Dissection of RAS downstream pathways in melanomagenesis: a role for Ral in transformation

Cutaneous malignant melanoma is considered one of the most deadly human cancers, based on both its penchant for metastatic spread and its typical resistance to currently available therapy. Long known to harbor oncogenic NRAS mutations, melanomas were more recently reported to be frequent bearers of activating mutations in BRAF, one of the effectors situated downstream of wild-type NRAS. NRAS and BRAF mutations are rarely found in the same melanoma, suggesting that they may possess important overlapping oncogenic activities. Here, we compare and contrast the oncogenic roles of the three major NRas downstream effectors, Raf, phosphatidylinositol 3-kinase (PI3K) and Ral guanine exchange factor (RalGEF), using genetically engineered Arf-deficient immortalized mouse melanocytes as a model system. Although no single downstream pathway could recapitulate all of the consequences of oncogenic NRas expression, our data indicate a prominent role for BRaf and PI3K in melanocyte senescence and invasiveness, respectively. More surprisingly, we discovered that constitutive RalGEF activation had a major impact on several malignant phenotypes, particularly anchorage-independent growth, indicating that this often overlooked pathway should be more carefully evaluated as a possible therapeutic target.

Percutaneous endoscopic gastrostomy (PEG) for enteral nutrition in patients with stroke

BACKGROUND

The use of percutaneous endoscopic gastrostomy (PEG) for enteral nutrition in patients admitted for stroke is difficult, varying and needs specific consideration. There is therefore need for more data on this patient group. We examined the indications, survival, tube removal and time with PEG in stroke patients and in other patients with PEG with the aim of providing guidance for the management of enteral nutrition via PEG in stroke patients.

METHODS

Retrospective assessment of data from all stroke patients and patients with other diseases (control group) who had received PEG for enteral nutrition during a period of 8.5 years.

RESULTS

Eighty-three stroke patients with dysphagia received PEG after unsuccessful use of nasogastric tubes or long-term tube feeding. Early mortality rate was 19% in the stroke group, 26% in the older group (>74 years) and 12% in the younger group (60-74 years). The PEG tubes were later removed due to swallowing recovery in 20% of the older group and in 31% of the younger group. At 90 days, 50%-60% still needed PEG. The stroke patients were older compared to the control group (n = 115); 30-day mortality was similar but more patients recovered the ability to swallow.

CONCLUSIONS

Stroke patients are older than other patients who receive PEG; 27% have swallowing recovery and more than 75% have long-term need for PEG. Nasogastric tubes often fail, and the need for early PEG placement (within 2 weeks) must be assessed in appropriate patients. The patient's prognosis, the objective of nutritional treatment, duration of dysphagia, age and comorbidity should all be taken into consideration.

Metabolic radiolabeling: experimental tool or Trojan horse? (35)S-Methionine induces DNA fragmentation and p53-dependent ROS production

Despite the general assumption that widely used radiolabeled metabolites such as [(35)S]methionine and (3)H-thymidine do not adversely affect or perturb cell function, we and others have shown that such low-energy beta-emitters can cause cell cycle arrest and apoptosis of proliferating cells. The goal of the present study was to elucidate the targets and mechanisms of [(35)S]methionine-induced cellular toxicity. Comet analyses (single-cell electrophoresis) demonstrated dose-dependent DNA fragmentation in rabbit smooth muscle cells within a time frame (1-4 h) well within that of most radiolabeling protocols, whereas fluorescence analyses using a peroxide/hydroperoxide-sensitive dye revealed production of reactive oxygen species (ROS). Although ROS generation was inhibitable by antioxidants, DNA fragmentation was not inhibited and was in fact observed even under hypoxic conditions, suggesting that beta-radiation-induced DNA damage can occur independently of ROS formation. Studies with p53(+/+) and p53(-/-) human colorectal carcinoma cells further demonstrated the dissociation of early DNA damage from ROS formation in that both cell types exhibited DNA fragmentation in response to radiolabeling whereas only the p53(+/+) cells exhibited significant increases in ROS formation, which occurred well after significant DNA damage was observed. These findings demonstrate that metabolically incorporated low-energy beta-emitters such as [(35)S]methionine and (3)H-thymidine can induce DNA damage, thereby initiating cellular responses leading to cell cycle arrest or apoptosis. The results of this study require a reevaluation using low-energy beta-emitters to follow not only experimental protocols in vivo processes, but also acceptable exposure levels of these genotoxic compounds in the workplace and environment.

Barriers and enablers to physical activity and aerobic fitness deficits among childhood cancer survivors

BACKGROUND

Physical activity and aerobic fitness are modifiable risk factors for cardiovascular disease (CVD) after childhood cancer. How survivors engage in physical activity remains unclear, potentially increasing CVD risk. We assessed survivors' physical activity levels, barriers and enablers, fitness, and identified predictors of fitness and physical activity stage of change.

METHODS

Childhood cancer survivors (CCS; 8-18 years old) ≥1 year post-treatment were assessed for aerobic fitness (6-min walk test), used to extrapolate VO_2max , and body composition (InBody 570). Survivors self-reported physical activity to determine stage of change (Patient-Centered Assessment and Counselling for Exercise). Physical activity and fitness were compared with guidelines and CVD-risk cut-points (VO_2max  < 42 mL/kg/min: males; VO_2max  < 35 mL/kg/min: females). Multiple regression and mediator-moderator analysis were used to identify fitness predictors and stage of change.

RESULTS

One hundred two survivors (12.8 ± 3.3 years) participated (46% acute lymphoblastic leukaemia). Forty percent of males (VO_2max  = 43.3 ± 6.3 mL/kg/min) and 28% of females (VO_2max  = 36.5 ± 5.9 mL/kg/min) were in the CVD-risk category, while 25% met physical activity guidelines. Most prevalent physical activity barriers were fatigue (52%), preferring television instead of exercise (38%), and lacking time (34%). Predictive factors for reduced fitness included being older, female, higher waist-to-height ratio, higher screen time, and moderated by lower physical activity (r²  = 0.91, P < .001). Survivors with higher physical activity stage of change were male, lower body fat percentage, lower screen time, and lived with both parents (r = 0.42, P = .003).

CONCLUSION

Aerobic fitness and physical activity of CCS is low compared with population norms, potentially increasing CVD risk. Addressing physical activity barriers and enablers, including reducing screen time, could promote regular physical activity, reducing CVD risk.

The Effect of Resistance Training on Body Composition During and After Cancer Treatment: A Systematic Review and Meta-Analysis

BACKGROUND

Changes in body composition during cancer treatments have been linked with poorer outcomes, and increased morbidity and mortality. The effect of resistance training (RT) on body composition in cancer cohorts is debated.

OBJECTIVE

We conducted a systematic review and meta-analysis to determine the effect of RT on body composition during and after treatment.

METHODS

We searched five electronic databases for articles up to 1 February 2021 and included randomized controlled trials that compared RT with a non-exercise control in adults with cancer. Risk of bias was assessed using the RoB 2 tool. Pairwise, random-effects meta-analysis was used to synthesize the available data.

RESULTS

Overall, we included 15 studies (n = 1368). After treatment (11 studies), RT increased lean mass with moderate heterogeneity {0.41 kg [95% confidence interval (CI) 0.05, 0.76], p = 0.029; I² = 47.1%, p = 0.02} and decreased fat mass with substantial heterogeneity (- 0.59 kg [95% CI - 1.05, - 0.12], p = 0.019; I² = 69.1%, p < 0.001). During treatment (4 studies), RT did not increase lean mass (0.71 kg [95% CI - 0.04, 1.45], p = 0.05; I² = 0.0%, p = 0.75) or reduce fat mass (0.00 kg [95% CI - 5.31, 5.30], p = 0.99; I² = 0.0%, p = 0.62), both with no heterogeneity.

CONCLUSION

Modest improvements in body composition were observed following RT after cancer treatment; however, no changes were observed during treatment. These adaptations are markedly lower than those observed in healthy cohorts but may be clinically meaningful for the cancer survivorship population. At present it is unclear if these diminished adaptations are due to ineffective exercise prescriptions in cancer cohorts or due to an innate anabolic resistance as a result of cancer and its treatments.

STUDY REGISTRATION

Open Science Framework (osf.io/x6z72).

The Use of Activity Trackers in Interventions for Childhood Cancer Patients and Survivors: A Systematic Review

Activity trackers have emerged as promising devices used to motivate and/or objectively monitor physical activity (PA) levels. It is unknown how activity trackers have been used in interventions for children and adolescents affected by cancer. This review aimed to investigate the effectiveness of wearable activity trackers to monitor and/or improve PA levels and health outcomes in pediatric oncology. Based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses, we conducted an electronic search of four databases (Cumulative Index to Nursing and Allied Health Literature [CINAHL], Medline, Embase, and SportDiscus) between January 2000 and March 2020. The review included PA interventions that used an activity tracker with children (≤18 years) diagnosed with cancer. We excluded studies including adult participants (>18 at time of study participation) and cross-sectional or case-report studies. Twelve studies examining 517 children and adolescent patients and survivors of pediatric cancer (age range: 4-18 years) were included. Intervention delivery ranged from 2 weeks to 12 months. Two of 12 studies reported increases in PA and 6 showed improvements in health outcomes, including aerobic fitness and negative mood. PA interventions using activity trackers within pediatric oncology are highly diverse in study design, study population, and intervention features. Preliminary data suggest that interventions using wearable activity trackers may have a positive impact on health outcomes in children and adolescents affected by cancer. Future research is needed to establish optimal intervention approaches to using activity trackers to increase PA in children affected by cancer.

Accuracy of perceived physical activity and fitness levels among childhood cancer survivors

BACKGROUND

Childhood cancer survivors do not engage in sufficient physical activity and have low fitness levels. Perceived physical activity and fitness levels may influence survivors' engagement in health behaviours. We aimed to investigate survivors' perceptions of physical activity and fitness levels and identify how accurate their perceptions were. We further explored survivors' attitudes toward physical activity, including perceived importance and desire to increase activity levels.

PROCEDURE

We recruited 116 childhood cancer survivors (8-18 years) and assessed their perceived physical activity levels using a questionnaire and the Godin's Leisure Score Index. Accuracy of their perceptions was established by comparing their perceived physical activity levels with the recommended guidelines. Survivors reported their perceived fitness levels using the International Fitness Scale. We compared survivors' perceptions with their performance on the 6-minute walk test using weighted Cohen's kappa to determine interrater agreement between perceived and objectively measured fitness.

RESULTS

Most survivors did not meet the physical activity guidelines (<420 min/week). One-third incorrectly perceived whether their self-reported physical activity levels were appropriate (84% underestimated, while 16% overestimated). Survivors had average fitness and were inaccurate at perceiving their fitness level. Survivors highly valued the importance of being able to do physical activity, and 89% reported a desire to increase their physical activity.

CONCLUSIONS

Our results reveal that many survivors are not accurate when perceiving their physical activity and fitness levels. Emphasising the need for objective fitness assessments, and patient education in clinical practice may support survivors to accurately perceive their physical activity and fitness levels, thus improving health behaviours.

Parents' understanding of genome and exome sequencing for pediatric health conditions: a systematic review

Genome and exome sequencing (GS/ES) are increasingly being used in pediatric contexts. We summarize evidence regarding the actual and perceived understanding of GS/ES of parents of a child offered testing for diagnosis and/or management of a symptomatic health condition. We searched four databases (2008-2021) and identified 1264 unique articles, of which 16 met inclusion criteria. We synthesized data from qualitative and quantitative studies and organized results using Ayuso et al. (2013)'s framework of key elements of information for informed consent to GS/ES. Many of the parents represented had prior experience with genetic testing and accessed a form of genetic counseling. Parents' understanding was varied across the domains evaluated. Parents demonstrated understanding of the various potential direct clinical benefits to their child undergoing GS/ES, including in relation to other genetic tests. We found parents had mixed understanding of the nature of potential secondary findings, and of issues related to data privacy, confidentiality, and usage of sequencing results beyond their child's clinical care. Genetic counseling consultations improved understanding. Our synthesis indicates that ES/GS can be challenging for families to understand and underscores the importance of equipping healthcare professionals to explore parents' understanding of ES/GS and the implications of testing for their child.

A Digital Educational Intervention With Wearable Activity Trackers to Support Health Behaviors Among Childhood Cancer Survivors: Pilot Feasibility and Acceptability Study

BACKGROUND

Childhood cancer survivors are at increased risk of cardiometabolic complications that are exacerbated by poor health behaviors. Critically, many survivors do not meet physical activity guidelines.

OBJECTIVE

The primary aim was to evaluate the feasibility and acceptability of iBounce, a digital health intervention for educating and engaging survivors in physical activity. Our secondary aims were to assess the change in survivors' physical activity levels and behaviors, aerobic fitness, and health-related quality of life (HRQoL) after participating in the iBounce program.

METHODS

We recruited survivors aged 8 to 13 years who were ≥12 months post cancer treatment completion. The app-based program involved 10 educational modules, goal setting, and home-based physical activities monitored using an activity tracker. We assessed objective physical activity levels and behaviors using cluster analysis, aerobic fitness, and HRQoL at baseline and after the intervention (week 12). Parents were trained to reassess aerobic fitness at home at follow-up (week 24).

RESULTS

In total, 30 participants opted in, of whom 27 (90%) completed baseline assessments, and 23 (77%) commenced iBounce. Our opt-in rate was 59% (30/51), and most (19/23, 83%) of the survivors completed the intervention. More than half (13/23, 57%) of the survivors completed all 10 modules (median 10, IQR 4-10). We achieved a high retention rate (19/27, 70%) and activity tracker compliance (15/19, 79%), and there were no intervention-related adverse events. Survivors reported high satisfaction with iBounce (median enjoyment score 75%; ease-of-use score 86%), but lower satisfaction with the activity tracker (median enjoyment score 60%). Parents reported the program activities to be acceptable (median score 70%), and their overall satisfaction was 60%, potentially because of technological difficulties that resulted in the program becoming disjointed. We did not observe any significant changes in physical activity levels or HRQoL at week 12. Our subgroup analysis for changes in physical activity behaviors in participants (n=11) revealed five cluster groups: most active, active, moderately active, occasionally active, and least active. Of these 11 survivors, 3 (27%) moved to a more active cluster group, highlighting their engagement in more frequent and sustained bouts of moderate-to-vigorous physical activity; 6 (56%) stayed in the same cluster; and 2 (18%) moved to a less active cluster. The survivors' mean aerobic fitness percentiles increased after completing iBounce (change +17, 95% CI 1.7-32.1; P=.03) but not at follow-up (P=.39).

CONCLUSIONS

We demonstrated iBounce to be feasible for delivery and acceptable among survivors, despite some technical difficulties. The distance-delivered format provides an opportunity to engage survivors in physical activity at home and may address barriers to care, particularly for regional or remote families. We will use these pilot findings to evaluate an updated version of iBounce.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry ACTRN12621000259842; https://anzctr.org.au/Trial/Registration/TrialReview.aspx?ACTRN=ACTRN12621000259842.

Patterns of physical activity and sedentary behavior in child and adolescent cancer survivors assessed using wrist accelerometry: A cluster analysis approach

Physical activity levels among childhood cancer survivors are typically quantified as a total amount using time spent in various intensities. Yet, most analyses do not consider the transitory nature of children's behaviors and a more detailed approach could provide complimentary information. We aimed to explore various behavior profiles of survivors' daily and hourly physical activity patterns. We measured 8-18-year-old survivors' activity levels over 7 days using wrist accelerometry and cluster analysis. Of the 37 participant datasets, survivors engaged in mean (SD) 36.3 (19.0) min/day of MVPA and 4.1 (1.9) hrs/day of sedentary activity. The cluster analysis revealed five daily movement patterns: 'most active' (prevalence 11%), 'active' (22%), 'moderately active + moderately sedentary' (35%), 'moderately active + high sedentary' (5%) and 'least active' (27%). Younger survivors and those with less time since treatment completion were more likely to be in the active clusters. Hourly behaviors were characterized by short bursts of MVPA and moderate bouts of sedentary activity. Our approach provides an insightful analysis into the nature and timing of childhood cancer survivors' movement behaviours. Our findings may assist in the development of targeted interventions to improve physical activity levels.

HPV-Related Multi-Phenotypic Sinonasal Carcinoma with Aggressive Clinical Behavior; A Rare Case

Introduction/Objective

Human Papilloma Virus (HPV)-related multiphenotypic sinonasal carcinoma, previously known as HPV-related sinonasal carcinoma with adenoid cystic carcinoma-like features, is a rare type of sinonasal carcinoma with both epithelial-derived and salivary gland-type morphologic features. It is associated with high-risk HPV, but lacks MYB gene rearrangements.

Methods/Case Report

We report a case of a 59-year-old male who presented with a rapidly growing sinonasal mass. On MRI, a left nasal cavity lesion was identified growing laterally along the frontal process of the maxilla, extending into the middle meatus and into the maxillary sinus. Patient underwent a complex left medial maxillectomy, spheno- ethmoidectomy, and sinusotomy. On gross evaluation, the left inferior turbinate and sidewall demonstrated a 4 cm unremarkable turbinate with attached friable soft tissue. Microscopic examination revealed sections of carcinoma with various architectural patterns comprised of foci with adenoid cystic carcinoma-like morphology, basaloid squamous cell carcinoma and adenocarcinoma. The tumor showed positive immunostaining for P40, but focal reactivity to S100 and rare scattered reactivity with CD117. INI-1 immunostain was retained in tumor cells. P16 immunostain was strong and diffuse and high-risk cocktail HPV RNA ISH was positive. However, MYB FISH testing was equivocal.

Morphologic and immunophenotypic findings were consistent with HPV-related multiphenotypic sinonasal carcinoma. The tumor involved the olfactory nerve fibers requiring a skull base resection and showed extension into the dura mater.

Results (if a Case Study enter NA)

NA

Conclusion

HPV related multiphenotypic sinonasal carcinoma is a recently described entity that can pose significant diagnostic challenge. It typically has an indolent clinical course with potential for late recurrences. This case study highlights the potential aggressive nature of this type of sinonasal carcinoma, despite association with high-risk HPV, and use of ancillary testing in aiding diagnosis.

[Association of nm23-H1 with orthopedic oncological conditions]

OBJECTIVE

To explore the correlation between nm23-H1 gene and malignant and semi-malignant bone tumors.

METHOD

Thirty surgical specimens were collected, including 8 osteosarcomas, 7 giant cell tumors, 4 chondrosarcomas, 2 Ewing's sarcomas, 2 malignant fibrohistocytomas, 1 neurofibrosarcoma, 1 schwannoma, and 5 metastatic cancers. The expression of nm23-H1 in these specimens was observed by in situ hybridization and immunohistochemical staining.

RESULT

The expression of nm23-H1 in 4 cases of primary giant cell tumor (GCT) was high, but was low or absent in 3 recurrent ones. In 4 cases of chondrosarcomas, the expression was positive. Its expression was basically negative in Ewing's tumor, malignant fibrous histiocytoma and metastatic sarcomas.

CONCLUSION

There is no association of nm23-H1 with osteosarcoma.

Abstract WP340: Impact of Increasing Primary Stroke Center Transfers on Comprehensive Stroke Center Capacity

Introduction: Given the time-sensitive benefits of acute stroke (AS) treatments, stroke systems of care must balance reducing door-in-door-out (DIDO) time at primary stroke centers (PSCs) with capacity limits at comprehensive stroke centers (CSCs). For example transferring more AS patients earlier in the process (e.g., prior vascular imaging for large vessel occlusion) from PSCs would result in more inappropriate transfers to CSCs that could overburden these centers.We conducted a simulation to estimate the balance between increased AS transfers from PSCs to CSCs and the percent of CSC time on “bypass” (inability to accept transfers to neuro-ICU).

Methods: Clinicians from 3 Chicago-area CSCs and 3 affiliated PSCs and the Chicago Emergency Medical Services (EMS) created a PSC DIDO process map. We assumed CSC time on bypass is affected by AS and non-AS admissions from the CSC and from the affiliated PSCs. Input data were obtained fromtheChicago region registry (e.g., # PSC to CSC transfers), peer reviewed literature (US average transfer rate of AS patients to CSCs), EMS (PSC-CSC affiliations), and CSCs (e.g., average bed occupancy rates). CSC size was estimated by #neuro-ICU beds: small (12 beds), medium (23 beds), and large (28 beds). The simulation output was % time of CSC on “bypass”.

Results: Table shows % time of CSC on bypass by varying PSC AS transfer rates for each category of CSC size. Larger increases in PSC transfer rates resulted in modest increases in CSC bypass rates, particularly for medium and large CSCs. Validation with data from one CSC showed < 4% overestimate of CSC % time on bypass.

Conclusion: CSCs with more beds have efficiencies of scale leading to lower % time on bypass, even with increases in PSC AS transfer rates proportionate to CSC size. This model allows stroke systems of care to compute regional CSCs’ % time on bypass based on actual PSCs’ transfer rates and CSC size.

Pharmacokinetics and taste acceptance of an alcohol-free oxtriphylline solution

As follow-up to earlier studies done on the pharmacokinetics of theophylline preparations in young children, an alcohol-free oxtriphylline syrup preparation was studied. Oxtriphylline syrup demonstrated no appreciable change in the pharmacokinetic parameter of half-life in this young age group. Therapeutic dose relationship were studied in conjunction with trough level measurements. Patient acceptance of this preparation is judged to be excellent.

Mechanism of apoptosis and determination of cellular fate in chromium(VI)-exposed populations of telomerase-immortalized human fibroblasts

The cellular responses to carcinogen exposure influence cellular fate, which in turn modulates the neoplastic response. Certain hexavalent chromium [Cr(VI)] compounds are implicated as occupational respiratory carcinogens at doses that are both genotoxic and cytotoxic. We examined the mechanism of Cr(VI)-induced apoptosis in normal human fibroblasts (BJ) immortalized by human telomerase gene transfection (BJ-hTERT), and we assessed the spectrum of cumulative cellular fates [(a) regaining of replicative potential; (b) terminal growth arrest; or (c) apoptosis] for a narrow range of increasingly genotoxic doses of Cr(VI). Exposure of BJ-hTERT cells to Cr(VI) resulted in a dose-dependent increase in apoptosis that involved mitochondrial disruption as evidenced by mitochondrial membrane depolarization and cytochrome c release. The initial response to Cr(VI) exposure was inhibition of cell cycle progression. At the lowest dose tested (1 microM; 32% clonogenic survival), the cell cycle inhibition led to terminal growth arrest but no apoptosis. The fraction of terminally growth arrested cells increased as the dose was increased to 3 microM but then decreased at 4, 5, and 6 microM as apoptosis became the predominant cell fate. Our results suggest that cell populations exposed to Cr(VI) have a different spectrum of responses, depending on the extent of DNA damage, and that the regaining of replicative potential after relatively higher genotoxic exposures may be attributable to either escape from, or resistance to, terminal growth arrest or apoptosis.

Parent perceptions of their child's and their own physical activity after treatment for childhood cancer

PURPOSE

Parents are important facilitators of physical activity for children, yet little is known about the perceptions of parents of childhood cancer survivors. We investigated parent perceptions of their own and their child's physical activity levels after cancer treatment and examined associations with clinical, demographic, and psychosocial factors.

METHODS

We conducted a cross-sectional survey among 125 parents and 125 survivors. Parents reported on the perceived importance of their child being physically active and concerns regarding exercising after cancer treatment.

RESULTS

Parents and survivors self-reported median (range) of 127.5 (0-1260) and 220 (0-1470) min/week of moderate-to-vigorous physical activity. Most parents (n = 109, 98%) believed that physical activity was highly important for their child. Some parents (n = 19, 17%) reported concerns, most commonly regarding exercise safety (n = 7, 22%). Parents were more likely to perceive that their child should increase physical activity if their child was an adolescent and had high body fat percentage.

CONCLUSIONS

Physical activity levels varied widely among survivors, reflecting factors including parents' lifestyles, limited understanding of exercise benefits and perceptions of risk. Given survivors' insufficient physical activity levels and sedentary behaviour among families, embedding physical activity promotion into health systems and follow-up support could benefit the entire family unit.