Genome-wide Association Study Identifies Two Susceptibility Loci for Osteosarcoma

Osteosarcoma is the most common primary bone malignancy of adolescents and young adults. In order to better understand the genetic etiology of osteosarcoma, we performed a multi-stage genome-wide association study (GWAS) consisting of 941 cases and 3,291 cancer-free adult controls of European ancestry. Two loci achieved genome-wide significance: rs1906953 at 6p21.3, in the glutamate receptor metabotropic 4 [GRM4] gene (P = 8.1 ×10-9), and rs7591996 and rs10208273 in a gene desert on 2p25.2 (P = 1.0 ×10-8 and 2.9 ×10-7). These two susceptibility loci warrant further exploration to uncover the biological mechanisms underlying susceptibility to osteosarcoma

An evaluation of the factors that affect the health-related quality of life of children following myelosuppressive chemotherapy

PurposeThe purposes of this study, in children who were assessed 1 week after the administration of myelosuppressive chemotherapy were: to compare the total and subscale scores on a generic measure of health-related quality of life (HRQOL) to normative data from healthy children and describe the relationships between demographic, clinical, and symptom characteristics of children with cancer and generic and disease-specific dimensions of HRQOL.MethodsPatients (n = 61) were predominantly male (52.5%), minority (63.9%), and 14.7 years of age. Children completed the Memorial Symptom Assessment Scale for 10- to 18-year olds, the PedsQL™ Generic and Cancer Modules, and the Karnofsky Performance Status (KPS) scale 1 week after the start of a chemotherapy cycle.ResultsThe mean number of symptoms per patient was 10.6. Compared with the normative sample, children with cancer reported significantly lower scores for the total scale and all of the subscales except emotional and social functioning. No significant differences were found between any demographic characteristics and total or subscale scores on the generic or disease-specific measures of HRQOL. Lower KPS scores were associated with poorer generic and disease-specific HRQOL scores. In addition, a higher number of symptoms was associated with poorer generic and disease-specific HRQOL scores. Finally, higher symptom distress scores were associated with poorer generic and disease-specific HRQOL scores.ConclusionAmong the demographic, clinical, and symptom characteristics studied, poorer functional status and higher symptom burden were associated with significant decreases in HRQOL in children who received myelosuppressive chemotherapy

Genome-wide association study identifies two susceptibility loci for osteosarcoma

Osteosarcoma is the most common primary bone malignancy of adolescents and young adults. To better understand the genetic etiology of osteosarcoma, we performed a multistage genome-wide association study consisting of 941 individuals with osteosarcoma (cases) and 3,291 cancer-free adult controls of European ancestry. Two loci achieved genome-wide significance: a locus in the GRM4 gene at 6p21.3 (encoding glutamate receptor metabotropic 4; rs1906953; P = 8.1 × 10⁻⁹) and a locus in the gene desert at 2p25.2 (rs7591996 and rs10208273; P = 1.0 × 10⁻⁸ and 2.9 × 10⁻⁷, respectively). These two loci warrant further exploration to uncover the biological mechanisms underlying susceptibility to osteosarcoma

Nucleoside transport in normal and neoplastic cells

The permeation of nucleosides across the plasma membrane of mammalian cells is complex and mediated by at least five distinct transporters that differ in their sensitivity to inhibitors and in their specificity for nucleosides. The basic properties and permeant specificity of these transporters are summarized in Table 3. It appears that there may be differences in the distribution of these transporters in tumors and normal tissues that might be exploited for chemotherapeutic purposes. The human tumor cell lines examined express predominantly the NBMPR-sensitive equilibrative transporter es which can be blocked by low concentrations of NBMPR and dipyridamole. It is reasonable to expect that tumors with transport properties similar to the CCRF-CEM and Rh28 cell lines (Table 1) that have no detectable NBMPR-insensitive transport activity will be highly susceptible to the therapeutic approach of combining a transport inhibitor such as dipyridamole or NBMPR with an inhibitor of de novo pyrimidine biosynthesis. On the other hand, this approach to therapy is unlikely to succeed against tumors with transport phenotypes similar to the WI-L2 cell line that may permit the salvage nucleosides in the presence of these inhibitors. The majority of tumor cells examined, however, fall between these extremes, and it is not yet known what level of NBMPR-insensitive transport activity can be tolerated without seriously compromising this therapeutic approach. With respect to normal tissues, the mature absorptive cells of the intestine have predominantly Na+-dependent nucleoside transporters that are insensitive to NBMPR and dipyridamole. The proliferating crypt cells also appear to have Na+-dependent nucleoside transport, although they may also have an NBMPR-sensitive component of transport (Belt, unpublished data). Bone marrow granulocyte-macrophage progenitor cells also appear to have one or more concentrative nucleoside transporters. Thus these tissues, which are most vulnerable to the toxicity of antimetabolites, may be able to salvage nucleosides in the presence of inhibitors of equilibrative transport and be protected from the toxicity of de novo synthesis inhibitors. It is likely, however, that a successful application of this therapeutic approach will require the analysis of the nucleoside transport phenotype of individual tumors in order to identify those patients that may benefit from such therapy. Since the development of antibodies (66-68) and cDNA probes (69, 70) for the various nucleoside transporters is currently underway in several laboratories, it is likely that analysis of the nucleoside transport phenotype of tumors from biopsy material will be feasible in the future. © 1993

Imaging Tumor Necrosis with Ferumoxytol.

Ultra-small superparamagnetic iron oxide nanoparticles (USPIO) are promising contrast agents for magnetic resonance imaging (MRI). USPIO mediated proton relaxation rate enhancement is strongly dependent on compartmentalization of the agent and can vary depending on their intracellular or extracellular location in the tumor microenvironment. We compared the T1- and T2-enhancement pattern of intracellular and extracellular USPIO in mouse models of cancer and pilot data from patients. A better understanding of these MR signal effects will enable non-invasive characterizations of the composition of the tumor microenvironment.Six 4T1 and six MMTV-PyMT mammary tumors were grown in mice and imaged with ferumoxytol-enhanced MRI. R1 relaxation rates were calculated for different tumor types and different tumor areas and compared with histology. The transendothelial leakage rate of ferumoxytol was obtained by our measured relaxivity of ferumoxytol and compared between different tumor types, using a t-test. Additionally, 3 patients with malignant sarcomas were imaged with ferumoxytol-enhanced MRI. T1- and T2-enhancement patterns were compared with histopathology in a descriptive manner as a proof of concept for clinical translation of our observations.4T1 tumors showed central areas of high signal on T1 and low signal on T2 weighted MR images, which corresponded to extracellular nanoparticles in a necrotic core on histopathology. MMTV-PyMT tumors showed little change on T1 but decreased signal on T2 weighted images, which correlated to compartmentalized nanoparticles in tumor associated macrophages. Only 4T1 tumors demonstrated significantly increased R1 relaxation rates of the tumor core compared to the tumor periphery (p<0.001). Transendothelial USPIO leakage was significantly higher for 4T1 tumors (3.4±0.9x10-3 mL/min/100cm3) compared to MMTV-PyMT tumors (1.0±0.9x10-3 mL/min/100 cm3). Likewise, ferumoxytol imaging in patients showed similar findings with high T1 signal in areas of tumor necrosis and low signal in areas of intracellularly compartmentalized iron.Differential T1- and T2-enhancement patterns of USPIO in tumors enable conclusions about their intracellular and extracellular location. This information can be used to characterize the composition of the tumor microenvironment

Physical Performance Limitations in the Childhood Cancer Survivor Study Cohort

Physical performance limitations are one of the potential long-term consequences following diagnosis and treatment for childhood cancer. The purpose of this review is to describe the risk factors for and the participation restrictions that result from physical performance limitations among childhood cancer survivors who participated in the Childhood Cancer Survivor Study (CCSS). Articles previously published from the CCSS cohort related to physical performance limitations were reviewed and the results summarized. Our review showed that physical performance limitations are prevalent among childhood cancer survivors and may increase as they age. Host-based risk factors for physical disability include an original diagnosis of bone tumor, brain tumor, or Hodgkin's disease; female sex; and an income less than $20,000 per year. Treatment-based risk factors include radiation and treatment with a combination of alkylating agents and anthracyclines. Musculoskeletal, neurologic, cardiac, pulmonary, sensory, and endocrine organ system dysfunction also increase the risk of developing a physical performance limitation. In summary, monitoring of physical performance limitations in an aging cohort of childhood cancer survivors is important and will help determine the impact of physical performance limitations on morbidity, mortality, and caregiver burden. In addition, in developing restorative and preventive interventions for childhood cancer survivors, we must take into account the special needs of survivors with physical disability to optimize their health and enhance participation in daily living activities

Health Status of Adult Long-term Survivors of Childhood Cancer: A Report from the Childhood Cancer Survivor Study

Context: Adult survivors of childhood cancer are at risk for medical and psychosocial sequelae that may adversely affect their health status. Objectives: To compare the health status of adult survivors of childhood cancer and siblings and to identify factors associated with adverse outcomes. Design, Setting, and Participants: Health status was assessed in 9535 adult participants of the Childhood Cancer Survivor Study, a cohort of long-term survivors of childhood cancer who were diagnosed between 1970 and 1986. A randomly selected cohort of the survivors\u27 siblings (n=2916) served as a comparison group. Main Outcome Measures: Six health status domains were assessed: general health, mental health, functional status, activity limitations, cancer-related pain, and cancer-related anxiety/fears. The first 4 domains were assessed in the control group. Results: Survivors were significantly more likely to report adverse general health (odds ratio [OR], 2.5; 95% confidence interval [CI], 2.1-3.0; P\u3c.001), mental health (OR, 1.8; 95% CI, 1.6-2.1; P\u3c.001), activity limitations (OR, 2.7; 95% CI, 2.3-3.3; P\u3c.001), and functional impairment (OR, 5.2; 95% CI, 4.1-6.6; P\u3c.001), compared with sibiings. Forty-four percent of survivors reported at least 1 adversely affected health status domain. Sociodemographic factors associated with reporting at least 1 adverse health status domain included being female (OR, 1.4; 95% CI, 1.3-1.6; P\u3c.001), lower level of educational attainment (OR, 2.0; 95% CI, 1.8-2.2; P\u3c.001), and annual income less than $20000 (OR, 1.8; 95% CI, 1.6-2.1; P\u3c.001). Relative to those survivors with childhood leukemia, an increased risk was observed for at least 1 adverse health status domain among those with bone tumors (OR, 2.1; 95% CI, 1.8-2.5; P\u3c.001), central nervous system tumors (OR, 1.7; 95% CI, 1.5-2.0; P\u3c.001), and sarcomas (OR, 1.2; 95% CI, 1.1-1.5; P=.01). Conclusion: Clinicians caring for adult survivors of childhood cancer should be aware of the substantial risk for adverse health status, especially among females, those with low educational attainment, and those with low household incomes