A pooled analysis of extremely low-frequency magnetic fields and childhood brain tumors

Pooled analyses may provide etiologic insight about associations between exposure and disease. In contrast to childhood leukemia, no pooled analyses of childhood brain tumors and exposure to extremely low-frequency magnetic fields (ELF-MFs) have been conducted. The authors carried out a pooled analysis based on primary data (1960-2001) from 10 studies of ELF-MF exposure and childhood brain tumors to assess whether the combined results, adjusted for potential confounding, indicated an association. The odds ratios for childhood brain tumors in ELF-MF exposure categories of 0.1-<0.2 μT, 0.2-<0.4 μT, and ≥0.4 μT were 0.95 (95% confidence interval: 0.65, 1.41), 0.70 (95% CI: 0.40, 1.22), and 1.14 (95% CI: 0.61, 2.13), respectively, in comparison with exposure of <0.1 μT. Other analyses employing alternate cutpoints, further adjustment for confounders, exclusion of particular studies, stratification by type of measurement or type of residence, and a nonparametric estimate of the exposure-response relation did not reveal consistent evidence of increased childhood brain tumor risk associated with ELF-MF exposure. These results provide little evidence for an association between ELF-MF exposure and childhood brain tumors.

Inverse association of high-fat diet preference and anxiety-like behavior: a putative role for urocortin 2

The aim of this study was to investigate whether the preference for a palatable high-fat diet (HFD) is associated with response to novelty and with anxiety-like behavior in rats and whether such fat preference correlates with gene expression of hypothalamic neuropeptides related to feeding. We subjected male rats to two tests of exploration of novel environments: the multivariate concentric square field (MCSF) and the elevated plus maze (EPM). The rats were then exposed to a 5-day test of preference for a palatable HFD versus reference diets. Messenger RNA (mRNA) levels of 21 neuropeptides were investigated by quantitative polymerase chain reaction. We found a strong positive correlation of HFD preference and open-arm activity in the EPM (% open-arm time, r(s) = 0.629, df = 26, P < 0.001). Thus, HFD preference was inversely associated with anxiety-like behavior. The same association was found for HFD preference and behavior in the MCSF (bridge entries, r(s) = 0.399, df = 23, P = 0.048). In addition, the HFD preference was positively correlated (r(s) = 0.433, df = 25, P = 0.021) with hypothalamic mRNA levels of urocortin 2 (Ucn 2). Moreover, behavior in the EPM was significantly correlated with expression levels of the receptor for Ucn 2, the corticotropin-releasing factor receptor 2, in the hypothalamus (r(s) = 0.382, df = 33, P = 0.022, pituitary (r(s) = 0.494, df = 31, P = 0.004) and amygdala (r(s) = 0.381, df = 30, P = 0.032). We conclude that preference for palatable HFD is inversely associated with anxiety and propose that Ucn 2 signaling may play a role in this association.

Help-seeking behaviour in patients with lymphoma

Reducing cancer mortality is a priority for the UK Government and emphasis has been placed on introducing targets to ensure prompt diagnosis. Help seeking is the first step on the pathway to diagnosis and should occur promptly; however, patients with lymphoma take longer to seek help for symptoms than those with many other cancers. Despite this, the help seeking behaviour of these patients has not been investigated. This qualitative study examined the beliefs and actions about help seeking among 32 patients, aged 65 and over and newly diagnosed with lymphoma in West Yorkshire during 2000. Patients reported an extremely wide range of symptoms which were not always interpreted as serious or potentially caused by cancer. This, in association with a clear lack of knowledge about lymphoma, often led to help seeking being deferred. The range and characteristics of symptoms can largely be explained in terms of variations in the type, site and size of the lymphoma. The UK Government targets focus on the time after help seeking, yet for lymphoma it is also crucial to reduce the time taken to seek help. More education about the potential symptoms of this disease is needed among the general public.

Referral pathways and diagnosis: UK government actions fail to recognize complexity of lymphoma

To gain survival advantages potentially associated with prompt diagnosis, the UK government introduced identical waiting-time targets for all cancers, and guidelines to ensure that general practitioners make appropriate hospital referrals. For lymphoma, the evidence guiding these actions is limited. This study examined referral pathways in patients with lymphoma and variations in time to diagnosis by discipline of first referral. A case series study was conducted including all patients aged over 25 years, newly diagnosed with lymphoma in the UK county of West Yorkshire, during 2000. Data were extracted from primary care and hospital records of 189 patients. Referral pathways were described, and the number of days between first referral and diagnosis calculated. A distinct referral pathway did not exist; patients were initially referred to many disciplines. Surgical referrals predominated, and only 12% of patients were sent directly to haematology. Time to diagnosis varied by discipline and was shorter for patients sent to haematology than for most other common disciplines. UK government actions to ensure the prompt diagnosis of patients with lymphoma are not evidence-based. The complexity of the referral pathway in patients with lymphoma, which affects time to diagnosis, has been underestimated. Further government actions should be evidence-based, ensuring prompt diagnosis of lymphoma from whatever discipline patients originate.

Hodgkin's lymphoma and infection: findings from a UK case-control study

Between 1998 and 2003, 214 people with Hodgkin's lymphoma and 214 controls randomly selected from population registers in the north of England (after matching for age and sex) were recruited and their primary care medical records examined for details of clinical diagnoses due to infectious and non-infectious conditions in the preceding 15 years. In the year before diagnosis of Hodgkin's lymphoma, almost all cases (99%) visited their general practitioner (GP) at least once. In comparison with controls, the excess was evident both for visits with an infection (odd's ratio (OR)=2.1; 95% confidence interval (CI) 1.4–3.2) and for visits with non-infectious problems (OR=17.2; 95% CI 6.7–43.9). During the rest of the 15-year period prior to diagnosis, the proportion of people visiting their GP with a non-infectious condition did not differ between cases and controls. In contrast, compared to controls, there was an excess of cases visiting the GP with an infection, a finding that was evident for at least a decade prior to diagnosis and increased linearly with time (P=0.02). This excess was not due to a specific infection(s) and may reflect underlying immune abnormality. Alternatively, infection may cause B-cell proliferation from which a malignant clone may evolve.

Birth order and sibship size: evaluation of the role of selection bias in a case-control study of non-Hodgkin's lymphoma

Substantial heterogeneity has been observed among case-control studies investigating associations between non-Hodgkin's lymphoma and familial characteristics, such as birth order and sibship size. The potential role of selection bias in explaining such heterogeneity is considered within this study. Selection bias according to familial characteristics and socioeconomic status is investigated within a United Kingdom-based case-control study of non-Hodgkin's lymphoma diagnosed during 1998-2001. Reported distributions of birth order and maternal age are each compared with expected reference distributions derived using national birth statistics from the United Kingdom. A method is detailed in which yearly data are used to derive expected distributions, taking account of variability in birth statistics over time. Census data are used to reweight both the case and control study populations such that they are comparable with the general population with regard to socioeconomic status. The authors found little support for an association between non-Hodgkin's lymphoma and birth order or family size and little evidence for an influence of selection bias. However, the findings suggest that between-study heterogeneity could be explained by selection biases that influence the demographic characteristics of participants.

Molar pregnancy and childhood cancer: a population-based linkage study from Denmark

We observed a relative risk of 1.40 (95% confidence interval; 0.86-2.16) for cancers diagnosed under the age 20 in 6192 offspring of 3431 mothers with a molar pregnancy, indicating it is not a major determinant of childhood cancer.

Reduced intensity allogeneic umbilical cord blood transplantation in children and adolescent recipients with malignant and non-malignant diseases

There is a significant amount of morbidity and mortality following myeloablative umbilical cord blood transplantation (UCBT). Reduced intensity (RI) conditioning offers an alternative to myeloablative conditioning before UCBT. We investigated RI-UCBT in 21 children and adolescents with malignant (n=14), and non-malignant diseases (n=7). RI conditioning consisted of fludarabine (150-180 mg/m2) with either busulfan (< or = 8 mg/kg)+rabbit antithymocyte globulin (R-ATG; n=16) or cyclophosphamide+R-ATG+/-etoposide (n=5). Human leukocyte antigen match: 4/6 (n=13), 5/6 (n=5) and 6/6 (n=3). The median total nucleated cell and CD34+ cell dose per kilogram were 3.58 x 10(7) and 2.54 x 10(5), respectively. The median time for neutrophil and platelet engraftment was 17.5 and 52 days, respectively. There were six primary graft failures (chronic myelogenous leukemia (CML), beta-thalassemia, hemophagocytic lymphohistiocytosis (HLH) and myelodysplastic syndrome (MDS)). The probability of developing grade II to grade IV acute graft-versus-host disease (GVHD) and chronic GVHD was 28.6 and 16.7%, respectively. Incidence of transplant-related mortality (TRM) was 14%. The 5 years overall survival (OS) in all patients was 59.8%. The 5 years OS for patients with average versus poor-risk malignancy was 77.8 versus 22.2% (P=0.03). RI-UCBT may result in graft failure in specific high-risk chemo-naïve patients (CML, beta-thalassemia, HLH and MDS), but in more heavily pretreated pediatric and adolescent recipients results in rapid engraftment and may be associated with decreased severe GVHD and TRM.

Haplotype uncertainty in association studies

Inferring haplotypes from genotype data is commonly undertaken in population genetic association studies. Within such studies the importance of accounting for uncertainty in the inference of haplotypes is well recognised. We investigate the effectiveness of correcting for uncertainty using simple methods based on the output provided by the PHASE haplotype inference methodology. In case-control analyses investigating non-Hodgkin lymphoma and haplotypes associated with immune regulation we find little effect of making adjustment for uncertainty in inferred haplotypes. Using simulation we introduce a higher degree of haplotype uncertainty than was present in our study data. The simulation represents two genetic loci, physically close on a chromosome, forming haplotypes. Considering a range of allele frequencies, degrees of linkage between the loci, and frequency of missing genotype data, we detail the characteristics of genetic regions which may be susceptible to the influence of haplotype uncertainty. Within our evaluation we find that bias is avoided by considering haplotype probabilities or using multiple imputation, provided that for each of these methods haplotypes are inferred separately for case and control populations; furthermore using multiple imputation provides the facility to incorporate haplotype uncertainty in the estimation of confidence intervals. We discuss the implications of our findings within the context of the complexity of haplotype inference for larger marker rich regions as would typically be encountered in genetic analyses.

Targeted immunotherapy with gemtuzumab ozogamicin (GO) following reduced intensity allogeneic stem cell transplantation (RI AlloSCT) to reduce minimal residual disease (MRD) in children with acute myeloid leukemia (AML): MRD monitoring by Wilms tumor gene

9532

Background: RI vs myeloablative (MA) AlloSCT in adults with AML is associated with significantly less transplant related mortality but increased rate of relapse, presumably secondary to MRD (Alyea et al; Blood, 2005). Quantification of the WT1 has been used successfully to detect MRD in children with acute myeloid leukemia (AML) (Kletzel et al; Pediatr Dev Pathol, 2002). GO has induced ORR in >30% of patients with overt relapsed CD33+ AML and may have a better effect in the setting of MRD (Sievers et al; J Clin Oncol, 2001). We have shown that RI AlloSCT followed by 2 doses of GO in average risk AML has resulted in >94% donor chimerism (Roman/Cairo, Clin Can Res, 2005). We explored changes in MRD prior to and after consolidation with 2 doses of GO targeted immunotherapy in children with average risk AML post RI AlloSCT. Methods: 11 pts, 11 years (0.5–21) with CD33+ (8 CR1, 3 CR2) received fludarabine 30 mg/m2x6d and busulfan 3.2–4 mg/kgx2d. Donors: 7 6/6 HLA related peripheral blood stem cells (RPBSC), 1 5/6 RPBSC, 1 6/6 related cord blood (CB) and 2 4/6 unrelated CB. GOx2 was administered =60d post AlloSCTx2 (8wks apart), at 4.5–7.5 mg/m2 (dose escalation). Samples were collected for WT1 analysis prior to and after each dose of GO (n=5). WT1 levels were determined by quantitative RT-PCR and compared with WT1 expression in a K562 leukemia line. Positive MRD was a ratio of K562 WT/patient's WT1>0.5. Results: The MTD for GO post RI AlloSCT has not been reached. 8/11 are NED (3 deaths: 1 relapse, 1 graft failure, 1 cGVHD) Pre GO WT1–0.079±0.07 (n=5), pre GO-dose #2–0.012±0.016 (n=3). One of these patients had detectable MRD (WT1–1.56) prior to the GO-dose #2, no MRD at 1year and is alive and in remission at 2 years post GOx2. The fifth patient entered transplant with +MRD (WT-0.866), relapsed after the first dose of GO and died of relapse prior to receiving the second dose. Conclusions: Targeted therapy with GOx2 may be useful in eradicating MRD in patients post RI AlloSCT. A larger cohort is necessary to assess the impact of GO (at the MTD) on MRD post RI AlloSCT in children with AML.

No significant financial relationships to disclose.

A pilot study of myeloablative (MA) autologous stem Cell (Auto SCT) followed by reduced intensity (RI) allogeneic transplantation (AlloSCT) in children with relapsed/refractory(R/R) Hodgkin’s disease (HD)

20007

Background: Allo SCT may benefit patients with R/R HD by providing a graft vs lymphoma effect. Peggs et al (Lancet 2005) demonstrated durable engraftment and reduced non relapse mortality (NRM) in HD pts post RI Allo SCT. Carella et al (JCO2000) and Gutman et al (BMT2005) demonstrated the success of MA Auto SCT followed by RI AlloSCT in adults with refractory lymphoma. We investigated the feasibility of MA Auto SCT followed by RI Allo SCT in children with R/R HD. Methods: MA conditioning prior to AutoSCT was CTX 1,500 mg/m2 x 4 d, BCNU 100 mg/m2 x 3d, VP-16 800 mg/m2 x 3d. AlloSCT conditioning was fludarabine 30 mg/m2 x 5d, busulfan 3.2 mg/kg x 2d, and R ATG 2 mg/kg x 4d (unrel. donor). CD20+ patients received rituximab (375 mg/m2/wk x4) and all pts received involved field radiotherapy (IFRT). Results: Ten pts have enrolled, 2 pts did not proceed (parental withdrawal) to RI AlloSCT (Donors: 1 MRD, 2 MUD, 5 UCB). Median time to RI AlloSCT after MA Auto SCT was 142 d (97–219). The median cell dose was 3.43 x 107 TNC/kg for UCB grafts (n=5). Engraftment was achieved at a median of 20.5 d for PMN and 46.5 d for PLT. Donor chimerism reached ≥ 95% in all pts by day 100 with a median follow up of 703d (128–2025). Toxicities were grade (3) hematuria (n=1), (3–4) infection (n=7), (4) pulmonary fibrosis (n=1), (4) hearing loss (n=1), (4) neurotoxicity (n=1). GVHD: grade II-III aGVHD (3/8), cGVHD (3/8). Six patients are alive and NED post allo SCT. There has been one NRM (cGVHD) and one relapse mortality. The OS at one year is 66.7%. Conclusions: MA AutoSCT followed by RI AlloSCT is feasible and well tolerated in pediatric pts with R/R HD. A larger study with longer follow up is required to determine if this approach will reduce relapse, long term toxicity and/or improve survival.

No significant financial relationships to disclose.

Phase II trial of capecitabine and docetaxel as second line therapy for locally advanced and metastatic pancreatic cancer

15029

Background: Docetaxel and Capecitabine in combination are synergistic in preclinical models. The role of second line chemotherapy in pancreatic cancer is palliative and the role under investigation. Methods: Capecitabine 800 mg/m2 PO bid on days 1–14 in combination with docetaxel 30 mg/m2 IV on days 1 and 8 of each 21-day cycle were given to patients with advanced and metastatic pancreatic cancer previously treated with Gemcitabine. A 3-stage sequential design phase II trial was used with early stopping rules for efficacy at 13 and 26 enrolled patients Results: Twenty-four patients are evaluable for toxicity and evaluable for response. Thirteen are females and 11 male patients. Median age was 65 years. ECOG PS was as follows: PS 0: 2 patients; PS 1: 15 patients; PS 2: 5 patients. Three patients achieved a PR, with a RR of 12.5%. Stable disease for 2 or more cycles was observed in 70.8% of patients (n=17). 45 % (n=11) of patients had a 50% or more decrease in CA 19–9 levels. Treatment was well tolerated with no toxic deaths. Grade III and IV toxicities consisted of fatigue in 4 pts (17%); hand-foot syndrome in 4 patients (17%); diarrhea, anemia and mucositis in 2 patients (9%) and peripheral neuropathy in one patient (4%) Conclusions: The combination of capecitabine and docetaxel is active and well tolerated in pancreatic cancer previously treated with gemcitabine based-therapy. Enrollment continues.

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XPS and 1H NMR study of thermally stabilized Rh/CeO2 catalysts submitted to reduction/oxidation treatments

Rh/CeO2 catalysts submitted to different H2 reduction, Ar+ sputtering, and oxidation treatments have been studied by X-ray photoelectron (XPS) and 1H nuclear magnetic resonance (NMR) spectroscopies. Depending on the reduction temperature, two stages have been identified in the reduction of the catalyst: below 473 K, reduction increases the amount of OH and Ce3+ species; above this temperature, reduction produces oxygen vacancies at the surface of the support. Volumetric and microcalorimetric techniques have been used to study hydrogen adsorption on the catalyst, and 1H NMR spectroscopy was used to differentiate hydrogen adsorbed on the metal from that adsorbed on the support. From 1H NMR and TEM results, the main metal particle size (38 A) in the Rh/CeO2 catalyst has been estimated. The influence of the support reduction on the metal adsorption capacity has also been investigated, showing that formation of oxygen vacancies at the metal-support interface enhances the electronic perturbation and decreases the hydrogen adsorption on metal particles. The comparison of data reported on catalysts of high and low surface area supports has shown that both processes are shifted to higher temperatures in the Rh/CeO2 catalyst of lower surface area.

Investigation of the sources of residential power frequency magnetic field exposure in the UK Childhood Cancer Study

There is an unexplained association between exposure to the magnetic fields arising from the supply and use of electricity, and increase in risk of childhood leukaemia. The UK Childhood Cancer Study (UKCCS) provides a large and unique source of information on residential magnetic field exposure in the UK. The purpose of this supplementary study was to investigate a sample of UKCCS homes in order to identify the particular sources that contribute to elevated time-averaged exposure. In all, 196 homes have been investigated, 102 with exposures estimated on the basis of the original study to be above 0.2 microT, and 21 higher than 0.4 microT, a threshold above which a raised risk has been observed. First, surveys were carried out outside the property boundaries of all 196 study homes, and then, where informed consent had been obtained, assessments were conducted inside the properties of 19 homes. The study found that low-voltage (LV) sources associated with the final electricity supply accounted together for 77% of exposures above 0.2 microT, and 57% of those above 0.4 microT. Most of these exposures were linked to net currents in circuits inside and/or around the home. High-voltage (HV) sources, including the HV overhead power lines that are the focus of public concern, accounted for 23% of the exposures above 0.2 microT, and 43% of those above 0.4 microT. Public health interest has focused on the consideration of precautionary measures that would reduce exposure to power frequency magnetic fields. Our study provides a basis for considering the options for exposure mitigation in the UK. For instance, in elevated-exposure homes where net currents are higher than usual, if it is possible to reduce the net currents, then the exposure could be reduced for a sizeable proportion of these homes. Further investigations would be necessary to determine whether this is feasible.

Childhood acute lymphoblastic leukemia and infections in the first year of life: a report from the United Kingdom Childhood Cancer Study

The United Kingdom Childhood Cancer Study was designed to examine the relation between childhood cancer and preceding exposure to infectious diseases. The authors analyzed the relation between diagnosis (1991-1996) of acute lymphoblastic leukemia (ALL) at ages 2-5 years and clinically diagnosed infections in infancy. Almost all study children (96% of both cases and controls) were taken to a general practitioner for a non-immunization-associated visit at least once before their first birthday. Children diagnosed with ALL had significantly more clinically diagnosed infectious episodes in infancy than did controls; the average number of episodes was 3.6 (95% confidence interval (CI): 3.3, 3.9) versus 3.1 (95% CI: 2.9, 3.2). This case-control difference was most apparent in the neonatal period (< or =1 month); 18% of controls and 24% of ALL cases were diagnosed with at least one infection (odds ratio = 1.4, 95% CI: 1.1, 1.9; p < 0.05). Cases who had more than one neonatal infectious episode tended to be diagnosed with ALL at a comparatively young age; the mean age at ALL diagnosis was 37.7 months for cases with two or more episodes versus 45.3 months for cases with only one episode or none (p < 0.01). These findings support the hypothesis that a dysregulated immune response to infection in the first few months of life promotes transition to overt ALL later in childhood.