Stationary-to-migratory transition in glioblastoma stem-like cells driven by a fatty acid-binding protein 7-RXRα neurogenic pathway

BACKGROUND

Glioblastoma (GBM) stem-like cells (GSCs) are crucial drivers of treatment resistance and tumor recurrence. While the concept of "migrating" cancer stem cells was proposed a decade ago, the roles and underlying mechanisms of the heterogeneous populations of GSCs remain poorly defined.

METHODS

Cell migration using GBM cell lines and patient-derived GSCs was examined using Transwell inserts and the scratch assay. Single-cell RNA sequencing data analysis were used to map GSC drivers to specific GBM cell populations. Xenografted mice were used to model the role of brain-type fatty acid-binding protein 7 (FABP7) in GBM infiltration and expansion. The mechanism by which FABP7 and its fatty acid ligands promote GSC migration was examined by gel shift and luciferase gene reporter assays.

RESULTS

A subpopulation of FABP7-expressing migratory GSCs was identified, with FABP7 upregulating SOX2, a key modulator for GBM stemness and plasticity, and ZEB1, a prominent factor in GBM epithelial-mesenchymal transition and invasiveness. Our data indicate that GSC migration is driven by nuclear FABP7 through activation of RXRα, a nuclear receptor activated by polyunsaturated fatty acids (PUFAs).

CONCLUSION

Infiltrative progression in GBM is driven by migratory GSCs through activation of a PUFA-FABP7-RXRα neurogenic pathway.

Does Loosening the Inclusion Criteria of the CROSS Trial Impact Outcomes in the Curative-Intent Trimodality Treatment of Oesophageal and Gastroesophageal Cancer Patients?

AIM

To determine the efficacy of preoperative chemoradiotherapy as per the CROSS protocol for oesophageal/gastroesophageal junction cancer (OEGEJC), when expanded to patients outside of the inclusion/exclusion criteria defined in the original clinical trial.

MATERIALS AND METHODS

Data were collected retrospectively on 229 OEGEJC patients referred for curative-intent preoperative chemoradiotherapy. Outcomes including pathological complete response (pCR), overall survival (OS), cancer-specific survival and recurrence-free survival (RFS) of patients who met CROSS inclusion criteria (MIC) versus those who failed to meet criteria (FMIC) were determined.

RESULTS

In total, 42.8% of patients MIC, whereas 57.2% FMIC; 16.6% of patients did not complete definitive surgery. The MIC cohort had higher rates of pCR, when compared with the FMIC cohort (33.3% versus 20.6%, P = 0.039). The MIC cohort had a better RFS, cancer-specific survival and OS compared with the FMIC cohort (P = 0.006, P = 0.004 and P = 0.009, respectively). Age >75 years and pretreatment weight loss >10% were not associated with a poorer RFS (P = 0.541 and 0.458, respectively). Compared with stage I-III patients, stage IVa was associated with a poorer RFS (hazard ratio (HR) = 2.158; 95% confidence interval (CI) = 1.339-3.480, P = 0.001). Tumours >8 cm in length or >5 cm in width had a trend towards worse RFS (HR = 2.060; 95% CI = 0.993-4.274, P = 0.052).

CONCLUSION

Our study showed that the robust requirements of the CROSS trial may limit treatment for patients with potentially curable OEGEJC and can be adapted to include patients with a good performance status who are older than 75 years or have >10% pretreatment weight loss. However, the inclusion of patients with celiac nodal metastases or tumours >8 cm in length or >5 cm in width may be associated with poor outcomes.

Feasibility of Implementing Cancer-Specific Community-Based Exercise Programming: A Multi-Centre Randomized Trial

BACKGROUND

There is growing recognition of the importance of reporting preliminary work on the feasibility of a trial. The present study aimed to assess the feasibility of (1) a proposed fitness testing battery, and (2) processes related to the implementation of cancer-specific exercise programming in a community setting.

METHODS/DESIGN

A randomized controlled implementation feasibility trial was performed in advance of a large-scale implementation study. Eligible participants within 18 months of a cancer diagnosis were randomized to immediate or delayed community-based exercise at YMCA locations in Calgary and Edmonton, Canada for an 8-week period. The primary outcome for the trial was the feasibility of the physical fitness testing battery, defined as a 70% or greater completion rate across the 24-week study period. The Reach, Effectiveness, Adoption, Implementation and Maintenance (RE-AIM) framework was used to evaluate processes related to implementation of the exercise program across the two sites.

RESULTS

Eighty participants were recruited, 73 (91%) completed the 8-week trial, and 68 (85%) completed the 16- and 24-week follow-ups. Sixty participants (75%) completed the full physical fitness test battery at each time point, and 59 (74%) completed the patient-reported outcome measures. Statistically significant between-group differences were found in favor of the exercise group for functional aerobic capacity, upper and lower extremity strength, and symptoms. Differences were found between the sites, however, in completion rates and processes related to program implementation.

DISCUSSION

Findings suggest the need for minor adaptations to the physical fitness battery and outcome measures to better fit the community context. While findings support feasibility, context-specific challenges related to implementation processes were identified.

ACE-Neuro: A tailored exercise oncology program for neuro-oncology patients – Study protocol

Background

Methods

Conclusion

•

Neuro-oncology patients require access to tailored exercise oncology programs.

•

The feasibility of a tailored neuro-oncology exercise program is being examined.

•

Patients are referred and triaged via the electronic medical record.

•

Intervention includes tailored exercise, an activity tracker, and health coaching.

•

This work supports the implementation of exercise within neuro-oncology care.

How well do European patients understand cancer-associated thrombosis? A patient survey

Ongoing concerns regarding the morbidity and mortality from cancer-associated thrombosis led the European Cancer Patient Coalition (ECPC), the voice of cancer patients across Europe, to create a pan-European cancer-associated awareness patient survey to assess cancer-associated thrombosis (CAT) knowledge among a large population of patients with cancer. The ECPC survey represents the largest of its kind among patients/caregivers with CAT. It identified significant gaps in patient awareness and knowledge of CAT as well as a need for educational CAT-related discussions and interventions between healthcare professionals and patients with cancer and their caregivers. The aim of this paper is to highlight these gaps and to provide awareness of what/when information should be shared with patients/caregivers. Notably, the importance of providing information on how to reduce their risk of CAT, the role of anticoagulant prophylaxis and treatment (short- and long-term) including possible side-effects, and finally how to identify CAT symptoms early. Here we outline what type of information should be provided, as well as when and how to best discuss CAT with our oncology patients and their caregivers along the cancer care continuum, to reduce the risk of CAT and associated complications with a goal of improving patient outcomes.

Oncology Patients' Experiences With Novel Electronic Patient Portals to Support Care and Treatment: Qualitative Study With Early Users and Nonusers of Portals in Alberta, Canada

Background

With the current proliferation of clinical information technologies internationally, patient portals are increasingly being adopted in health care. Research, conducted mostly in the United States, shows that oncology patients have a keen interest in portals to gain access to and track comprehensive personal health information. In Canada, patient portals are relatively new and research into their use and effects is currently emerging. There is a need to understand oncology patients’ experiences of using eHealth tools and to ground these experiences in local sociopolitical contexts of technology implementation, while seeking to devise strategies to enhance portal benefits.

Objective

The purpose of this study was to explore the experiences of oncology patients and their family caregivers when using electronic patient portals to support their health care needs. We focused on how Alberta’s unique, 2-portal context shapes experiences of early portal adopters and nonadopters, in anticipation of a province-wide rollout of a clinical information system in oncology facilities.

Methods

This qualitative descriptive study employed individual semistructured interviews and demographic surveys with 11 participants. Interviews were audio-recorded and transcribed verbatim. Data were analyzed thematically. The study was approved by the University of Alberta Human Research Ethics Board.

Results

Participants currently living with nonactive cancer discussed an online patient portal as one among many tools (including the internet, phone, videoconferencing, print-out reports) available to make sense of their diagnosis and treatment, maintain connections with health care providers, and engage with information. In the Fall of 2020, most participants had access to 1 of 2 of Alberta’s patient portals and identified ways in which this portal was supportive (or not) of their ongoing health care needs. Four major themes, reflecting the participants’ broader concerns within which the portal use was occurring, were generated from the data: (1) experiencing doubt and the desire for transparency; (2) seeking to become an informed and active member of the health care team; (3) encountering complexity; and (4) emphasizing the importance of the patient–provider relationship.

Conclusions

Although people diagnosed with cancer and their family caregivers considered an online patient portal as beneficial, they identified several areas that limit how portals support their oncology care. Providers of health care portals are invited to recognize these limitations and work toward addressing them.

Repeat Resection in Recurrent Glioblastoma (3rGBM) Trial: a randomized care trial

BACKGROUND

The prognosis for patients with recurrent glioblastoma (GBM) is dismal, and the question of repeat surgery at time of recurrence is common. Re-operation in the management of these patients remains controversial, as there is no randomized evidence of benefit. An all-inclusive pragmatic care trial is needed to evaluate the role of repeat resection.

METHODS

3rGBM is a multicenter, pragmatic, prospective, parallel-group randomized care trial, with 1:1 allocation to repeat resection or standard care with no repeat resection. To test the hypothesis that repeat resection can improve overall survival by at least 3 months (from 6 to 9 months), 250 adult patients with prior resection of pathology-proven glioblastoma for whom the attending surgeon believes repeat resection may improve quality survival will be enrolled. A surrogate measure of quality of life, the number of days outside of hospital/nursing/palliative care facility, will also be compared. Centers are invited to participate without financial compensation and without contracts. Clinicians may apply to local authorities to approve an investigator-led in-house trial, using a common protocol, web-based randomization platform, and simple standardized case report forms.

DISCUSSION

The 3rGBM trial is a modern transparent care research framework with no additional risks, tests, or visits other than what patients would encounter in normal care. The burden of proof remains on repeat surgical management of recurrent GBM, because this management has yet to be shown beneficial. The trial is designed to help patients and surgeons manage the uncertainty regarding optimal care.

CLINICAL TRIAL REGISTRATION

http://www.clinicaltrials.gov. Unique identifier: NCT04838782.

Clinical Uncertainty and Equipoise in the Management of Recurrent Glioblastoma

BACKGROUND

A significant proportion of glioblastoma (GBM) patients are considered for repeat resection, but evidence regarding best management remains elusive. Our aim was to measure the degree of clinical uncertainty regarding reoperation for patients with recurrent GBM.

METHODS

We first performed a systematic review of agreement studies examining the question of repeat resection for recurrent GBM. An electronic portfolio of 37 pathologically confirmed recurrent GBM patients including pertinent magnetic resonance images and clinical information was assembled. To measure clinical uncertainty, 26 neurosurgeons from various countries, training backgrounds, and years' experience were asked to select best management (repeat surgery, other nonsurgical management, or conservative), confidence in recommended management, and whether they would include the patient in a randomized trial comparing surgery with nonsurgical options. Agreement was evaluated using κ statistics.

RESULTS

The literature review did not reveal previous agreement studies examining the question. In our study, agreement regarding best management of recurrent GBM was slight, even when management options were dichotomized (repeat surgery vs. other options; κ=0.198 [95% confidence interval: 0.133-0.276]). Country of practice, years' experience, and training background did not change results. Disagreement and clinical uncertainty were more pronounced within clinicians with (κ=0.167 [0.055-0.314]) than clinicians without neuro-oncology fellowship training (κ=0.601 [0.556-0.646]). A majority (51%) of responders were willing to include the patient in a randomized trial comparing repeat surgery with nonsurgical alternatives in 26/37 (69%) of cases.

CONCLUSION

There is sufficient uncertainty and equipoise regarding the question of reoperation for patients with recurrent glioblastoma to support the need for a randomized controlled trial.

Aggressive Childhood-onset Papillary Craniopharyngioma Managed With Vemurafenib, a BRAF Inhibitor

The papillary subtype of craniopharyngioma (CP) rarely occurs in children and commonly presents as a suprasellar lesion. Patients with papillary CPs frequently harbor the BRAF-V600E mutation, and treatment with a BRAF inhibitor results in tumor shrinkage in several patients. Herein, we report a patient with childhood-onset papillary CP treated with vemurafenib for 40 months after multiple surgeries. At age 10, he presented with growth failure secondary to an intrasellar cystic lesion. He had 3 transsphenoidal surgeries before age 12 and a 4^th surgery 25 years later for massive tumor recurrence. Pathology showed a papillary CP with positive BRAF-V600E mutation. Rapid tumor regrowth 4 months after surgery led to treatment with vemurafenib that resulted in tumor reduction within 6 weeks. Gradual tumor regrowth occurred after a dose reduction of vemurafenib because of elevated liver enzymes. He had further surgeries and within 7 weeks after stopping vemurafenib, there was massive tumor recurrence. He resumed treatment with vemurafenib before radiation therapy and similar tumor shrinkage occurred within 16 days. In this patient with childhood-onset papillary CP that was refractory to multiple surgeries, the use of vemurafenib resulted in significant tumor shrinkage that allowed for the completion of radiation therapy and tumor control.

Risk factors for venous thromboembolism in endometrial cancer

Background

Venous thromboembolism (vte) in malignancy is associated with poor outcomes. We conducted a retrospective review of vte in patients with endometrial cancer to characterize the vte incidence, identify factors that contribute to vte risk, and compare survival outcomes in patients with and without vte.

Methods

A retrospective chart review identified 422 eligible patients who underwent surgery for endometrial cancer (1 January 2014 to 31 July 2016). The primary outcome was vte. Binary logistic regression identified risk factors for vte; significant risk factors were included in a multivariate analysis. Kaplan-Meier estimates are reported, and log rank tests were used to compare the Kaplan-Meier curves. Risk-adjusted estimates for overall survival based on vte were determined using a multivariate Cox proportional hazards model.

Results

The incidence of vte was 6.16% overall and 0.7% within 60 days postoperatively. Non-endometrioid histology, stages 3 and 4 disease, laparotomy, and age (p < 0.1) were identified as factors associated with vte and were included in a multivariate analysis. The overall death rate in patients with vte was 42% (9% without vte): hazard ratio, 5.63; 95% confidence interval, 2.86 to 11.08; p < 0.0001. Adjusting for age, stage of disease, and histology, risk of death remained significant for patients with a vte: hazard ratio, 2.20; 95% confidence interval, 1.09 to 4.42; p = 0.0271.

Conclusions

A method to identify patients with endometrial cancer who are at high risk for vte is important, given the implications of vte for patient outcomes and the frequency of endometrial cancer diagnoses. Factors identified in our study might assist in the recognition of such patients.

Outcomes of Patients With Advanced Gastrointestinal Cancer in Relationship to Opioid Use: Findings From Eight Clinical Trials

BACKGROUND

This study assessed the patterns of opioid use among patients with advanced gastrointestinal cancers who were included in 8 clinical trials and evaluated the impact of opioid use on survival outcomes of included patients.

METHODS

Deidentified datasets from 8 clinical trials evaluating first-line systemic treatment of advanced gastrointestinal cancers were accessed from the Project Data Sphere platform (ClinicalTrial.gov identifiers: NCT01124786, NCT00844649, NCT00290966, NCT00678535, NCT00699374, NCT00272051, NCT00305188, and NCT00384176). These trials evaluated patients with pancreatic carcinoma, gastric carcinoma, hepatocellular carcinoma (HCC), and colorectal carcinoma. Multivariable logistic regression analysis was used to evaluate factors predicting the use of opioids. Kaplan-Meier survival estimates were used to compare survival outcomes in each disease entity among patients who did or did not receive opioid treatment. Multivariable Cox regression analysis was then used to further assess the impact of opioid use on survival outcomes in each disease entity.

RESULTS

A total of 3,441 participants were included in the current analysis. The following factors predicted a higher probability of opioid use within logistic regression analysis: younger age at diagnosis (odds ratio [OR], 0.990; 95% CI, 0.984-0.997; P=.004), nonwhite race (OR for white vs nonwhite, 0.749; 95% CI, 0.600-0.933; P=.010), higher ECOG score (OR for 1 vs 0, 1.751; 95% CI, 1.490-2.058; P<.001), and pancreatic primary site (OR for colorectal vs pancreatic, 0.241; 95% CI, 0.198-0.295; P<.001). Use of opioids was consistently associated with worse overall survival (OS) in Kaplan-Meier survival estimates of each disease entity (P=.008 for pancreatic cancer; P<.001 for gastric cancer, HCC, and colorectal cancer). In multivariable Cox regression analysis, opioid use was associated with worse OS among patients with pancreatic cancer (hazard ratio [HR], 1.245; 95% CI, 1.063-1.459; P=.007), gastric cancer (HR, 1.725; 95% CI, 1.403-2.122; P<.001), HCC (HR, 1.841; 95% CI, 1.480-2.290; P<.001), and colorectal cancer (HR, 1.651; 95% CI, 1.380-1.975; P<.001).

CONCLUSIONS

Study findings suggest that opioid use is consistently associated with worse OS among patients with different gastrointestinal cancers. Further studies are needed to understand the underlying mechanisms of this observation and its potential implications.

Feasibility of performance-based functional assessment in brain tumour survivors

INTRODUCTION

Rehabilitation and exercise interventions are beneficial for the physical and psychological health of cancer survivors. Current clinic-based performance status measures do not accurately capture the survivor's functioning, or rehabilitation and exercise needs. Our primary objective was to explore the feasibility of performing a performance-based functional assessment with brain tumour survivors as a means to inform needs for rehabilitation and exercise.

METHODS

A feasibility study was conducted with survivors of brain and other neurological cancers attending new patient or follow-up clinics. Survivors were assessed using the Short Physical Performance Battery (SPPB), grip strength and Rosow-Breslau Physical Activity Self-Assessment (RSB).

RESULTS

We approached 40 survivors with brain tumours, and 30 agreed to participate in the study. The SPPB was inversely correlated with Eastern Cooperative Oncology Group (ECOG) scores (r = -.73; p < .01), but scores on the SPPB for individuals classified as ECOG 1 ranged from 5 to 12 out of 12, indicating a large variability in functional scores within this ECOG grade.

CONCLUSION

Implementation of objective functional testing is feasible in the neuro-oncology outpatient clinic. The SPPB appears to best inform the functional status of survivors with brain tumours, facilitating more individualised exercise and rehabilitation referrals.

Outcomes of advanced gastrointestinal (GI) cancer patients in relationship to opioid use: An individual patient data pooled analysis from eight clinical trials

687

Background: The current study aims at assessing the patterns of opioid use, and evaluating the impact of opioid use on survival outcomes among patients with advanced GI cancers who were included in eight clinical trials. Methods: De-identified datasets of eight clinical trials evaluating first-line systemic treatment for advanced GI cancers (NCT01124786; NCT00844649; NCT00290966; NCT00678535; NCT00699374; NCT00272051; NCT00305188; NCT00384176) were accessed from the Project Data Sphere platform. These trials evaluated patients with pancreatic, gastric, hepatocellular and colorectal carcinoma. Multivariable logistic regression analysis was used to evaluate factors predicting the use of opioids. Kaplan-Meier survival estimates were used to compare survival outcomes in each disease entity among patients who did or did not receive opioid treatment. Multivariable Cox regression analysis was used to assess the impact of opioid use on survival outcomes in each disease entity. Results: A total of 3441 participants were included in the current analysis. The following factors predicted a higher probability of opioid use within logistic regression analysis: younger age (P = 0.004), non-white race (P = 0.010), higher ECOG score (P < 0.001) and pancreatic primary site (P < 0.001). Use of opioids was consistently associated with worse overall survival in Kaplan-Meier survival estimates of each disease entity (for pancreatic cancer: P = 0.008; for gastric cancer: P < 0.001; for hepatocellular carcinoma: P < 0.001 and for colorectal cancer: P < 0.001). Within multivariable Cox regression analysis, opioid use was associated with worse overall survival among patients with pancreatic cancer (HR = 1.245; 95% CI: 1.063-1.459; P = 0.007), gastric cancer (HR = 1.725; 95% CI: 1.403-2.122; P < 0.001), hepatocellular carcinoma (HR = 1.841; 95 CI: 1.480-2.290; P < 0.001) and colorectal cancer (HR = 1.651; 95% CI: 1.380-1.975; P < 0.001). Conclusions: Opioid use is consistently associated with worse overall survival among patients with different GI cancers. Further studies are needed to evaluate the underlying mechanisms of this observation.

Influence of Treatment With Tumor-Treating Fields on Health-Related Quality of Life of Patients With Newly Diagnosed Glioblastoma: A Secondary Analysis of a Randomized Clinical Trial

Importance

Tumor-treating fields (TTFields) therapy improves both progression-free and overall survival in patients with glioblastoma. There is a need to assess the influence of TTFields on patients' health-related quality of life (HRQoL).

Objective

To examine the association of TTFields therapy with progression-free survival and HRQoL among patients with glioblastoma.

Design, Setting, and Participants

This secondary analysis of EF-14, a phase 3 randomized clinical trial, compares TTFields and temozolomide or temozolomide alone in 695 patients with glioblastoma after completion of radiochemotherapy. Patients with glioblastoma were randomized 2:1 to combined treatment with TTFields and temozolomide or temozolomide alone. The study was conducted from July 2009 until November 2014, and patients were followed up through December 2016.

Interventions

Temozolomide, 150 to 200 mg/m2/d, was given for 5 days during each 28-day cycle. TTFields were delivered continuously via 4 transducer arrays placed on the shaved scalp of patients and were connected to a portable medical device.

Main Outcomes and Measures

Primary study end point was progression-free survival; HRQoL was a predefined secondary end point, measured with questionnaires at baseline and every 3 months thereafter. Mean changes from baseline scores were evaluated, as well as scores over time. Deterioration-free survival and time to deterioration were assessed for each of 9 preselected scales and items.

Results

Of the 695 patients in the study, 639 (91.9%) completed the baseline HRQoL questionnaire. Of these patients, 437 (68.4%) were men; mean (SD) age, 54.8 (11.5) years. Health-related quality of life did not differ significantly between treatment arms except for itchy skin. Deterioration-free survival was significantly longer with TTFields for global health (4.8 vs 3.3 months; P < .01); physical (5.1 vs 3.7 months; P < .01) and emotional functioning (5.3 vs 3.9 months; P < .01); pain (5.6 vs 3.6 months; P < .01); and leg weakness (5.6 vs 3.9 months; P < .01), likely related to improved progression-free survival. Time to deterioration, reflecting the influence of treatment, did not differ significantly except for itchy skin (TTFields worse; 8.2 vs 14.4 months; P < .001) and pain (TTFields improved; 13.4 vs 12.1 months; P < .01). Role, social, and physical functioning were not affected by TTFields.

Conclusions and Relevance

The addition of TTFields to standard treatment with temozolomide for patients with glioblastoma results in improved survival without a negative influence on HRQoL except for more itchy skin, an expected consequence from the transducer arrays.

Trial Registration

clinicaltrials.gov Identifier: NCT00916409.

Community-based exercise for health promotion and secondary cancer prevention in Canada: protocol for a hybrid effectiveness-implementation study

INTRODUCTION

Cancer care has expanded from a disease-focused, survival-oriented model to an approach that now considers how survivors can live well in the aftermath of intensive therapy, where they may deal with significant changes to their bodies, mental health or emotional well-being. Research evidence supports the benefit of exercise during and following cancer treatments for cancer-related symptoms, physical functioning and fitness, and health-related quality of life. To move this efficacy evidence into practice, we designed and launched a 5-year study to evaluate the relative benefit from implementing a clinic-to-community-based cancer and exercise model of care.

METHODS AND ANALYSIS

A hybrid effectiveness and implementation trial design is being used to evaluate the effectiveness of delivery of community-based exercise and to collect data on implementation of the programme. The study opened in January 2017, with estimated completion by January 2022. The programme will be delivered in seven cities across the province of Alberta, Canada, with sites including three academic institutions, six YMCA locations, Wellspring Edmonton and Calgary, and six municipal fitness centres. Participants are adult cancer survivors (n=2500) from all tumour groups and stages and at any time point along their cancer treatment trajectory, up to 3 years post treatment completion. Survivors take part in a minimum of 60 min of mild-to-moderate intensity full body exercise twice weekly for a 12-week period. The primary effectiveness outcome is the proportion of participants meeting or exceeding 150 min of moderate intensity exercise per week at 1-year follow-up. The Reach, Effectiveness, Adoption, Implementation and Maintenance (RE-AIM) framework will be utilised to capture individual-level and organizational-level impact of the exercise programme at 12 and 24 weeks and 1-year follow-up. The cohort of survivors participating in the study will allow for long-term (>5-year) evaluation of rates of cancer recurrence and secondary cancers beyond the funding period.

ETHICS AND DISSEMINATION

The study was approved by the Health Research Ethics Board of Alberta. The study is funded by Alberta Innovates and the Alberta Cancer Foundation. The study will help to answer critical questions on the effectiveness of cancer-specific community-based exercise programming in both the short-term and the long-term. Collectively, the findings will help to inform the acceptability, adoption, feasibility, reach and sustainability of community-based exercise.

TRIAL REGISTRATION NUMBER

NCT02984163; Pre-results.

Accuracy of Resting Energy Expenditure Predictive Equations in Patients With Cancer

BACKGROUND

Our purpose was to assess the accuracy of resting energy expenditure (REE) equations in patients with newly diagnosed stage I-IV non-small cell lung, rectal, colon, renal, or pancreatic cancer.

METHODS

In this cross-sectional study, REE was measured using indirect calorimetry and compared with 23 equations. Agreement between measured and predicted REE was assessed via paired t-tests, Bland-Altman analysis, and percent of estimations ≤ 10% of measured values. Accuracy was measured among subgroups of body mass index (BMI), stage (I-III vs IV), and cancer type (lung, rectal, and colon) categories. Fat mass (FM) and fat-free mass (FFM) were assessed using dual x-ray absorptiometry.

RESULTS

Among 125 patients, most had lung, colon, or rectal cancer (92%, BMI: 27.5 ± 5.6 kg/m² , age: 61 ± 11 years, REE: 1629 ± 321 kcal/d). Thirteen (56.5%) equations yielded REE values different than measured (P < 0.05). Limits of agreement were wide for all equations, with Mifflin-St. Jeor equation having the smallest limits of agreement, -21.7% to 11.3% (-394 to 203 kcal/d). Equations with FFM were not more accurate except for one equation (Huang with body composition; bias, limits of agreement: -0.3 ± 11.3% vs without body composition: 2.3 ± 10.1%, P < 0.001). Bias in body composition equations was consistently positively correlated with age and frequently negatively correlated with FM. Bias and limits of agreement were similar among subgroups of patients.

CONCLUSION

REE cannot be accurately predicted on an individual level, and bias relates to age and FM.

A TITE-CRM phase I/II study of disulfiram and copper with concurrent radiation therapy and temozolomide for newly diagnosed glioblastoma

2033

Background: Disulfiram (DSF) has shown promising activity against glioblastoma in preclinical studies and is more effective when combined with copper (Cu). Our previous phase I study established the maximum tolerated dose (MTD) of DSF when combined with adjuvant temozolomide (TMZ). This phase I/II study aims to establish the MTD when disulfiram and copper are combined with concurrent radiation therapy (RT) and TMZ for newly diagnosed glioblastoma and to explore preliminary efficacy. Methods: Eligible patients were treated with standard RT and TMZ plus escalating doses of DSF (250 mg - 375 mg PO QD) and Cu (2 mg PO TID), followed by adjuvant TMZ plus DSF (500 mg/day) and Cu. The time-to-event continual reassessment method (TITE-CRM) was used to continuously estimate the probability of dose-limiting toxicity (DLT) and to assign patients to doses with an estimated DLT probability of approximately 20% with a margin of 5%. Tumor mutations were evaluated with next-generation sequencing for all patients. Results: Eighteen glioblastoma patients were treated with the study therapy: 8 with DSF of 250 mg/day and 10 with 375 mg/day. Three DLTs were observed: 1 with 250 mg/day (grade 2 urinary incontinence and ataxia), and 2 with 375 mg/day (both grade 3 elevated liver enzymes). DSF had an estimated DLT probability of 10% (95% CI: 3-29%) at 250 mg/day, and 21% (95% CI: 7-42%) at 375 mg/day. After a median follow-up of 12.3 months, 1-year progression-free survival (PFS) was 57%, and 1-year overall survival (OS) was 69%. There was no significant difference in PFS/OS when stratified by DSF doses, surgical extent, or MGMT methylation status. However, glioblastomas with IDH1 (n = 6), BRAF (n = 2), or NF1 (n = 1) mutations had significantly better PFS and OS than those without the mutations: 1-year PFS: 100% vs 22%, respectively, p = 0.001; 1-year OS: 100% vs 42%, respectively, p = 0.006. Conclusions: The MTD of DSF with RT/TMZ/Cu for glioblastoma is 375 mg/day, and the recommended phase II dose is 250 mg/day. Although confirmation with larger sample size is needed, the combination demonstrates promising preliminary efficacy for the subset of glioblastoma with IDH1, BRAF, and NF1 mutations. Clinical trial information: NCT02715609.

Evaluation of laboratory disturbance risk when adding low-dose cotrimoxazole for PJP prophylaxis to regimens of high-grade glioma patients taking RAAS inhibitors

BACKGROUND

Cotrimoxazole is associated with the development of hyponatremia, hyperkalemia and elevated serum creatinine, especially when combined with inhibitors of the renin-angiotensin-aldosterone system (RAAS). Pneumocystis jirovecii pneumonia (PJP) prophylaxis is the standard of care for high-grade glioma (HGG) patients receiving temozolomide concurrently with radiotherapy, low-dose cotrimoxazole being the preferred agent. Many of these patients are also taking renin-angiotensin-aldosterone system inhibitors, however the risk of significant laboratory disturbance in these patients remains undescribed.

OBJECTIVE

We evaluated whether high-grade glioma patients taking renin-angiotensin-aldosterone system inhibitors receiving low-dose cotrimoxazole for Pneumocystis jirovecii pneumonia prophylaxis are at additional risk of laboratory disturbances in comparison with their non-renin-angiotensin-aldosterone system counterparts.

METHODS

We conducted a retrospective chart review of adult neuro-oncology patients treated for WHO Grade III or IV glioma between 2013 and 2016. Patient serum Na, K, creatinine, and eGFR were compared (renin-angiotensin-aldosterone system vs. non-renin-angiotensin-aldosterone system) using the chi-square test. Binary logistic regression analysis was then performed to account for differences between cohorts.

RESULTS

Of 63 patients (35 non-renin-angiotensin-aldosterone system, 28 renin-angiotensin-aldosterone system), patients in the renin-angiotensin-aldosterone system cohort were more likely to experience a laboratory disturbance (odds ratio=3.17, p = 0.03). Overall, these disturbances were moderate, but were slightly more common and slightly more severe in the renin-angiotensin-aldosterone system cohort.

CONCLUSION

Adding low-dose cotrimoxazole for Pneumocystis jirovecii pneumonia prophylaxis to the regimens of patients with high-grade glioma taking renin-angiotensin-aldosterone system inhibitors increases the risk of laboratory disturbances. While these are generally moderate, some patients are at risk of significant electrolyte abnormalities requiring intervention.

Management of Medical Oncology Services in Canada: Redefined Workload With a Novel Supply-and-Demand Workforce Projection Model

Purpose:

We developed a workforce-planning model to predict Canadian medical oncologist (MO) supply and clinical demand during the next 10 years.

Materials and Methods:

A forward calculation model was created to forecast the balance of MO supply and demand. MO supply was estimated by using Canadian Institute for Health Information, Canadian Medical Association, and Canadian Post-MD Education Registry data. Care demand was estimated by using data from Canadian Cancer Statistics and Alberta Cancer Registry. The Canadian Royal College MO Committee confirmed its face validity.

Results:

The MO workforce is expected to grow from 541 staff in 2016 to 830 staff in 2026. During this period, new hires will increase from 39 to 56 per year, and departures will increase from 15 to 24 per year. Although cancer incidence rates will grow from 202,149 to 257,497, a projected increase in MO supply will mean fewer initial consultations, from an average of 168.5 consultations per MO in 2016 to 129.2 consultations per MO in 2026. The initiation of systemic therapy is projected to remain stable at 102.3 new systemic therapy starts per MO per year.

Conclusion:

We have developed a forward calculation MO workforce model that predicts a growing Canadian MO workforce and redefines MO workload dynamics. MO providers will increasingly support more follow-up care with the initiation of multiple lines of systemic therapy relative to the medical management of patients at the time of initial cancer diagnosis. Workload metrics, including follow-up and new therapy initiation rates, must be measured to appropriately to meet increasingly complex and growing care demands.

ClotAssist: A program to treat cancer-associated thrombosis in an outpatient pharmacy setting

Stable cancer patients diagnosed with a pulmonary embolus or deep vein thrombosis are commonly referred to the emergency department for management. This practice strains an already overburdened emergency department and is associated with long wait times and poor disease/injection education for patients. This pilot study sought to determine if stable cancer patients with newly diagnosed cancer-associated thrombosis could be effectively managed by community-based pharmacists who followed an evidence-based protocol to prescribe and initiate low-molecular weight heparin therapy. We hypothesized that this novel care pathway could provide faster patient care with more comprehensive disease education, self-injection training, and follow-up. Fifty-five patients with various cancers, including gastroesophageal, urogenital, breast, brain, and lung were enrolled into this pilot study. We observed that this alternative first-dose treatment pathway provided safe and effective treatment of venous thromboembolism combined with excellent patient satisfaction. Following their interaction with the pharmacist, patients felt confident about their ability to self-inject and about their venous thromboembolism management overall. No occurrences of bleeding or other side-effects were observed. This pilot study demonstrates that community-based pharmacists are capable of delivering complex care services in the outpatient environment, particularly in the management of venous thromboembolism.

PO-42 - A novel approach to a common problem: after-hours care of cancer patients diagnosed with VTE

INTRODUCTION

Oncologists often receive phone calls from radiologists after regular working hours or while on call, informing them that a cancer patient has been diagnosed with a blood clot. In these situations, there may not be nursing staff available to contact the patient and provide teaching for Low Molecular Weight Heparin (LMWH) injections. As a result, patients are often sent to the emergency for injection and teaching, taxing an already overburdened emergency department. This problem constitutes an important care gap.

AIM

In Alberta, Canada, pharmacists are able to prescribe medications including LMWH. We designed an after-hours program to provide care for cancer patients diagnosed with VTE.

MATERIALS AND METHODS

Once the oncologist is made aware of the patient with a clot, a simple one page document is filled out and faxed to a 24-hour outpatient pharmacy outlining the following: patient demographics, clot location, systemic therapy, current anticoagulant and anti-platelet agents. The oncologist has the option to specify desired LMWH. The patient goes to the pharmacy where the pharmacist weighs the patient, reviews blood work electronically and prescribes the LMWH. Also provided are injection teaching and telephone follow-up. A specific algorithm is followed with the pharmacist able to contact the on call oncologist in specific situations where the patient's condition falls outside of the algorithm guideline. The pharmacist is able to order blood work, particularly to evaluate for Heparin Induced Thrombocytopenia. Patients must follow up with their oncologist within 7 days of diagnosis.

RESULTS

This program has been run as a pilot and preliminary data will be presented at the ICTHIC meeting. Specifically, we will assess usage of the program, appropriateness of therapy chosen according to Canadian practice guidelines, as well as patient, pharmacist and physician satisfaction with the program.

CONCLUSIONS

We believe that this outpatient pharmacy program is innovative, will decrease burden on emergency departments, and takes advantage of our pharmacists' ability to independently assess patients and write prescriptions. This program may serve as a model for other cancer centers looking for a novel way to provide after-hours care of patients diagnosed with VTE.

Disulfiram when Combined with Copper Enhances the Therapeutic Effects of Temozolomide for the Treatment of Glioblastoma

PURPOSE

Glioblastoma is one of the most lethal cancers in humans, and with existing therapy, survival remains at 14.6 months. Current barriers to successful treatment include their infiltrative behavior, extensive tumor heterogeneity, and the presence of a stem-like population of cells, termed brain tumor-initiating cells (BTIC) that confer resistance to conventional therapies.

EXPERIMENTAL DESIGN

To develop therapeutic strategies that target BTICs, we focused on a repurposing approach that explored already-marketed (clinically approved) drugs for therapeutic potential against patient-derived BTICs that encompass the genetic and phenotypic heterogeneity of glioblastoma observed clinically.

RESULTS

Using a high-throughput in vitro drug screen, we found that montelukast, clioquinol, and disulfiram (DSF) were cytotoxic against a large panel of patient-derived BTICs. Of these compounds, disulfiram, an off-patent drug previously used to treat alcoholism, in the presence of a copper supplement, showed low nanomolar efficacy in BTICs including those resistant to temozolomide and the highly infiltrative quiescent stem-like population. Low dose DSF-Cu significantly augmented temozolomide activity in vitro, and importantly, prolonged in vivo survival in patient-derived BTIC models established from both newly diagnosed and recurrent tumors. Moreover, we found that in addition to acting as a potent proteasome inhibitor, DSF-Cu functionally impairs DNA repair pathways and enhances the effects of DNA alkylating agents and radiation. These observations suggest that DSF-Cu inhibits proteasome activity and augments the therapeutic effects of DNA-damaging agents (temozolomide and radiation).

CONCLUSIONS

DSF-Cu should be considered as an adjuvant therapy for the treatment of patients with glioblastoma in both newly diagnosed and recurrent settings. Clin Cancer Res; 22(15); 3860-75. ©2016 AACR.

Association between cytoplasmic CRABP2, altered retinoic acid signaling, and poor prognosis in glioblastoma

Retinoic acid (RA), a metabolite of vitamin A, is required for the regulation of growth and development. Aberrant expression of molecules involved in RA signaling has been reported in various cancer types including glioblastoma multiforme (GBM). Cellular retinoic acid-binding protein 2 (CRABP2) has previously been shown to play a key role in the transport of RA to retinoic acid receptors (RARs) to activate their transcription regulatory activity. Here, we demonstrate that CRABP2 is predominantly located in the cytoplasm of GBM tumors. Cytoplasmic, but not nuclear, CRABP2 levels in GBM tumors are associated with poor patient survival. Treatment of malignant glioma cell lines with RA results in a dose-dependent increase in accumulation of CRABP2 in the cytoplasm. CRABP2 knockdown reduces proliferation rates of malignant glioma cells, and enhances RA-induced RAR activation. Levels of CRYAB, a small heat shock protein with anti-apoptotic activity, and GFAP, an astrocyte-specific intermediate filament protein, are greatly reduced in CRABP2-depleted cells. Restoration of CRYAB expression partially but significantly reversed the effect of CRABP2 depletion on RAR activation. Our combined in vivo and in vitro data indicate that: (i) CRABP2 is an important determinant of clinical outcome in GBM patients, and (ii) the mechanism of action of CRABP2 in GBM involves sequestration of RA in the cytoplasm and activation of an anti-apoptotic pathway, thereby enhancing proliferation and preventing RA-mediated cell death and differentiation. We propose that reducing CRABP2 levels may enhance the therapeutic index of RA in GBM patients.

Canadian consensus recommendations on the management of venous thromboembolism in patients with cancer. Part 2: treatment

Patients with cancer are at increased risk of venous thromboembolism (vte). Anticoagulation therapy is used to treat vte; however, patients with cancer have unique clinical circumstances that can often make decisions surrounding the administration of therapeutic anticoagulation complicated. No national Canadian guidelines on the management of established cancer-associated thrombosis have been published. We therefore aimed to develop a consensus-based, evidence-informed guideline on the topic. PubMed was searched for clinical trials and meta-analyses published between 2002 and 2013. Reference lists of key articles were hand-searched for additional publications. Content experts from across Canada were assembled to review the evidence and make recommendations. Low molecular weight heparin is the treatment of choice for cancer patients with established vte. Direct oral anticoagulants are not recommended for the treatment of vte at this time. Specific clinical scenarios, including the presence of an indwelling venous catheter, renal insufficiency, and thrombocytopenia, warrant modifications in the therapeutic administration of anticoagulation therapy. Patients with recurrent vte should receive extended (>3 months) anticoagulant therapy. Incidental vte should generally be treated in the same manner as symptomatic vte. There is no evidence to support the monitoring of anti-factor Xa levels in clinically stable cancer patients receiving prophylactic anticoagulation; however, levels of anti-factor Xa could be checked at baseline and periodically thereafter in patients with renal insufficiency. Follow-up and education about the signs and symptoms of vte are important components of ongoing patient care.

Phase II study of PX-866 in recurrent glioblastoma

BACKGROUND

Glioblastoma (GBM) is the most aggressive malignancy of the central nervous system in adults. Increased activity of the phosphatidylinositol-3-OH kinase (PI3K) signal transduction pathway is common. We performed a phase II study using PX-866, an oral PI3K inhibitor, in participants with recurrent GBM.

METHODS

Patients with histologically confirmed GBM at first recurrence were given oral PX-866 at a dose of 8 mg daily. An MRI and clinical exam were done every 8 weeks. Tissue was analyzed for potential predictive markers.

RESULTS

Thirty-three participants (12 female) were enrolled. Median age was 56 years (range 35-78y). Eastern Cooperative Oncology Group performance status was 0-1 in 29 participants and 2 in the remainder. Median number of cycles was 1 (range 1-8). All participants have discontinued therapy: 27 for disease progression and 6 for toxicity (5 liver enzymes and 1 allergic reaction). Four participants had treatment-related serious adverse events (1 liver enzyme, 1 diarrhea, 2 venous thromboembolism). Other adverse effects included fatigue, diarrhea, nausea, vomiting, and lymphopenia. Twenty-four participants had a response of progression (73%), 1 had partial response (3%, and 8 (24%) had stable disease (median, 6.3 months; range, 3.1-16.8 months). Median 6-month progression-free survival was 17%. None of the associations between stable disease and PTEN, PIK3CA, PIK3R1, or EGFRvIII status were statistically significant.

CONCLUSIONS

PX-866 was relatively well tolerated. Overall response rate was low, and the study did not meet its primary endpoint; however, 21% of participants obtained durable stable disease. This study also failed to identify a statistically significant association between clinical outcome and relevant biomarkers in patients with available tissue.

Economic analysis of bevacizumab, cetuximab, and panitumumab with fluoropyrimidine-based chemotherapy in the first-line treatment of KRAS wild-type metastatic colorectal cancer (mCRC)

OBJECTIVE

Colorectal cancer (CRC) is the third most commonly diagnosed cancer in Canada (excluding non-melanoma skin cancers). Bevacizumab is a recombinant humanized monoclonal antibody that selectively binds to human vascular endothelial growth factor. A sub-study confirmed its effectiveness in KRAS wild-type patients. Recent evidence has shown clinical benefit from anti-epidermal growth factor treatments cetuximab and panitumumab in these patients. The cost-effectiveness, to the Canadian healthcare system, of fluoropyrimidine-based chemotherapy (FBC) in combination with bevacizumab, cetuximab, or panitumumab was assessed for first-line treatment of KRAS wild-type mCRC patients.

METHODS

A Markov model was developed and calibrated to progression-free/overall survival, using separately reported trial survival and adverse event results for each comparator. Health-state resource utilization was derived from published data and oncologist input. Utilities and unit prices were obtained from published literature and standard Canadian sources.

RESULTS

Results per patient are over a lifetime horizon, to a maximum of 10 years, with 5% annual discounting. Comparators are ordered by total cost and the incremental cost-effectiveness ratio (ICER) of each is determined against the previous non-dominated therapy. Compared to FBC alone, bevacizumab + FBC has an ICER of $131,600 per QALY gained. Compared to bevacizumab + FBC, panitumumab + FBC is dominated and cetuximab + FBC has an ICER of $3.8 million per QALY. In probabilistic sensitivity analysis, bevacizumab + FBC had ∼100%, ∼100%, and 98.9% probabilities of being more cost-effective than both of the other combination treatments at thresholds of $50,000/QALY, $100,000/QALY, and $200,000/QALY, respectively.

CONCLUSION

For first-line treatment of KRAS-WT mCRC, bevacizumab + FBC is associated with substantially lower costs as compared to panitumumab + FBC or cetuximab + FBC. Key limitations were that survival curves and adverse event rates were taken from separate clinical trials and that an indirect comparison was not included. Given these findings, bevacizumab is likely to offer the best value for money for this patient population.

Phase II study of PX-866 in recurrent glioblastoma

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Background: Glioblastoma (GBM) is the most aggressive malignancy of the central nervous system. The majority have genetic changes that increase the activity of the phosphatidylinositol-3-OH kinase (PI3K) signal transduction pathway, critical for cell motility, proliferation, and survival. We present the results of PX-866, an oral PI3K inhibitor, in patients (pts) with recurrent GBM. Methods: A multinomial design of response and early progression (< 8 weeks on study) was used. In stage 1 (15 pts), 0 responses and ≥ 10 early progressions would stop accrual; after full accrual, ≥ 4 responses OR ≤ 13 early progressions was prespecified as of interest. Pts with histologically confirmed GBM, at first recurrence after chemoradiation and adjuvant temozolomide were given PX-866 8 mg daily on this single-arm phase II study. MRI and clinical exam were done every cycle (8 weeks). Tumour tissue was collected for analysis of potential markers of PI3K inhibitory activity (PTEN, EGFRviii, PIK3CA mutations). Results: A total of 33 pts were enrolled, eligible and evaluable. Median age was 56 (range 35-78), 12 were female; 29 had performance status (PS) 0-1 and 4 had PS 2. Median time from initial diagnosis to enrolment was 308 days (range 141-1256). Median number of cycles was 1 (range 1-7). Thirty-two pts have discontinued therapy, 26 due to disease/symptomatic progression and 6 due to toxicity (5 LFT elevation and 1 allergic reaction). Other adverse effects (AE): fatigue (16 pts/2 grade 3), diarrhea (11 pts/5 grade 3), nausea (19 pts/1 grade 3), vomiting (11 pts/1 grade 3) and lymphopenia (29 pts/7 grade 3/4). Five pts had related serious AEs (1 LFTs, 1 GI and 3 venous thromboembolism) All pts were evaluable for response; 25 had a best response of progression, 1 had partial response (overall response rate 3%) and seven (21%) had stable disease (SD, median 7.3 months; range 3.1-13.6). Six month PFS was 17%. In preliminary analyses, no statistical association was found between SD and PTEN or EGFRviii status (results pending in 16 pts). Conclusions: PX-866 was relatively well tolerated. Overall response rate was low, and the study did not meet its primary endpoint; however, 21% of pts obtained durable stable disease. Further correlative work is required to identify the predictor of this effect. Clinical trial information: NCT01259869.

Canadian recommendations for the treatment of recurrent or progressive glioblastoma multiforme

Recommendation 1: Multidisciplinary ApproachTo optimize treatment outcomes, the management of patients with recurrent glioblastoma should be individualized and should involve a multidisciplinary team approach, including neurosurgery, neuropathology, radiation oncology, neuro-oncology, and allied health professions.Recommendation 2: ImagingThe standard imaging modality for assessment of recurrent glioblastoma is Gd-enhanced magnetic resonance imaging (mri). Tumour recurrence should be assessed according to the criteria set out by the Response Assessment in Neuro-Oncology Working Group. The optimal timing and frequency of mri after chemoradiation and adjunctive therapy have not been established.Recommendation 3: Pseudo-progressionProgression observed by mri after chemoradiation can be pseudo-progression. Accordingly, treated patients should not be classified as having progressive disease by Gd-enhancing mri within the first 12 weeks after the end of radiotherapy unless new enhancement is observed outside the radiotherapy field or viable tumour is confirmed by pathology at the time of a required re-operation. Adjuvant temozolomide should be continued and follow-up imaging obtained.Recommendation 4: Repeat SurgerySurgery can play a role in providing symptom relief and confirming tumour recurrence, pseudo-progression, or radiation necrosis. However, before surgical intervention, it is essential to clearly define treatment goals and the expected impact on prognosis and the patient's quality of life. In the absence of level 1 evidence, the decision to re-operate should be made according to individual circumstances, in consultation with the multidisciplinary team and the patient.Recommendation 5: Re-irradiationRe-irradiation is seldom recommended, but can be considered in carefully selected cases of recurrent glioblastoma.Recommendation 6: Systemic TherapyClinical trials, when available, should be offered to all eligible patients. In the absence of a trial, systemic therapy, including temozolomide rechallenge or anti-angiogenic therapy, may be considered. Combination therapy is still experimental; optimal drug combinations and sequencing have not been established.

O6-Methylguanine-DNA methyltransferase is a novel negative effector of invasion in glioblastoma multiforme

The dismal prognosis of glioblastoma multiforme (GBM) is mostly due to the high propensity of GBM tumor cells to invade. We reported an inverse relationship between GBM angiogenicity and expression of the DNA repair protein O(6)-methylguanine-DNA methyltransferase (MGMT), which has been extensively characterized for its role in resistance to alkylating agents used in GBM treatment. In the present study, given the major role of angiogenesis and invasion in GBM aggressiveness, we aimed to investigate the relationship between MGMT expression and GBM invasion. Stable overexpression of MGMT in the U87MG cell line significantly decreased invasion, altered expression of invasion-related genes, decreased expression of α(5)β(1) integrin and focal adhesion kinase, and reduced their spindle-shaped morphology and migration compared with the empty vector control. Conversely, short hairpin RNA-mediated stable knockdown of MGMT or its pharmacologic depletion in the MGMT-positive T98G cell line were required for increased invasion. The inverse relationship between MGMT and invasion was further validated in primary GBM patient-derived cell lines. Using paraffin-embedded tumors from patients with newly diagnosed GBM (n = 59), tumor MGMT promoter hypermethylation (MGMT gene silencing) was significantly associated with increased immunohistochemical expression of the proinvasive matricellular protein secreted protein acidic and rich in cysteine (SPARC; P = 0.039, χ(2) test). Taken together, our findings highlight for the first time the role of MGMT as a negative effector of GBM invasion. Future studies are warranted to elucidate the role of SPARC in the molecular mechanisms underlying the inverse relationship between MGMT and GBM invasion and the potential use of MGMT and SPARC as biomarkers of GBM invasion.

Does neurologic deterioration help to differentiate between pseudoprogression and true disease progression in newly diagnosed glioblastoma multiforme?

Enlarging or new lesions frequently appear on magnetic resonance imaging (mri) after concurrent administration of radiation therapy and temozolomide in glioblastoma multiforme (gbm) patients. However, in nearly half such cases, the observed radiologic changes are not due to true disease progression, but instead are a result of a post-radiation inflammatory state called "pseudoprogression." Retrospective studies have reported that neurologic deterioration at the time of the post-chemoradiotherapy mri is found more commonly in patients with true disease progression. We report a gbm patient with both radiologic progression on the post-chemoradiotherapy mri and concomitant neurologic deterioration, and we caution against incorporating clinical deterioration into the management schema of patients with possible pseudoprogression.

Lipidized glioblastoma: pathological and molecular characteristics

We report a rare case of a 33-year-old man with a lipidized glioblastoma multiforme (GBM) in the right posterior frontal region. Histologically the tumor had all the typical features of a GBM but with the rare observation of lipidized differentiation. There were multiple mitoses, extensive vascular proliferation, focal necrosis and the tumor cells had abundant xanthomatous cytoplasm and marked nuclear pleomorphism. The tumor showed immunoreactivity with GFAP. The O(6) - methylguanine methyltransferase (MGMT) promoter was methylated and there were no isocitrate dehydrogenase (IDH)1 and IDH2 mutations. To the best of our knowledge, this is the first time MGMT promoter status and IDH mutation assessment have been reported in a case of lipidized GBM.

Predictors of pathologic complete response (pCR) after neoadjuvant chemoradiation (Neo CRT) for rectal cancer: A multicenter population-based study

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Background: pCR to Neo CRT for rectal cancer is associated with better outcomes and used as an early indicator of response. To assess the rate and predictors of pCR, as well as access to care, we performed a retrospective study in two Canadian provinces. Methods: Cancer registries identified consecutive patients with clinical stage I-III rectal cancer from the Tom Baker Cancer Center, Cross Cancer Institute, and Dr. H. Bliss Murphy Cancer Centre who received Neo CRT and had curative intent surgery (Sx) from 2005 to 2011. Patient, tumor and therapy characteristics were correlated with response. Results: 301 patients were included of which 59 (19.6%) had a pCR to Neo CRT. At a median follow-up of 17 months, disease free survival was 96.7% for pCR vs 82.3% for non-pCR (p=0.005). 43 (73%) patients with pCR received adjuvant chemotherapy including bolus FU 27 (63%), capecitabine 10 (23%) and oxaliplatin-based 6 (14%). Median time from diagnosis to consult was 4 weeks (wks), from consult to start of Neo CRT 3.3 wks and start of CRT to Sx 13 wks. On multivariate analysis a low pre-op CEA (p=0.0323) was a significant independent predictor of pCR while statin use at initial consult (p=0.077) and higher pre-op hemoglobin (p=0.0974) trended toward significance when adjusted for clinical stage. Conclusions: Rates of pCR in a population based setting are substantial. A lower pre-op CEA is associated with a pCR to Neo CRT. Statin use and pre-op hemoglobin require further investigation. Our access to care data provides a baseline for future comparisons. [Table: see text]

Is there a role for clinical practice guidelines in multidisciplinary tumor board meetings? A descriptive study of knowledge transfer between research and practice

The aim of this study was to characterize practice patterns and decision-making processes of healthcare providers attending weekly neuro-oncology tumor board meetings, and to assess their familiarity with clinical practice guidelines (CPGs) in neuro-oncology. Members of the Neuro-Oncology Tumor Team at two tertiary cancer centers completed a web-based questionnaire assessing characteristics of weekly tumor board meetings and perceptions of CPGs. Twenty-three (66%) tumor team members responded. Diagnostic imaging results and interpretation, medical, surgical, and/or radiation treatment planning, and pathology results and interpretation were the most commonly identified aspects of patient care discussed at tumor board meetings, and almost all respondents indicated that these meetings were "very beneficial" to their own practice. When deciding on a treatment plan, respondents rely most on the clinical expertise of colleagues, medical literature, personal experience, active clinical trial protocols, and published CPGs. Opinions of the local CPGs varied considerably, and while 56% of respondents supported regular discussion of them during meetings, only 32% indicated that they were routinely reviewed. Updating the literature more frequently, implementing a formal grading system for the evidence, and incorporating clinical care pathways were the most frequently cited methods to improve the CPGs. Tumor board meetings are beneficial to the treatment planning process for neuro-oncology patients.

Quality of life (QoL) assessment in patients (pts) with K-RAS wild-type (WT) chemotherapy refractory metastatic colorectal cancer (mCRC) treated with cetuximab (CET) plus brivanib alaninate (BRIV) or placebo: Results of the NCIC Clinical Trials Group and AGITG CO.20 trial

542

Background: The CO.20 trial randomized pts with K-RAS WT chemotherapy refractory mCRC to receive CET + BRIV (Arm A) or CET + placebo (Arm B). Although overall survival (primary endpoint) was not significantly improved (HR=0.88, p=0.12) in this heavily pre-treated population, progression free survival (PFS) favoured Arm A (HR=0.72 p<0.0001).

Methods: Patients with K-RAS WT mCRC previously treated with or with contraindications to a fluoropyrimidine, irinotecan, and oxaliplatin were randomized to a loading dose of IV CET followed by weekly IV CET + BRIV 800 mg PO daily or CET + placebo daily. QoL, a secondary endpoint, was assessed using the EORTC QLQ-C30 at baseline and at 2, 4, 6, 8, 12, 16 and 24 weeks until progression or clinical deterioration. Co-primary QoL endpoints were defined a priori as definitive deterioration (first worsening from baseline of ≥10 points) on the physical function (PF) and Global scales. Time to QoL deterioration (DET) was measured from randomization using the Hochberg procedure to adjust for multiple testing.

Results: 721 (358 Arm A) of 750 randomized pts were assessable for QoL. QoL compliance did not differ by arm and declined in follow-up from 87% to 47% over time. Baseline Global and PF scores did not differ by arm. Median time to QoL DET was 1.6 vs 1.1 mo for Global (p=0.02) and 5.6 vs 1.7 mo. for PF (p<0.0001) in Arm B vs A, respectively. Secondary QoL response evaluation showed a greater proportion of patients on Arm A to have worsening on the PF (31 vs 17% at 6 wks) and cognitive functioning scales, and on the fatigue, nausea, appetite and diarrhea symptom scales. Clinical adverse events ≥ Grade 3 were more common on Arm A than B including fatigue (25 vs 10%), hypertension, rash, diarrhea, abdominal pain, dehydration and anorexia.

Conclusions: Despite a PFS benefit, the combination of CET + BRIV worsened time to QoL DET on the PF and Global scales of EORTC QLQ-C30 in pts with chemotherapy refractory K-RAS WT mCRC. This result may be due to higher rates of fatigue and gastrointestinal adverse events observed with the combination.

Cohort study evaluating the impact of a discharge letter (DL) compared with usual care on adherence to surveillance following treatment for stage II/III colorectal cancer (CRC)

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Background: The 2005 ASCO guidelines recommend surveillance testing and frequencies following surgical +/− adjuvant therapy for stage II/III CRC. In Canada, many patients are discharged from their oncologist to their primary care physician (PCP) for ongoing surveillance. However, adherence to surveillance recommendations is low. This cohort study evaluated adherence to surveillance 1 year after treatment of stage II/III CRC prior to and following implementation of a DL.

Methods: Cohort 1 (C1) patients were retrospectively identified from the Alberta Cancer Registry following adjuvant therapy (as applicable) at a tertiary cancer centre (07/2006 - 09/2007). Cohort 2 (C2) patients were prospectively identified from the Registry and clinic records following adjuvant therapy (as applicable), as those discharged from the centre (10/2007 - 4/2009); DL was sent to the patient and PCP recommending surveillance tests and dates. Clinical, laboratory, diagnostic imaging, and endoscopy data was collated. Adherence at 1 year follow-up was compared between cohorts using Kaplan-Meier time-to-event analyses.

Results: C1 (n=218) was larger than C2 (n=114) despite the longer accrual time for C2. There were no differences between cohorts by age, sex, primary site of disease, stage, or adjuvant oxaliplatin use. During year 1 of follow-up, 11.8% and 11.4% recurred (local or metastatic) and 6.5% and 2.7% died (p=0.1) in C1 and C2 respectively. Comparing C1 with C2, 14.8% vs. 23.0% of patients had one CEA test within 3 months, 45.2% vs. 72.2% within 6 months, and 71.7% vs. 85.1% within 1 year (p<0.001). Only 44.0% (C1) and 68.6% (C2) had 2 CEA tests within 1 year. Only 3.9% (C1) vs. 6.6% (C2) of patients had 4 CEA tests within the year following treatment as recommended. The rate of CT imaging was 32.3% (C1) and 56.1% (C2); endoscopy was 36.7% (C1) and 42.1% (C2).

Conclusions: Implementation of a DL improved compliance with surveillance at 1 year of follow-up following discharge from a tertiary cancer centre, although optimal adherence remains low. However, adherence to CT imaging nearly doubled. Evaluation of compliance at 3 years of follow-up is ongoing.

Determination of the methylation status of MGMT in different regions within glioblastoma multiforme

Epigenetic silencing of the MGMT gene through promoter methylation correlates with improved survival in Glioblastoma Multiforme (GBM) patients receiving concurrent chemoradiotherapy. Although the clinical benefit is primarily seen in patients with methylated MGMT promoter, some unmethylated patients also respond to Temozolomide. One possible explanation may be intratumoral heterogeneity. This study was designed to assess the methylation status of the MGMT promoter in different areas of GBM and determine if methylation status varied depending on the fixation technique (paraffin-embedding versus fresh frozen) used to store tissue. Using intraoperative navigation, biopsies were obtained from three distinct regions: the enhancing outer area, the non-enhancing inner core, and an area immediately outside the enhancing region. Only patients with GBM were included for evaluation and analysis. Samples taken from each area were divided with half stored by flash freezing and the other half stored using paraffin fixation. Methylation Specific-PCR (MS-PCR) was used for analysis of MGMT promoter methylation. Thirteen patients were included. Ten were male with a median age of 62 years. In each patient, samples were taken from the enhancing rim and the necrotic centre. However, it was not considered safe or feasible to obtain samples from the area immediately adjacent to the enhancing tumor rim in one case. All patients were homogeneous for methylation status throughout their tumor and tissue taken adjacent to it when frozen tissue was used. However, four patients had discrepancies in the MGMT promoter status between the frozen and paraffin-embedded blocks and one patient was not homogeneous within the tumor when paraffin-embedded tissue was used. MGMT promoter methylation status was homogeneous in all GBM tumors. Our observation that methylation status varied depending if the DNA was extracted from paraffin-embedded versus frozen tissue is concerning. Although the reason for this is unclear, we postulate that the timing from resection to fixation or the process of fixation itself may potentially alter methylation status in paraffin-embedded tumors.

Zinc modulation of ionic currents in the horizontal limb of the diagonal band of Broca

We examined modulation of ionic currents by Zn2+ in acutely dissociated neurons from the rat's horizontal limb of the diagonal band of Broca using the whole-cell patch-clamp technique. Application of 50 microM Zn2+ increased the peak amplitude of the transiently activated potassium current, I(A) (at + 30 mV), from 2.20+/-0.08 to 2.57+/-0.11 nA (n = 27). This response was reversible and could be repeated in 0 Ca2+/1 microM tetrodotoxin (n = 15). Zn2+ shifted the inactivation curve to the right, resulting in a shift in the half-inactivation voltage from 76.4+/-2.2 to -53.4+/-2.0 mV (n = 11), with no effect on the voltage dependence of activation gating (n = 15). There was no significant difference in the time to peak under control conditions (7.43+/-0.35 ms, n = 14) and in the presence of Zn2+ (8.20+/-0.57 ms, n = 14). Similarly, the time constant of decay of I(A) (tau(d)) at + 30 mV showed no difference (control: 38.68+/-3.68 ms, n = 15; Zn2+: 38.48+/-2.85 ms, n = 15). I(A) was blocked by 0.5-1 mM 4-aminopyridine. In contrast to its effects on I(A), Zn2+ reduced the amplitude of the delayed rectifier potassium current (I(K)). The reduction of outward K+ currents was reproducible when cells were perfused with 1 microM tetrodotoxin in a 0 Ca2+ external solution. The amplitude of the steady-state outward currents at +30 mV under these conditions was reduced from 6.40+/-0.23 (control) to 5.76+/-0.18 nA in the presence of Zn2+ (n = 16). The amplitudes of peak sodium currents (INa) were not significantly influenced (n = 10), whereas barium currents (I(Ba)) passing through calcium channels were potently modulated. Zn2+ reversibly reduced I(Ba) at -10 mV by approximately 85% from -2.06+/-0.14 nA under control conditions to -0.30+/-0.10 nA in the presence of Zn2+ (n = 14). Further analyses of Zn2+ effects on specific calcium channels reveals that it suppresses all types of high-voltage-activated Ca2+ currents. Under current-clamp conditions, application of Zn2+ resulted in an increase in excitability and loss of accommodation (n = 13), which appears to be mediated through its effects on Ca2+-dependent conductances.

Vasopressin receptor subtypes differentially modulate calcium-activated potassium currents in the horizontal limb of the diagonal band of Broca

The actions of vasopressin on acutely dissociated neurons within the rat horizontal limb of the diagonal band of Broca were examined using the whole-cell patch-clamp technique. Vasopressin elicited two distinct responses in 45 of 62 neurons. In one group of cells, 300 nM vasopressin decreased voltage-activated outward currents (26/45 cells) whereas in a second group, vasopressin increased outward currents (19/45 cells). The vasopressin-mediated decrease in outward currents was blocked by 1 microM Manning compound, a V1 receptor antagonist, suggesting that this response was mediated via V1 receptors. In contrast, the vasopressin-induced increase in outward current was blocked by 1 microM d(CH2)5)1,D-Ile2,Ile4,Arg8,Ala9, a V2 receptor antagonist, indicating that V2 receptor activation underlies this second response. When cells were perfused with 0 Ca2+/50 microM Cd2+, application of vasopressin did not cause any change in voltage-activated outward currents, suggesting that vasopressin modulates a calcium-dependent conductance. In the presence of 25 nM charybdotoxin, an Ic channel antagonist, vasopressin application did not influence outward currents, indicating that vasopressin modulates Ic. Currents through voltage-gated calcium channels which are responsible for activation of Ic were unaffected by vasopressin, suggesting a direct effect of vasopressin on Ic channels. These observations indicate a differential modulation of Ic channels by vasopressin via V1 and V2 receptors in the horizontal limb of the diagonal band of Broca. Our data also demonstrate the ionic mechanisms whereby vasopressin may act at V1 for V2 receptors to influence the excitability of the horizontal limb of the diagonal band of Broca neurons.

An electrophysiological study of neurons in the horizontal limb of the diagonal band of Broca

We examined the morphological and electrophysiological properties of neurons within the horizontal limb of the diagonal band of Broca (hDBB) and investigated the role of excitatory amino acid mediated synaptic transmission in this region. Whole cell patch-clamp recordings were obtained from hDBB neurons in rat forebrain slices. The hDBB cells examined in this study display a morphological and electrophysiological profile that is consistent with the type B, noncholinergic cell type. Cable analysis reveals that hDBB neurons are electrotonically compact and may therefore function as efficient relays for transmission of inputs to other forebrain target sites. Application of agonists for alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA), kainate, N-methyl-D-aspartate (NMDA), and metabotropic receptors all evoke inward currents in hDBB neurons. Pharmacological analyses of synaptic events indicate that evoked excitatory postsynaptic currents (EPSC) are either mediated by non-NMDA receptors alone or a combination of non-NMDA and NMDA receptors. In some neurons, the metabotropic receptor agonist, 1-aminocyclopentane-trans-1, 3-dicarboxylic acid, reduced EPSC amplitude without altering postsynaptic input conductance, thus suggesting a presynaptic locus of action. The electrical and pharmacological properties described for hDBB neurons may be physiologically relevant for the effective transmission of excitatory synaptic inputs to sites that receive projections from the hDBB.

Glutamate receptor subtypes mediate excitatory synaptic responses of rat lateral parabrachial neurons

We examined the role of specific excitatory amino acid (EAA) receptors in synaptic transmission within the lateral parabrachial nucleus (LPBN) using whole cell patch-recording techniques in a slice preparation. Two types of excitatory postsynaptic responses were observed. The first involved the contribution of non-N-methyl-D-aspartate (NMDA) receptors, which mediated a fast component, and NMDA receptors, which governed the late component of the excitatory postsynaptic current (EPSC). The second EPSC response was mediated solely by non-NMDA receptors. Both EPSC responses reversed near 0 mV. The fast component of the EPSC was attenuated by the non-NMDA antagonists [6-cyano-7-nitroquinoxaline-2,3-dione (CNQX), 6,7-dinitroquinoxaline-2,3-dione (DNQX), and 6-nitro-7-sulfamobenzoquinoxaline-2-3,-dione (NBQX)]. The late component was reduced by D,L-2-amino-5-phosphonovaleric acid (APV) and augmented in Mg(2+)-free external medium. EPSCs mediated solely by non-NMDA receptors were completely blocked by CNQX and NBQX but not affected by APV or Mg(2+)-free external medium. EPSCs were also markedly attenuated by the metabotropic-receptor agonist, trans-(1S,3R)-1-aminocyclopentane-1,3-dicarboxylic acid (trans-ACPD). We concluded that intra-LPBN stimulation causes the synaptic release of glutamate, which depolarizes LBPN neurons via non-NMDA and NMDA receptors. We also provide evidence that glutamate can negatively influence its own release via action on presynaptic metabotropic receptors.

Alterations in membrane potential after axotomy at different distances from the soma of an identified neuron and the effect of depolarization on neurite outgrowth and calcium channel expression

1. Intracellular recordings were made from the soma of an identified neuron B5 within the buccal ganglion of the mollusc, Helisoma trivolvis, during axotomy induced by crushing or cutting the esophageal nerve. Axotomy was associated with a rapid depolarization and occasionally a burst of action potentials (injury discharge). The magnitude of the membrane depolarization in the soma in response to axotomy decayed exponentially when the distance between the soma and site of injury was increased. Input resistance measurements taken during axotomy showed that a barrier to current flow formed rapidly and gradually recovered within 2 h. A barrier to the diffusion of intracellularly injected carboxyfluorescein formed at the site of injury within 15 min of axotomy. 2. To examine the effect of chronic depolarization on neurite outgrowth, the extracellular potassium ion concentration [K+]o was manipulated. The membrane potential of neurons B5 exhibited a 51.8 mV/decade potassium dependence between 20 and 150 mM [K+]o. The initiation of neurite outgrowth from axons crushed 800 microns from the soma and bathed in different concentrations of [K+]o was examined by fluorescence microscopy after filling neurons with Lucifer yellow. We compared the percentage of axons with sprouts 9 and 24 h after organ culture in saline containing [K+]o ranging from 0.1 to 50 mM. Sprouting occurred from 33% of neurons B5 in normal saline (1.7 mM [K+]o) after 9 h and from 100% of neurons after 24 h. No sprouting was observed from neurons B5 9 or 24 h after axotomy when bathed in saline containing reduced or elevated concentrations of [K+]o. 3. To examine the effects of chronic depolarizatin on neurite outgrowth over several days, neurons B5 were axotomized close to the soma and maintained in organ culture in Liebovitz medium (defined medium or medium conditioned with central ganglia). Neurite outgrowth was ranked from 0 to 5 after filling neurons with Lucifer yellow, and our analysis indicated that a small increase in neurite outgrowth occurred in medium supplemented with 10 mM potassium. 4. Elevated potassium did not trigger neurite outgrowth from isolated neurons B5 in cell culture within defined medium, but whole-cell patch-clamp analysis revealed that chronic depolarization associated with elevated potassium altered the expression of calcium currents. Low-voltage-activated (LVA) and high-voltage-activated (HVA) calcium currents were detected in acutely isolated neurons B5.(ABSTRACT TRUNCATED AT 400 WORDS)

Modulation of sprouting in organ culture after axotomy of an identified molluscan neuron

We examined a variety of factors that might modulate the initiation of neurite outgrowth in an attempt to identify means by which its initiation might be accelerated. We examined this initiation from an identified molluscan neuron, Helisoma trivolvis buccal neuron B5 after axotomy, and determined whether the site of injury, temperature, ion channel blockers, pH, the second messenger cAMP, and protein synthesis affect the initiation of neurite outgrowth. Neurite outgrowth was assayed from axotomized neurons by filling the neurons intracellularly with Lucifer Yellow and examining the percentage of axons that extended (sprouted) new process after 9 or 24 h in organ culture. About one-third (31%) of axotomized neurons sprouted from the site of injury after 9 h (n = 22), and 88% (n = 20) sprouted after 24 h in saline at 22 degrees-24 degrees C when the injury was located 800 microns from the soma. Elevating the temperature to 32 degrees C or moving the lesion site to 400 or 1500 microns from the soma did not significantly alter the incidence of sprouting. Blocking sodium channels with tetrodotoxin [TTX (2 x 10(-5) M)] did not significantly reduce the incidence of sprouting, whereas the sodium channel agonist, veratridine (10(-5) M) did. The calcium channel blocker lanthanum (10(-6)-10(-4) M), stimulated neurite outgrowth; however, the organic calcium channel blocker verapamil (10(-3)-10(-5) M), and the calcium ionophore A23187 (10(-5) M), had no effect on sprouting. Exposure of neurons to the potassium channel blocker tetraethylammonium [TEA (20 mM)], elevation of intracellular pH with NH4Cl (5 mM), or treatment with the adenylate cyclase activator forskolin (10(-5) M) reduced the incidence of sprouting, whereas dideoxy-forskolin (10(-5) M) had no effect. Inhibition of protein synthesis with anisomycin (2 x 10(-4) to 2 x 10(-6) M) did not significantly suppress sprouting 24 h after axotomy. Both D and L isomers of glutamate (300 microM) stimulated sprouting. The present results suggest that the initiation of sprouting is regulated locally at or near the site of injury, and that blocking specific ion channels may either inhibit or enhance the initiation of neurite outgrowth.