Background & Aims
Increasing evidence points towards a role of hepatitis C virus (HCV) infection in causing malignant lymphomas. We pooled case-control study data to provide robust estimates of the risk of non-Hodgkin’s lymphoma (NHL) subtypes after HCV infection.
The analysis included 7 member studies from the International Lymphoma Epidemiology Consortium (InterLymph) based in Europe, North America, and Australia. Adult cases of NHL (n = 4784) were diagnosed between 1988 and 2004 and controls (n = 6269) were matched by age, sex, and study center. All studies used third-generation enzyme-linked immunosorbent assays to test for antibodies against HCV in serum samples. Participants who were human immunodeficiency virus positive or were organ-transplant recipients were excluded.
HCV infection was detected in 172 NHL cases (3.60%) and in 169 (2.70%) controls (odds ratio [OR], 1.78; 95% confidence interval [CI], 1.40–2.25). In subtype-specific analyses, HCV prevalence was associated with marginal zone lymphoma (OR, 2.47; 95% CI, 1.44–4.23), diffuse large B-cell lymphoma (OR, 2.24; 95% CI, 1.68–2.99), and lymphoplasmacytic lymphoma (OR, 2.57; 95% CI, 1.14–5.79). Notably, risk estimates were not increased for follicular lymphoma (OR, 1.02; 95% CI, 0.65–1.60).
These results confirm the association between HCV infection and NHL and specific B-NHL subtypes (diffuse large B-cell lymphoma, marginal zone lymphoma, and lymphoplasmacytic lymphoma).
Descriptive studies have indicated a rising trend in Hodgkin lymphoma (HL) incidence in young adults, especially females. Increasing evidence has suggested that some risk factors associated with HL may vary by age or gender. Recent studies have reported an increased risk of HL associated with increasing body mass index (BMI), but the results have been inconsistent. The objectives of this study were to examine whether the associations between measures of body size (height, weight, and BMI) and HL risk vary by age and/or gender.
A population-based case-control study was conducted in Connecticut and Massachusetts. A total of 567 HL cases and 679 controls were recruited in 1997–2000. Unconditional logistic regression was used to calculate odds ratios (OR) and 95% confidence intervals (CIs).
Among younger women < 35 years old, being overweight (25–29.9 kg/m2) vs. normal weight (18.5–24.9 kg/m2) was significantly associated with an increased risk of HL (OR = 2.1, 95% CI = 1.1–4.0). The risk increased with increasing weight and BMI (P trends < 0.01). Among women ≥ 35 years old, by contrast, higher weight and BMI were associated with a reduced risk of HL (P trends < 0.01). Conversely, there was no significant association between BMI and risk of HL in younger or older males.
These findings show that the associations between body size and risk of HL vary by gender and age, and require confirmation in other populations.
Hodgkin lymphoma; body size; body mass index; height; weight
In cancer research, high-throughput profiling studies have been extensively conducted, searching for genes/SNPs associated with prognosis. Despite seemingly significant differences, different subtypes of the same cancer (or different types of cancers) may share common susceptibility genes. In this study, we analyze prognosis data on multiple subtypes of the same cancer, but note that the proposed approach is directly applicable to the analysis of data on multiple types of cancers. We describe the genetic basis of multiple subtypes using the heterogeneity model, which allows overlapping but different sets of susceptibility genes/SNPs for different subtypes. An accelerated failure time (AFT) model is adopted to describe prognosis. We develop a regularized gradient descent approach, which conducts gene-level analysis and identifies genes that contain important SNPs associated with prognosis. The proposed approach belongs to the family of gradient descent approaches, is intuitively reasonable, and has affordable computational cost. Simulation study shows that when prognosis-associated SNPs are clustered in a small number of genes, the proposed approach outperforms alternatives with significantly more true positives and fewer false positives. We analyze an NHL (non-Hodgkin lymphoma) prognosis study with SNP measurements, and identify genes associated with the three major subtypes of NHL, namely DLBCL, FL and CLL/SLL. The proposed approach identifies genes different from using alternative approaches and has the best prediction performance.
Integrative analysis; Cancer Prognosis; Gradient descent; NHL; SNP
Solvent exposure has been inconsistently linked to the risk for non-Hodgkin lymphoma (NHL). The aim of this study was to determine whether the association is modified by genetic variation in immune genes. A population-based case–control study involving 601 incident cases of NHL and 717 controls was carried out in 1996–2000 among women from Connecticut. Thirty single nucleotide polymorphisms in 17 immune genes were examined in relation to the associations between exposure to various solvents and the risk for NHL. The study found that polymorphism in interleukin 10 (IL10; rs1800890) modified the association between occupational exposure to organic solvents and the risk for diffuse large B-cell lymphoma (Pfor interaction=0.0058). The results remained statistically significant after adjustment for false discovery rate. Compared with women who were never occupationally exposed to any organic solvents, women who were exposed to organic solvents at least once had a significantly increased risk for diffuse large B-cell lymphoma if they carried the IL10 (rs1800890) TT genotype (odds ratio=3.31, 95% confidence interval: 1.80–6.08), but not if they carried the AT/AA genotype (odds ratio=1.14, 95% confidence interval: 0.72–1.79). No significant interactions were observed for other immune gene single nucleotide polymorphisms and various solvents in relation to NHL overall and its major subtypes. The study provided preliminary evidence supporting a role of immune gene variations in modifying the association between occupational solvent exposure and the risk for NHL.
immune genes; non-Hodgkin lymphoma; occupational exposure; single nucleotide polymorphism; solvents
Studies of smoking and risk of non-Hodgkin lymphoma (NHL) have yielded inconsistent results, possibly due to subtype heterogeneity and/or genetic variation impacting the metabolism of tobacco-derived carcinogens, including substrates of the N-acetyltransferase enzymes NAT1 and NAT2.
We conducted a pooled analysis of 5,026 NHL cases and 4,630 controls from seven case–control studies in the international lymphoma epidemiology consortium to examine associations between smoking, variation in the N-acetyltransferase genes NAT1 and NAT2, and risk of NHL subtypes. Smoking data were harmonized across studies, and genetic variants in NAT1 and NAT2 were used to infer acetylation phenotype of the NAT1 and NAT2 enzymes, respectively. Pooled odds ratios (ORs) and 95 % confidence intervals (95 % CIs) for risk of NHL and subtypes were calculated using joint fixed effects unconditional logistic regression models.
Current smoking was associated with a significant 30 % increased risk of follicular lymphoma (n = 1,176) but not NHL overall or other NHL subtypes. The association was similar among NAT2 slow (OR 1.36; 95 % CI 1.07–1.75) and intermediate/rapid (OR 1.27; 95 % CI 0.95–1.69) acetylators (pinteraction = 0.82) and also did not differ by NAT1*10 allelotype. Neither NAT2 phenotype nor NAT1*10 allelotype was associated with risk of NHL overall or NHL subtypes.
The current findings provide further evidence for a modest association between current smoking and follicular lymphoma risk and suggest that this association may not be influenced by variation in the N-acetyltransferase enzymes.
Non-Hodgkin lymphoma; Gene environment interaction; Cigarette smoking; N-acetyltransferase; Follicular lymphoma
To test the hypothesis that genetic variations in DNA repair genes may modify the association between occupational exposure to solvents and the risk of non-Hodgkin lymphoma (NHL).
A population-based case-control study was conducted in Connecticut women including 518 histologically confirmed incident NHL cases and 597 controls. Unconditional logistic regression models were used to estimate odds ratios (OR) and effect modification from the 30 SNPs in 16 DNA repair genes of the association between solvent exposure and risk of NHL overall and subtypes.
SNPs in MGMT (rs12917) and NBS1 (rs1805794) significantly modified the association between exposure to chlorinated solvents and NHL risk (Pforinteraction = 0.0003 and 0.0048 respectively). After stratified by major NHL histological subtypes, MGMT (rs12917) modified the association between chlorinated solvents and risk of diffuse large B-cell lymphoma (Pforinteraction = 0.0027) and follicular lymphoma (Pforinteraction = 0.0024). A significant interaction was also observed between occupational exposure to benzene and BRCA2 (rs144848) for NHL overall (Pforinteraction = 0.0042).
Our study results suggest that genetic variations in DNA repair genes modify the association between occupational exposure to solvents and risk of NHL.
Non-Hodgkin Lymphoma; Occupational Exposure; Solvents; Single Nucleotide Polymorphism; DNA Repair Genes
Evaluate the hypothesis that relation of breast cancer associated with dietary fiber intakes varies by type of fiber, menopausal, and the tumor’s hormone receptor status.
A case-control study of female breast cancer was conducted in Connecticut. A total of 557 incident breast cancer cases and 536 age frequency-matched controls were included in the analysis. Information on dietary intakes was collected through in-person interviews with a semi-quantitative food frequency questionnaire and was converted into nutrient intakes. Odds ratios and 95% confidence intervals were estimated by unconditional logistic regression.
Among pre-menopausal women, higher intake of soluble fiber (highest versus lowest quartile of intake) was associated with a significantly reduced risk of breast cancer (OR = 0.38, 95% CI, 0.15–0.97, Ptrend = 0.08). When further restricted to pre-menopausal women with ER− tumors, the adjusted OR for the highest quartile of intake was 0.15 (95% CI, 0.03–0.69, Ptrend = 0.02) for soluble fiber intake. Among post-menopausal women, no reduced risk of breast cancer was observed for either soluble or insoluble fiber intakes or among ER+ or ER− tumor groups.
The results from this study show that dietary soluble fiber intake is associated with a significantly reduced risk of ER− breast cancer among pre-menopausal women. Additional studies with larger sample size are needed to confirm these results.
Dietary fiber intake; Breast cancer; Estrogen receptor; Menopausal status; Case-control studies
Benign metastasizing leiomyoma (BML) occurs in a low proportion of uterine leiomyomas and treatment methods for BML are diverse and controversial. The study introduces preliminary experiences in the diagnosis and treatment of BML with the purpose of finding a suitable management strategy for these patients.
Three patients with BML were treated in our department from April 2008 to July 2012. Each of these patients presented with multiple nodules in both lungs, where we performed video-assisted thoracoscopic wedge resection to harvest enough tissue for histopathologic and immunohistochemical examination. The patients were treated with medical castration or surgical castration after the diagnosis of BML.
The ultimate pathologic results ruled out the possibility of leiomyosarcoma and other metastatic diseases, and confirmed that the pulmonary lesions were BML. The lung lesions remained stable in two patients who were treated by surgical castration, and the lung nodules regressed in one patient treated with gonadotropin-releasing hormone analogues.
The diagnosis of BML is based on the medical history of uterine myomas and histopathologic and immunohistochemical examination of lung nodules. Video-assisted thoracoscopic wedge resection is the best way to harvest tissue for diagnosis. The better outcomes in BML seem to call for medical intervention, either chemical or surgical, after diagnosis is made.
Benign neoplasms; Castration; Metastasis; Pulmonary; Rare diseases
Sexual function among testicular cancer survivors is a concern because affected men are of reproductive age when diagnosed. We conducted a case-control study among United States military men to examine whether testicular cancer survivors experienced impaired sexual function.
A total of 246 testicular cancer cases and 236 ethnicity and age matched controls were enrolled in the study in 2008-2009. The Brief Male Sexual Function Inventory (BMSFI) was used to assess sexual function.
Compared to controls, cases scored significantly lower on sex drive (5.77 vs. 5.18), erection (9.40 vs. 8.63), ejaculation (10.83 vs. 9.90), and problem assessment (10.55 vs. 9.54). Cases were significantly more likely to have impaired erection (OR 1.72; 95% CI 1.11-2.64), ejaculation (OR 2.27; 95% CI 1.32-3.91), and problem assessment (OR 2.36; 95% CI 1.43-3.90). In histology and treatment analysis, nonseminoma, chemotherapy and radiation treated cases risk of erectile dysfunction, delayed ejaculation, and/or problem assessment were greater when compared to controls.
This study provides evidence that testicular cancer survivors are more likely to have impaired sexual functioning compared to demographically matched controls. The observed impaired sexual functioning appeared to vary by treatment regimen and histologic subtype.
Testicular cancer; sexual function; military men
It has been hypothesized that the risk of testicular germ cell tumors (TGCT) is associated with maternal hormone levels. To examine the hypothesis, some studies have used perinatal factors as surrogates for hormone levels. To determine the validity of this assumption, hormone-perinatal factor relationships were examined in the Collaborative Perinatal Project.
Maternal estradiol, estriol and testosterone levels in first and third trimester serum samples were correlated with perinatal factors among 300 mothers representative of populations at high (white Americans) or low (black Americans) risk of TGCT.
Among white participants, testosterone levels, were negatively associated with maternal height (p<0.01) and age (p=0.02), and positively associated with maternal weight (p=0.02) and BMI (p<0.01), while estradiol levels were negatively associated with height (p=0.03) and positively associated with son’s birthweight (p=0.04). Among black participants, estriol levels were negatively associated with maternal weight (p=0.01), BMI (p=0.02) and gestational age p<0.01), and positively associated with son’s birthweight (p<0.01), length (p=0.04) and head circumference (p=0.03).
These findings indicate that the use of perinatal characteristics as surrogates for hormone levels should be limited to a specific ethnic group. Among white men, previously reported associations of TGCT with maternal weight and age may be due to lower maternal testosterone levels.
testicular cancer; maternal hormones; perinatal factors
Being overweight and obese increases oxidative stress in the body. To test the hypothesis that genetic variations in oxidative stress pathway genes modify the relationship between body mass index (BMI) and risk of non-Hodgkin lymphoma (NHL), we conducted a population-based case–control study in Connecticut women.
Individuals who were overweight/obese (BMI ≥ 25) were compared with normal and underweight individuals (BMI < 25), and their risk of NHL stratified assuming a dominant allele model for each oxidative stress pathway single-nucleotide polymorphism.
Polymorphisms in AKR1A1, AKR1C1, AKR1C3, CYBA, GPX1, MPO, NCF2, NCF4, NOS1, NOS2A NOS3, OGG1, ATG9B, SOD1, SOD2, SOD3,RAC1, and RAC2 genes after false discovery rate adjustment did not modify the association between BMI and risk of NHL overall and histologic subtypes.
The results suggest that common genetic variations in oxidative stress genes do not modify the relationship between BMI and risk of NHL.
Studies of BMI and oxidative stress independently may elevate NHL risk, but this study suggests no interaction of the two risk factors. Future studies with larger study populations may reveal interactions.
Nitrate and nitrite are precursors in the formation of N-nitroso compounds. We recently found a 40% increased risk of NHL with higher dietary nitrite intake and significant increases in risk for follicular and T-cell lymphoma. It is possible that these compounds also affect NHL prognosis by enhancing cancer progression in addition to development by further impairing immune system function. To test the hypothesis that nitrate and nitrite intake affects NHL survival, we evaluated the association in study participants that have been followed post-disease diagnosis in a population-based case-control study among women in Connecticut. We did not observe a significant increasing trend of mortality for NHL overall or by subtype for nitrate or nitrite intake for deaths from NHL or death from any cause, although a borderline significant protective trend was observed for follicular lymphoma with increasing nitrate intake. We did not identify a difference in overall survival for nitrate (P = 0.39) or for nitrite (P = 0.66) or for NHL specific survival for nitrate (P = 0.96) or nitrite (P = 0.17). Thus, our null findings do not confer support for the possibility that dietary nitrate and nitrite intake impacts NHL survival by promoting immune unresponsiveness.
The complement system plays an important role in inflammatory and immune responses, and recent evidence has suggested that it may also play a role in lymphomagenesis. We evaluated the association between genetic variation in complement system genes and risk of non-Hodgkin lymphoma (NHL) in a population-based case–control study conducted among women in Connecticut. Tag SNPs in 30 complement genes were genotyped in 432 Caucasian incident cases and 494 frequency-matched controls. A gene-based analysis that adjusted for the number of tag SNPs genotyped in each gene showed a significant association with NHL overall (P = 0.04) as well as with diffuse large B-cell lymphoma (DLBCL) (P = 0.01) for the C1RL gene. A SNP-based analysis showed that a C>T base substitution for C1RL rs3813729 (odds ratio (OR)CT = 0.60, 95% confidence interval (CI) = 0.42–0.87, Ptrend = 0.0062) was associated with a decreased risk of overall NHL, as well as for DLBCL (ORCT = 0.39, 95% CI = 0.20–0.73; Ptrend = 0.0034). Additionally, SNPs (C2 rs497309, A>C and C3 rs344550, G>C) in two complement genes were positively associated with marginal zone lymphoma (MZL) and C1QG was associated with CLL/SLL, but these results were based on a limited number of cases. Our results suggest a potential role of the complement system in susceptibility to NHL; however, our results should be viewed as exploratory and further replication is needed to clarify these preliminary findings.
lymphoma; C1RL; innate immunity; SNP
Cytokines play a critical role in regulating the immune system. In the tumor microenvironment, they influence survival, proliferation, differentiation, and movement of both tumor and stromal cells, and regulate tumor interactions with the extracellular matrix. Given these biologic properties, there is reason to hypothesize that cytokine activity influences the pathogenesis of non-Hodgkin lymphoma (NHL).
We investigated the effect of genetic variation in cytokine genes on NHL prognosis and survival by evaluating genetic variation in individual SNPs as well as the combined effect of multiple deleterious genotypes. Survival information from 496 female incident NHL cases diagnosed during 1996–2000 in Connecticut were abstracted from Connecticut Tumor Registry in 2008. Survival analyses were conducted by comparing Kaplan-Meier curves and hazard ratios (HR) were computed using Cox proportional hazard models adjusting for demographic and tumor characteristics for genes that were suggested by previous studies to be associated with NHL survival.
We found that the variant IL6 genotype is significantly associated (HR=0.42; 95%CI: 0.23–0.77) with a decreased risk of death, as well as relapse and secondary cancer occurrence, among those with NHL. We also found that risk of death, relapse, and secondary cancers varied by specific SNPs for the follicular, DLBCL, and CLL/SLL histologic types. We identified combinations of polymorphisms whose combined deleterious effect significantly alter overall NHL survival and disease-free survival.
Our study provides evidence that the identification of genetic polymorphisms in cytokine genes may help improve the prediction of NHL survival and prognosis.
Non-Hodgkin lymphoma; Cytokines; Single nucleotide polymorphisms; Survival
We conducted a population-based case-control study in Connecticut women to test the hypothesis that genetic variations in Th1 and Th2 cytokine genes may modify the association between blood transfusion and risk of non-Hodgkin lymphoma (NHL). Compared with women without blood transfusion, women with a history of transfusion had an increased risk of NHL if they carried IL10RA (rs9610) GG genotype [odds ratio (OR) = 1.9, 95% confidence interval (CI): 1.1–3.2] or TNF (rs1800629) AG/AA genotypes (OR = 1.6, 95% CI: 0.9–2.7). We also found women with a history of transfusion had a decreased risk of NHL if they carried IL10RA (rs9610) AG/AA genotypes (OR = 0.6, 95% CI: 0.4–0.9) or TNF (rs1800629) GG genotype (OR = 0.7, 95% CI: 0.5–1.0). A similar pattern was also observed for B-cell lymphoma but not for T-cell lymphoma. Statistically significant interactions with blood transfusion were observed for IL10RA (rs9610) (Pforinteraction = 0.003) and TNF (rs1800629) (Pforinteraction = 0.012) for NHL overall and IL10RA (rs9610) (Pforinteraction = 0.001) and TNF (rs1800629) (Pforinteraction = 0.019) for B-cell lymphoma. The results suggest that genetic polymorphisms in TNF and IL10RA genes may modify the association between blood transfusion and NHL risk.
To test the hypothesis that bladder cancer is a heterogeneous disease.
Patients and Methods
We examined the temporal trends of bladder cancer by histological subtype and by disease stage and grade using the National Cancer Institute's Surveillance, Epidemiology, and End Results data collected in 1973–2007.
The age-adjusted incidence rates of bladder cancer showed a slight decrease from 1973 to 2007 (annual percentage change [APC] = −0.4, P < 0.05).
Although the age-adjusted incidence rates of non-papillary transitional cell carcinoma decreased by about 53% from 7.9 per 100 000 in 1973 to 3.7 per 100 000 in 2007 (APC = −2.2, P < 0.05), the age-adjusted incidence rates of papillary transitional cell carcinoma increased by about 56% from 6.8 per 100 000 in 1973 to 10.6 per 100 000 in 2007 (APC=0.5, P < 0.05).
Among other rare histological subtypes, except for small cell carcinoma which showed a slightly rising trend, squamous cell carcinoma, adenocarcinoma and others all presented a decreasing trend.
Similar patterns were found for different stages (localized, regional and distant), but a dramatic increasing trend of grade IV was found between 1998 and 2007 when a corresponding decreasing trend was shown for grades I, II and III.
The results support the hypothesis that bladder cancer is a heterogeneous disease and taking disease heterogeneity into consideration in future epidemiological studies is essential.
bladder cancer; transitional cell carcinoma; papillary transitional cell carcinoma; non-papillary transitional cell carcinoma; incidence; mortality
Background and Aims
Primary hepatocellular carcinoma (HCC) is usually presented in inflamed fibrotic/cirrhotic liver with extensive lymphocyte infiltration. We examined the associations between the HCC early recurrence and alterations in serum levels of inflammatory cytokines.
A cohort of 105 HCC patients with chronic hepatitis B virus infection were included. Pre-therapy, we quantified their serum concentrations of Th1-, Th2-, Th17-, Treg-related, and other cytokines that have been reported to be associated with poor prognosis in human cancers. IL17-producing T-cells were generated in vitro from HCC patients and co-cultured with HCC cell lines separated by a 0.4 µM transwell.
All the 105 cases of HCC patients had liver cirrhosis. The patients who suffered from HCC early recurrence had higher pre-therapy serum levels of IL17 and lower levels of IL10 than those who did not suffer from recurrence after curative hepatectomy. After adjustment for general tumor clinicopathological factors, elevated serum levels of IL17 (≥0.9 pg/ml) was found to be an independent risk factor for HCC early recurrence with a hazard ratio of 2.46 (95%CI 1.34–4.51). Patients with bigger tumors (>5 cm in diameter) and elevated serum levels of IL17 had the highest risk of early recurrence as compared to those with only one of these factors (P = 0.009) or without any (P<0.001). These factors showed similar effects on the HCC patient overall survival. Intrahepatic infiltrated T-cells in HCC patients were identified as the major IL17-producing cells. Proliferation of HCC cells, QGY-7703, was augmented QGY-7703, was augmented in the presence of IL17-producing T-cells. This effect diminished after neutralizing antibody against human IL17A or TNFα was included.
Both tumors and IL17 from liver infiltrated T-cells contributed to HCC early recurrence and progression after curative resection. Pre-therapy serum IL17 levels may serve as an additional indicator for predicting high-risk patients.
Evidence from previous studies has suggested there may be physical and mental changes in health among testicular cancer survivors. No studies have been conducted in the United States, however.
Study participants were initially enrolled in the US Servicemen's Testicular Tumor Environmental and Endocrine Determinants (STEED) study between 2002 and 2005. A total of 246 TGCT (testicular germ cell tumor) cases and 236 non-testicular cancer controls participated in the current study, and completed a self-administered questionnaire. Mean time since diagnosis for cases was 14 years, and no less than five for all cases. Component scores determined from responses to questions about physical and mental health on SF36 were tabulated to yield two summary measures, physical component scores (PCS), and mental component scores (MCS). Component and summary scores were normalized to a score of 50 with a standard deviation of 10 by a linear T-score transformation.
Overall, cases may not suffer greatly in different quality of life than controls. When all cases and controls are compared, TGCT cases had lower PCS (mean: 51.9 95% CI: 50.6–53.2, P value: 0.037) than controls (mean: 53.6 95% CI: 52.7–54.6). MCS were not significantly different (P value: 0.091). In multivariate analyses, several physical health components were worse for TGCT cases such as role-physical (OR 1.19, 95% CI: 1.01–1.39) and general health (OR 1.26, 95% CI: 1.07–1.49) compared to controls. However, TGCT cases treated with chemotherapy had lower PCS (cases: 50.2, 95% CI: 47.6–52.8; controls: 53.6, 95% CI: 52.7–54.6, P value: 0.0032) and MCS (cases: 49.3, 95% CI: 46.5–52.1; controls: 52.0, 95% CI: 50.9–53.2, P value: 0.039). TGCT cases who received treatments other than chemotherapy did not differ from controls in either PCS or MCS.
Physical and general health limitations may affect testicular cancer survivors. Men treated with chemotherapy, however, may be most likely to suffer adverse health outcomes due to a combination of body-wide effects on physical and mental factors which affect various aspects of physical health, mental health, and overall quality of life. And in particular, physical functioning, role–physical, and general health are strongly affected.
Health status; Quality of life; Testicular cancer
Despite decades of intensive research, Non-Hodgkin Lymphoma (NHL) remains poorly understood and is largely incurable. NHL is a heterogeneous group of malignancies with multiple subtypes, each of which has distinct morphologic, immunophenotypic, and clinical features. Identifying the risk factors for NHL may improve our understanding of the underlying biological mechanisms and have an impact on clinical practice.
This article provides a review of several aspects of NHL, including epidemiology and subtype classification, clinical, environmental, genetic, and genomic risk factors identified for etiology and prognosis, and available statistical and bioinformatics tools for identification of genetic and genomic risk factors from the analysis of high-throughput studies.
Multiple clinical and environmental risk factors have been identified. However, they have failed to provide practically effective prediction. Genetic and genomic risk factors identified from high-throughput studies have suffered a lack of reproducibility. The identification of genetic/genomic risk factors demands innovative statistical and bioinformatics tools. Although multiple analysis methods have been developed, there is still room for improvement. There is a critical need for well-designed, prospective, large-scale pangenomic studies.
NHL; etiology; prognosis; risk factors; bioinformatics analysis
To elucidate the influence of recreational physical activity, body mass index (BMI), and waist circumference on the risk of specific types of urinary incontinence.
We conducted a population-based cross-sectional survey in Gansu, China among 2603 women aged 20 years or older.
The study found that BMI was positively associated with urinary incontinence (P for trend = 0.008) and the association was mainly observed for stress urinary incontinence (OR = 1.4, 95% CI: 1.1, 1.9 for BMI = 24.0–27.9 kg/m2; OR = 2.3, 95% CI: 1.5, 3.6 for BMI ≥ 28.0 kg/m2; P for trend = 0.0005). A positive association between stress incontinence (OR = 1.7, 95% CI: 1.2, 2.5) and waist circumference was observed for women who had waist circumference between 70 cm and 75 cm compared to waist circumference less than 70 cm. Recreational physical activity was inversely associated with overall and mixed urinary incontinence (P for trend <0.0001 for both). A significant interaction between physical activity and waist circumference was found for overall (P = 0.0007) and stress incontinence (P = 0.001).
The findings that physical activity inversely associated with urinary incontinence and its interaction with waist circumference warrant further investigation, particularly in prospective studies.
Recreational physical activity; Body mass index; Waist circumference; Female urinary incontinence
The incidence rates of non-Hodgkin lymphoma (NHL) have steadily increased over the last several decades in the United States, and the temporal trends in incidence can only be partially explained by the HIV epidemic. In 1992, an international workshop sponsored by the United States National Cancer Institute concluded that there was an “emerging epidemic” of NHL and emphasized the need to investigate the factors responsible for the increasing incidence of this disease. Over the past two decades, numerous epidemiological studies have examined the risk factors for NHL, particularly for putative environmental and lifestyle risk factors, and international consortia have been established in order to investigate rare exposures and NHL subtype-specific associations. While few consistent risk factors for NHL aside from immunosuppression and certain infectious agents have emerged, suggestive associations with several lifestyle and environmental factors have been reported in epidemiologic studies. Further, increasing evidence has suggested that the effects of these and other exposures may be limited to or stronger for particular NHL subtypes. This paper examines the progress that has been made over the last twenty years in elucidating the etiology of NHL, with a primary emphasis on lifestyle factors and environmental exposures.
Background. Despite an increase in the number of molecular epidemiological studies conducted in recent years to evaluate the association between human papillomavirus (HPV) infection and risk of bladder cancer, the studies remain inconclusive.
Methods. The prevalence of HPV in bladder cancer was estimated by pooling data from 52 studies, taking into consideration the heterogeneity from major related parameters including study region, histological type, HPV DNA specimen, publication calendar period, and detection method. Moreover, the association of HPV infection with bladder cancer was tested by a meta-analysis with 19 case-control studies.
Results. An HPV prevalence of 16.88% (95% confidence interval [CI], 15.53%–18.31%) among the bladder cancer cases was revealed, most of whom were high-risk HPV types (15.82% [95% CI, 14.37%–17.36%]). The prevalence varied by region, types of HPV DNA specimen, and polymerase chain reaction primers used. A significantly increased risk of bladder cancer was shown for the positivity of overall HPV (odds ratio, 2.84 [95% CI, 1.39–5.80]), which was also infuenced by HPV type, study region, HPV DNA specimen, and detection method.
Conclusions. Infection of high-risk HPV types, especially HPV16, may play a role in bladder carcinogenesis.
During the past several decades, an increasing incidence of thyroid cancer has been observed worldwide. Nitrate inhibits iodide uptake by the thyroid, potentially disrupting thyroid function. An increased risk of thyroid cancer associated with nitrate intake was recently reported in a cohort study of older women in Iowa. We evaluated dietary nitrate and nitrite intake and thyroid cancer risk overall and for subtypes in the National Institutes of Health-American Association of Retired Persons (NIH-AARP) Diet and Health Study, a large prospective cohort of 490,194 men and women, ages 50–71 years in 1995–1996. Dietary intakes were assessed using a 124-item food frequency questionnaire. During an average of 7 years of follow-up we identified 370 incident thyroid cancer cases (170 men, 200 women) with complete dietary information. Among men, increasing nitrate intake was positively associated with thyroid cancer risk (relative risk (RR) for the highest quintile versus lowest quintile RR=2.28, 95% CI: 1.29–4.04l; p-trend <0.001); however, we observed no trend with intake among women (p-trend=0.61). Nitrite intake was not associated with risk of thyroid cancer for either men or women. We evaluated risk for the two main types of thyroid cancer. We found positive associations for nitrate intake and both papillary (RR = 2.10; 95%CI: 1.09–4.05; p-trend=0.05) and follicular thyroid cancer (RR= 3.42; 95%CI: 1.03–11.4; p-trend=0.01) among men. Nitrite intake was associated with increased risk of follicular thyroid cancer (RR= 2.74; 95%CI: 0.86–8.77; p-trend=0.04) among men. Our results support a role of nitrate in thyroid cancer risk and suggest that further studies to investigate these exposures are warranted.
Immune deficiency is one of the best characterized and strongest known risk factors for non-Hodgkin lymphoma (NHL). We studied the association between single nucleotide polymorphisms (SNPs) in integrin genes that are important components in human innate immunity and the risk of NHL in a population-based case–control study of women in Connecticut, USA. A total of 373 tag SNPs in 33 gene regions were included in the analysis of 448 cases and 525 controls. The ADAM19 rs11466782 SNP was associated with an increased risk of lymphoma (OR, 1.73; 95 % CI, 1.28–2.35; P additive = 0.0004), and the ICAM3 rs2304240 (OR, 0.67; 95 % CI, 0.52–0.86; P additive = 0.002) and the PTGDR rs708486 SNPs (OR, 0.75; 95 % CI, 0.63–0.90; P additive = 0.002) were associated with reduced risk of lymphoma. Two gene regions (ADAM19 (P=0.009) and ICAM3 (P=0.009)) displayed global associations with lymphoma risk at the P<0.01 level. While our results suggest that genetic polymorphisms in integrin genes may play a role in the genesis of lymphoma in women, they should be viewed as exploratory until they are replicated in additional populations.
lymphoma; integrin; innate immunity; single nucleotide polymorphism