To investigate the potential role of vitamin or mineral supplementation on the risk of head and neck cancer (HNC), we analyzed individual-level pooled data from 12 case-control studies (7,002 HNC cases and 8,383 controls) participating in the International Head and Neck Cancer Epidemiology consortium. There were a total of 2,028 oral cavity cancer, 2,465 pharyngeal cancer, and 874 unspecified oral/pharynx cancer, 1,329 laryngeal cancer and 306 overlapping HNC cases. Odds ratios (OR) and 95% confidence intervals (CIs) for self reported ever use of any vitamins, multivitamins, vitamin A, vitamin C, vitamin E, and calcium, beta-carotene, iron, selenium, and zinc supplements were assessed. We further examined frequency, duration and cumulative exposure of each vitamin or mineral when possible and stratified by smoking and drinking status. All ORs were adjusted for age, sex, race/ethnicity, study center, education level, and pack-years of smoking, frequency of alcohol drinking and fruit/vegetable intake. A decreased risk of HNC was observed with ever use of vitamin C (OR=0.76, 95% CI=0.59-0.96) and with ever use of calcium supplement (OR=0.64, 95% CI=0.42-0.97). The inverse association with HNC risk was also observed for 10 or more years of vitamin C use (OR=0.72, 95% CI=0.54-0.97) and more than 365 tablets of cumulative calcium intake (OR=0.36, 95% CI=0.16-0.83), but linear trends were not observed for the frequency or duration of any supplement intake. We did not observe any strong associations between vitamin or mineral supplement intake and the risk of head and neck cancer.
vitamin supplement; mineral supplement; head and neck cancer
To clarify the role of previous lung diseases (chronic bronchitis, emphysema, pneumonia, and tuberculosis) in the development of lung cancer, the authors conducted a pooled analysis of studies in the International Lung Cancer Consortium. Seventeen studies including 24,607 cases and 81,829 controls (noncases), mainly conducted in Europe and North America, were included (1984–2011). Using self-reported data on previous diagnoses of lung diseases, the authors derived study-specific effect estimates by means of logistic regression models or Cox proportional hazards models adjusted for age, sex, and cumulative tobacco smoking. Estimates were pooled using random-effects models. Analyses stratified by smoking status and histology were also conducted. A history of emphysema conferred a 2.44-fold increased risk of lung cancer (95% confidence interval (CI): 1.64, 3.62 (16 studies)). A history of chronic bronchitis conferred a relative risk of 1.47 (95% CI: 1.29, 1.68 (13 studies)). Tuberculosis (relative risk = 1.48, 95% CI: 1.17, 1.87 (16 studies)) and pneumonia (relative risk = 1.57, 95% CI: 1.22, 2.01 (12 studies)) were also associated with lung cancer risk. Among never smokers, elevated risks were observed for emphysema, pneumonia, and tuberculosis. These results suggest that previous lung diseases influence lung cancer risk independently of tobacco use and that these diseases are important for assessing individual risk.
bronchitis; chronic; emphysema; lung diseases; lung neoplasms; meta-analysis; pneumonia; pulmonary disease; chronic obstructive; tuberculosis
The present study was designed to explore the association of angiotensin converting enzyme (ACE) gene insertion/deletion (I/D, rs4646994) polymorphism, plasma ACE activity, and circulating ACE mRNA expression with essential hypertension (EH) in a Chinese population. In addition, a new detection method for circulating ACE mRNA expression was explored.
The research was approved by the ethics committee of Zhejiang Provincial Center for Disease Prevention and Control. Written informed consent was obtained prior to the investigation. 221 hypertensives (cases) and 221 normotensives (controls) were interviewed, subjected to a physical examination, and provided blood for biochemical and genetic tests. The ACE mRNA expression was analyzed by real time fluorescent quantitative Reverse Transcription PCR (FQ-RT-PCR). We performed logistic regression to assess associations of ACE I/D genotypes, ACE activity, and ACE mRNA expression levels with hypertension.
The results of the multivariate logistic regression analysis showed that the additive model (ID, DD versus II) of the ACE genotype revealed an association with hypertension with adjusted OR of 1.43(95% CI: 1.04-1.97), and ACE ID genotype with adjusted OR of 1.72(95% CI: 1.01-2.92), DD genotype with adjusted OR of 1.94(95% CI: 1.01-3.73), respectively. In addition, our data also indicate that plasma ACE activity (adjusted OR was 1.13(95% CI: 1.08-1.18)) was significantly related to hypertension. However, the plasma ACE mRNA expressions were not different between the cases and controls.
ACE I/D polymorphism and ACE activity revealed significant influence on hypertension, while circulating ACE mRNA expression was not important factors associated with hypertension in this Chinese population. The detection of circulating ACE mRNA expression by FQ-RT-PCR might be a useful method for early screening and monitoring of EH.
Body-mass-index (BMI) has been inversely associated with lung and upper aerodigestive tract (UADT) cancers. However, only a few studies have assessed BMI change in adulthood in relation to cancer. To understand the relationship between BMI change and these cancers in both men and women, we analyzed data from a population-based case-control study conducted in Los Angeles County. Adulthood BMI change was measured as the proportional change in BMI between age 21 and one year prior to interview or diagnosis. Five categories of BMI change were included and individuals with no more than a 5% loss or gain were defined as having a stable BMI (reference group). Adjusted odds ratios (ORs) and their 95% confidence intervals (CIs) were estimated using logistic regression models. Potential confounders included age, gender, ethnicity, education, tobacco smoking, and energy intake. For UADT cancers, we also adjusted for alcohol drinking status and frequency. A BMI gain of 25% or higher in adulthood was inversely associated with lung cancer (OR 0.53, 95% CI 0.33-0.84) and UADT cancers (OR 0.44, 95% CI 0.27-0.71). In subgroup analyses, a BMI gain of ≥25% was inversely associated with lung and UADT cancers among current and former smokers, as well as among current and former alcohol drinkers. The inverse association persisted among moderate and heavy smokers (≥20 pack-years). The observed inverse associations between adulthood BMI gain and lung and UADT cancers indicate a potential role for body weight-related biological pathways in the development of lung and UADT cancers.
BMI; lung cancer; upper aerodigestive tract cancer; tobacco smoking; metabolism
Alcohol and tobacco consumption are well recognized risk factors for head and neck cancer (HNC). Evidence suggests that genetic predisposition may also play a role. Only a few epidemiologic studies, however, have considered the relation between HNC risk and family history of HNC and other cancers. We pooled individual- level data across 12 case-control studies including 8,967 HNC cases and 13,627 controls. We obtained pooled odds ratios (OR) using fixed and random effect models, and adjusting for potential confounding factors. All statistical tests were two-sided. A family history of HNC in first-degree relatives increased the risk of HNC (OR=1.7, 95% confidence interval, CI, 1.2-2.3). The risk was higher when the affected relative was a sibling (OR=2.2, 95% CI 1.6-3.1) rather than a parent (OR=1.5, 95% CI 1.1-1.8), and for more distal HNC anatomic sites (hypopharynx and larynx). The risk was also higher, or limited to, subjects exposed to tobacco. The OR rose to 7.2 (95% CI 5.5-9.5) among subjects with family history, who were alcohol and tobacco users. A weak but significant association (OR=1.1, 95% CI 1.0-1.2) emerged for family history of other tobacco-related neoplasms, particularly with laryngeal cancer (OR=1.3, 95% CI 1.1-1.5). No association was observed for family history of non-tobacco related neoplasms and the risk of HNC (OR=1.0, 95% CI 0.9-1.1). Familial factors play a role in the etiology of HNC. In both subjects with and without family history of HNC, avoidance of tobacco and alcohol exposure may be the best way to avoid HNC.
Head and neck cancer; family history; pooled analysis; tobacco; alcohol
We investigated the association between diet and head and neck cancer (HNC) risk using data from the International Head and Neck Cancer Epidemiology (INHANCE) Consortium. The INHANCE pooled data included 22 case-control studies with 14,520 cases and 22,737 controls. Center-specific quartiles among the controls were used for food groups and frequencies per week were used for single food items. A dietary pattern score combining high fruit and vegetable intake and low red meat intake, was created. Odds ratios (OR) and 95% confidence intervals (CI) for the dietary items on the risk of HNC were estimated with a two-stage random effects logistic regression model. An inverse association was observed for higher frequency intake of fruit (4th vs. 1st quartile OR=0.52, 95% CI=0.43–0.62, ptrend<0.01) and vegetables (OR=0.66, 95% CI=0.49–0.90, ptrend=0.01). Intake of red meat (OR=1.40, 95% CI=1.13–1.74, ptrend=0.13) and processed meat (OR=1.37, 95% CI=1.14–1.65, ptrend<0.01) were positively associated with HNC risk. Higher dietary pattern scores, reflecting high fruit/vegetable and low red meat intake, were associated with reduced HNC risk (per score increment OR=0.90, 95% CI=0.84–0.97).
Diet; head and neck cancer; fruit and vegetable; red meat; processed meat
Asthma has been hypothesized to be associated with lung cancer (LC) risk. We conducted a pooled analysis of 16 studies in the International Lung Cancer Consortium (ILCCO) to quantitatively assess this association and compared the results with 36 previously published studies. In total, information from 585 444 individuals was used. Study-specific measures were combined using random effects models. A meta-regression and subgroup meta-analyses were performed to identify sources of heterogeneity. The overall LC relative risk (RR) associated with asthma was 1.28 [95% confidence intervals (CIs) = 1.16–1.41] but with large heterogeneity (I2 = 73%, P < 0.001) between studies. Among ILCCO studies, an increased risk was found for squamous cell (RR = 1.69, 95%, CI = 1.26–2.26) and for small-cell carcinoma (RR = 1.71, 95% CI = 0.99–2.95) but was weaker for adenocarcinoma (RR = 1.09, 95% CI = 0.88–1.36). The increased LC risk was strongest in the 2 years after asthma diagnosis (RR = 2.13, 95% CI = 1.09–4.17) but subjects diagnosed with asthma over 10 years prior had no or little increased LC risk (RR = 1.10, 95% CI = 0.94–1.30). Because the increased incidence of LC was chiefly observed in small cell and squamous cell lung carcinomas, primarily within 2 years of asthma diagnosis and because the association was weak among never smokers, we conclude that the association may not reflect a causal effect of asthma on the risk of LC.
It is unknown whether the established risk factors for malignant melanoma in whites influence malignant melanoma risk in non-whites. We examined the risk factors for melanoma among 39,325 whites and 101,229 non-whites/multiracials (Japanese American [47.5%], Latino American [34.8%], Native Hawaiian [2.1%] and multiracial [15.6%], excluding African Americans) in the Multiethnic Cohort study. With an average follow-up of 12.7 years, 581 invasive malignant melanoma (IMM) and 412 melanoma in situ (MIS) cases were identified, of which 107 (IMM) and 74 (MIS) were among non-whites/multiracials. The relative risks (RRs) and 95% confidence intervals (CIs) were estimated by Cox proportional hazards models using days from cohort entry as the underlying time variable. Among non-white/multiracial males, location of IMM tumors differed from those of white males (p<0.001); and non-white/multiracial females were more likely to be diagnosed with later stage of disease (p<0.001). After adjusting for potential confounders, age at cohort entry, male sex, higher education, and sunburn susceptibility phenotypes were associated with an increased risk of invasive malignant melanoma in non-whites/multiracials (p<0.05). The risk estimates for age at cohort entry and lighter hair and eye color were greater in non-whites/multiracials than in whites (p-heterogeneity=0.062, 0.016, and 0.005, respectively). For MIS risk, RRs between whites and non-whites/multiracials also differed for study location and education (p-heterogeneity ≤ 0.015). In conclusion, similar to whites, age at cohort entry, male sex, and susceptibility to sunburn phenotypes may be predictive of malignant melanoma risk in non-white populations excluding African-Americans.
melanoma risk factors; non-whites
More than 30 prostate cancer (PCa) risk-associated loci have been identified in populations of European descent by genome-wide association studies (GWAS). We hypothesized that a subset of these loci may be associated with PCa risk in Chinese men. To test this hypothesis, 33 single nucleotide polymorphisms (SNPs), one each from the 33 independent PCa risk-associated loci reported in populations of European descent, were investigated for their associations with PCa risk in a case-control study of Chinese men (1,108 cases and 1,525 controls). We found that 11 of the 33 SNPs were significantly associated with PCa risk in Chinese men (P < 0.05). The reported risk alleles were associated with increased risk for PCa, with allelic odds ratios ranging from 1.12 to 1.44. The most significant locus was located on 8q24 Region 2 (rs16901979, P = 5.14×10−9) with a genome-wide significance (P < 10−8), and three loci reached the Bonferroni correction significance level (P < 1.52×10−3), including 8q24 Region 1 (rs1447295, P = 7.04×10−6), 8q24 Region 5 (rs10086908, P = 9.24×10−4), and 8p21 (rs1512268, P = 9.39×10−4). Our results suggest that a subset of the PCa risk-associated SNPs discovered by GWAS among men of European descent is also associated with PCa risk in Chinese men. This finding provides evidence of ethnic differences and similarity in genetic susceptibility to PCa. GWAS in Chinese men are needed to identify Chinese-specific PCa risk-associated SNPs.
A recent genome-wide association study has identified five new genetic variants for prostate cancer susceptibility in a Japanese population, but it is unknown whether these newly identified variants are associated with prostate cancer risk in other populations, including Chinese men. We genotyped these five variants in a case–control study of 1524 patients diagnosed with prostate cancer and 2169 control subjects from the Chinese Consortium for Prostate Cancer Genetics (ChinaPCa). We found that three of the five genetic variants were associated with prostate cancer risk (P = 4.33 × 10−8 for rs12653946 at 5p15, 4.43 × 10−5 for rs339331 at 6q22 and 8.42 × 10−4 for rs9600079 at 13q22, respectively). A cumulative effect was observed in a dose-dependent manner with increasing numbers of risk variant alleles (Ptrend = 2.58 × 10−13), and men with 5–6 risk alleles had a 2-fold higher risk of prostate cancer than men with 0–2 risk alleles (odds ratio = 2.26, 95% confidence interval = 1.78–2.87). Furthermore, rs339331 T allele was significantly associated with RFX6 and GPRC6A higher messenger RNA expression, compared with the C allele. However, none of the variants was associated with clinical stage, Gleason score or family history. These results provide further evidence that the risk loci identified in Japanese men also contribute to prostate cancer susceptibility in Chinese men.
A history of diabetes is associated with an increased risk of several types of cancers. Whether diabetes is a risk factor for head and neck cancer (HNC) has received little attention.
We pooled data from 12 case-control studies including 6,448 cases and 13,747 controls, and estimated odds ratios (OR) and 95% confidence intervals (CI) for the associations between diabetes and HNC, adjusted for age, education level, sex, race/ethnicity, study center, cigarette smoking, alcohol use and body mass index (BMI).
We observed a weak association between diabetes and the incidence of HNC overall (OR, 1.09; 95% CI, 0.95–1.24). However, we observed a modest association among never smokers (OR, 1.59; 95% CI, 1.22–2.07), and no association among ever smokers (OR, 0.96; 95% CI, 0.83–1.11); likelihood ratio test for interaction p=0.001.
A history of diabetes was weakly associated with HNC overall, but we observed evidence of effect modification by smoking status, with a positive association among those who never smoked cigarettes.
This study suggests that glucose metabolism abnormalities may be a HNC risk factor in subgroups of the population. Prospective studies incorporating biomarkers are needed to improve our understanding of the relationship between diabetes and HNC risk, possibly providing new strategies in the prevention of HNC.
head and neck cancer; head and neck squamous cell carcinoma; diabetes; INHANCE
Greater tobacco smoking and alcohol consumption and lower body mass index (BMI) increase odds ratios (OR) for oral cavity, oropharyngeal, hypopharyngeal and laryngeal cancers; however, there are no comprehensive sex-specific comparisons of ORs for these factors.
We analyzed 2,441 oral cavity (925 females and 1,516 males), 2,297 oropharynx (564 females and 1,733 males), 508 hypopharynx (96 females and 412 males) and 1,740 larynx (237 females and 1,503 males) cases from the INHANCE consortium of 15 head and neck cancer case-control studies. Controls numbered from 7,604 to 13,829 subjects, depending on analysis. Analyses fitted linear-exponential excess ORs models.
ORs were increased in underweight (<18.5 BMI) relative to overweight and obese categories (≥25 BMI) for all sites and were homogeneous by sex. ORs by smoking and drinking in females compared to males were significantly greater for oropharyngeal cancer (p<0.01 for both factors), suggestive for hypopharyngeal cancer (p=0.05 and p=0.06, respectively), but homogeneous for oral cavity (p=0.56 and p=0.64) and laryngeal (p=0.18 and p=0.72) cancers.
The extent that OR modifications of smoking and drinking by sex for oropharyngeal and, possibly, hypopharyngeal cancers represent true associations, or derive from unmeasured confounders or unobserved sex-related disease subtypes (e.g., human papillomavirus positive oropharyngeal cancer) remains to be clarified.
Alcohol consumption; cigarette smoking; interactions; odds ratio models
We examined the relationship of insulin-like growth factor-I (IGF-I) and its primary growth factor, IGF binding protein-3 (IGFBP-3) with malignant melanoma using interview data and sera from cases (n=286) and controls (n=289) in a population-based case-control study conducted in 1986–1992 on Oahu, Hawaii. Serum IGF-I and IGFBP-3 concentrations were measured by ELISA. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated by unconditional logistic regression and adjusted for age, sex, education, number of blistering sunburns, ability to tan, hair color, energy intake, BMI, height, smoking status, and drinking status. An inverse relationship was found between IGF-I concentration and melanoma (OR for upper vs. lower tertile: 0.44, 95% CI: 0.25–0.79), but clear associations were not observed between malignant melanoma and upper tertiles of IGFBP-3 and the IGF-1:IGFBP-3 molar ratio. The inverse association with IGF-I was strongest among subjects who did not report a history of non-melanoma skin cancer (NMSC) (OR for ≥ vs. < median: 0.39, 95% CI: 0.24–0.65), and a positive association was found among those with such a history (OR: 3.6, 95% CI: 1.0–13; pinteraction=0.0035). Our findings observed here between serum IGF-I and malignant melanoma warrants replication in studies with a larger sample size and a prospective design.
Malignant melanoma; insulin-like growth factor-I (IGF-I); insulin-like growth factor binding protein-3 (IGFBP-3)
Green tea has been found to possess anti-inflammatory, anti-oxidative and anti-carcinogenic properties. The present study examines the association between green tea drinking and hepatocellular carcinoma (HCC) and its interactions with other risk or protective factors and single nucleotide polymorphisms (SNP) of inflammation and oxidative stress related genes.
A population-based case-control study with 204 primary HCC cases and 415 healthy controls was conducted in Taixing, China. Epidemiological data were collected using a standard questionnaire. SNPs of genes of the inflammation and metabolic pathways were genotyped at the UCLA Molecular Epidemiology Laboratory. Logistic regression was performed to estimate adjusted odds ratios and 95% confidence intervals.
Longer duration and larger quantities of green tea consumption were inversely associated with primary HCC. Individuals who drank green tea longer than 30 years were at lowest risk (adjusted OR = 0.44, 95% CI: 0.19-0.96) compared with non-drinkers. A strong interaction was observed between green tea drinking and alcohol consumption (adjusted OR for interaction = 3.40, 95% CI: 1.26-9.16). Green tea drinking was also observed to have a potential effect modification on HBV/HCV infection, smoking and polymorphisms of inflammation related cytokines, especially for IL-10.
Green tea consumption may protect against development of primary HCC. Potential effect modifications of green tea on associations between primary HCC and alcohol drinking, HBV/HCV infection, and inflammation-related SNPs were suggested.
Green tea; Primary hepatocellular carcinoma; Inflammation; Alcohol
Ample studies suggest that the cyclooxygenase-2 (COX-2)/prostaglandin E2 (PGE2) pathway plays a pivotal role in carcinogenesis and that COX-2 inhibition may help prevent lung cancer. Therefore, we conducted a randomized, double-blind, placebo-controlled trial of the COX-2 selective inhibitor celecoxib (400 mg bid for 6 months) in former-smokers (age ≥45, ≥30 pack-years of smoking, ≥1 year of sustained abstinence from smoking). We assessed the impact of celecoxib on cellular and molecular events associated with lung cancer pathogenesis; the primary endpoint was bronchial Ki-67 labeling index (Ki-67 LI). Of 137 randomized subjects, 101 completed both baseline and 6-month bronchoscopies and were evaluable for the primary endpoint analysis. The beneficial effect on Ki-67 LI was greater in the celecoxib arm (versus placebo) in a mixed-effects analysis (P = 0.0006), and celecoxib significantly decreased Ki-67 LI by an average of 34%, whereas placebo increased Ki-67 LI by an average of 3.8% (P = 0.04; t-test). Participants crossed over to the other study arm at 6 months. Therefore, at 12 months all remaining participants had received 6 months of celecoxib, and their decreases in Ki-67 LI correlated with a reduction and/or resolution of lung nodules on computed tomography. Celecoxib significantly reduced plasma c-reactive protein and interleukin-6 mRNA and protein and increased 15(S)-hydroxy-eicosatetraenoic acid levels in BAL samples. The baseline ratio of COX-2 to 15-hydroxyprostaglandin dehydrogenase mRNA in bronchoalveolar lavage (BAL) cells was a significant predictive marker of Ki-67 response to celecoxib (P = 0.002). Our collective findings support the continued investigation of celecoxib for lung cancer chemoprevention in former smokers at a low risk of cardiovascular disease.
COX-2; 15-PGDH; PGE2; CRP; IL-6; 15-HETE
Hepatitis C virus (HCV)/human immunodeficiency virus (HIV) co-infection has become a serious public health problem especially in high risk groups such as injection drug users in China. However, the impact of HIV infection and antiretroviral therapy (ART) on HCV viral load which is usually regarded as a predictor of liver disease progress had not been well studied in this country.
To explore correlations of HIV co-infection and ART with plasma HCV load among HCV-infected patients in an ethnic minority area in Yunnan Province, China.
Patients and Methods
HCV/HIV co-infected patients and HCV mono-infected controls were examined and compared for plasma HCV RNA and related risk factors.
A total of 145 HCV/HIV co-infected patients and 25 HCV mono-infected controls were studied. The majority of the participants were male, belonged to an ethnic minority and were younger than 45 years old. HCV viral suppression rate with undetectable plasma HCV viral load was 28.3% in the HCV/HIV co-infected patients, 36% among HCV mono-infected controls and 29.4% overall. ART-prescribed HCV/HIV co-infected patients had significantly higher HCV viral loads (IQR: (3.80-6.44)*log10 copies ml-1) than those naïve to ART (IQR: (undetectable-6.41)*log10 copies ml-1) and HCV mono-infected patients (IQR: (undetectable-5.44)*log10 copies ml-1). Men, from the Dai minority and those with more than six years education, were also shown to have a higher plasma HCV viral load,according to multiple logistic regression analysis.
ART potentially increases the plasma HCV viral load among HCV/HIV coinfected patients in an ethnic minority area in China. Future large scale prospective cohort studies are needed to address the controversy associated between HIV co-infection and the natural history of HCV.
HIV; Coinfection; Antiretroviral therapy, Highly Active; Viral load
Sequence variants located at 15q25 have been associated with lung cancer and propensity to smoke. We recently reported an association between rs16969968 and risk of upper aerodigestive tract (UADT) cancers (oral cavity, oropharynx, hypopharynx, larynx and esophagus) in women (odds ratio (OR) =1.24, P=0.003) with little effect in men (OR=1.04, P=0.35).
In a coordinated genotyping study within the International Head and Neck Cancer Epidemiology (INHANCE) consortium, we have sought to replicate these findings in an additional 4,604 cases and 6,239 controls from 10 independent UADT cancer case-control studies.
rs16969968 was again associated with UADT cancers in women (OR=1.21, 95% confidence interval(CI)=1.08–1.36, P=0.001) and a similar lack of observed effect in men (OR=1.02, 95%CI=0.95–1.09, P=0.66) (P-heterogeneity=0.01). In a pooled analysis of the original and current studies, totaling 8,572 UADT cancer cases and 11,558 controls, the association was observed among females (OR=1.22, 95%CI=1.12–1.34, P=7×10−6) but not males (OR=1.02, 95%CI=0.97–1.08, P=0.35) (P-heterogeneity=6×10−4). There was little evidence for a sex difference in the association between this variant and cigarettes smoked per day, with male and female rs16969968 variant carriers smoking approximately the same amount more in the 11,991 ever smokers in the pooled analysis of the 14 studies (P-heterogeneity=0.86).
This study has confirmed a sex difference in the association between the 15q25 variant rs16969968 and UADT cancers.
Further research is warranted to elucidate the mechanisms underlying these observations.
genetic variants; 15q25; nicotinic acetylcholine receptor; upper aerodigestive tract cancers; cigarettes per day
We conducted a genome-wide association study on 969 bladder cancer cases and 957 controls from Texas. For fast-track validation, we evaluated 60 SNPs in three additional US populations and validated the top SNP in nine European populations. A missense variant (rs2294008) in the PSCA gene showed consistent association with bladder cancer in US and European populations. Combining all subjects (6,667 cases, 39,590 controls), the overall P-value was 2.14 × 10−10 and the allelic odds ratio was 1.15 (95% confidence interval 1.10–1.20). rs2294008 alters the start codon and is predicted to cause truncation of nine amino acids from the N-terminal signal sequence of the primary PSCA translation product. In vitro reporter gene assay showed that the variant allele significantly reduced promoter activity. Resequencing of the PSCA genomic region showed that rs2294008 is the only common missense SNP in PSCA. Our data identify rs2294008 as a new bladder cancer susceptibility locus.
Tobacco smoke and its metabolites are carcinogens that increase tissue oxidative stress and induce target tissue inflammation. We hypothesized that genetic variation of inflammatory pathway genes plays a role in tobacco-related carcinogenesis and is modified by tobacco smoking. We evaluated the association of 12 single nucleotide polymorphisms of eight inflammation-related genes with tobacco-related cancers (lung, oropharynx, larynx, esophagus, stomach, liver, bladder, and kidney) using three case-control studies from: Los Angeles (population-based; 611 lung and 553 upper aero-digestive tract cancer cases and 1,040 controls); Taixing, China (population-based; 218 esophagus, 206 stomach, 204 liver cancer cases, and 415 controls); and Memorial Sloan-Kettering Cancer Center (hospital-based; 227 bladder cancer cases and 211 controls). After adjusting for age, education, ethnicity, gender, and tobacco smoking, IL10 rs1800871 was inversely associated with oropharyngeal cancer (CT+TT versus CC adjusted odds ratio [aOR]: 0.69, 95% confidence interval [CI]: 0.50–0.95), and among never smokers was positively associated with lung cancer (TT versus CT+CC aOR: 2.5, 95% CI: 1.3–5.1) and inversely with oropharyngeal cancer (CT+TT versus CC aOR: 0.63, 95% CI: 0.41–0.95). Among all pooled never smokers (588 cases and 816 controls), TNF rs1799964 was inversely associated with smoking-related cancer (CC versus CT+TT aOR: 0.36, 95% CI: 0.17–0.77). Bayesian correction for multiple comparisons suggests that chance is unlikely to explain our findings (although epigenetic mechanisms may be in effect), which support our hypotheses, suggesting that IL10 rs1800871 is a susceptibility marker for oropharyngeal and lung cancers, and that TNF rs1799964 is associated with smoking-related cancers among never smokers.
IL10; TNF; single nucleotide polymorphisms; inflammation; tobacco-related cancer
The evidence for the human carcinogenic effects of alcohol drinking on the risk of cancers of the oral cavity and pharynx has been considered sufficient in the IARC Monograph 44 on alcohol and cancer in 1988. We evaluated human carcinogenic evidence related to oral and pharyngeal cancer risk based on cohort and case-control studies published from 1988 to 2009. A large body of evidence from epidemiological studies of different designs and conducted in different populations has consistently supported that alcohol consumption is strongly associated with an increase in risk of oral and pharyngeal cancer. The relative risks are 3.2–9.2 for more than 60 grams/day (or more than 4 drinks/day) when adjusted for tobacco smoking and other potential confounders. A strong dose-response relationship on intensity of alcohol use is reported in most of the studies. However, no apparent association is observed for the duration of alcohol use. Compared with current drinkers, a decreased risk is associated with alcohol cessation for about 10–15 years. Similar associations have been observed among non-smokers in over 20 studies. Generally, the dominant type of alcohol consumption in each population is associated with the greatest increases in risk. A large number of studies on joint exposure of alcohol and tobacco consumption demonstrate a more than multiplicative synergistic effect.
Alcohol Consumption; Oral Cavity; Pharynx; Neoplasm
Emerging preclinical data suggests that tea possess anticarcinogenic and antimutagenic properties. We therefore hypothesize that white tea extract (WTE) is capable of favorably modulating apoptosis, a mechanism associated with lung tumorigenesis.
We examined the effects of physiologically relevant doses of WTE on the induction of apoptosis in the nonsmall cell lung cancer (NSCLC) cell lines, A549 (adenocarcinoma) and H520 (squamous cell carcinoma) cells. We further characterized the molecular mechanisms responsible for the WTE-induced apoptosis, including the induction of PPAR-γ and the 15-lipoxygenase (15-LOX) signaling pathway.
We found that WTE was effective in inducing apoptosis in both A549 and H520 cells, and inhibition of PPAR-γ with GW 9662 partially reversed the WTE-induced apoptosis. We further demonstrate that WTE increased PPAR-γ activation and mRNA expression, concomitantly increased 15-HETE release, and up-regulated 15-LOX-1 and 2 mRNA expression by A549 cells. Inhibition of 15-LOX with NGDA, as well as caffeic acid, abrogated the WTE-induced PPAR-γ activation and up-regulation of PPAR-γ mRNA expression in A549 cells. WTE also induced cyclin-dependent kinase inhibitor 1A (CDKN1A) mRNA expression and activated caspase 3. Inhibition of caspase 3 abrogated the WTE-induced apoptosis.
Our findings indicate that WTE is capable of inducing apoptosis in NSCLC cell lines. The induction of apoptosis appears to be mediated, in part, through the up-regulation of the PPAR-γ and 15-LOX signaling pathways, with enhanced activation of caspase 3. Our findings support the future investigation of WTE as an antineoplastic and chemopreventive agent for lung cancer.
15-HETE; Caspase 3; chemoprevention
Background Head and neck cancer (HNC) risk is elevated among lean people and reduced among overweight or obese people in some studies; however, it is unknown whether these associations differ for certain subgroups or are influenced by residual confounding from the effects of alcohol and tobacco use or by other sources of biases.
Methods We pooled data from 17 case–control studies including 12 716 cases and the 17 438 controls. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated for associations between body mass index (BMI) at different ages and HNC risk, adjusted for age, sex, centre, race, education, tobacco smoking and alcohol consumption.
Results Adjusted ORs (95% CIs) were elevated for people with BMI at reference (date of diagnosis for cases and date of selection for controls) ≤18.5 kg/m2 (2.13, 1.75–2.58) and reduced for BMI >25.0–30.0 kg/m2 (0.52, 0.44–0.60) and BMI ≥30 kg/m2 (0.43, 0.33–0.57), compared with BMI >18.5–25.0 kg/m2. These associations did not differ by age, sex, tumour site or control source. Although the increased risk among people with BMI ≤18.5 kg/m2 was not modified by tobacco smoking or alcohol drinking, the inverse association for people with BMI > 25 kg/m2 was present only in smokers and drinkers.
Conclusions In our large pooled analysis, leanness was associated with increased HNC risk regardless of smoking and drinking status, although reverse causality cannot be excluded. The reduced risk among overweight or obese people may indicate body size is a modifier of the risk associated with smoking and drinking. Further clarification may be provided by analyses of prospective cohort and mechanistic studies.
BMI; head and neck cancer; smoking
Genome-wide association studies have identified three chromosomal regions at 15q25, 5p15, and 6p21 as being associated with the risk of lung cancer. To confirm these associations in independent studies and investigate heterogeneity of these associations within specific subgroups, we conducted a coordinated genotyping study within the International Lung Cancer Consortium based on independent studies that were not included in previous genome-wide association studies.
Genotype data for single-nucleotide polymorphisms at chromosomes 15q25 (rs16969968, rs8034191), 5p15 (rs2736100, rs402710), and 6p21 (rs2256543, rs4324798) from 21 case–control studies for 11 645 lung cancer case patients and 14 954 control subjects, of whom 85% were white and 15% were Asian, were pooled. Associations between the variants and the risk of lung cancer were estimated by logistic regression models. All statistical tests were two-sided.
Associations between 15q25 and the risk of lung cancer were replicated in white ever-smokers (rs16969968: odds ratio [OR] = 1.26, 95% confidence interval [CI] = 1.21 to 1.32, Ptrend = 2 × 10−26), and this association was stronger for those diagnosed at younger ages. There was no association in never-smokers or in Asians between either of the 15q25 variants and the risk of lung cancer. For the chromosome 5p15 region, we confirmed statistically significant associations in whites for both rs2736100 (OR = 1.15, 95% CI = 1.10 to 1.20, Ptrend = 1 × 10−10) and rs402710 (OR = 1.14, 95% CI = 1.09 to 1.19, Ptrend = 5 × 10−8) and identified similar associations in Asians (rs2736100: OR = 1.23, 95% CI = 1.12 to 1.35, Ptrend = 2 × 10−5; rs402710: OR = 1.15, 95% CI = 1.04 to 1.27, Ptrend = .007). The associations between the 5p15 variants and lung cancer differed by histology; odds ratios for rs2736100 were highest in adenocarcinoma and for rs402710 were highest in adenocarcinoma and squamous cell carcinomas. This pattern was observed in both ethnic groups. Neither of the two variants on chromosome 6p21 was associated with the risk of lung cancer.
In this international genetic association study of lung cancer, previous associations found in white populations were replicated and new associations were identified in Asian populations. Future genetic studies of lung cancer should include detailed stratification by histology.