Occupation and risk of prostate cancer in Canadian men: A case-control study across eight Canadian provinces

BackgroundThe etiology of prostate cancer continues to be poorly understood, including the role of occupation. Past Canadian studies have not been able to thoroughly examine prostate cancer by occupation with detailed information on individual level factors.MethodsOccupation, industry and prostate cancer were examined using data from the National Enhanced Cancer Surveillance System, a large population-based case-control study conducted across eight Canadian provinces from 1994 to 1997. This analysis included 1737 incident cases and 1803 controls aged 50 to 79 years. Lifetime occupational histories were used to group individuals by occupation and industry employment. Odds ratios and 95% confidence intervals were calculated and adjustments were made for known and possible risk factors.ResultsBy occupation, elevated risks were observed in farming and farm management (OR = 1.37, 95% CI 1.02–1.84), armed forces (OR = 1.33, 95% CI 1.06-1.65) and legal work (OR = 2.58, 95% CI 1.05–6.35). Elevated risks were also observed in office work (OR = 1.20, 95% CI 1.00–1.43) and plumbing (OR = 1.77, 95% CI 1.07–2.93) and with ≥10 years duration of employment. Decreased risks were observed in senior management (OR = 0.65, 95% CI 0.46–0.91), construction management (OR = 0.69, 95% CI 0.50–0.94) and travel work (OR = 0.37, 95% CI 0.16–0.88). Industry results were similar to occupation results, except for an elevated risk in forestry/logging (OR = 1.54, 95% CI 1.06–2.25) and a decreased risk in primary metal products (OR = 0.70, 95% CI 0.51–0.96).ConclusionThis study presents associations between occupation, industry and prostate cancer, while accounting for individual level factors. Further research is needed on potential job-specific exposures and screening behaviours.     

MicroRNA-related polymorphisms and non-Hodgkin lymphoma susceptibility in the Multicenter AIDS Cohort Study

BackgroundMicroRNAs, small non-coding RNAs involved in gene regulation, are implicated in lymphomagenesis. We evaluated whether genetic variations in microRNA coding regions, binding sites, or biogenesis genes (collectively referred to as miRNA-SNPs) were associated with risk of AIDS-associated non-Hodgkin lymphoma (AIDS-NHL), and serum levels of four lymphoma-related microRNAs.MethodsTwenty-five miRNA-SNPs were genotyped in 180 AIDS-NHL cases and 529 HIV-infected matched controls from the Multicenter AIDS Cohort Study (MACS), and real-time polymerase chain reaction was used to quantify serum microRNA levels. Adjusted odds ratios (ORs) estimated using conditional logistic regression evaluated associations between miRNA-SNPs and AIDS-NHL risk. A semi-Bayes shrinkage approach was employed to reduce likelihood of false-positive associations. Adjusted mean ratios (MR) calculated using linear regression assessed associations between miRNA-SNPs and serum microRNA levels.ResultsDDX20 rs197412, a non-synonymous miRNA biogenesis gene SNP, was associated with AIDS-NHL risk (OR = 1.34 per minor allele; 95% CI: 1.02–1.75), and higher miRNA-222 serum levels nearing statistical significance (MR = 1.21 per minor allele; 95% CI: 0.98–1.49). MiRNA-196a2 rs11614913 was associated with decreased central nervous system (CNS) AIDS-NHL (CT vs. CC OR = 0.52; 95% CI: 0.27–0.99). The minor allele of HIF1A rs2057482, which creates a miRNA-196a2 binding site, was associated with systemic AIDS-NHL risk (OR = 1.73 per minor allele; 95% CI: 1.12–2.67), and decreased CNS AIDS-NHL risk (OR = 0.49 per minor allele; 95% CI: 0.25–0.94).ConclusionsThis study suggests that a few miRNA-SNPs are associated with AIDS-NHL risk and may modulate miRNA expression. These results support a role for miRNA in AIDS-NHL and may highlight pathways to be targeted for risk stratification or therapeutics.     

Birth weight and other perinatal factors and childhood CNS tumors: A case–control study in California

AimsWe conducted a large registry-based study in California to investigate the association of perinatal factors and childhood CNS tumors, with analysis by tumor subtype.MethodsWe linked California cancer and birth registries to obtain information on 3308 cases and 3308 controls matched on age and sex. We examined the association of birth weight, gestational age, birth order, parental ages, maternal conditions during pregnancy, newborn abnormalities and the risk of childhood CNS tumors using conditional logistic regression, with adjustment for potential confounders.ResultsThe odds ratio (OR) per 1000 g increase in birth weight was 1.11 (95% CI: 0.99–1.24) for total childhood CNS tumors, 1.17 (95% CI: 0.97–1.42) for astrocytoma and 1.28 (95% CI: 0.90–1.83) for medulloblastoma. Compared to average-for-gestational age, large-for-gestational age infants were at increased risk of glioma (OR = 1.86, 95% CI: 0.99–3.48), while small-for-gestational age infants were at increased risk of ependimoma (OR = 2.64, 95% CI: 1.10–6.30). Increased risk of childhood CNS tumors was observed for 5-year increase in maternal and paternal ages (OR = 1.06, 95% CI: 1.00–1.12 and 1.05, 95% CI: 1.00–1.10 respectively). Increased risk of astrocytoma was detected for 5-year increase in paternal age (OR = 1.08; 95% CI: 1.00–1.16) and increased risk of glioma for maternal age ≥ 35 years old (OR = 1.87; 95% CI: 1.00–3.52). Maternal genital herpes during pregnancy was associated with a pronounced increase in risk of total CNS tumors (OR = 2.74; 95% CI: 1.16–6.51). Other (non-sexually transmitted) infections during pregnancy were associated with decreased risk of total CNS tumors (OR = 0.28, 95% CI: 0.09–0.85). Maternal blood/immune disorders during pregnancy were linked to increased risk of CNS tumors (OR = 2.28, 95% CI: 1.08–4.83) and medulloblastoma (OR = 7.13, 95% CI: 0.82–61.03). Newborn CNS abnormalities were also associated with high risk of childhood CNS tumors (OR = 4.08, 95% CI: 1.13–14.76).ConclusionsOur results suggest that maternal genital herpes, blood and immunological disorders during pregnancy and newborn CNS abnormalities were associated with increased risk of CNS tumors. Maternal infections during pregnancy were associated with decreased risk of CNS tumors. Advanced maternal and paternal ages may be associated with a slightly increased risk of CNS tumors. Factors associated with CNS tumor subtypes varied by subtype, an indicator of different etiology for different subtypes.     

Ascaris lumbricoides and Trichuris trichiura infections associated with wastewater and human excreta use in agriculture in Vietnam

BackgroundWe assessed the risk of helminth infections in association with the use of wastewater and excreta in agriculture in Hanam province, northern Vietnam. In two cross-sectional surveys, we obtained samples from 1,425 individuals from 453 randomly selected households. Kato-Katz thick smear and formalin-ether concentration techniques were used for helminth diagnosis in two stool samples per person. Socio-demographic and water, sanitation and hygiene related characteristics, including exposure to human and animal excreta and household wastewater management, were assessed with a questionnaire.ResultsOverall 47% of study participants were infected with any helminth (Ascaris lumbricoides 24%, Trichuris trichiura 40% and hookworm 2%). Infections with intestinal protozoa were rare (i.e. Entamoeba histolytica 6%, Entamoeba coli 2%, Giardia lamblia 2%, Cryptosporidium parvum 5% and Cyclospora cayetanensis 1%). People having close contact with polluted Nhue River water had a higher risk of helminth infections (odds ratio [OR] = 1.5, 95% confidence interval [CI] 1.1–2.2) and A. lumbricoides (OR = 2.1, 95% CI 1.4–3.2), compared with those without contact. The use of human excreta for application in the field had an increased risk for a T. trichiura infection (OR = 1.5, 95% CI 1.0–2.3). In contrast, tap water use in households was a protective factor against any helminth infection (i.e. T. trichiura OR = 0.6, 95% CI 0.4–0.9). Prevalences increased with age and males had generally lower prevalences (OR = 0.8, 95% CI 0.6–1.0), participants performing agricultural (OR = 1.5, 95% CI 1.1–2.1) and having a low educational level (OR = 1.7, 95% CI 1.2–2.4) were significantly associated with helminth infections. None of the factors related to household's sanitary condition, type of latrine, household's SES, use of animal excreta, and personal hygiene practices were statistically significant associated with helminth infection.ConclusionsOur study suggests that in agricultural settings, direct contact with water from Nhue River and the use of human excreta as fertiliser in the fields are important risk factors for helminth infection. Daily use of clean water is likely to reduce the risk of worm infection. Deworming policies and national programs should give more attention to these agricultural at risk populations.     

An updated meta-analysis on the association of TGF-β1 gene promoter -509C/T polymorphism with colorectal cancer risk

AimPublished data on the association between transforming growth factor-β1 (TGF-β1) gene promoter-509C/T polymorphism and colorectal cancer (CRC) risk are inconsistent and inconclusive. To derive a more precise estimation of this association, a meta-analysis was carried out.MethodsMeta-analysis was performed to evaluate reported studies of the relationship between TGF-β1 gene promoter-509C/T polymorphism and colorectal cancer risk using fixed-effects model and random-effects model.ResultsWe observed an increased colorectal cancer risk among subjects carrying TGF-β1 gene promoter-509CC + CT genotype (odds ratio (OR) = 1.18%, 95% confidence interval (95% CI): 1.06–1.32) using 4440/6785 cases/controls in total population. We observed an increased risk of the TGF-β1 gene promoter -509CC, CT and CC + CT polymorphisms for colorectal cancer in population-based study (OR = 1.36, 95% CI: 1.19–1.56, OR = 1.18, 95% CI: 1.03–1.34 and OR = 1.26, 95% CI: 1.12–1.43, respectively) in stratified analysis. We observed an increased colorectal risk among CC and CC + CT carriers in European and American population (OR = 1.22, 95% CI: 1.04–1.43 and OR = 1.18, 95% CI: 1.02–1.38, respectively). We also observed an increased risk of colon cancer among subjects carrying CC + CT genotype (OR = 1.31, 95% CI: 1.05–1.63).ConclusionsThe present meta-analysis results suggest that TGF-β1 gene promoter -509C allele variant is a possible risk factor for developing colorectal cancer. Recommendations for further studies include pooling of individual data to verify results from the study and to facilitate evaluation of multigenic effects and detailed analysis of effect modification by environmental and lifestyle factors.     

Obesity,physical activity and cancer risks: Results from the Cancer,Lifestyle and Evaluation of Risk Study (CLEAR)

IntroductionPhysical activity (PA) has been associated with lower risk of cardiovascular diseases, but the evidence linking PA with lower cancer risk is inconclusive. We examined the independent and interactive effects of PA and obesity using body mass index (BMI) as a proxy for obesity, on the risk of developing prostate (PC), postmenopausal breast (BC), colorectal (CRC), ovarian (OC) and uterine (UC) cancers.MethodsWe estimated odds ratios (OR) and 95% confidence intervals (CI), adjusting for cancer specific confounders, in 6831 self-reported cancer cases and 1992 self-reported cancer-free controls from the Cancer Lifestyle and Evaluation of Risk Study, using unconditional logistic regression.ResultsFor women, BMI was positively associated with UC risk; specifically, obese women (BMI ≥30 kg/m²) had nearly twice the risk of developing UC compared to women with healthy-BMI-range (<25 kg/m²) (OR = 1.99;CI:1.31–3.03). For men, BMI was also positively associated with the risk of developing any cancer type, CRC and PC. In particular, obese men had 37% (OR = 1.37;CI:1.11–1.70), 113% (OR = 2.13;CI:1.55–2.91) and 51% (OR = 1.51;CI:1.17-1.94) higher risks of developing any cancer, CRC and PC respectively, when compared to men with healthy-BMI-range (BMI<25 kg/m²).Among women, PA was inversely associated with the risks of CRC, UC and BC. In particular, the highest level of PA (versus nil activity) was associated with reduced risks of CRC (OR = 0.60;CI:0.44–0.84) and UC (OR = 0.47;CI:0.27–0.80). Reduced risks of BC were associated with low (OR = 0.66;CI:0.51–0.86) and moderate (OR = 0.72;CI:0.57–0.91) levels of PA. There was no association between PA levels and cancer risks for men.We found no evidence of an interaction between BMI and PA in the CLEAR study.ConclusionThese findings suggest that PA and obesity are independent cancer risk factors.     

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

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

Risk factors for Kaposi's sarcoma among HIV-positive individuals in a case control study in Cameroon

BackgroundIndividuals co-infected with Kaposi's sarcoma herpesvirus (KSHV) and Human Immunodeficiency Virus (HIV) are at greatly increased risk of developing Kaposi's sarcoma (KS). The objective of the current analysis is to identify risk cofactors for KS among HIV-positive individuals.MethodsWe conducted a case-control study of KS in Cameroon on 161 HIV-positive and 14 HIV-negative cases and 680 HIV-positive and 322 HIV-negative controls. Participants answered a physician-administered questionnaire and provided blood and saliva specimens. Antibodies against KSHV lytic, K8.1, and latent, ORF73, antigens were measured by ELISA to determine KSHV serostatus. Conditional logistic regression was performed to determine multivariate odds ratios (OR) and 95% confidence intervals (CI) for risk factors associated with KS among HIV-positive cases and controls.ResultsOverall, 98% (158) of HIV-positive cases, 100% (14) of HIV-negative cases, 81% (550) of HIV-positive controls, and 80% (257) of HIV-negative controls were KSHV seropositive. Risk factors for KS among HIV-positive individuals included KSHV seropositivity (OR = 9.6; 95% CI 2.9, 31.5), non-use of a mosquito bed net (OR 1.9; 95% CI 1.2, 2.9), minority ethnicity (OR = 3.1; 95% CI 1.1, 9.3), treatment from a traditional healer (OR = 2.3; 95% CI 1.5, 3.7), history of transfusion (OR = 2.4; 95% CI 1.5, 3.9), and family history of cancer (OR = 1.9; 95% CI 1.1, 3.1).ConclusionKSHV seroprevalence of ≥80% indicates a high prevalence in the general population in Cameroon. Among HIV-positive individuals, the strong association of KS with non-use of mosquito nets and treatment from traditional healers are compelling findings, consistent with recently reported data from East Africa.     

Impact of HLA-class I alleles on response to HCV treatment in a cohort of Egyptian patients

Extensive allele diversity is observed in HLA associations with response to HCV combined therapy (pegylated interferon + ribavitin) in different global ethnic populations. The aim of the study is to assess the frequency and association of certain HLA-class I alleles in Egyptian persons with persistent HCV and others with sustained viral response (SVR).Material and methodsThe study was a retrospective cohort study that included 246 HCV patients who received combined therapy; 106 cases responded to treatment (SVR) and 140 individuals did not respond to treatment (persistent HCV infection). Both groups are subjected to genotyping for HLA-class I.ResultsAccording to logistic regression analysis, Cw17 was considered as the most predictor allele as it was the highest significant allele (OR = 16.70; 95% CI: 2.64–105.58; P = 0.003), whereas the presence of the HLA-B45 and HLA-B27 alleles has a 19.35-fold risk and 15.7 fold risk, respectively of non-response to interferon therapy in chronic HCV patients (OR = 19.35; 95% CI: 1.05–357.24; P = 0.04) and (OR = 15.69; 95% CI: 1.179–208.9; P = 0.04) can act also as high predictor alleles, and the lowest significant predictor allele was B44 (OR = 6.535; 95% CI: 1.55–27.63; P = 0.01). The presence of the HLA-A alleles might have a limited role in prediction for the non-responders, as the A32 was significantly higher among the SVR patients, but, it cannot have a predictor role (OR: 0.161, CI: 0.03–1.056, P = 0.049).ConclusionCw17, HLA-B45, and HLA-B27 alleles can predict the nonresponders to HCV combined therapy.     

Birth weight and other perinatal characteristics and childhood leukemia in California

Aims. We conducted a large registry-based study in California to investigate the association of perinatal factors and childhood leukemia with analysis of two major subtypes, acute lymphocytic leukemia (ALL) and acute myeloid leukemia (AML). Methods. We linked California cancer and birth registries to obtain information on 5788 cases and 5788 controls matched on age and sex (1:1). We examined the association of birth weight, gestational age, birth and pregnancy order, parental ages, and specific conditions during pregnancy and risk of total leukemia, ALL and AML using conditional logistic regression, with adjustment for potential confounders. Results. The odds ratio (OR) per 1000 g increase in birth weight was 1.11 for both total leukemia and ALL. The OR were highest for babies weighing ≥4500 g with reference <2500 g: 1.59 (95% CI: 1.05–2.40) and 1.70 (95% CI: 1.08–2.68) for total leukemia and ALL, respectively. For AML, increase in risk was also observed but the estimate was imprecise due to small numbers. Compared to average-for-gestational age (AGA), large-for-gestational age (LGA) babies were at slightly increased risk of total childhood leukemia (OR = 1.10) and both ALL and AML (OR = 1.07 and OR = 1.13, respectively) but estimates were imprecise. Being small-for-gestational age (SGA) was associated with reduced risk of childhood leukemia (OR = 0.81, 95% CI: 0.67–0.97) and ALL (OR = 0.77, 95% CI: 0.63–0.94), but not AML. Being first-born was associated with decreased risk of AML only (OR = 0.70; 95% CI: 0.53–0.93). Compared to children with paternal age <25 years, children with paternal age between 35 and 45 years were at increased risk of total childhood leukemia (OR = 1.12; 95% CI: 1.04–1.40) and ALL (OR = 1.23; 95% CI: 1.04–1.47). None of conditions during pregnancy examined or maternal age were associated with increased risk of childhood leukemia or its subtypes. Conclusions. Our results suggest that high birth weight and LGA were associated with increased risk and SGA with decreased risk of total childhood leukemia and ALL, being first-born was associated with decreased risk of AML, and advanced paternal age was associated with increased risk of ALL. These findings suggest that associations of childhood leukemia and perinatal factors depend highly on subtype of leukemia.     

Multiple myeloma and occupation: A pooled analysis by the International Multiple Myeloma Consortium

Objective: We investigated occupational risk of multiple myeloma (MM) in a pooled analysis of five international case–control studies. Methods: We calculated the odds ratio and its 95% confidence interval for selected occupations with unconditional regression analysis in 1959 MM cases and 6192 controls, by pooling study-specific risks using random-effects meta-analysis. Exposure to organic solvents was assessed with a job-exposure matrix (JEM). Results: Gardeners and nursery workers combined, most likely exposed to pesticides, showed a 50% increase in risk (OR = 1.50, 95% CI 0.9–2.3), while other farming jobs did not. Metal processors (OR = 1.55, 95% CI 0.9–2.3), female cleaners (OR = 1.32, 95% CI 1.0–1.8), and high level exposure to organic solvents (OR = 1.38, 95% CI 0.96–1.8) also showed moderately increased risks. Conclusions: Additional case–control studies of MM aetiology are warranted to further investigate the nature of the repeatedly reported increase in MM risk in several occupational groups.     

Tobacco and alcohol as risk factors for oesophageal cancer in a high incidence area in South Africa

BackgroundThe Eastern Cape Province of South Africa, which includes the former Transkei has high rates of squamous cell oesophageal cancer (OC), thought to be caused mainly by nutritional deficiencies and fungal contamination of staple maize. A hospital-based case-control study was conducted at three of the major referral hospitals in this region to measure, among other suspected risk factors, the relative importance of tobacco smoking and alcohol consumption for the disease in this population.MethodsIncident cases (n = 670) of OC and controls (n = 1188) were interviewed using a structured questionnaire which included questions on tobacco and alcohol-related consumption. Odds ratios (ORs) with 95% confidence intervals for each of the risk factors were calculated using unconditional multiple logistic regression models.ResultsA monotonic dose-response was observed across the categories of each tobacco-related variable in both sexes. Males and females currently smoking a total of >14 g of tobacco per day were observed to have over 4-times the odds of developing OC (males OR = 4.36, 95% CI 2.24–8.48; females OR = 4.56, 95% CI 1.46–14.30), with pipe smoking showing the strongest effect. Similar trends were observed for the alcohol-related variables. The quantity of ethanol consumed was the most important factor in OC development rather than any individual type of alcoholic beverage, especially in smokers. Males and females consuming >53 g of ethanol per day had approximately 5-times greater odds in comparison to non-drinkers (males OR = 4.72, 95% CI 2.64–8.41; females OR = 5.24, 95% CI 3.34–8.23) and 8.5 greater odds in those who smoked >14 g tobacco daily. The attributable fractions for smoking and alcohol consumption were 58% and 48% respectively, 64% for both factors combined.ConclusionTobacco and alcohol use are major risk factors for OC development in this region.ImpactThis study provides evidence for further reinforcement of cessation of smoking and alcohol consumption to curb OC development.     

Case-control study of birth characteristics and the risk of hepatoblastoma

Background: Hepatoblastoma is a malignant embryonal tumor typically diagnosed in children younger than five years of age. Little is known on hepatoblastoma etiology. Methods: We matched California Cancer Registry records of hepatoblastomas diagnosed in children younger than age 6 from 1988 to 2007 to birth records using a probabilistic record linkage program, yielding 261 cases. Controls (n = 218,277), frequency matched by birth year to all cancer cases in California for the same time period, were randomly selected from California birth records. We examined demographic and socioeconomic information, birth characteristics, pregnancy history, complications in pregnancy, labor and delivery, and abnormal conditions and clinical procedures relating to the newborn, with study data taken from birth certificates. Results: We observed increased risks for hepatoblastoma among children with low [1500–2499 g, Odds Ratio (OR) = 2.02, 95% confidence interval (CI) 1.29–3.15] and very low birthweight (<1500 g, OR = 15.4, 95% CI 10.7–22.3), preterm birth <33 weeks (OR = 7.27, 95% CI 5.00, 10.6), small size for gestational age (OR = 1.75, 95% CI 1.25–2.45), and with multiple birth pregnancies (OR = 2.52, 95% CI 1.54–4.14). We observed a number of pregnancy and labor complications to be related to hepatoblastoma, including preeclampsia, premature labor, fetal distress, and congenital anomalies. Conclusion: These findings confirm previously reported associations with low birthweight and preeclampsia. The relation with multiple birth pregnancies has been previously reported and may indicate a relation to infertility treatments.     

Body mass index,height and early-onset basal cell carcinoma in a case-control study

IntroductionBasal cell carcinoma (BCC) is the most common malignancy in the US. Body mass index (BMI) and height have been associated with a variety of cancer types, yet the evidence regarding BCC is limited. Therefore, we evaluated BMI and height in relation to early-onset BCC (under age 40) and explored the potential role of ultraviolet (UV) radiation exposure and estrogen-related exposures in the BMI-BCC relationship.MethodsBCC cases (n = 377) were identified through a central dermatopathology facility in Connecticut. Control subjects (n = 389) with benign skin conditions were randomly sampled from the same database and frequency matched to cases on age (median = 36, interquartile range 33–39), gender, and biopsy site. Participants reported weight (usual adult and at age 18), adult height, sociodemographic, phenotypic, and medical characteristics, and prior UV exposures. We calculated multivariate odds ratios (ORs) and 95% confidence intervals (CIs) using unconditional logistic regression models.ResultsAdult BMI was inversely associated with early-onset BCC (obese vs. normal OR = 0.43, 95% CI = 0.26–0.71). A similar inverse association was present for BMI at age 18 (OR = 0.54, 95% CI = 0.34–0.85). Excluding UV exposures from the BMI models and including estrogen-related exposures among women only did not alter the association between BMI and BCC, indicating limited mediation or confounding. We did not observe an association between adult height and BCC (OR per cm = 1.00, 95% CI = 0.98–1.02).ConclusionsWe found a significant inverse association between BMI and early-onset BCC, but no association between height and BCC. This association was not explained by UV exposures or estrogen-related exposures in women.     

Childhood passive smoke exposure is associated with adult head and neck cancer

Introduction: Passive smoke is carcinogenic but its association with head and neck squamous cell carcinoma (HNSCC) is uncertain. Methods: We conducted a case-control study of childhood passive smoke exposure (CPSE) and HNSCC in 858 cases and 806 frequency-matched controls using an interviewer-administered questionnaire. Odds ratios (OR) and 95% confidence intervals (CI) were estimated with logistic regression controlling for adult smoking in the total study population, and in never-smokers only (184 cases and 415 controls). CPSE was also studied in oropharyngeal separately from other HNSCC using polytomous logistic regression. Results: CPSE was associated with HNSCC (OR, 1.28; 95% CI, 1.01–1.63) after controlling for adult smoking and other factors. This association was similar in magnitude, although not statistically significant, among subjects who never smoked as adults (OR, 1.19, 95% CI, 0.80–1.76). CPSE was associated more strongly with oropharyngeal cancer (a HNSCC subtype commonly associated with human papillomavirus (HPV) infection) than with HNSCC at non-oropharyngeal sites (OR, 2.02; 95% CI, 1.01–4.06, N = 52 cases vs. OR, 1.04; 95% CI, 0.68–1.60, N = 132 cases; P-for-heterogeneity = 0.08). Conclusions: Data from this large US-based case control study suggest a role for CPSE in HNSCC etiology.     

Metabolic syndrome in relation to Barrett⿿s esophagus and esophageal adenocarcinoma: Results from a large population-based case-control study in the Clinical Practice Research Datalink

Gastroesophageal reflux disease (GERD) causes local chronic inflammation that increases risks of Barrett⿿s esophagus (BE) and esophageal adenocarcinoma (EA), yet symptomatic GERD is absent in approximately half of all such patients. Obesity exacerbates GERD and is also a component of metabolic syndrome (MetS). We evaluated the hypothesis that MetS is a GERD-independent mechanism by which obesity is associated with increased risks of BE and EA using data from the UK Clinical Practice Research Datalink. BE cases (n = 10,215) and EA cases (n = 592) were each individually matched to five population controls based on age, sex, and general practice. MetS was defined as occurrence of at least three of the following: obesity, type 2 diabetes, hypertension, and high cholesterol. Odds ratios (OR) and 95% confidence intervals (CI) were estimated using conditional logistic regression. MetS was marginally associated with BE (OR = 1.12, 95%CI 1.00⿿1.25). Similar effects were found for the individual component factors of obesity, hypertension, and high cholesterol. History of GERD modified the association (P-_{effect modification} <1E⿿5), with the MetS-BE association confined to patients without a history of GERD (OR = 1.33, 95%CI 1.12⿿1.58). No association between MetS and risk of EA was detected in the main or stratified analyses. In this large population-based case-control study, individuals with MetS had a marginally increased risk of BE in the absence of GERD. The systemic inflammatory state (MetS) may represent a reflux-independent inflammatory pathway that increases the risk of BE. MetS did not increase risk of EA in this study population.     

Risk of malignant childhood germ cell tumors in relation to demographic,gestational, and perinatal characteristics

BackgroundChildhood germ cell tumors (GCTs) are a rare assortment of neoplasms, with mostly unknown etiology, that are believed to originate very early in life. Few studies have examined risk factors by histologic subtype, despite evidence of different risk profiles.Materials and methodsIn this population-based case-control study, 451 childhood malignant GCT cases ages 0–5 years were identified from the California Cancer Registry. Differentiating between common histologic subtypes, we identified 181 yolk sac tumors, 216 teratomas, and 54 rarer subtypes. Cases were linked to their birth certificates and 271,381 controls, frequency matched by birth year, were randomly selected from California birthrolls to investigate the contributions of demographic, gestational, and pregnancy factors using unconditional logistic regression analysis.ResultsCompared to non-Hispanic whites, Asian/Pacific Islander children were at an increased risk for developing GCTs (odds ratio [OR] = 1.94; 95% confidence interval [CI] = 1.47, 2.56). Among pregnancy complications and procedures, yolk sac tumors were positively associated with the presence of fetopelvic disproportion (OR = 2.97; 95% CI = 1.55, 5.68), while teratomas were strongly associated with polyhydramnios or oligohydramnios (OR = 14.76; 95% CI = 7.21, 30.19) and the presence of an ear, face, or neck anomaly at birth (OR = 93.70; 95% CI = 42.14, 208.82).ConclusionsMalignant yolk sac tumors and malignant teratomas exhibited distinct demographic and gestational characteristics; additionally, complications in pregnancy and labor may be brought on by specific histologic subtypes.     

High levels of plasma selenium are associated with metabolic syndrome and elevated fasting plasma glucose in a Chinese population: A case-control study

BackgroundSelenium is important for human health and involved in various metabolic processes. Deficiency of selenium associates with increased risk for cancer and cardiovascular diseases. There has been an increase use of selenium supplements for the treatment of autoimmune thyroid conditions. However, the potential biological effects of selenium overload arouse the public concern. The aim of this study was to investigate the associations of plasma selenium concentrations of adults with metabolic syndrome (MS) in Chinese population.MethodsA matched case-control study including 204 metabolic syndrome patients and 204 healthy controls was conducted in 2012. The MS cases were defined according to the criteria of Chinese Diabetes Society (CDS). Healthy controls without abnormality of metabolic components were matched with cases in age, gender and region. Plasma concentrations of selenium were determined by graphite furnace atomic absorption spectrometry (GFAAS). Fasting plasma glucose (FPG), total cholesterol (TC), triglycerides (TG), high density lipoprotein cholesterol (HDL), and low density lipoprotein cholesterol (LDL) were detected by automatic biochemical analyzer.ResultsThe median levels of plasma selenium in MS group were 146.3 (107.3–199.4) μg/L, which were significantly higher than that in the control group (127.4: 95.7–176.0) μg/L; Plasma levels of selenium were related to the risk of MS in dose-response manner. Risk of MS was significantly higher in subjects with plasma selenium in the highest tertile (T3: ≥176.0 μg/L) compared to those in the lowest tertile (T1: <95.7 μg/L) [odds ratio (OR) = 2.416 (95% CI: 1.289–4.526)]. The plasma levels of selenium were positively correlated with fasting plasma glucose (FPG) (r_s = 0.268, P < 0.001). Plasma selenium at the median (T2: 95.7–176.0 μg/L) or upper tertile (T3: ≥176.0 μg/L) was associated with increased risk of elevated FPG (defined by FPG ≥ 6.1 mmol/L) as compared with the lowest tertile (T1: ≤95.7 μg/L) [T2 vs. T1, OR = 3.487 (1.738–6.996); T3 vs. T1, OR = 6.245 (3.005–12.981)].ConclusionsHigher levels of plasma selenium might increase the risk of metabolic syndrome and elevated fasting plasma glucose. Selenium supplements should be used with prudence for CVD and cancer prevention.     

Polymorphisms of tumor-related genes IL-10, PSCA,MTRR and NOC3L are associated with the risk of gastric cancer in the Chinese Han population

BackgroundGastric cancer is the fourth most common cancer in the world. Environmental and genetic factors both play critical roles in the etiology of gastric cancer. Hundreds of SNPs have been identified to have association with the risk of gastric cancer in many races. In this study, 25 SNPs in genes for IL-10, IL-1B, MTRR, TNF-а, PSCA, PLCE1 and NOC3L were analyzed to further evaluate their associations with gastric cancer susceptibility in the Chinese Han population.MethodsTwo hundred and seventy nine gastric cancer patients and 296 healthy controls were recruited in this study. SNP genotyping was conducted using Sequenom MassARRAY RS1000. Data management and statistical analyses were conducted by Sequenom Typer 4.0 Software and Pearson's χ² test.ResultsOne protective allele and three risk alleles for gastric cancer patients were found in this study. The allele “G” of rs1801394 in MTRR showed an association with a decreased risk of gastric cancer: odds ratio (OR) = 0.74, 95% confidence interval (95% CI) = 0.57–0.97, P = 0.030 in the additive model; OR = 0.495, 95% CI = 0.26–0.95, P = 0.034 in the recessive model. The other three SNPs, the allele “C” of rs1800871 in IL10 (OR = 1.33, 95% CI = 1.04–1.90; P = 0.026 in the additive model; OR = 1.46, 95% CI = 1.04–2.06; P = 0.030 in the recessive model), the allele “A” of rs2976391 in PSCA (OR = 1.30, 95% CI = 1.01–1.66; P = 0.041 in the additive model and OR = 1.48, 95% CI = 1.04–2.11, P = 0.028 in the recessive model), and the allele “G” of rs17109928 in NOC3L gene (OR = 1.34, 95% CI = 1.01–1.78; P = 0.042 by additive model analysis; OR = 1.47, 95% CI = 1.04–2.07, P = 0.028 by dominant model analysis), showed an association with an increased risk of gastric cancer.ConclusionsThese results indicate the importance of four gastric cancer susceptibility polymorphisms of IL-10, NOC3L, PSCA and MTRR in the Chinese Han population, which could be used in the determination of gastric cancer risk in clinical practice.     

Hypomethylation of repetitive elements in blood leukocyte DNA and risk of gastric lesions in a Chinese population

BackgroundTo explore the association between hypomethylation of repetitive elements (LINE-1, Sat2, and ALU) in blood leukocyte DNA and risks of gastric lesions, and development of gastric cancer (GC), a population-based study was conducted in a high-risk area of GC in China.MaterialsMethylation levels were determined by MethyLight in 902 subjects with various gastric lesions from two cohort studies at baseline and 276 subjects with long-term follow-up data.ResultsThe frequency of LINE-1 or Sat2 hypomethylation was significantly increased in subjects with dysplasia (DYS) compared with superficial gastritis/chronic atrophic gastritis. The odds ratios (ORs) were 2.22 [95% confidence interval (CI): 1.45–3.40] for LINE-1 and 1.58 (95% CI: 1.14–2.21) for Sat2. A dose–response pattern was found for the risk of DYS and LINE-1 hypomethylation (P-trend < 0.001). Further stratified analysis indicated that the frequency of LINE-1 or Sat2 hypomethylation was higher in subjects with Helicobacter pylori infection. The ORs were 1.83 (95% CI: 1.12–2.99) for LINE-1 and 1.44 (95% CI: 1.01–2.05) for Sat2. The follow-up data indicated that the risk of progression to GC was increased in intestinal metaplasia (IM) subjects with LINE-1 hypomethylation (OR = 2.82; 95% CI: 1.17–6.77) or Sat2 hypomethylation (OR = 2.78; 95% CI: 1.15–6.74). The risk of progression to GC was also increased in DYS subjects with Sat2 hypomethylation (OR = 5.24; 95% CI: 2.00–13.74).ConclusionsThese findings suggest that hypomethylation of repetitive elements in blood leukocytes is associated with the risks of advanced gastric lesions and development of GC.