The epidemiology of non-Hodgkin lymphoma

Combating relapsed and refractory Mantle cell lymphoma with novel therapeutic armamentarium: Recent advances and clinical prospects

Mantle cell lymphoma (MCL) is a rare, aggressive subtype of non-Hodgkin's lymphoma (NHL), accounting for 5% of all cases. Due to its virulence factor, it is an incurable disease and keeps relapsing despite an intensive treatment regimen. Advancements in research and drug discovery have shifted the treatment strategy from conventional chemotherapy to targeted agents and immunotherapies. The establishment of the role of Bruton tyrosine kinase led to the development of ibrutinib, a first-generation BTK inhibitor, and its successors. A conditioning regimen based immunotherapeutic agent like ibritumumob, has also demonstrated a viable response with a favorable toxicity profile. Brexucabtagene Autoleucel, the only approved CAR T-cell therapy, has proven advantageous for relapsed/refractory MCL in both children and adults. This article reviews certain therapies that could help update the current approach and summarizes a few miscellaneous agents, which, seldom studied in trials, could alleviate the regression observed in traditional therapies. DATA AVAILABILITY: The datasets generated during and/or analyzed during the current study are available from the corresponding author on reasonable request.

Exploring the molecular mechanisms and shared gene signatures between rheumatoid arthritis and diffuse large B cell lymphoma

The relationship between rheumatoid arthritis (RA) and diffuse large B-cell lymphoma (DLBCL) is well characterized, but the molecular mechanisms underlying this association have not been clearly investigated. Our study aimed to identify shared gene signatures and molecular mechanisms between RA and DLBCL. We selected multiple Gene Expression Omnibus (GEO) datasets (GSE93272, GSE83632, GSE12453, GSE1919) to obtain gene expression levels and clinical information about patients with RA and DLBCL. Weighted gene co-expression network analysis (WGCNA) was used to research co-expression networks associated with RA and DLBCL. Subsequently, we performed enrichment analysis of shared genes and screened the most significant core genes. We observed expression of the screened target gene, galectin 2 (LGALS2), in DLBCL patients and its impact on patient prognosis. Finally, we analyzed the molecular functional mechanism of LGALS2 and observed its relationship with the immune response in DLBCL using single-sample Gene Set Enrichment Analysis (ssGSEA). WGCNA recognized two major modules for RA and DLBCL, respectively. Shared genes (551) were identified for RA and DLBCL by observing the intersection. In addition, a critical shared gene, LGALS2, was acquired in the validation tests. Next, we found that the expression level of LGALS2 gradually decreased with tumor progression in DLBCL and that increased expression of LGALS2 predicted a better prognosis for DLBCL patients. ssGSEA revealed that LGALS2 is involved in immune-related pathways and has a significant regulatory effect on human immune responses. Additionally, we observed that LGALS2 is closely related to the sensitivity of multiple chemotherapeutic drugs. There is extremely little research on the molecular mechanism of correlation between RA and DLBCL. Our study identified that LGALS2 is a potential therapeutic target and an immune-related biomarker for patients with RA and DLBCL.

miRNA signature associated with R-CHOP refractoriness in patients diagnosed with diffuse large B cell lymphoma

Refractoriness remains as one of the challenges in patients with lymphoma under chemotherapy, and among biological regulators in cells driving this type of response are microRNAs (miRNAs). Different genes are constantly turned on or off according to the miRNAs expression profiles affecting the drug response in patients and their stability in serum and plasma makes them potential prognostic biomarkers in several diseases. Here we described a profile of miRNAs in plasma of diffuse large B cell lymphoma (DLBCL) patients. miRNA expression arrays were carried using pre-treatment plasma samples of sixteen patients, followed by a comparison between the responder and the non-responders. After six cycles of R–CHOP treatment, twelve out of sixteen patients were clinically diagnosed with complete response while in four patients no clinical response was observed. Between these groups, a signature of fifteen differential expressed miRNAs was found. The circulating miRNAs in plasma of patients with no response were related to the drug resistance in other types of cancer, by targeting genes involved in cell proliferation and apoptosis, among other cell processes.

Prediagnostic serum concentrations of organochlorine pesticides and non-Hodgkin lymphoma: A nested case-control study in the Norwegian Janus Serum Bank Cohort

BACKGROUND

Much of the marked increase in incidence of non-Hodgkin lymphoma (NHL) over the past few decades remains unexplained. Organochlorines, including organochlorine pesticides (OCPs), have been implicated as possible contributors to the increase, but the evidence is inconsistent.

OBJECTIVES

To investigate the relation between pre-diagnostic levels of OCPs and risk of NHL in a case-control study nested within the population-based Janus Serum Bank Cohort in Norway.

METHODS

Prediagnostic concentrations of 11 OCPs or OCP metabolites were measured in baseline blood samples collected between 1972 and 1978 from 190 cases and 190 controls matched on sex, county, age at blood draw, and date of blood draw. We conducted conditional logistic regression to estimate adjusted odds ratios (ORs) and 95% confidence intervals (95% CIs) for each quartile of lipid-corrected OCP/metabolite relative to the lowest quartile.

RESULTS

We observed non-significantly elevated ORs across quartiles of β-hexachlorocyclohexane compared to the lowest quartile (OR range: 1.40-1.82) although with no apparent monotonic exposure-response relationship. We also found an inverse association between risk of NHL and o,p'-DDT (OR for Q₄ vs. Q₁ = 0.44, 95% CI: 0.19, 1.01; p-trend = 0.05). In analyses stratified by age at blood collection and duration of follow-up, several other analytes, primarily chlordane-related compounds, showed inverse associations among younger participants or those with longer follow-up time between blood draw and NHL diagnosis.

CONCLUSIONS

We found only limited evidence of positive association between selected OCPs and development of NHL.

Mechanistic Insights into Chemoresistance Mediated by Oncogenic Viruses in Lymphomas

Viral lymphomagenesis induced by infection with oncogenic viruses, such as Kaposi’s sarcoma associated herpesvirus (KSHV), Epstein–Barr virus (EBV) and human T-cell leukemia virus (HTLV-1), represents a group of aggressive malignancies with a diverse range of pathological features. Combined chemotherapy remains the standard of care for these virus-associated lymphomas; however, frequent chemoresistance is a barrier to achieving successful long-term disease-free survival. There is increasing evidence that indicates virus-associated lymphomas display more resistance to cytotoxic chemotherapeutic agents than that observed in solid tumors. Although the tumor microenvironment and genetic changes, such as key oncogene mutations, are closely related to chemoresistance, some studies demonstrate that the components of oncogenic viruses themselves play pivotal roles in the multidrug chemoresistance of lymphoma cells. In this review, we summarize recent advances in the understanding of the mechanisms through which oncogenic viruses mediate lymphoma cell chemoresistance, with a particular focus on KSHV and EBV, two major oncogenic viruses. We also discuss the current challenges to overcome these obstacles in the treatment of virus-associated lymphomas.

Treatment modalities of non-Hodgkin lymphoma patients over 65 years of age: A two-center experience

OBJECTIVE

This study was conducted with the aim of making the contribution to a decision for treatment and determination of the modalities in patients diagnosed with non-Hodgkın lymphoma which increasingly become widespread in the geriatric population.

MATERIALS AND METHODS

Ninety-one patients aged over 65 years diagnosed with lymphoma and treated in Bezmialem Vakıf University Medical Faculty Hospital and Haseki Training and Research Hospital between 2008 and 2013 were retrospectively evaluated. Finally, 63 patients for whom data could be reached were included in the study.

RESULTS

Examining the results, histological diagnoses of our patients were as follows: diffuse large B-cell lymphoma (50.8%), follicular lymphoma (23.8%), marginal zone lymphoma (12.7%), mantle cell lymphoma (4.8%), T-cell lymphoma (4.8%), lymphoplasmacytic lymphoma (1.6%) and small lymphocytic lymphoma (1.6%). Stages at the time of diagnosis were early stage by 33.3% and late stage by 66.7%. Of the patients, 36.5% had a low-intermediate and 63.5% a high-intermediate International Prognostic Index score. According to the Eastern Cooperative Oncology Group scoring, 34.9% of the patients have an Eastern Cooperative Oncology Group score of 2-4. Activities of daily living score of 33.3% patients was under 5. Looking at the responses to treatment, the complete response was found in 50.8%, partial response in 4.8%, stable disease in 1.6% and progressive disease in 9.5% of the patients. The mean follow-up duration of patients was found as 25.2 months and disease-free survival after remission as 20.2 months.

CONCLUSION

We found that we have achieved a complete remission in more than half of our patients (50.8%). Based on this, treatment should aim remission in elderly patients.

A lower ALC/AMC ratio is associated with poor prognosis of peripheral T-cell lymphoma-not otherwise specified

Peripheral T-cell lymphomas-not otherwise specified (PTCL-NOS) generally have poor patient outcomes, with a 5-year survival rate of ∼32%. The most common prognostic system for patients with PTCL-NOS, the PTCL-U score, is often inadequate because it does not take into consideration the role of host immunity or the microenvironment induced by the tumor. In this paper we aimed to determine the correlation between the Absolute Lymphocyte Count/Absolute Monocyte Count (ALC/AMC) ratio and the prognosis of PTCL-NOS. Retrospective data from 58 patients diagnosed with PTCL-NOS were analyzed. We found that PTCL-NOS patients with lower ALC/AMC ratios (ALC/AMC < 2) had shorter overall survival (OS) and progression-free survival (PFS) periods (OS: P < 0.001; PFS: P = 0.001) compared with other patients (ALC/AMC ≥ 2). When we combined ALC/AMC ratio and PTCL-U scores, patients could be clearly divided into 3 groups with significantly different prognoses. This study suggests that the ALC/AMC ratio may be a simple, effective, and independent prognostic factor for OS and PFS, and may be helpful to identify high-risk PTCL-NOS patients. Since the ALC/AMC ratio is related to host immunity and tumor microenvironment and reflects immune status and individual differences, combining ALC/AMC with PTCL-U may be a better prognostic guide for PTCL-NOS patients.

Prognostic impact of absolute lymphocyte count/absolute monocyte count ratio and prognostic score in patients with nasal-type, extranodal natural killer/T-cell lymphoma

Nasal-type, extranodal natural killer/T-cell lymphoma is a heterogeneous disorder with poor prognosis, requiring risk stratification in this population. The combined value of baseline absolute lymphocyte count and absolute monocyte count provided prognostic information in some malignancies. However, the evidence requires validation in extranodal natural killer/T-cell lymphoma. Aiming to investigate the prognostic significance of absolute lymphocyte count/absolute monocyte count ratio and absolute lymphocyte count/absolute monocyte count prognostic score for extranodal natural killer/T-cell lymphoma, a retrospective research was carried out. A total of 264 patients with newly diagnosed extranodal natural killer/T-cell lymphoma were analyzed in this study. The patients' absolute lymphocyte count and absolute monocyte count tested at initial diagnosis were collected. Receiver operating curve analysis showed that the optimal cut-off values for absolute lymphocyte count and absolute monocyte count were 1.0 × 10⁹ and 0.5 × 10⁹L^-1, respectively, and for absolute lymphocyte count/absolute monocyte count ratio was 2.85. After a median follow-up of 27 months (range 1-87 months), the 3-year overall survival and progression-free survival was 75.4% and 67.6%, respectively. Patients with absolute lymphocyte count/absolute monocyte count ratio ≥ 2.85 had better 3-year overall survival and progression-free survival than those with absolute lymphocyte count/absolute monocyte count ratio <2.85 (p < 0.001). According to absolute lymphocyte count/absolute monocyte count prognostic score, significant difference has been noticed in 3-year overall survival and progression-free survival (p < 0.001) and high absolute lymphocyte count/absolute monocyte count prognostic score was associated with poorer survival. The International Prognostic Index and Korean Prognostic Index were used for prognosis and showed no significant difference. When adding absolute lymphocyte count/absolute monocyte count ratio and absolute lymphocyte count/absolute monocyte count prognostic score to the International Prognostic Index and Korean Prognostic Index model, additional prognostic information was found. These results suggest that absolute lymphocyte count/absolute monocyte count ratio and absolute lymphocyte count/absolute monocyte count prognostic score might be useful prognostic factors in extranodal natural killer/T-cell lymphoma.

[Multicentric lymphoma in 411 dogs - an epidemiological study]

OBJECTIVE

To provide an overview of the epidemiology of canine multicentric lymphoma in Germany.

MATERIAL AND METHODS

A total of 411 dogs with multicentric malignant lymphoma were retrospectively analysed regarding breed, age, sex, weight and the number of animals dogs with hypercalcaemic lymphoma and B-/T-immunophenotype, and compared to two reference populations (total own clinic population, n   =   52  142; dogs with health insurance in Germany, n   =   123  423).

RESULTS

In total, 298 (72.5%) of the 411 dogs belonged to 86 different breeds, while 113 (27.5%) dogs were mixed breed. In comparison to both reference populations, a breed predisposition for the American Pitbull Terrier (odds ratio [OR] 5.2 and 18.5), American Staffordshire Terrier (OR 3.3 and 4.6), Briard (OR 5.6 and 9.5), Bullmastiff (OR 7.8 and 5.0), Irish Setter (OR 3.3 and 4.1) and Rottweiler (OR 2.8 and 3.6) was found. Golden Retrievers (n = 22, OR 1.3 and 0.9) and Bernese Mountain Dogs (n = 22, OR 2.4 and 2.0) were frequently affected in absolute numbers, but when compared to the reference populations an OR < 3 was detected. Mean body weight was 30.2 ± 13.7 kg; only 75 (18%) dogs weighed < 15 kg. Amongst the small dogs (< 15 kg), there was a large number of West Highland White Terriers (n = 12). Mean age of the dogs with lymphoma was 7.9 ± 2.7 years. Dogs weighing ≥ 15 kg were significantly (p < 0.001) younger (7.6 ± 2.4 years) compared to dogs weighing < 15 kg (9.3 ± 3.2 years). Dogs with a B-cell immunophenotype (8.5 ± 2.6 years) were significantly older compared to dogs with a T-cell immunophenotype (6.4 ± 1.8 years) (p < 0.001). There was no gender predisposition (54% male, 46% female). Hypercalcaemia as an indicator of T-cell lymphoma was present in 44 (11.4%) of the dogs. A T-cell and B-cell immunophenotype was found in 20.6% and 79.4% of the dogs, respectively.

CLINICAL RELEVANCE

This study confirms previous data about breed predispositions for canine malignant multicentric lymphoma and demonstrates that further breeds are predisposed (Briard, West Highland White Terrier, Irish Setter). Small-breed dogs (< 15 kg BM) appear to be affected with lymphoma at a greater age.

Are epidemiological data on lymphoma incidence comparable? Results from an application of the coding recommendations of WHO, InterLymph, ENCR and SEER to a cancer registry dataset

PURPOSE

The REAL classification of 1994 and the subsequent WHO classification of 2001 can be considered a breakthrough of international harmonization of lymphoma characterization, terminology and codification. These efforts promised to produce internationally comparable cancer registry data in the future. However, in practice discrepancies of usage of these classifications occurred which hamper comparability of registration outcome and must be taken into account by epidemiologic research.

METHODS

In order to analyze such discrepancies, we used the assignment recommendations of the World Health Organisation 2008, InterLymph 2010, European Network of Cancer Registry 2009 and Surveillance, Epidemiology, and End Results Program 2010 for lymphoid neoplasms in groups and major NHL groups. We used data of the Federal State Cancer Registry of Baden-Wuerttemberg 2010-2011 to test differences in incidence outcome when evaluated according to the different recommendations of these institutions.

RESULTS

Depending on the recommendations of the above institutions, extraction of lymphoid neoplasms provided 4021, 4295, 3873 and 3848 incident cases, respectively. Case numbers for some major NHL groups diverge substantially by recommendation.

CONCLUSIONS

Epidemiologists must be aware of potential discrepancies in coding conventions of cancer registries and have to consider them in comparative data analyses. Cancer registries should make transparent which recommendations were applied for lymphoma codification, currently and in the past. Conversion rules should be offered to ascertain proper mapping of lymphoma entities which were coded under varying coding practices over time.

Autologous hematopoietic stem cell transplantation in elderly patients (≥ 70 years) with non-Hodgkin's lymphoma: A French Society of Bone Marrow Transplantation and Cellular Therapy retrospective study

INTRODUCTION

Limited data is available on the feasibility of high-dose chemotherapy followed by autologous hematopoietic stem cell transplantation (AHSCT) in elderly patients over 70 years of age with non-Hodgkin's lymphoma (NHL).

MATERIALS AND METHODS

In the setting of the Société Française de Greffe de Moelle et de Thérapie Cellulaire (SFGM-TC) group, we retrospectively analyzed 81 consecutive patients with NHL over 70 years of age who received AHSCT.

RESULTS

The median age at AHSCT was 72.3 years [70-80]. Patients' were diagnosed with diffuse large B-cell lymphoma (n=40), follicular lymphoma (n=16), mantle cell lymphoma (n=15), T-cell lymphoma (n=5), and other (n=5). Hematopoietic Cell Transplantation Comorbidity Index (HCT-CI) was 0 in 73% of patients. Main conditionings were BEAM (Carmustine-Etoposide-Cytarabine-Melphalan, n=61) and melphalan alone (n=14). Median delays to reach 0.5×10⁹/L neutrophils and 20 × 10(9)/L platelets were of 12 [9-76] days and 12 [0-143] days, respectively. One hundred day and one year cumulative incidence of NRM was 5.4% and 8.5%, respectively. The main cause of death remains relapse.

CONCLUSION

In conclusion, this study revealed that AHSCT seemed to be acceptable in patients over 70 years of age with NHL. Patient age is not a limiting factor if clinical condition is adequate.

Joint occurrence of Merkel cell carcinoma and non-Hodgkin lymphomas in four Nordic countries

The objective of this study was to assess the reciprocal association between non-Hodgkin lymphoma (NHL) and Merkel cell carcinoma (MCC) using the data of four Nordic Cancer Registries. Data for this study were drawn from the Danish, Finnish, Norwegian, and Swedish cancer registries. Standardized incidence ratios (SIRs) for MCC among NHL patients, and for NHL among MCC patients, were calculated. There were 109 838 individuals with NHL and 1411 individuals with MCC, of which 28 had joint occurrence of NHL and MCC. In 18 cases, NHL was diagnosed first, and in 10 cases, MCC was diagnosed first. The SIR for MCC after NHL was 4.34 (95% confidence interval 2.57-6.85). The SIR for NHL after MCC was 3.13 (1.50-5.77). Although the absolute frequency of joint occurrence of MCC and NHL is low, individuals suffering from one of the cancer forms have an increased risk of the other.

Characteristics of TCRζ, ZAP-70, and FcɛRIγ gene expression in patients with T- and NK/T-cell lymphoma

Abnormal expression of key signaling molecules and defective T-cell function play a crucial role in the pathogenesis of T-cell immunodeficiency in hematological malignancies. To understand the molecular basis of T-cell signaling abnormalities and TCRζ chain deficiencies in T- and NK/T-cell lymphoma, the expression level of the TCRζ, ZAP-70, and FcɛRIγ genes in peripheral blood mononuclear cells from 25 patients with T-cell lymphoma, 16 patients with NK/T-cell lymphoma (NK/T-CL), and 26 healthy individuals was determined. In addition, their relationship with disease stage and TCRζ 3' untranslated region (3'UTR) splice variants was analyzed in this study. The expression level of all three genes was significantly altered with disease progression, and a decreasing trend was found in patients compared with healthy controls. TCRζ and ZAP-70 were significantly positively related in all samples, and a negative relationship between TCRζ and FcɛRIγ was significantly lost in NK/T-CL patients. Moreover, distinct expression patterns were defined for patient groups with different TCRζ 3'UTR isoforms. In conclusion, a lower expression pattern for all three genes may indicate a weaker immune status based on reduced TCRζ and ZAP-70 expression without the complementary effects of FcɛRIγ, while aberrant TCRζ 3'UTR splicing may contribute to T-cell receptor (TCR) signaling regulation in T cells from patients with T- and NK/T-cell lymphoma.

Genetic polymorphisms in the one-carbon metabolism pathway genes and susceptibility to non-Hodgkin lymphoma

Corroborating evidence related to the role of aberrations on one-carbon metabolism (OCM) genes has been inconsistent. We evaluated the association between polymorphisms in 12 single nucleotide polymorphisms (SNPs) in 8 OCM genes (CBS, FPGS, FTHFD, MTRR, SHMT1, SLC19A1, TCN1, and TYMS), and non-Hodgkin lymphoma (NHL) risk in a multi-ethnic population which includes Malay, Chinese and Indian ethnic subgroups. Cases (N = 372) and controls (N = 722) were genotyped using the Sequenom MassARRAY platform. Our results of the pooled subjects showed a significantly enhanced NHL risk for CBS Ex9 + 33C > T (T versus C: OR 1.55, 95% CI 1.22-1.96, P = 0.0003), CBS Ex18-319G > A (A versus G: OR 1.15, 95% CI 1.14-1.83; P = 0.002), SHMT1 Ex12 + 236 T > C (T versus C: OR 1.44, 95% CI 1.15-1.81, P = 0.002), and TYMS Ex8 + 157C > T (T versus C: OR 1.29, 95% CI 1.06-1.57, P = 0.01). Haplotype analysis for CBS SNPs showed a significantly decreased risk of NHL in subjects with haplotype CG (OR 0.69, 95% CI 0.56-0.86, P = <0.001). The GG haplotype for the FTHFD SNPs showed a significant increased risk of NHL (OR 1.40, 95% CI 1.12-1.76, P = 0.002). For the TYMS gene, haplotype CAT at TYMS (OR 0.67, 95% CI 0.49-0.90, P = 0.007) was associated with decreased risk of NHL, while haplotype TAC (OR 1.29, 95% CI 1.05-1.58, P = 0.01) was found to confer increased risk of NHL. Our study suggests that variation in several OCM genes (CBS, FTHFD, SHMT1, TCN1, and TYMS) may influence susceptibility to NHL.

Relationship between ambient ultraviolet radiation and non-Hodgkin lymphoma subtypes: a U.S. population-based study of racial and ethnic groups

Associations between ultraviolet radiation (UVR) exposure and non-Hodgkin lymphoma (NHL) have been inconsistent, but few studies have examined these associations for specific subtypes or across race/ethnicities. We evaluated the relationship between ambient UVR exposure and subtype-specific NHL incidence for whites, Hispanics and blacks in the United States for years 2001-2010 (n = 187,778 cases). Incidence rate ratios (IRRs) and 95% confidence intervals (CIs) were calculated for UVR quintiles using Poisson regression. Incidence was lower for the highest UVR quintile for chronic/small lymphocytic/leukemia (CLL/SLL) (IRR = 0.87, 95% CI: 0.77-0.97), mantle cell (IRR = 0.82, 95% CI: 0.69-0.97), lymphoplasmacytic (IRR = 0.58, 95% CI: 0.42-0.80), mucosa-associated lymphoid tissue (MZLMALT) (IRR = 0.74, 95% CI: 0.60-0.90), follicular (FL) (IRR = 0.76, 95% CI: 0.68-0.86), diffuse large B-cell (IRR = 0.84, 95% CI: 0.76-0.94;), peripheral T-cell other (PTCL) (IRR = 0.76, 95% CI: 0.61-0.95) and PTCL not otherwise specified (PNOS) (IRR = 0.77, 95% CI: 0.61-0.98). Trends were significant for MZLMALT, FL, DLBCL, BNOS and PTCL, with FL and DLBCL still significant after Bonferroni correction. We found interaction by race/ethnicity for CLL/SLL, FL, Burkitt, PNOS and MF/SS, with CLL/SLL and FL still significant after Bonferroni correction. Some B-cell lymphomas (CLL/SLL, FL and Burkitt) suggested significant inverse relationships in whites and Hispanics, but not in blacks. Some T-cell lymphomas suggested the most reduced risk for the highest quintile of UVR among blacks (PNOS and MF/SS), though trends were not significant. These findings strengthen the case for an inverse association of UVR exposure, support modest heterogeneity between NHL subtypes and suggest some differences by race/ethnicity.

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.

A retrospective study on 73 elderly patients (≥75years) with aggressive B-cell non Hodgkin lymphoma: clinical significance of treatment intensity and comprehensive geriatric assessment

OBJECTIVE

The clinical outcome of elderly (≥75years) patients with aggressive B-cell non-Hodgkin lymphoma (B-NHL) is not firmly established because few studies have specifically addressed this issue. In addition, the usefulness of a comprehensive geriatric assessment (CGA) in B-NHL still needs to be deeply explored.

MATERIALS AND METHODS

We evaluated the prognostic factors of 73 patients aged ≥75years (median age: 78) with B-NHL treated by clinical judgment with curative anthracycline-based approaches (n=36) or with conservative treatments without anthracyclines (n=37). Analysis of clinical outcomes also included baseline CGA stratification.

RESULTS

The curative approaches resulted in a better clinical outcome than conservative approaches [overall response rate: 91.2% vs. 69.7%, P=0.003; 2-year progression-free survival: 47.2% vs. 21.6%, P=0.006; and 2-year overall survival (OS): 58.3% vs 24.3%, P=0.003] with similar safety profiles. Independent of treatment type, patients classified as "fit" and "intermediate" by CGA presented with better OS compared to patients classified as "frail" (P<0.001). Patients classified as "fit" and "intermediate" who were receiving curative treatments presented with a significantly better OS when compared with those treated conservatively on the basis of clinical judgment. A curative anthracycline-based therapy (P=0.048), the response to treatment (P=0.017) and a "frail" condition (P=0.031) were the only factors affecting OS in multivariate analysis.

CONCLUSIONS

Present data indicates that even in elderly patients with B-NHL curative anthracycline-based therapies are more effective than conservative approaches. However, choice of treatment should rely more on objective than on subjective parameters. Therefore, further prospective trials are warranted to better define the CGA role in hematopoietic malignancies.

Prognostic significance of peripheral monocyte count in patients with extranodal natural killer/T-cell lymphoma

Background

Extranodal natural killer/T-cell lymphoma (ENKL) has heterogeneous clinical manifestations and prognosis. This study aims to evaluate the prognostic impact of absolute monocyte count (AMC) in ENKL, and provide some immunologically relevant information for better risk stratification in patients with ENKL.

Methods

Retrospective data from 163 patients newly diagnosed with ENKL were analyzed. The absolute monocyte count (AMC) at diagnosis was analyzed as continuous and dichotomized variables. Independent prognostic factors of survival were determined by Cox regression analysis.

Results

The AMC at diagnosis were related to overall survival (OS) and progression-free survival (PFS) in patients with ENKL. Multivariate analysis identified AMC as independent prognostic factors of survival, independent of International Prognostic Index (IPI) and Korean prognostic index (KPI). The prognostic index incorporating AMC and absolute lymphocyte count (ALC), another surrogate factor of immune status, could be used to stratify all 163 patients with ENKL into different prognostic groups. For patients who received chemotherapy followed by radiotherapy (102 cases), the three AMC/ALC index categories identified patients with significantly different survivals. When superimposed on IPI or KPI categories, the AMC/ALC index was better able to identify high-risk patients in the low-risk IPI or KPI category.

Conclusion

The baseline peripheral monocyte count is shown to be an effective prognostic indicator of survival in ENKL patients. The prognostic index related to tumor microenvironment might be helpful to identify high-risk patients with ENKL.

Single-nucleotide polymorphisms in genes encoding for CC chemokines were not associated with the risk of non-Hodgkin lymphoma

BACKGROUND

Chemokines play a pivotal role in immune regulation and response, and previous studies suggest an association between immune deficiency and non-Hodgkin lymphoma (NHL).

METHODS

We evaluated the association between NHL and polymorphisms in 18 genes (CCL1, CCL2, CCL5, CCL7, CCL8, CCL11, CCL13, CCL18, CCL20, CCL24, CCL26, CCR1, CCR3, CCR4, CCR6, CCR7, CCR8, and CCR9) encoding for the CC chemokines using data from a population-based case-control study of NHL conducted in Connecticut women.

RESULTS

CCR8 was associated with diffuse large B-cell lymphoma (DLBCL; P = 0.012), and CCL13 was associated with chronic lymphocytic leukemia (CLL) or small lymphocytic lymphoma (SLL; P = 0.003) at gene level. After adjustment for multiple comparisons, none of the genes or single-nucleotide polymorphisms (SNP) were associated with risk of overall NHL or NHL subtypes.

CONCLUSIONS

Our results suggest that the genes encoding for CC chemokines are not significantly associated with the risk of NHL, and further studies are needed to verify these findings.

IMPACT

Our data indicate that CC chemokine genes were not associated with NHL risk.

Increased cancer burden among pesticide applicators and others due to pesticide exposure

A growing number of well-designed epidemiological and molecular studies provide substantial evidence that the pesticides used in agricultural, commercial, and home and garden applications are associated with excess cancer risk. This risk is associated both with those applying the pesticide and, under some conditions, those who are simply bystanders to the application. In this article, the epidemiological, molecular biology, and toxicological evidence emerging from recent literature assessing the link between specific pesticides and several cancers including prostate cancer, non-Hodgkin lymphoma, leukemia, multiple myeloma, and breast cancer are integrated. Although the review is not exhaustive in its scope or depth, the literature does strongly suggest that the public health problem is real. If we are to avoid the introduction of harmful chemicals into the environment in the future, the integrated efforts of molecular biology, pesticide toxicology, and epidemiology are needed to help identify the human carcinogens and thereby improve our understanding of human carcinogenicity and reduce cancer risk.

Household endotoxin levels and the risk of non-Hodgkin lymphoma

OBJECTIVE

Endotoxin, a component of the outer membrane of gram-negative bacteria, elicits a strong innate and inflammatory immune response associated with the secretion of proinflammatory cytokines, including tumor necrosis factor-alpha (TNF-α). Because TNF-α polymorphisms that increase TNF-α production are associated with an increased risk of non-Hodgkin lymphoma (NHL), we hypothesized that increased levels of household endotoxin would be associated with an increased NHL risk.

METHODS

We evaluated this association in the National Cancer Institute/Surveillance, Epidemiology and End Results (NCI/SEER) NHL multicenter population-based case-control study. Used vacuum cleaner bags were collected from participants during a home interview. Dust samples from the bags of 594 cases and 442 controls were analyzed for endotoxin [endotoxin unit (EU)/mg of dust] using the kinetic chromogenic Limulus amebocyte lysate assay. Multivariable logistic regression was used to estimate the effect of endotoxin on NHL risk adjusted for age, sex, race, education, study center, and farm exposure.

RESULTS

Endotoxin was not associated with NHL overall [odds ratio (OR) for highest quartile of endotoxin levels = 0.81, 95 % confidence interval (CI) = 0.55, 1.20; p for trend = 0.35] or with diffuse large B-cell lymphoma (OR = 0.63, 95 % CI = 0.34, 1.16; p = 0.31) or follicular lymphoma (OR = 1.07, 95 % CI = 0.61, 1.89; p = 0.73) subtypes. Both working and living on a farm were associated with higher household endotoxin levels compared to never working (p = 0.009) or living (p = 0.01) on a farm. Excluding farmers from the analysis did not change the results.

CONCLUSIONS

We found no evidence of a role for household endotoxin in NHL etiology.

The association between early life and adult body mass index and physical activity with risk of non-Hodgkin lymphoma: impact of gender

PURPOSE

To evaluate the association of body mass index (BMI) and physical activity (PA) during adulthood and at the age of 18 years with risk of non-Hodgkin lymphoma (NHL).

METHODS

We enrolled 950 newly diagnosed NHL patients and 1146 frequency-matched clinic-based controls. Height, weight, and PA (recent adult and at the age of 18 years) were self-reported. Odds ratios (ORs), 95% confidence intervals, and tests for trend were estimated using unconditional logistic regression adjusted for age, gender, and residence.

RESULTS

BMI at the age of 18 years was associated with an increased NHL risk (OR, 1.38 for highest vs. lowest quartile; p-trend = .0012), which on stratified analysis was specific to females (OR, 1.90; p-trend = .00025). There was no association of adult BMI with NHL risk. Higher PA in adulthood (OR, 1.03; p-trend = .85) or at the age of 18 years (OR, 0.88; 95% confidence interval, 0.72-1.07) was not associated with risk, but there was an inverse association for adult PA that was specific to females (OR, 0.71; p-trend = .039). Only BMI at the age of 18 years remained significantly associated with NHL risk when modeled together with PA in adulthood or at the age of 18 years. There was little evidence for heterogeneity in these results for the common NHL subtypes.

CONCLUSIONS

Early adult BMI may be of greatest relevance to NHL risk, particularly in females.

Pesticide induced immunotoxicity in humans: a comprehensive review of the existing evidence

The immune system can be the target of many chemicals, with potentially severe adverse effects on the host's health. In Western countries pesticides, together with new and modified patterns of exposure to chemicals, have been implicated in the increasing prevalence of diseases associated with alterations of the immune response, such as hypersensitivity reactions, certain autoimmune diseases and cancers. Xenobiotics may initiate, facilitate or exacerbate pathological immune processes, resulting in immunotoxicity by induction of mutations in genes coding for immunoregulatory factors, modifying immune tolerance and activation pathways. The purpose of this article is to update the evidence of pesticide immunotoxicity. Even if experimental data as well as sporadic human studies indicate that some pesticides can affect the immune system, overall, existing epidemiological studies are inadequate to raise conclusions on the immunotoxic risk associated to pesticide exposure. The available studies on the effects of pesticides on human immune system have several limitations including poor indication on exposure levels, multiple chemical exposures, heterogeneity of the approach, and difficulty in giving a prognostic significance to the slight changes often observed. Further studies are necessary, and they should be preferably carried out through comparison of pre and post-exposure findings in the same group of subjects with a matched control group. Attempt should be made to define the prognostic significance of slight changes often observed. Animal and in vitro studies are also important and necessary to scientifically support epidemiological evidences on pesticide-induced immunotoxicity.

SMARCAL1 deficiency predisposes to non-Hodgkin lymphoma and hypersensitivity to genotoxic agents in vivo

Schimke immuno-osseous dysplasia (SIOD) is a multisystemic disorder with prominent skeletal, renal, immunological, and ectodermal abnormalities. It is caused by mutations of SMARCAL1 (SWI/SNF-related, matrix-associated, actin-dependent regulator of chromatin, subfamily a-like 1), which encodes a DNA stress response protein. To determine the relationship of this function to the SIOD phenotype, we profiled the cancer prevalence in SIOD and assessed if defects of nucleotide excision repair (NER) and nonhomologous end joining (NHEJ), respectively, explained the ectodermal and immunological features of SIOD. Finally, we determined if Smarcal1(del/del) mice had hypersensitivity to irinotecan (CPT-11), etoposide, and hydroxyurea (HU) and whether exposure to these agents induced features of SIOD. Among 71 SIOD patients, three had non-Hodgkin lymphoma (NHL) and one had osteosarcoma. We did not find evidence of defective NER or NHEJ; however, Smarcal1-deficient mice were hypersensitive to several genotoxic agents. Also, CPT-11, etoposide, and HU caused decreased growth and loss of growth plate chondrocytes. These data, which identify an increased prevalence of NHL in SIOD and confirm hypersensitivity to DNA damaging agents in vivo, provide guidance for the management of SIOD patients.

Medical conditions and risk of adult myeloid leukemia

PURPOSE

Although a few previous studies have reported positive associations between adult myeloid leukemia and a history of certain medical conditions, the etiology of most cases remains largely unknown. Our purpose was to examine associations between certain medical conditions and adult myeloid leukemia.

METHODS

Using logistic regression, we evaluated associations between 16 self-reported medical conditions and myeloid leukemia in a case-control study of 670 cases [including 420 acute myeloid leukemia (AML) and 186 chronic myelogenous leukemia (CML)] and 701 population-based controls.

RESULTS

We observed significant positive associations between AML and ulcerative colitis (odds ratio (OR) = 3.8; 95 % confidence interval (CI), 1.1-13) and between CML and peptic ulcer (OR = 2.0; 95% CI, 1.1-3.8). A personal cancer history increased both AML (OR = 2.6; 95% CI, 1.7-3.9) and CML (OR = 3.5; 95% CI, 2.0-5.8) risk even after excluding individuals who reported prior radiation and/or chemotherapy treatment.

CONCLUSION

Certain inflammatory medical conditions and a personal history of cancer, independent from therapy, are associated with an increased risk of myeloid leukemia.

Analysis of matched geographical areas to study potential links between environmental exposure to oil refineries and non-Hodgkin lymphoma mortality in Spain

Background

Emissions from refineries include a wide range of substances, such as chrome, lead, nickel, zinc, arsenic, cadmium, benzene, dioxins and furans, all of which are recognized by the International Agency for Research on Cancer (IARC) as carcinogens.

Various studies have shown an association between non-Hodgkin lymphoma (NHL) and residence in the vicinity of industrial areas; however, evidence of specific association between refineries and residence in the vicinity has been suggested but not yet established.

The aim of this study is to investigate potential links between environmental exposure to emissions from refineries and non-Hodgkin lymphoma mortality in Spain.

The spatial distribution of NHL in Spain has an unusual pattern with regions some showing higher risk than others.

Methods

We designed an analysis of matched geographical areas to examine non-Hodgkin lymphoma mortality in the vicinity of the 10 refineries sited in Spain over the period 1997-2006. Population exposure to refineries was estimated on the basis of distance from town of residence to the facility in a 10 km buffer.

We defined 10 km radius areas to perform the matching, accounting for population density, level of industrialization and socio-demographic factors of the area using principal components analysis.

For the matched towns we evaluated the risk of NHL mortality associated with residence in the vicinity of the refineries and with different regions using mixed Poisson models. Then we study the residuals to assess a possible risk trend with distance.

Results

Relative risks (RRs) associated with exposure showed similar values for women and for men, 1.09 (0.97-1.24) and 1.12 (0.99-1.27). RRs for two regions were statistically significant: Canary Islands showed an excess of risk of 1.35 (1.05-1.72) for women and 1.50 (1.18-1.92) for men, whilst Galicia showed an excess of risk of 1.35 (1.04-1.75) for men, but not significant excess for women.

Conclusions

The results suggest a possible increased risk of NHL mortality among populations residing in the vicinity of refineries; however, a potential distance trend has not been shown. Regional effects in the Canary Islands and Galicia are significantly greater than the regional average.

Occupational pesticide exposures and cancer risk: a review

A review of the epidemiological literature linking pesticides to cancers in occupational studies worldwide was conducted, with particular focus on those articles published after the release of IARC Monograph 53 (1991): Occupational Exposures in Insecticide Applications and Some Pesticides. Important new data are now available. Chemicals in every major functional class of pesticides including insecticides, herbicide, fungicides, and fumigants have been observed to have significant associations with an array of cancer sites. Moreover, associations were observed with specific chemicals in many chemical classes of pesticides such as chlorinated, organophosphate, and carbamate insecticides and phenoxy acid and triazine herbicides. However, not every chemical in these classes was found to be carcinogenic in humans. Twenty-one pesticides identified subsequent to the last IARC review showed significant exposure-response associations in studies of specific cancers while controlling for major potential confounders. This list is not an exhaustive review and many of these observations need to be evaluated in other epidemiological studies and in conjunction with data from toxicology and cancer biology. Nonetheless, it is reasonable and timely for the scientific community to provide a multidisciplinary expert review and evaluation of these pesticides and their potential to produce cancer in occupational settings.

Coeliac disease characteristics, compliance to a gluten free diet and risk of lymphoma by subtype

OBJECTIVE

Coeliac disease is associated with an increased risk of malignant lymphomas. We investigated the importance of coeliac disease characteristics and diet compliance for risk of lymphoma.

METHODS

In a nested case-control design, we identified 59 patients with lymphoma and 137 matched controls from a population-based cohort of 11,650 inpatients with coeliac disease. We assessed coeliac disease characteristics at diagnosis and dietary compliance collected prospectively from medical records during follow-up.

RESULTS

Poor compliance was not significantly associated with risk of lymphoma overall (odds ratio 1.83, 95% confidence interval 0.78-4.31) nor of lymphoma subtypes. Risk estimates differed by subtype; risk of T-cell lymphoma (odds ratio 1.01, confidence interval 0.32-3.15) or intestinal lymphoma (odds ratio 0.66, confidence interval 0.17-2.56) was unelevated, whereas there was an indication of a risk increase of B-cell lymphoma (odds ratio 4.74, confidence interval 0.89-25.3) or extraintestinal lymphoma (odds ratio 3.00, confidence interval 0.73-12.3) following poor compliance. History of weight loss (odds ratio 2.89, confidence interval 1.00-8.29) at coeliac disease diagnosis was associated with an increased risk of lymphoma when excluding tumours occurring with short latency (<3 years).

CONCLUSIONS

Compliance to a gluten-free diet did not significantly alter lymphoma risk, but a moderate effect cannot be excluded. Weight loss, a potential marker of coeliac disease severity, may be associated with lymphoma risk.

Susceptibility of patients with rheumatic diseases to B-cell non-Hodgkin lymphoma

Autoimmune rheumatic diseases (ARD), such as systemic lupus erythematosus (SLE), rheumatoid arthritis (RA) and Sjögren's syndrome (SS), have consistently been associated with the development of B-cell non-Hodgkin lymphoma (BCNHL). In this Review, we focus on reports published since 2006 and summarize the data regarding the BCNHL subtypes and clinical findings associated with this increased risk. Patients with these ARD, particularly those with detectable autoantibodies and systemic involvement, are at increased risk of developing BCNHL, especially diffuse large B-cell lymphoma and marginal zone lymphoma. SS shows the strongest association with BCNHL. Male sex, advanced age, prolonged disease course and increased disease severity, but not family history of autoimmune conditions, seem to be associated with an increased risk of non-Hodgkin lymphoma. Chronic immune stimulation, genetic and environmental factors and some immunosuppressive drugs might be involved in lymphomagenesis in these patients. The reason why some ARD are associated with BCNHL and other autoimmune diseases are not remains unclear. These associations are important as they provide information about the mechanisms of lymphomagenesis, and might help identify new therapeutic targets.

Infectious agents and lymphoma

In the past 25 years revelations on the genesis of human cancer have come at an increasing pace. Research on oncogenic infectious agents, especially viruses, has helped us to understand the process of malignant transformation of cells because the cellular events in viral-driven transformation mirror, often brilliantly, basic cellular processes that culminate in cancer, even those not associated with viruses. Infectious agents, especially viruses, account for several of the most common malignancies-up to 20% of all cancers. Some of these cancers are endemic, with a high incidence in certain geographic locations, but sporadic/lower incidence in other parts of the world. Lymphomas arise frequently in association with infectious agents such as Epstein-Barr virus, human immunodeficiency virus, human herpes virus 8, Helicobacter pylori, and hepatitis C virus. In this review, we will focus on the association between infectious agents and lymphomas, with a look at the molecular mechanisms they use to disturb cell regulation and eventually result in cancer.

The retrovirus XMRV is not directly involved in the pathogenesis of common types of lymphoid malignancy

BACKGROUND

A novel retrovirus, xenotropic murine leukemia virus-related virus (XMRV), has been detected in prostate cancer samples and in peripheral blood mononuclear cells (PBMC) from patients with chronic fatigue syndrome. In addition, the virus has been identified in PBMCs from healthy controls. These data suggest that XMRV is circulating in the human population. XMRV is closely related to murine leukemia viruses, which cause lymphoid malignancies in mice. The aim of this study was to determine whether XMRV is directly associated with common forms of human lymphoma or leukemia.

METHODS

DNA samples from 368 patients with lymphoid malignancies and 139 patients with benign lymphadenopathy or other malignant disease were screened for XMRV, using three specific and sensitive quantitative PCR assays.

RESULTS

XMRV was not detected in any sample using any of the three assays.

CONCLUSIONS

The data suggest that this virus is not directly involved in the pathogenesis of common types of lymphoid malignancy and that XMRV is not a prevalent blood borne infection, at least in the United Kingdom.

IMPACT

There is no evidence that XMRV is associated with lymphoid malignancies, and further studies should resolve inconsistencies in results of studies examining XMRV prevalence.

Inverse association between soy intake and non-Hodgkin lymphoma risk among women: a case-control study in Japan

BACKGROUND

Non-Hodgkin lymphoma (NHL) is one of the common malignant tumors worldwide. Environmental factors, such as diet have an important association with the risk of cancer. Although soy intake has been associated with a reduced risk of several cancers, its association with NHL is not known.

PATIENTS AND METHODS

We evaluated the association between soy consumption and risk of NHL by conducting a hospital-based case-control study in 302 patients with NHL and 1510 age- and sex-matched control subjects. Odds ratio (OR) and 95% confidence intervals (CIs) for groups with moderate (27-51 g/day) to high (>51 g/day) relative to low (<27 g/day) intake were calculated using multivariate conditional logistic regression model.

RESULTS

Soy intake was significantly associated with a reduced risk of NHL in women but not in men (OR [95% CI] for moderate and high intake: women, 0.64 [0.42-1.00] and 0.66 [0.42-1.02], respectively; men, 1.40 [0.87-2.24] and 1.33 [0.82-2.15], respectively; P-interaction = 0.02). This finding appeared consistent across NHL subtypes.

CONCLUSION

These results indicate the potential importance of certain ingredients in soy for lymphomagenesis. Further studies to evaluate the mechanism behind the association between soy intake and lymphomagenesis are warranted.

Risk factors for early-onset and late-onset post-transplant lymphoproliferative disorder in kidney recipients in the United States

Solid-organ transplant recipients have an elevated risk for some malignancies because of the requirement for immunosuppression [1]. In particular, non-Hodgkin's lymphoma (NHL) is common and comprises one end of a spectrum of post-transplant lymphoproliferative disorder (PTLD) ranging from benign hyperplasia to lymphoid malignancy [2]. PTLD risk is influenced by the type of organ transplanted, the age and Epstein-Barr virus (EBV) serostatus of the transplant recipient, and the intensity of immunosuppression [3-9]. PTLD incidence is high immediately after transplantation, decreases subsequently, and then rises again 4-5 years from transplantation [10,11]. This incidence pattern suggests the presence of separate early-onset and late-onset PTLD subtypes. Early-onset PTLDs tend to be EBV-positive and, when extranodal, are more likely than late-onset PTLDs to be localized to the transplanted organ [12,13]. Late-onset PTLD is less likely to be associated with EBV and, overall, is more likely than early-onset PTLD to be extranodal [13,14]. The Scientific Registry of Transplant Recipients (SRTR) includes data on a large number of solid-organ transplant recipients in the United States and information on malignancies diagnosed post-transplantation. We used these data to conduct a retrospective cohort study among kidney transplant recipients to examine differences in risk factors between early-onset PTLD and late-onset PTLD.

Pesticide exposure and lymphohaematopoietic cancers: a case-control study in an agricultural region (Larissa, Thessaly, Greece)

BACKGROUND

The causality of lymphohaematopoietic cancers (LHC) is multifactorial and studies investigating the association between chemical exposure and LHC have produced variable results. The aim of this study was to investigate the relationships between exposure to pesticides and LHC in an agricultural region of Greece.

METHODS

A structured questionnaire was employed in a hospital-based case control study to gather information on demographics, occupation, exposure to pesticides, agricultural practices, family and medical history and smoking. To control for confounders, backward conditional and multinomial logistic regression analyses were used. To assess the dose-response relationship between exposure and disease, the chi-square test for trend was used.

RESULTS

Three hundred and fifty-four (354) histologically confirmed LHC cases diagnosed from 2004 to 2006 and 455 sex- and age-matched controls were included in the study. Pesticide exposure was associated with total LHC cases (OR 1.46, 95% CI 1.05-2.04), myelodysplastic syndrome (MDS) (OR 1.87, 95% CI 1.00-3.51) and leukaemia (OR 2.14, 95% CI 1.09-4.20). A dose-response pattern was observed for total LHC cases (P = 0.004), MDS (P = 0.024) and leukaemia (P = 0.002). Pesticide exposure was independently associated with total LHC cases (OR 1.41, 95% CI 1.00 - 2.00) and leukaemia (OR 2.05, 95% CI 1.02-4.12) after controlling for age, smoking and family history (cancers, LHC and immunological disorders). Smoking during application of pesticides was strongly associated with total LHC cases (OR 3.29, 95% CI 1.81-5.98), MDS (OR 3.67, 95% CI 1.18-12.11), leukaemia (OR 10.15, 95% CI 2.15-65.69) and lymphoma (OR 2.72, 95% CI 1.02-8.00). This association was even stronger for total LHC cases (OR 18.18, 95% CI 2.38-381.17) when eating simultaneously with pesticide application.

CONCLUSIONS

Lymphohaematopoietic cancers were associated with pesticide exposure after controlling for confounders. Smoking and eating during pesticide application were identified as modifying factors increasing the risk for LHC. The poor pesticide work practices identified during this study underline the need for educational campaigns for farmers.

Association between red blood cell transfusions and development of non-Hodgkin lymphoma: a meta-analysis of observational studies

The incidence of non-Hodgkin lymphoma (NHL) has increased steadily for the past few decades. Previous studies have suggested an association between blood transfusions and NHL. The main objective of this study was to evaluate this relationship with a meta-analysis of observational studies. A literature search was undertaken, looking for case-control and cohort studies evaluating the risk of developing NHL in persons who received allogeneic blood transfusions; 14 studies were included. Outcome was calculated and reported as relative risk (RR). Heterogeneity was assessed with Cochrane Q and I2 statistics. Dissemination bias was evaluated by funnel plot visualization and trim-and-fill analysis. Quality assessment was performed with the Newcastle-Ottawa scale. Our analysis showed a RR of developing NHL of 1.05 (95% CI, 0.89-1.25; P = .42) and 1.34 (95% CI, 1.15-1.55; P < .01) in case-control and cohort studies, respectively. When pooling all studies, RR was 1.2 (95% CI, 1.07-1.35; P < .01). In subset analysis, RR of chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) was 1.66 (95% CI, 1.08-2.56; P = .02). The RR of NHL was elevated in both men and women and in persons receiving transfusions either before or after 1992. Blood transfusions appear to increase the risk of developing NHL; however, the risk of CLL/SLL appears higher than for other NHL subtypes.

Birth order and risk of non-hodgkin lymphoma--true association or bias?

There is inconsistent evidence that increasing birth order may be associated with risk of non-Hodgkin lymphoma (NHL). The authors examined the association between birth order and related variables and NHL risk in a pooled analysis (1983-2005) of 13,535 cases and 16,427 controls from 18 case-control studies within the International Lymphoma Epidemiology Consortium (InterLymph). Overall, the authors found no significant association between increasing birth order and risk of NHL (P-trend = 0.082) and significant heterogeneity. However, a significant association was present for a number of B- and T-cell NHL subtypes. There was considerable variation in the study-specific risks which was partly explained by study design and participant characteristics. In particular, a significant positive association was present in population-based studies, which had lower response rates in cases and controls, but not in hospital-based studies. A significant positive association was present in higher-socioeconomic-status (SES) participants only. Results were very similar for the related variable of sibship size. The known correlation of high birth order with low SES suggests that selection bias related to SES may be responsible for the association between birth order and NHL.

Clustering of concordant and discordant cancer types in Swedish couples is rare

BACKGROUND

Spouses are exposed to common environmental cancer risk factors during adulthood. Investigating the aggregation of cancer in couples might provide valuable insights into cancer development.

METHODS

The 2008 update of the Swedish Family-Cancer Database includes over 2 million couples with at least one child in common with one single partner. We quantified the contribution of shared adulthood environment by standardised incidence ratios (SIRs) and population attributable fractions (PAFs). Estimated SIRs were used to build an etiological map reflecting the similarity of cancers by adult environmental exposures.

RESULTS

Increased risks of concordant types amongst spouses were found for lung, upper aerodigestive tract and skin cancers (SIRs from 1.24 to 1.97),which are probably related to shared exposure to smoking and UV radiation. PAFs were low with the highest value of 1.46% for uterus cancer in wives of men affected by prostate cancer. Further analysis, based on all non-sex-specific concordant and discordant types, revealed a clustering of lung, stomach, pancreas and bladder cancers sharing smoking as a risk factor. This aggregation was used as a cut-point to identify further "novel" clusters.

CONCLUSION

Shared lifestyles including smoking and drinking habits as well as human papilloma virus infection (HPV) might be associated with an excess of cancer incidence amongst spouses. We observed significantly an increased risk for smoking-related cancers such as lung, upper aerodigestive tract and oesophageal cancers. The present population-based study confirms that the lifestyle shared by spouses plays a minor role in cancer causation. Only strong environmental risk factors such as smoking seem to influence cancer development in adulthood. The proposed etiological map based on 24 cancer types identifies novel clusters--for example, non-Hodgkin lymphoma and leukaemia, bone cancer and myeloma--that are not completely explained by established risk factors. Some of the identified clusters relied on reproduced associations between cancer risks amongst husband and wives; however, the role of chance cannot be excluded.

Incidence and mortality rates of selected infection-related cancers in Puerto Rico and in the United States

BACKGROUND

In 2002, 17.8% of the global cancer burden was attributable to infections. This study assessed the age-standardized incidence and mortality rates of stomach, liver, and cervical cancer in Puerto Rico (PR) for the period 1992-2003 and compared them to those of Hispanics (USH), non-Hispanic Whites (NHW), and non-Hispanic Blacks (NHB) in the United States (US).

METHODS

Age-standardized rates [ASR(World)] were calculated based on cancer incidence and mortality data from the PR Cancer Central Registry and SEER, using the direct method and the world population as the standard. Annual percent changes (APC) were calculated using the Poisson regression model from 1992-2003.

RESULTS

The incidence and mortality rates from stomach, liver and cervical cancer were lower in NHW than PR; with the exception of mortality from cervical cancer which was similar in both populations. Meanwhile, the incidence rates of stomach, liver and cervical cancers were similar between NHB and PR; except for NHB women who had a lower incidence rate of liver cancer than women in PR. NHB had a lower mortality from liver cancer than persons in PR, and similar mortality from stomach cancer.

CONCLUSIONS

The burden of liver, stomach, and cervical cancer in PR compares to that of USH and NHB and continues to be a public health priority. Public health efforts are necessary to further decrease the burden of cancers associated to infections in these groups, the largest minority population groups in the US. Future studies need to identify factors that may prevent infections with cancer-related agents in these populations. Strategies to increase the use of preventive strategies, such as vaccination and screening, among minority populations should also be developed.