Lymphoma subtype incidence rates in children and adolescents: first report from Brazil

BackgroundLymphoma is the third most common pediatric malignancy. The purpose of this study was to analyze the incidence rates of lymphoma in children and adolescents in Brazil.MethodsAll cases of Hodgkin lymphoma (HL), non-Hodgkin lymphoma (NHL), and Burkitt lymphoma (BL) were extracted from 14 population-based cancer registries (PBCRs) from 2000 to 2005, and included children and adolescents 0–19 years old. Analyses included age-adjusted incidence rates (AAIRs) and age-specific incidence rates (ASIRs) by each PBCR. A social exclusion index (SEI) was built and used as proxy for socioeconomic status (SES) levels. Correlations between SES and incidence rates were investigated using Spearman's test.ResultsThe median incidence of lymphoma was 22.7/million. AAIRs of lymphomas varied from 12.9 (Salvador) to 34.5 per million (São Paulo). Median AAIR was 8.8/million, 9.8/million, and 2.9/million for NHL, HL, and BL, respectively. In all PBCRs except that of Recife, AAIR was slightly higher in males than females. The median ASIR was highest for HL (18.5/million) at 15–19 years for both genders. For NHL there were two peaks for ASIR: 11.1/million (1–4 years of age) and 13.2/million (15–19 years of age). The median ASIR for BL was highest among children aged 1–4 years (4.7/million) and in males. Higher SEI correlated with higher incidence of HL (P = 0.06), whereas rates of NHL and BL did not correlate with SEI. Borderline different incidence rates were observed in HL correlated with cities with higher SEIs.ConclusionIncidence rates of lymphomas in Brazil do not differ compared to rates reported worldwide, although SES differences deserve further investigation.     

Birth characteristics and risk of lymphoma in young children

BackgroundLymphoma is the third most common childhood malignancy and comprises two types, Hodgkin lymphoma (HL) and non-Hodgkin lymphoma (NHL). The etiology of pediatric lymphomas is largely unknown, but has been suggested to have prenatal origins.MethodsIn this population-based study, California birth certificates were identified for 478 lymphoma cases diagnosed in children 0–5 years of age between 1988 and 2007; 208,015 controls frequency-matched by birth year were randomly selected from California birth records.ResultsCompared to non-Hispanic whites, Hispanic children had an increased risk of HL (odds ratio (OR) and 95% confidence interval (CI) 2.43 [1.14, 5.17]), and in particular, were diagnosed more often with the mixed cellularity subtype. For all types of lymphoma, we observed an about twofold risk increase with indicators for high risk pregnancies including tocolysis, fetopelvic disproportion and previous preterm birth. NHL risk doubled with the complication premature rupture of membranes (OR and 95% CI 2.18 [1.12, 4.25]) and HL with meconium staining of amniotic fluids (OR and 95% CI 2.55 [1.01, 6.43]).ConclusionThese data support previously reported associations between Hispanic ethnicity and HL and suggest that pregnancy related factors, such as intra-uterine infections and factors associated with preterm labor, may be involved in lymphoma pathogenesis.     

Genetic Variation in DNA Repair Pathways and Risk of Non-Hodgkin's Lymphoma

Molecular and genetic evidence suggests that DNA repair pathways may contribute to lymphoma susceptibility. Several studies have examined the association of DNA repair genes with lymphoma risk, but the findings from these reports have been inconsistent. Here we provide the results of a focused analysis of genetic variation in DNA repair genes and their association with the risk of non-Hodgkin''s lymphoma (NHL). With a population of 1,297 NHL cases and 1,946 controls, we have performed a two-stage case/control association analysis of 446 single nucleotide polymorphisms (SNPs) tagging the genetic variation in 81 DNA repair genes. We found the most significant association with NHL risk in the ATM locus for rs227060 (OR = 1.27, 95% CI: 1.13–1.43, p = 6.77×10⁻⁵), which remained significant after adjustment for multiple testing. In a subtype-specific analysis, associations were also observed for the ATM locus among both diffuse large B-cell lymphomas (DLBCL) and small lymphocytic lymphomas (SLL), however there was no association observed among follicular lymphomas (FL). In addition, our study provides suggestive evidence of an interaction between SNPs in MRE11A and NBS1 associated with NHL risk (OR = 0.51, 95% CI: 0.34–0.77, p = 0.0002). Finally, an imputation analysis using the 1,000 Genomes Project data combined with a functional prediction analysis revealed the presence of biologically relevant variants that correlate with the observed association signals. While the findings generated here warrant independent validation, the results of our large study suggest that ATM may be a novel locus associated with the risk of multiple subtypes of NHL.     

Systemic Lupus Erythematous and Malignancy Risk: A Meta-Analysis

Background

Pilot studies have estimated cancer incidence in patients with systemic lupus erythematous (SLE). However, the results have been inconclusive. To ascertain the correlation between SLE and malignancy more comprehensively and precisely, we conducted a meta-analysis.

Methods

PubMed, the Cochrane Library and Embase databases through June 2014, were searched to identify observational studies evaluating the association between SLE and malignancy. The outcomes from these studies were measured as relative risks (RRs). A random or fixed effects model was chosen to calculate the pooled RR according to heterogeneity test. Between-study heterogeneity was assessed by estimating I² index. Publication bias was assessed by Egger’s test.

Results

A total of 16 papers, including 59,662 SLE patients, were suitable for the meta-analysis. Of these papers, 15 reported RRs for overall malignancy, 12 for non-Hodgkin lymphoma (NHL) and lung cancer, 7 for bladder cancer, 6 for Hodgkin lymphoma (HL) and leukemia, 5 for skin melanoma, and liver and thyroid cancers, 4 for multiple myeloma (MM), and esophageal and vaginal/vulvar cancers and 3 for laryngeal and non-melanoma skin cancers. The pooled RRs were 1.28 (95% CI, 1.17–1.41) for overall cancer, 5.40 (95% CI, 3.75–7.77) for NHL, 3.26(95% CI, 2.17–4.88) for HL, 2.01(95% CI, 1.61–2.52) for leukemia, 1.45(95% CI, 1.04–2.03) for MM, 4.19(95% CI, 1.98–8.87) for laryngeal cancer, 1.59 (95% CI, 1.44–1.76) for lung cancer, 1.86(95% CI, 1.21–2.88) for esophageal cancer, 3.21(95% CI, 1.70–6.05) for liver cancer, 3.67(95% CI, 2.80–4.81) for vaginal/vulvar cancer, 2.11(95% CI, 1.12–3.99) for bladder cancer, 1.51(95% CI, 1.12–2.03) for non-melanoma skin cancer, 1.78(95% CI, 1.35–2.33) for thyroid cancer, and 0.65(95% CI, 0.50–0.85) for skin melanoma. Only the meta-analyses of overall malignancy, NHL, and liver and bladder cancers produced substantial heterogeneity (I², 57.6% vs 74.3% vs 67.7% vs 82.3%). No apparent publication bias was detected except for NHL studies.

Conclusions

Our data support an association between SLE and malignancy, not only demonstrating an increased risk for NHL, HL, leukemia, and some non-hematologic malignancies, including laryngeal, lung, liver, vaginal/vulvar, and thyroid malignancies, but also a reduced risk for skin melanoma. Although an increased risk of MM, and esophageal, bladder and non-melanoma skin cancers was identified from the accumulated data in these studies, this observation requires confirmation.     

High parental occupational social contact and risk of childhood hematopoietic,brain and bone cancers

BackgroundThe etiology of childhood cancer is largely unknown, though some research suggests an infectious origin of hematopoietic, central nervous system (CNS) and bone cancers.MethodsWe examined parental occupational social contact as a proxy for exposure to infectious agents and risk of childhood cancer. This population-based case-control study utilized a linkage of four Danish data-registries, and included 3581 cases (<17 years, diagnosed 1973–2012) and 358,100 age-matched controls. We examined the risks of leukemia, lymphoma, CNS and bone cancer related to high occupational social contact from (1) conception to birth and (2) birth to diagnosis.ResultsAcute lymphoblastic leukemia (ALL) and bone cancer were inversely associated with high maternal social contact from conception to birth (OR: 0.86, 95% CI: 0.67–1.10) and birth to diagnosis (OR: 0.54, 95% CI: 0.34–0.86). Children of fathers with high social contact from birth to diagnosis had an increased risk of bone cancers, particularly in rural areas (OR: 1.65, 95% CI: 1.03–2.63). Parental social contact was associated with increased risk of astrocytoma, with strongest associations found in first-born children (maternal: OR: 1.54, 95% CI: 1.02–2.32; paternal: OR: 1.82, 95% CI: 1.05–3.17).ConclusionOur results support the notion of a role of infections for some cancer types.     

The Functional TP53 rs1042522 and MDM4 rs4245739 Genetic Variants Contribute to Non-Hodgkin Lymphoma Risk

As a heterogeneous kind of malignances, Non-Hodgkin lymphoma (NHL) is the most common hematologic cancer worldwide with the significantly increased morbidity in China. Accumulated evidences demonstrated that oncoprotein MDM4 plays a crucial role in the TP53 tumor suppressor signaling pathway. An rs4245739 A>C polymorphism locating in the MDM4 3′-untranslated region creates a miR-191 target site and results in allele-specific MDM4 expression. In this study, we examined the association between this polymorphism as well as the TP53 Arg72Pro (rs1042522 G>C) genetic variant and Non-Hodgkin Lymphoma (NHL) risk in a Chinese Han population. Genotypes were determined in 200 NHL cases and 400 controls. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated by logistic regression. We found significantly increased NHL risk among carriers of the TP53 72Pro allele compared with those with the 72Arg allele (P = 0.002 for the Pro/Pro genotype). We also observed a significantly decreased NHL risks among carriers of the MDM4 rs4245739 C allele compared with those with the A allele in Chinese (P = 0.014 for the AC genotype). Stratified analyses revealed the associations between these SNPs and NHL risk are especially noteworthy in young or male individuals. Additionally, the associations are much pronounced in NHL patients with B-cell lymphomas or grade 3 or 4 disease. Our results indicate that the TP53 Arg72Pro and the MDM4 rs4245739 polymorphisms contribute to NHL susceptibility and support the hypothesis that genetic variants in the TP53 pathway genes can act as important modifiers of NHL risk.     

Male-origin microchimerism and endometrial cancer: A prospective case-cohort study

BackgroundMany women carry male cells of presumed fetal origin–so-called male-origin microchimerism (MOM)–in their circulation and tissues. Studies have found reduced risks of hormone dependent cancers, including breast and ovarian cancer, among MOM-positive women. The aim of this study was to investigate the association between MOM and endometrial cancer.MethodsWe designed a prospective case-cohort study including 76 cases and 505 controls from the Diet, Cancer and Health cohort aged 50–64 years and cancer-free at enrolment in 1993–1997. We analyzed blood samples for the presence of Y-chromosome (DYS14). We examined the association between MOM and endometrial cancer in weighted Cox regression models. As a negative control outcome, we studied the association between MOM and injuries to test for spurious associations.ResultsWe detected MOM in 65.9% controls and 54.0% cases. While we observed no overall association between MOM and endometrial cancer (HR=0.73, 95% CI: 0.47–1.15), we found a borderline significantly reduced rate of Type 1 endometrial cancer (HR=0.66, 95% CI: 0.39–1.00), but not other types of endometrial cancers (HR=1.00, 95% CI: 0.35–2.90). The reduced rate was not modified by hormonal exposure (P = 0.79). We found no association between MOM and risk of injuries (HR=0.96, 95% CI: 95% CI: 0.78–1.21).ConclusionsOur study suggests that MOM is inversely associated with Type 1 endometrial cancer, without evidence of an interaction with hormonal exposure. We encourage future research to confirm our findings.     

Membrane-bound/soluble IL-2 receptor (IL-2R) and levels of IL-1α, IL-2, and IL-6 in the serum and in the PBMC culture supernatants from 17 patients with hematological malignancies

The present study investigated the peripheral blood mononuclear cells (PBMC) blastic responses to PHA, PHA plus recombinant IL-2 (rIL-2) and rIL-2 alone; the expression of membrane-bound IL-2R on PHA-stimulated PBMC; and the levels of IL-1α, IL-2, IL-6, and sIL-2R in serum and in culture supernatants from PHA-stimulated PBMC in 17 patients with hematological malignancies (mean age 58.5 yr, range 22–82): 6 with non-Hodgkin’s lymphoma (NHL), 4 with Hodgkin’s lymphoma (HL), 5 with Hairy cell leukemia, 1 with chronic myelogenous leukemia, and 1 with chronic lymphocytic leukemia. The patients with HL and NHL with active disease (AD) were separated from those in clinical remission. The patients with AD were studied at diagnosis (obviously before therapy) and the patients in clinical remission were out of therapy since at least 6 mo. The lymphocyte blastogenic response to PHA was significantly lower in patients with HL and NHL with AD than in the control group. The response to rIL-2 alone was in the same range in the control group and in HL and NHL AD patients. By adding rIL-2 to PHA there was an increase of the blastogenic response of the same patients. The percentage of CD25 expressed on PHA-stimulated lymphocytes from patients with HL and NHL AD and from normal subjects is in the same range. Serum levels of IL-2, IL-6, and sIL-2R were significantly higher in HL and NHL AD patients than in controls as well as in all other hematological malignancies. Supernatants derived from PHA-stimulated PBMC were assessed for the presence of cytokines and sIL-2R by ELISA. The levels of IL-2, IL-6, and sIL-2R were significantly lower in HL and NHL AD patients than in controls as well as in all other hematological malignancies.     

Gray zones around diffuse large B cell lymphoma. Conclusions based on the workshop of the XIV meeting of the European Association for Hematopathology and the Society of Hematopathology in Bordeaux, France

The term “gray-zone” lymphoma has been used to denote a group of lymphomas with overlapping histological, biological, and clinical features between various types of lymphomas. It has been used in the context of Hodgkin lymphomas (HL) and non-Hodgkin lymphomas (NHL), including classical HL (CHL), and primary mediastinal large B cell lymphoma, cases with overlapping features between nodular lymphocyte predominant Hodgkin lymphoma and T-cell/histiocyte-rich large B cell lymphoma, CHL, and Epstein–Barr-virus-positive lymphoproliferative disorders, and peripheral T cell lymphomas simulating CHL. A second group of gray-zone lymphomas includes B cell NHL with intermediate features between diffuse large B cell lymphoma and classical Burkitt lymphoma. In order to review controversial issues in gray-zone lymphomas, a joint Workshop of the European Association for Hematopathology and the Society for Hematopathology was held in Bordeaux, France, in September 2008. The panel members reviewed and discussed 145 submitted cases and reached consensus diagnoses. This Workshop summary is focused on the most controversial aspects of gray-zone lymphomas and describes the panel’s proposals regarding diagnostic criteria, terminology, and new prognostic and diagnostic parameters.     

Space-Time Clustering of Non-Hodgkin Lymphoma Using Residential Histories in a Danish Case-Control Study

Non-Hodgkin lymphoma (NHL) is a frequent cancer and incidence rates have increased markedly during the second half of the 20^th century; however, the few established risk factors cannot explain this rise and still little is known about the aetiology of NHL. Spatial analyses have been applied in an attempt to identify environmental risk factors, but most studies do not take human mobility into account. The aim of this study was to identify clustering of NHL in space and time in Denmark, using 33 years of residential addresses. We utilised the nation-wide Danish registers and unique personal identification number that all Danish citizens have to conduct a register-based case-control study of 3210 NHL cases and two independent control groups of 3210 each. Cases were identified in the Danish Cancer Registry and controls were matched by age and sex and randomly selected from the Civil Registration System. Residential addresses of cases and controls from 1971 to 2003 were collected from the Civil Registration System and geocoded. Data on pervious hospital diagnoses and operations were obtained from the National Patient Register. We applied the methods of the newly developed Q-statistics to identify space-time clustering of NHL. All analyses were conducted with each of the two control groups, and we adjusted for previous history of autoimmune disease, HIV/AIDS or organ transplantation. Some areas with statistically significant clustering were identified; however, results were not consistent across the two control groups; thus we interpret the results as chance findings. We found no evidence for clustering of NHL in space and time using 33 years of residential histories, suggesting that if the rise in incidence of NHL is a result of risk factors that vary across space and time, the spatio-temporal variation of such factors in Denmark is too small to be detected with the applied method.     

Commentary on the WHO classification of tumors of lymphoid tissues (2008): ��Gray zone�� lymphomas overlapping with Burkitt lymphoma or classical Hodgkin lymphoma

The 2008 WHO Classification of Tumors of Haematopoietic and Lymphoid Tissues has introduced two new categories of high-grade B-cell lymphomas: entities in which features of diffuse large B-cell lymphoma (DLBCL) overlap with Burkitt lymphoma (DLBCL/BL) or classical Hodgkin lymphoma (DLBCL/HL). The DLBCL/BL category encompasses cases that resemble Burkitt lymphoma morphologically, but have one or more immunophenotypic or molecular genetic deviations that would exclude it from the BL category; conversely, some cases have immunophenotypic and/or genetic features of BL, but display cytologic variability unacceptable for BL. Many of the cases in the DLBCL/BL category contain a translocation of MYC as well as either BCL2 or BCL6 (so-called double-hit lymphomas) and have a very aggressive clinical behavior. The DLBCL/HL category encompasses lymphomas that exhibit the morphology of classical Hodgkin lymphoma but the immunophenotype of DLBCL, or vice versa. Most DLBCL/HL cases described present as mediastinal masses, but this category is not limited to mediastinal lymphomas. These new categories acknowledge the increasing recognition of cases that display mixed features of two well-established diseases. Whether the existence of such cases reflects shortcomings of our current diagnostic armamentarium or a true disease continuum in which such hybrid or intermediate neoplasms actually exist remains to be determined.     

Genetic Features of Metachronous Esophageal Cancer Developed in Hodgkin’s Lymphoma or Breast Cancer Long-Term Survivors: An Exploratory Study

BackgroundDevelopment of novel therapeutic drugs and regimens for cancer treatment has led to improvements in patient long-term survival. This success has, however, been accompanied by the increased occurrence of second primary cancers. Indeed, patients who received regional radiotherapy for Hodgkin’s Lymphoma (HL) or breast cancer may develop, many years later, a solid metachronous tumor in the irradiated field. Despite extensive epidemiological studies, little information is available on the genetic changes involved in the pathogenesis of these solid therapy-related neoplasms.MethodsUsing microsatellite markers located in 7 chromosomal regions frequently deleted in sporadic esophageal cancer, we investigated loss of heterozygosity (LOH) and microsatellite instability (MSI) in 46 paired (normal and tumor) samples. Twenty samples were of esophageal carcinoma developed in HL or breast cancer long-term survivors: 14 squamous cell carcinomas (ESCC) and 6 adenocarcinomas (EADC), while 26 samples, used as control, were of sporadic esophageal cancer (15 ESCC and 11 EADC).ResultsWe found that, though the overall LOH frequency at the studied chromosomal regions was similar among metachronous and sporadic tumors, the latter exhibited a statistically different higher LOH frequency at 17q21.31 (p = 0.018). By stratifying for tumor histotype we observed that LOH at 3p24.1, 5q11.2 and 9p21.3 were more frequent in ESCC than in EADC suggesting a different role of the genetic determinants located nearby these regions in the development of the two esophageal cancer histotypes.ConclusionsAltogether, our results strengthen the genetic diversity among ESCC and EADC whether they occurred spontaneously or after therapeutic treatments. The presence of histotype-specific alterations in esophageal carcinoma arisen in HL or breast cancer long-term survivors suggests that their transformation process, though the putative different etiological origin, may retrace sporadic ESCC and EADC carcinogenesis.     

Epidemiology of pediatric primary malignant central nervous system tumors in Iran: A 10 year report of National Cancer Registry

BackgroundCNS tumors are the leading cause of cancer related deaths among children and adolescents. Nonetheless, the incidence of pediatric CNS tumors in developing countries is poorly understood. We aimed to provide epidemiologic features of primary malignant CNS tumors in Iranian children 0–19 years of age using National Cancer Registry (NCR) data bank.MethodsThe data recorded by NCR over a 10 year period (2000–2010) were reviewed.ResultsOf 1948 tumor cases, 93.3% were located in brain, 5.1% were found in the spinal cord & cauda equina, and 1.6% affected cranial nerves and other parts of the nervous system. The overall average annual age specific incidence rate was 1.43 per 100,000. Males were more likely to develop CNS tumors (1.65 per 100,000) compared to females (1.21 per 100,000, p < 0.01). Children under 5 years of age had the highest age specific incidence rate (1.86 per 100,000). Astrocytic tumors with the incidence rate of 0.61 per 100,000 were the most frequent specific histology followed by embryonal (0.38 per 100,000), and ependymal tumors (0.10 per 100,000). With regard to the histological distribution of tumors, some unique features including the high proportion of unspecified malignant neoplasms (7.6%) were noted.ConclusionThe overall incidence rate was markedly lower than western findings. Major differences were also observed in incidence rates of specific histologies. Although the discrepancies may be attributable to diversity in classification schemes and registration practices, a real ethnic and geographical variation in predisposition to development of pediatric CNS cancers is strongly suggested.     

Copy Number Variation Analysis on a Non-Hodgkin Lymphoma Case-Control Study Identifies an 11q25 Duplication Associated with Diffuse Large B-Cell Lymphoma

Recent GWAS have identified several susceptibility loci for NHL. Despite these successes, much of the heritable variation in NHL risk remains to be explained. Common copy-number variants are important genomic sources of variability, and hence a potential source to explain part of this missing heritability. In this study, we carried out a CNV analysis using GWAS data from 681 NHL cases and 749 controls to explore the relationship between common structural variation and lymphoma susceptibility. Here we found a novel association with diffuse large B-cell lymphoma (DLBCL) risk involving a partial duplication of the C-terminus region of the LOC283177 long non-coding RNA that was further confirmed by quantitative PCR. For chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL), known somatic deletions were identified on chromosomes 13q14, 11q22-23, 14q32 and 22q11.22. Our study shows that GWAS data can be used to identify germline CNVs associated with disease risk for DLBCL and somatic CNVs for CLL/SLL.     

Waveguide model of the hearing aid earmold system

Background

Epstein-Barr virus (EBV) is associated to the etio-pathogenesis of an increasing number of tumors. Detection of EBV in pathology samples is relevant since its high prevalence in some cancers makes the virus a promising target of specific therapies. RNA in situ hybridization (RISH) is the standard diagnostic procedure, while polymerase chain reaction (PCR)-based methods are used for strain (EBV type-1 or 2) distinction. We performed a systematic comparison between RISH and PCR for EBV detection, in a group of childhood B-cell Non-Hodgkin lymphomas (NHL), aiming to validate PCR as a first, rapid method for the diagnosis of EBV-associated B-cell NHL.

Methods

EBV infection was investigated in formalin fixed paraffin-embedded tumor samples of 41 children with B-cell NHL, including 35 Burkitt's lymphoma (BL), from Rio de Janeiro, Brazil, by in situ hybridization of EBV-encoded small RNA (EBER-RISH) and PCR assays based on EBNA2 amplification.

Results

EBV genomes were detected in 68% of all NHL. Type 1 and 2 accounted for 80% and 20% of EBV infection, respectively. PCR and RISH were highly concordant (95%), as well as single- and nested-PCR results, allowing the use of a single PCR round for diagnostic purposes. PCR assays showed a sensitivity and specificity of 96% and 100%, respectively, with a detection level of 1 EBV genome in 5,000–10,000 EBV-negative cells, excluding the possibility of detecting low-number EBV-bearing memory cells.

Conclusion

We describe adequate PCR conditions with similar sensitivity and reliability to RISH, to be used for EBV diagnostic screening in high grade B-NHL, in "at risk" geographic regions.     

Potential role of selection bias in the association between childhood leukemia and residential magnetic fields exposure: A population-based assessment

PurposeData from the Northern California Childhood Leukemia Study (NCCLS) were used to assess whether selection bias may explain the association between residential magnetic fields (assessed by wire codes) and childhood leukemia as previously observed in case–control studies.MethodsWiring codes were calculated for participating cases, n = 310; and non-participating cases, n = 66; as well as for three control groups: first-choice participating, n = 174; first-choice non-participating, n = 252; and replacement (non-first choice participating controls), n = 220.ResultsParticipating controls tended to be of higher socioeconomic status than non-participating controls, and lower socioeconomic status was related to higher wire-codes. The odds ratio (OR) for developing childhood leukemia associated with high wire-codes was 1.18 (95% CI: 0.85, 1.64) when all cases were compared to all first-choice controls (participating and non-participating). The OR for developing childhood leukemia in the high current category was 1.43 (95% CI: 0.91, 2.26) when participating cases were compared to first-choice participating controls, but no associations were observed when participating cases were compared to non-participating controls (OR = 1.06, 95% CI: 0.71, 1.57) or to replacement controls (OR = 1.06, 95% CI: 0.71, 1.60).ConclusionsThe observed risk estimates vary by type of control group, and no statistically significant association between wire codes and childhood leukemia is observed in the California population participating in the NCCLS.     

p53 codon 72 polymorphism and Hematological Cancer Risk: An Update Meta-Analysis

Background

Previous studies on the association of p53 codon 72 (Arg72Pro) polymorphism with hematological malignancies risk have produced conflicting results. The purpose of this meta-analysis is to define the effect of p53 Arg72Pro polymorphism on hematological malignancies risk.

Methodology/Principal Findings

Through searching PubMed databases (or hand searching) up to April 2012 using the following MeSH terms and keywords: “p53”, “codon 72” “polymorphism” and “leukemia”, or “lymphoma”, or “myeloma”, thirteen were identified as eligible articles in this meta-analysis for p53 Arg72Pro polymorphism (2,731 cases and 7, 356 controls), including nine studies on leukemia (1,266 cases and 4, 474 controls), three studies on lymphoma (1,359 cases and 2,652 controls), and one study on myeloma. The overall results suggested that p53 Arg72Pro polymorphism was not associated with hematological malignancies risk. In stratified analyses, significantly increased non-Hodgkin lymphomas risk was found in p53 Arg72Pro polymorphism heterozygote model (Arg/Pro vs. Arg/Arg: OR = 1.18, 95%CI: 1.02–1.35) and dominant model (Arg/Pro+Pro/Pro vs. Arg/Arg: OR = 1.18, 95%CI: 1.03–1.34), but no significant association was found between leukemia risk and p53 Arg72Pro polymorphism. Further studies showed no association between leukemia risk and p53 Arg72Pro polymorphism when stratified in subtypes of leukemias, ethnicities and sources of controls.

Conclusions/Significance

This meta-analysis indicates that the p53 Arg72Pro polymorphism may contribute to susceptibility to non-Hodgkin lymphomas.