Abstract BACKGROUND SJMB12 (NCT01878617) was among the first protocols to treat newly diagnosed MB incorporating molecular subgrouping. METHODS Tumors were subtyped and TP53 mutation assessed via immunohistochemistry. SHH patients were grouped into 2 strata: S1 (GTR/NTR; M0) and S2 (residual > 1.5 cm2; MYC/MYCN amplification; M+). Treatment consisted of maximal surgical resection followed by risk adapted craniospinal irradiation (CSI) (S1 = 23.4 Gy CSI; S2= 36); 54 Gy primary site. Patients then received 4 cycles of chemotherapy consisting of Vincristine 1 mg/m2 on Day 1 and Day 8; Cisplatin 75 mg/m2 on Day 1 and Cyclophosphamide 1.5 gm/m2 on Day 2 and 3 with Mesna and IV fluid support. PEG Filgrastim was administered on Day 4. Skeletally mature pts (males with bone age ≥ 17 yrs.; females with bone age ≥ 15 yrs.) were also treated with the smoothened inhibitor Vismodegib for 12 months. RESULTS Of the 660 patients accrued from 2013-2022, 110 were SHH (107 evaluable, 62 in S1 and 45 in S2). Median age was 12.2 yrs. (3.1-39.7) and 67 were males. 98 patients had GTR/NTR, 31 had M+ disease and 63 had nodular desmoplastic histology. TP53 mutation was detected in 7 (11.5%) S1 and 18 (40%) S2 pts. 5-year EFS for S1 and S2 were 84.5 ± 6.4% and 61 ± 11.5%, respectively. Five-year EFS of the S1 was 91.7 ± 5.4% and 28.6 ± 13.9% for TP53 wildtype and TP53 mutant cases, respectively, and 84.2 ± 10.1% and 25.0 ± 21.7% in the S2 cohort. CONCLUSION Patients with low-risk SHH MB lacking TP53 mutation have excellent survival and may be considered for therapy reduction. TP53 mutation, with or without M+ disease, leads to a dismal outcome that needs novel therapy for cure.

Supplementary Figure S1 & Table S1 from Expression Profiles of Osteosarcoma That Can Predict Response to Chemotherapy

Abstract BACKGROUND/RATIONAL: Following initial irradiation sparing therapy, many young children with relapsed medulloblastoma can be salvaged with craniospinal irradiation (CSI). However, the interval to relapse is short and neurocognitive sequelae remain a major concern. The contribution of molecular subgrouping may help refine indications and modalities of salvage strategies in this population. METHOD: From a cohort of 151 young children with molecularly characterized relapsed medulloblastoma, subset analysis of the SHH medulloblastoma was conducted to describe the practice of salvage radiotherapy and associated post-relapse survival (PRS). RESULTS: Sixty-seven SHH medulloblastoma patients (46 M0; 54 GTR; 11 non-ND/MBEN) received salvage therapy with curative intent. Before relapse, 54 (80.6%) received conventional chemotherapy (CC), 13 (19.4%) high-dose chemotherapy (HDC), while seven had additional focal radiotherapy (fRT). Median time to relapse was 11.1 months (range 3.8-41.0) and 43.3% were localized. Thirty patients (16 localized relapse) underwent surgery. Forty-seven (71.2%) received salvage radiotherapy (20 with CC; 10 with HDC; 15 alone, two unknown). CSI and fRT accounted for 82% and 18% respectively. CSI median dose was 36Gy (range 18-39Gy). Ten patients (eight with localized relapse) received CSI doses ≤23.4Gy. Nineteen patients (28.8%) did not receive any radiotherapy (nine HDC; 10 CC only). Radiotherapy was associated with better 3-year PRS (73.0% versus 36.1%; p=0.001). All patients treated with CSI ≤ 23.4Gy were alive at median follow-up of 69 months(24-142). Six of nine patients treated with HDC without irradiation were alive at last follow-up. Sixty-three percent of patients received reduced dose CSI(≤23.4Gy), fRT, or no radiotherapy, and their PRS did not significantly differ from those who received CSI ≥ 30.6Gy (p = 0.54). CONCLUSION: While salvage CSI provided PRS benefit in this SHH medulloblastoma cohort, we report the use of reduced salvage radiotherapy and irradiation avoidance in 63% of the patients, with 60% alive at last follow-up.

Medulloblastoma (MB) is characterized by highly invasive embryonal neuro-epithelial tumors that metastasize via cerebrospinal fluid. MB is difficult to treat and the chemotherapy is associated with significant toxicities and potential long-term disabilities. Previously, we showed that small molecule, clotam (tolfenamic acid: TA) inhibited MB cell proliferation and tumor growth in mice by targeting, survivin. Overexpression of survivin is associated with aggressiveness and poor prognosis in several cancers, including MB. The aim of this study was to test combination treatment involving Vincristine® (VCR), a standard chemotherapeutic drug for MB and TA against MB cells. DAOY and D283 MB cells were treated with 10 μg/mL TA or VCR (DAOY: 2 ng/mL; D283: 1 ng/mL) or combination (TA + VCR). These optimized doses were lower than individual IC50 values. The effect of single or combination treatment on cell viability (CellTiterGlo kit), Combination Index (Chou-Talalay method based on median-drug effect analysis), activation of apoptosis and cell cycle modulation (by flow cytometry using Annexin V and propidium iodide respectively) and the expression of associated markers including survivin (Western immunoblot) were determined. Combination Index showed moderate synergistic cytotoxic effect in both cells. When compared to individual agents, the combination of TA and VCR increased MB cell growth inhibition, induced apoptosis and caused cell cycle (G2/M phase) arrest. Survivin expression was also decreased by the combination treatment. TA is effective for inducing the anti-proliferative response of VCR in MB cells. MB has four distinct genetic/molecular subgroups. Experiments were conducted with MB cells representing two subgroups (DAOY: SHH group; D283: group 4/3). TA-induced inhibition of survivin expression potentially destabilizes mitotic microtubule assembly, sensitizing MB cells and enhancing the efficacy of VCR.

Introduction: Methylation-derived neutrophil-to-lymphocyte ratio (mdNLR) has been identified as a potential prognostic biomarker of outcomes in various cancers. We evaluated the prognostic value of blood-derived mdNLR within a retrospective cohort of pediatric medulloblastoma patients. Materials and methods: DNA methylation was measured in archival peripheral blood samples collected on 56 pediatric medulloblastoma patients. Hazard ratios (HR) and 95% confidence intervals (CI) for the association between mdNLR and survival were evaluated using Cox proportional hazard models. Results: Compared to patients who were alive at last follow-up (n = 43), the mean mdNLR value was slightly higher in deceased patients (n = 13) (12.3 vs. 5.2,P = 0.163). Elevated log-transformed mdNLR was suggestively associated with an increased likelihood of death in unadjusted models (HR=1.43, 95%CI: 0.92-2.22) and significantly associated with mortality in adjusted models (HR=1.61, 95%CI: 1.01-2.58). Discussion: Future work is warranted to investigate the relationship between mdNLR outcomes in specific pediatric medulloblastoma molecular subgroups.

INTRODUCTION: Gangliogliomas (GG) are low-grade mixed glial/neuronal tumors typically seen in children and young adults. They commonly arise in the cerebrum, cerebellum and brainstem and are often associated with seizures. Management is typically surgical. Adjuvant radiation therapy is occasionally used, but primary treatment with chemotherapy is not considered standard. Very rarely, GG involves the optic pathway, with this location being rarely amenable to surgery, threatens vision and mandates creative treatment approaches. Many GG have mutations in the BRAF proto-oncogene, critical for regulating the MAP kinase/ERKs signaling pathway which affects cell division and differentiation. METHODS/RESULTS: A 4-year-old boy presented with a many-year history of abnormal eye movements and progressive visual decline. Ophthalmologic examination revealed esotropia, optic atrophy and poor visual acuity. MRI scanning revealed an extensive bilateral infiltrative tumor involving the optic pathway, hypothalamus, thalami, midbrain and temporal lobes. An image-guided stereotactic biopsy revealed a typical WHO grade 1 ganglioglioma and tumor cell pyrosequencing revealed a BRAF codon 600 (V600E) mutation. There was no clinical or imaging evidence of NF1. Given the tumor’s unresectability and the reticence to use ionizing radiation therapy at such a young age, combination chemotherapy using carboplatin and vincristine was started. Tumor extent and contrast enhancement decreased dramatically during the one year chemotherapy journey and ophthalmologic parameters stabilized. CONCLUSIONS: The management of GG is typically surgical, with careful use of radiation therapy for select circumstances. Chemotherapy is not typically considered an effective therapy. However, this case suggests that GG can be chemosensitive, to standard low-grade glioma chemotherapy. The presence of the BRAF V600E mutation is common in GG and may afford a therapeutic management strategy for select cases, using BRAF inhibitors such as vemurafenib and dabrafenib. We recommend the ongoing reporting of novel treatment strategies for challenging-site GG and suggest BRAF analysis for such tumors.

HG-49. A TEXAS-OKLAHOMA PEDIATRIC NEURO-ONCOLOGY CONSORTIUM (TOPNOC) PHASE 2 STUDY OF VALPROIC ACID (VPA) AND RADIATION, FOLLOWED BY MAINTENANCE VPA AND BEVACIZUMAB IN CHILDREN WITH NEWLY DIAGNOSED DIFFUSE INTRINSIC PONTINE GLIOMA (DIPG) OR HIGH-GRADE GLIOMAS (HGG) Jack M. Su1, Jeffrey C. Murray2, Rene Y. McNall-Knapp3, Daniel Bowers4, Shafqat Shah5, Adekunle M. Adesina6, Arnold C. Paulino7, Xiao-Nan Li1, Eunji Jo8, Qianxing Mo8, Susan G. Hilsenbeck8, Jeremy Y. Jones9, Patricia A. Baxter1, Murali Chintagumpala1, and Susan M. Blaney1; Texas Children’s Cancer Center, Baylor College of Medicine, Houston, TX, USA; Cook’s Children’s Medical Center, Fortworth, TX, USA; Department of Pediatrics, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA; University of Texas Southwestern Medical Center, Dallas, TX, USA; University of Texas Health Science Center, Department of Pediatrics, Division of Hematology/Oncology, San Antonio, TX, USA; Texas Children’s Hospital, Department of Pathology, Houston, TX, USA; MD Anderson Cancer Center, Houston, TX, USA; Dan L Duncan Cancer Center, Department of Medicine, Biostatistics and Bioinformatics, Baylor College of Medicine, Houston, TX, USA; Singleton Department of Radiology, Texas Children’s Hospital, Baylor College of Medicine, Houston, TX, USA PURPOSE: To study the efficacy and tolerability of VPA and radiation, followed by VPA and bevacizumab in children with newly diagnosed DIPG or HGG. METHODS: Children 3-21 years of age with newly diagnosed DIPG or HGG were enrolled. Concurrent with radiation therapy, VPA was initiated at 15 mg/kg/day divided tid and dose-adjusted to maintain a trough range of 85-115 mcg/ml. VPA was continued post-XRT, and bevacizumab was started at 10 mg/kg bi-weekly four weeks after completing XRT. RESULTS: From September 2009 through December 2015, 20 DIPG and 18 HGG patients were enrolled. During radiation and VPA,grade-3orhigher toxicities included grade-5 tumor edema (1), grade-3 neutropenia (1), and grade-3 thrombocytopenia (1). During VPA and bevacizumab, the most common grade-3 or higher toxicities requiring treatment modifications were grade-3 thrombocytopenia (4), grade-3 weight gain (4), and grade-3 hypertension (3). Two patients discontinued protocol therapy prior to disease progression for grade-4 thrombosis (1) and grade-1 intra-tumoral hemorrhage (1). Median PFS and OS for DIPG were 7.9 (95% CI 5.4-8.1) and 10 (7.1-12.9) months, and estimated 1-year PFS was 13% (2-33%). Median PFS and OS for HGG were 8.7 (3.9-10.6) and 11 (7.7-21.2) months, and estimated 1-year PFS was 21% (5-45%). Of note, 3 patients with glioblastoma and mismatch-repair deficiencysyndrome,predicted tohave resistance toalkylatoragents, receivedprotocol therapy for 9, 10.4, and 16.7 months. CONCLUSION: Addition of VPA and bevacizumab to radiation was well-tolerated but did not appear to significantly improve PFS or OS in children with DIPG or HGG. Neuro-Oncology 18:iii48–iii77, 2016. doi:10.1093/neuonc/now073.45 #The Author(s) 2016. Published by Oxford University Press on behalf of the Society for Neuro-Oncology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com. D ow naded rom http/academ ic.p.com /neuro-oncology/aract/18/suppl_3/iii58/2469262 by gest on 16 D ecem er 2018

Adequately treated hydrocephalus is linked to attention problems in children. Few studies have specifically evaluated patients with tectal plate glioma (TPG)-associated obstructive hydrocephalus. Gass et al. (2015) conducted a review of clinical outcomes in children treated for TPG and found that subjects exhibited difficulties with problem solving, planning, impulsivity, cognitive flexibility, processing speed and sustained attention. Aarsen et al (2013) investigated long-term outcomes in 12 children with tectal tumors and found significant deficits with sustained attention and long-term memory. The present study aims to further investigate aspects of attention that may be impacted by treated hydrocephalus associated with pediatric TPG. Neuropsychological assessment data for seven subjects aged 7-17 years (M=11.28; SD=3.30) were analyzed. The Connors Continuous Performance Test (CPT) was administered to subjects 1-8 years following shunt, endoscopic ventriculostomy or both. CPT measures of omission (inattentiveness), commission (impulsivity), Hit Reaction Time (reaction time) and Hit Reaction Time Inter-Stimulus Intervals Change (sustained attention) were obtained for each subject. Four subjects scored in the average range for omission errors, one scored below average and two exhibited scale elevations. A one-sample Kolmogorov-Smirnoff test indicated the standardized T-scores for inattentiveness were not normally distributed (M=55.71, SD=14.17, p < 0.005). Similar analyses for impulsivity, reaction time and sustained attention were not statistically significant. Three subjects demonstrated slightly fast reaction times, three performed in the average range and one showed slowed reaction time. Although two subjects scored in the average range on the sustained attention variable, three displayed scale elevations. All subjects demonstrated at least one score outside of the average range: 43% for inattentiveness and impulsivity; 57% for reaction time and 71% for sustained attention. These findings suggest that children treated for tectal plate glioma with hydrocephalus are at risk for long term deficits for several aspects of attention and that further study is warranted.

PURPOSE Adolescent and young adult (AYA)-aged central nervous system (CNS) tumor survivors are an understudied population that is at risk of developing adverse health outcomes, such as obesity. Long-term follow-up guidelines recommend monitoring those at risk of obesity, thus motivating the need for an eating behavior questionnaire. An abbreviated online version of the Three-Factor Eating Questionnaire (TFEQ-R18v2) has been developed, but its applicability to this population is not yet known. This study investigated the instrument's factor structure and reliability in this population. METHODS AYA-aged CNS tumor survivors (n = 114) aged 15-39 years completed the TFEQ-R18V2 questionnaire online. Confirmatory factor analysis was used to examine the fit of the three-factor structure (uncontrollable eating, cognitive restraint, and emotional eating [EE]) and reliability (internal consistency of the TFEQ-R18v2). Associations between the three factors and body mass index (BMI) were assessed by linear regression. RESULTS The theorized three-factor structure was supported in our population (RMSEA = 0.056 and CFI = 0.98) and demonstrated good reliability (α of 0.81-0.93). EE (β = 0.07, 95% CI 0.02-0.13) was positively associated with BMI, whereas the other two subscale scores were not. CONCLUSION The TFEQ-R18v2 instrument holds promise for research and clinical use among AYA-aged CNS tumor survivors. The instrument may be a useful tool for researchers to develop tailored weight management strategies. It also may be a valuable tool for clinicians to monitor survivors who are at risk of obesity and to facilitate referral. Our results also suggest that EE in this population should be further investigated as a potential target for intervention.

Aim: Medulloblastoma is the most frequent malignant pediatric brain tumor. While survival rates have improved due to multimodal treatment including cisplatin-based chemotherapy, there are few prognostic factors for adverse treatment outcomes. Notably, genes involved in the nucleotide excision repair pathway, including ERCC2, have been implicated in cisplatin sensitivity in other cancers. Therefore, this study evaluated the role of ERCC2 DNA methylation profiles on pediatric medulloblastoma survival.Methods: The study population included 71 medulloblastoma patients (age < 18 years at diagnosis) and recruited from Texas Children's Cancer Center between 2004 and 2009. DNA methylation profiles were generated from peripheral blood samples using the Illumina Infinium Human Methylation 450 Beadchip. Sixteen ERCC2-associated CpG sites were evaluated in this analysis. Multivariable regression models were used to determine the adjusted association between DNA methylation and survival. Cox regression and Kaplan-Meier curves were used to compare 5-year overall survival between hyper- and hypo-methylation at each CpG site.Results: In total, 12.7% (n = 9) of the patient population died within five years of diagnosis. In our population, methylation of the cg02257300 probe (Hazard Ratio = 9.33; 95% Confidence Interval: 1.17-74.64) was associated with death (log-rank p = 0.01). This association remained suggestive after correcting for multiple comparisons (FDR p < 0.2). No other ERCC2-associated CpG site was associated with survival in this population of pediatric medulloblastoma patients.Conclusion: These findings provide the first evidence that DNA methylation within the promoter region of the ERCC2 gene may be associated with survival in pediatric medulloblastoma. If confirmed in future studies, this information may lead to improved risk stratification or promote the development of novel, targeted therapeutics. (C) 2016 Elsevier Ltd. All rights reserved.

Abstract Brain tumors are the leading cause of cancer related death in children, and there is biological differences between treatment naïve tumors and their therapy resistant relapses. As surgery is rarely an option for terminal brain tumors that have failed existing therapies, autopsy is frequently the only chance to obtain tumor tissues. Despite the urgent need of models of terminal brain tumors, it remains unknown if autopsied tumors can be used for in vitro and in vivo model development. To determine if (some) tumor cells can survival postmortem anoxia/starvation to proliferate in vitro and, more importantly, to form orthotopic xenograft tumors, we collected 29 autopsied brain tumors, including 15 diffuse intrinsic pontine gliomas (DIPG), 7 glioblastomas (GBM), 4 medulloblastomas (MB), 2 ependymoma and 1 atypical teratoid/rhabdoid tumor (ATRT), and made the following discoveries. i) A small fraction of tumor cells exhibited strong survival capacity and remained viable, ranging from 0.5%-40% (13.5% ± 10.9%), in tumors harvested 5-72 hrs (31.2 ± 25 hrs) after patients’ death. Cell viability, however, did not appear to be strictly correlated with the length of autopsy time (r = 0.17), suggesting that ample time should be given to the families to say goodbye to their loved ones. ii) While many autopsied tumor cells appear to have stayed alive for short terms in culture, only one pair of permanent lines (monolayer in FBS media and neurosphere in serum-free media) were established from a GBM tumor. iii) Direct implantation of tumor cells into matched locations in the brains of SCID mice led to the formation of xenograft tumors in 17 of 22 tumors (7 additional tumors are still pending). 8 of the 17 autopsy derived orthotopic (ADOX) models have been subtransplanted in mouse brains for > 3 times (5 DIPGs and 1 each of GBM, MB and ATRT). Detailed characterization confirmed their replication of histopathological features and genetic/genomic abnormalities of the patient tumors. iv) To identify the cellular origin of surviving patient tumor cells that propagated ADOX model formation, time course analysis of putative cancer stem cells (CD133, CD15, CD24/CD44, CD57, CD117) was performed. CD57+ tumor cells were found to be the most abundant subpopulations in the autopsied tumors, and their fractions increased in the ADOX tumors during serial subtransplantations. Additionally, CD57+ cells alone were able to form orthotopic xenografts, establishing their role as cancer stem cells. In conclusion, we have demonstrated that a fraction of tumor cells can survive the lengthy period of postmortem anoxia/starvation and regain tumorigenic capabilities in mouse brains; and identified CD57 as a new marker of the therapy-resistant cells with extraordinary survival and tumorigenic (TREST) capabilities. This novel panel of ADOX models should facilitate biological studies and preclinical drug screening of therapy-resistant pediatric brain tumors. Citation Format: Lin Qi, Baxter A. Patricia, Kogiso Mari, Du Yuchen, Lindsay Holly, Liu Zhigang, Xiumei Zhao, Yujing Zhang, Jack MF Su, Adekunle Adesina, Andrew W. Walter, Jeffery Murray, Rene McNall-Knapp, Javad Nazarian, Will Parsons, Murali Chintagumpala, Susan Blaney, Xiao-Nan Li. Autopsy derived orthotopic xenograft (ADOX) mouse models for terminal pediatric brain tumors. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1450. doi:10.1158/1538-7445.AM2015-1450

The outcome of localized osteosarcoma has remained constant over the past 30 years. Histological response to preoperative chemotherapy is the best predictor of outcome. Strategies to alter treatment based on histological response have not resulted in increased survival.

INTRODUCTION: Slowly growing deeply situated brain tumors in children pose a unique management dilemma. Considerations of watchful waiting, resection, chemotherapy and radiation therapy must be weighed carefully. With concerns over neurosurgical resection morbidity, the typical long-term ineffectiveness of chemotherapy and the feared sequelae of radiation therapy, our institution has chosen to manage select tumors using laser interstitial ablation via the stereotactic Visualase® system. METHODS: Five patients, ages 7, 8, 12, 15, 16 years had clinicoradiographic histories of slowly enlarging deep brain lesions characteristic of low-grade glial tumors. Locations included deep thalamus (2), cerebellar vermis (1), parieto-occiptal region (1) and a SEGA near a foramen of Monro (1). Options for management were discussed with each family, and laser ablation was decided upon. RESULTS: The patients were taken to the intraoperative MRI operating room for stereotactic needle biopsy and laser interstitial ablation during the same operation. Frozen section tissue analysis in all cases showed a low-grade glial tumor. Each patient underwent standard post-operative scanning, all showing evidence of lesional/peri-lesional signal change, a sign suggestive of desired zonal ablation injury to the tumor. Four patients had no evidence of post-procedure complications and were discharged several days post-procedure. One patient (cerebellar vermis) had significant post-ablation procedure ataxia and had evidence of incomplete ablation by virtue of tumor progression 16 months later, requiring a second ablation. None had evidence of concerning hemorrhage. All tumors were finalized as being low-grade glial (pilocytic) tumors. CONCLUSIONS: Stereotactic laser ablation therapy should be considered as an option in the management of select patients with deeply-situated glial tumors, in order to avoid potential serious neurosurgical morbidity via resection, or the dangers of irradiation. Continued long-term patient follow up will be needed in order to determine whether ablation therapy was successful. Further reporting on this technique by other investigators is suggested.

Overlaying visual cues on diagrams and animations can help students attend to relevant areas and facilitate problem solving. In this study we investigated the effects of visual cues on students' eye movements as they solved conceptual physics problems. Students (N=80) enrolled in an introductory physics course individually worked through four sets of problems, each containing a diagram, while their eye movements were recorded. Each diagram contained regions that were alternatively relevant to solving the problem correctly or related to common incorrect responses. Each problem set contained an initial problem, six isomorphic training problems, and a transfer problem. Those in the cued condition saw visual cues overlaid on the training problems. Students provided verbal responses. The cued group more accurately answered the (uncued) transfer problems, and their eye movements showed they more efficiently extracted the necessary information from the relevant area than the uncued group.

Research has demonstrated that attentional cues overlaid on diagrams and animations can help students attend to the relevant areas and facilitate problem solving. In this study we investigate the influence of visual cues and correctness feedback on students' reasoning as they solve conceptual physics problems containing a diagram. The participants (N= 90) were enrolled in an algebra-based physics course and were individually interviewed. During each interview students solved four problem sets each containing an initial problem, six isomorphic training problems, and a transfer problem. The cued conditions saw visual cues on the training problems, and the feedback conditions were told if their responses (answer and explanation) were correct or incorrect. We found that visual cues and correctness feedback significantly improves students' abilities to solve the training and transfer problems.

BACKGROUND: Osteosarcoma is the most common malignant bone tumor in children. Despite the advent of chemotherapy, the survival of osteosarcoma patients has not been significantly improved recently. Chemokines are a group of signaling molecules that have been implicated in tumorigenesis and metastasis. METHODS: The authors used an antibody microarray to identify chemokines that were elevated in the plasma samples of osteosarcoma patients. The results were validated using enzyme-linked immunosorbent assays on an independent set of samples. The tumor expressions of 3 chemokines were examined in 2 sets of osteosarcoma tissue arrays. The authors also evaluated the proliferative effect of the chemokines in 4 osteosarcoma cell lines. RESULTS: The authors found that the plasma levels of CXCL4, CXCL6, and CXCL12 in the osteosarcoma patients were significantly higher than those in the controls, and the results were validated by an independent osteosarcoma cohort (P < .05). However, CXCL4 (100%) and CXCL6 (91%) were frequently expressed in osteosarcoma, whereas CXCL12 was only expressed in 4%. Survival analysis further showed that higher circulating levels of CXCL4 and CXCL6, but not CXCL12, were associated with a poorer outcome of osteosarcoma patients. Addition of exogenous chemokines significantly promoted the growth of different osteosarcoma cells (P < .05). CONCLUSIONS: The results demonstrate that CXCL4 and CXCL6 are frequently expressed in osteosarcoma, and that the plasma levels of these 2 chemokines are associated with patient outcomes. Further study of these circulating chemokines may provide a promising approach for prognostication of osteosarcoma. Targeting these chemokines or their receptors may also lead to a novel therapeutic invention. Cancer 2011;117:207-17. (C) 2070 American Cancer Society.