 32% (20-46). Median Relative Dose Intensity for BCNU and MTX were 0.98 (0.31-1.1) and 0.96 (0.57-1.66) respectively. There were 2 presumed treatment-related deaths. One patient developed febrile neutropenia. Performance status, BS-BM score and presence of liver metastases were associated with OS in univariate analysis.

Conclusions

This combination appears to be effective and well tolerated in good performance status BC patients presenting with BM.

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.

Imaging patients with suspected brain tumour: guidance for primary care

The number of referrals by primary care practitioners to secondary care neurology services, particularly for headache, may be difficult to justify. Access to imaging by primary care practitioners could avoid referral without compromising patient outcomes, but the decision to refer is based on a number of complex factors. Due to the paucity of rigorous evidence in this area, available data are combined with expert opinion to offer support for GPs. The study suggests management for three levels of risk of tumour: red flags>1%; orange flags 0.1-1%; and yellow flags<0.1% but above the background population rate of 0.01%. Clinical presentations are stratified into these three groups. Important secondary causes of headache where imaging is normal should not be overlooked, and normal investigation does not eliminate the need for follow-up or appropriate management of headache.

Phase 2 trial of temozolomide using protracted low-dose and whole-brain radiotherapy for nonsmall cell lung cancer and breast cancer patients with brain metastases

BACKGROUND

Temozolomide (TMZ), an oral methylating imidazotetrazinone, has antitumor activity against gliomas, malignant melanomas, and brain metastasis and is presently administered as a 5-day oral schedule every 4 weeks.

METHODS

A single-institution phase 2 clinical trial was conducted to determine the efficacy and the safety profile of a new regimen based on a dose-intensified, protracted course of TMZ after whole-brain radiotherapy (WBRT). Patients were eligible if they had at least 1 bidimensionally measurable brain metastasis from breast cancer and nonsmall cell lung cancer (NSCLC). Twenty-seven patients were treated with 30 grays (Gy) of WBRT with concomitant TMZ (75 mg/m(2)/day) for 10 days, and subsequent TMZ at a dose of 75 mg/m(2) per day for 21 days every 4 weeks, for up to 12 cycles.

RESULTS

Two complete responses (7.4%) and 11 partial responses (40.7%) were achieved. The schedule appeared to be well tolerated, with grade 3 toxicity (graded according to National Cancer Institute Common Toxicity Criteria) observed in only 2 patients. The overall median survival was 8.8 months and the median progression-free survival was 6 months.

CONCLUSIONS

The concomitant use of WBRT and protracted low-dose TMZ appears to be an active, well-tolerated regimen. The observed antitumor activity suggests the need for further investigation of this schedule in combination with other anticancer agents for the concomitant treatment of brain metastases and primary cancers.

Improving accuracy in astrocytomas grading by integrating a robust least squares mapping driven support vector machine classifier into a two level grade classification scheme

Grading of astrocytomas is an important task for treatment planning; however, it suffers from significantly great inter-observer variability. Computer-assisted diagnosis systems have been propose to assist towards minimizing subjectivity, however, these systems present either moderate accuracy or utilize specialized staining protocols and grading systems that are difficult to apply in daily clinical practice. The present study proposes a robust mathematical formulation by integrating state-of-art technologies (support vector machines and least squares mapping) in a cascade classification scheme for separating low from high and grade III from grade IV astrocytic tumours. Results have indicated that low from high-grade tumours can be correctly separated with a certainty as high as 97.3%, whereas grade III from grade IV tumours with 97.8%. The overall performance was 95.2%. These high rates have been a result of applying the least squares mapping technique to features prior to classification. A significant byproduct of least squares mapping is that the number of support vectors of the SVM classifiers dropped dramatically from about 80% when no mapping was used to less than 5% when mapping was used. The latter is a clear indication that the SVM classifier has a greater potential to generalize well to new data. In this way, digital image analysis systems for automated grading of astrocytomas are brought closer to clinical practice.

Patterns of practice and survival in a retrospective analysis of 1722 adult astrocytoma patients treated between 1985 and 2001 in 12 Italian radiation oncology centers

PURPOSE

To analyze the patterns of practice and survival in a series of 1722 adult astrocytoma patients treated in 12 Italian radiotherapy centers.

METHODS AND MATERIALS

A total of 1722 patients were treated with postoperative radiotherapy (90% World Health Organization [WHO] Grade 3-4, 62% male, 44% aged >60 years, 25% with severe neurologic deficits, 44% after gross total resection, 52% with high-dose radiotherapy, and 16% with chemotherapy). Variations in the clinical-therapeutic features in three subsequent periods (1985 through 2001) were evaluated, along with overall survival for the different subgroups.

RESULTS

The proportion of women, of older patients, of those with worse neurologic performance status (NPS), with WHO Grade 4, and with smaller tumors increased with time, as did the proportion of those treated with radical surgery, hypofractionated radiotherapy, and more sophisticated radiotherapy techniques, after staging procedures progressively became more accurate. The main prognostic factors for overall survival were age, sex, neurologic performance status, WHO grade, extent of surgery, and radiation dose.

CONCLUSIONS

Recently, broader selection criteria for radiotherapy were adopted, together with simpler techniques, smaller total doses, and larger fraction sizes for the worse prognostic categories. Younger, fit patients are treated more aggressively, more often in association with chemotherapy. Survival did not change over time. The accurate evaluation of neurologic status is therefore of utmost importance before the best treatment option for the individual patient is chosen.

Targeting of melanoma brain metastases using engineered neural stem/progenitor cells

Brain metastases are an increasingly frequent and serious clinical problem for cancer patients, especially those with advanced melanoma. Given the extensive tropism of neural stem/progenitor cells (NSPCs) for pathological areas in the central nervous system, we expanded investigations to determine whether NSPCs could also target multiple sites of brain metastases in a syngeneic experimental melanoma model. Using cytosine deaminase-expressing NSPCs (CD-NSPCs) and systemic 5-fluorocytosine (5-FC) pro-drug administration, we explored their potential as a cell-based targeted drug delivery system to disseminated brain metastases. Our results indicate a strong tropism of NSPCs for intracerebral melanoma metastases. Furthermore, in our therapeutic paradigm, animals with established melanoma brain metastasis received intracranial implantation of CD-NSPCs followed by systemic 5-FC treatment, resulting in a significant (71%) reduction in tumor burden. These data provide proof of principle for the use of NSPCs for targeted delivery of therapeutic gene products to melanoma brain metastases.

Phase I study of capecitabine in combination with temozolomide in the treatment of patients with brain metastases from breast carcinoma

BACKGROUND

A single-institution Phase I clinical trial was conducted to determine the maximum tolerated dose (MTD) and define the safety profile of temozolomide and capecitabine when used in combination to treat brain metastases from breast cancer.

METHODS

Patients were eligible if they had bidimensionally measurable supratentorial or infratentorial brain metastasis from histologically confirmed breast carcinoma. Patients could have received up to 3 prior chemotherapy regimens. Temozolomide and capecitabine were administered concomitantly to 4 sequential cohorts at different dosing levels on Days 1-5 and Days 8-12, with cycles repeated every 21 days until disease progression.

RESULTS

Twenty-four patients with multiple brain lesions were treated, including 14 patients with newly diagnosed brain metastases and 10 patients with recurrent brain metastases. Only 1 patient was chemotherapy-naive. Fatigue and nausea were the most commonly observed toxicities observed at any dose levels. Significant antitumor activity was observed, with a total of 1 complete and 3 partial responses (18% objective response rate) in the brain. The median response duration was 8 weeks (range, 6-64 weeks) and the median time to progression in the brain was 12 weeks (range, 3-70 weeks). Neurocognitive function improved or remained stable in patients with a response or stable disease.

CONCLUSIONS

The combination of temozolomide and capecitabine is an active, well-tolerated regimen. The observed antitumor activity warrants further evaluation of this combination as an alternative to or in combination with whole-brain radiation therapy for the treatment of multiple brain metastases.

Biomarkers for risk assessment in molecular epidemiology of cancer

One out of four deaths in the USA is due to cancer. Identification of populations at risk of developing cancer is important as it provides opportunities for prevention and treatment of cancer. Biomarkers are measurable indicators of exposure effects and susceptibility or disease state, and are used to understand the mechanisms of cancer progression. In recent molecular epidemiology studies genomic, proteomic, and epigenomic markers have been utilized which exhibit high sensitivity and specificity for different tumor types and can be assayed in biofluids and other specimens collected by non-invasive technologies. The current challenges and future directions in the field are discussed in this article.

Perfusion MR imaging of brain tumors

Brain tumors rank second as the cause of cancer-related deaths in children and adults younger than 34 years old, and they are seen in adults of all ages. Primary malignant brain tumors are associated with the third highest cancer-related mortality rate and a disproportionate level of disability and morbidity. Considering this, accurate diagnosis and grading of brain tumors are critical to determining prognosis and therapy. Equally important is to evaluate for tumor status during therapy to assess for therapeutic response and treatment-related complications. Brain tumors can be characterized as a heterogeneous group of neoplasm with a correspondingly wide variation in malignant phenotype and a diverse array of imaging features. Magnetic resonance (MR) imaging with intravenous contrast agent is the test of choice to diagnose and monitor brain tumors before, during, and after therapy. Recent advances in imaging methods such as diffusion-weighted imaging, perfusion imaging, and spectroscopic imaging all have in common the ability to provide quantitative cellular, hemodynamic, and metabolic information that may enhance our understanding of brain tumor biology, help us to better assess treatment response, more accurately determine tumor activity during therapy, and differentiate recurrent tumor and treatment related complications. In this article, we will review the basics of brain tumor imaging and focus on the role of perfusion MR imaging in improving accurate diagnosis and monitoring brain tumors during therapy. Both strengths and shortcomings of perfusion MR imaging over standard anatomic MR imaging will be discussed as will important pitfalls of the technique.