Correspondence to: Xiao-Ou Shu, MD, PhD, Vanderbilt Epidemiology Center, 2525 West End Ave, Ste 600 (IMPH), Nashville, TN 37203-1738 (e-mail: email@example.com) and Yong-Bing Xiang, MD, MSc, Shanghai Cancer Institute, No. 25, Lane 2200, Xie Tu Road, Shanghai 200032, People’s Republic of China (e-mail: firstname.lastname@example.org).Background
Epidemiologic studies on the relationship between vitamin intake and liver cancer risk are sparse and inconsistent.
We evaluated vitamin intake from diet and supplements and risk of liver cancer in 132 837 women and men from China who were recruited into the Shanghai Women’s Health Study from 1997 to 2000 or the Shanghai Men’s Health Study from 2002 to 2006. In-person interviews, using a validated food-frequency questionnaire, were conducted to collect data on dietary habits. Follow-up consisted of in-person surveys and record linkage. Hazard ratios and 95% confidence intervals were estimated using Cox proportional hazard models with adjustment for potential confounders to compare liver cancer risk among participants with high vs low vitamin intake. All statistical tests were two-sided.
After excluding the first 2 years of follow-up, 267 participants (including 118 women and 149 men) developed liver cancer during an average of 10.9 (Shanghai Women’s Health Study) or 5.5 (Shanghai Men’s Health Study) years of follow-up. Dietary vitamin E intake was inversely associated with liver cancer risk (P
trend = .01), as was vitamin E supplement use (hazard ratio = 0.52, 95% confidence interval = 0.30 to 0.90). This association was consistent among participants with and without self-reported liver disease or a family history of liver cancer. Vitamin C and multivitamin use was associated with increased risk among participants with self-reported liver disease or family history of liver cancer, whereas intake of vitamin C and other vitamins from dietary sources was unrelated to liver cancer risk.
Vitamin E intake, either from diet or supplements, may reduce the risk of liver cancer.
Age at natural menopause (ANM) is a complex trait with high heritability and is associated with several major hormonal-related diseases. Recently, several genome-wide association studies (GWAS), conducted exclusively among women of European ancestry, have discovered dozens of genetic loci influencing ANM. No study has been conducted to evaluate whether these findings can be generalized to Chinese women.
We evaluated the index single nucleotide polymorphisms (SNPs) in 19 GWAS-identified genetic susceptibility loci for ANM among 3,533 Chinese women who had natural menopause. We also investigated 3 additional SNPs which were in LD with the index SNP in European-ancestry but not in Asian-ancestry populations. Two genetic risk scores (GRS) were calculated to summarize SNPs across multiple loci one for all SNPs tested (GRSall), and one for SNPs which showed association in our study (GRSsel). All 22 SNPs showed the same association direction as previously reported. Eight SNPs were nominally statistically significant with P≤0.05: rs4246511 (RHBDL2), rs12461110 (NLRP11), rs2307449 (POLG), rs12611091 (BRSK1), rs1172822 (BRSK1), rs365132 (UIMC1), rs2720044 (ASH2L), and rs7246479 (TMEM150B). Especially, SNPs rs4246511, rs365132, rs1172822, and rs7246479 remained significant even after Bonferroni correction. Significant associations were observed for GRS. Women in the highest quartile began menopause 0.7 years (P = 3.24×10−9) and 0.9 years (P = 4.61×10−11) later than those in the lowest quartile for GRSsel and GRSall, respectively.
Among the 22 investigated SNPs, eight showed associations with ANM (P<0.05) in our Chinese population. Results from this study extend some recent GWAS findings to the Asian-ancestry population and may guide future efforts to identify genetic determination of menopause.
To assess the associations between cruciferous vegetable (CV) intake, GST gene polymorphisms and colorectal cancer (CRC) in a population of Chinese men.
Using incidence density sampling, CRC cases (N = 340) diagnosed prior to December 31, 2010 within the Shanghai Men’s Health Study were matched to non-cases (N = 673). CV intake was assessed from a food frequency questionnaire and by isothiocyanate (ITC) levels from spot urine samples. GSTM1 and GSTT1 were categorized as null (0 copies) versus non-null (1 or 2 copies). Conditional logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (95% CIs) for the association between CV intake and GST gene variants with CRC and statistical interactions were evaluated.
CRC risk was not associated with CV intake, whether measured by self-report or by urinary ITC, nor with GST gene variants. No statistical interactions were detected between CV intake and GST gene variants on the odds of CRC. Stratifying by timing of urine sample collection and excluding CRC cases diagnosed in the first two years did not materially alter the results.
This study provides no evidence supporting the involvement of CV intake in the development of CRC in Chinese men.
brassicaceae; China; colorectal neoplasms; glutathione S-transferase M1; glutathione S-transferase T1; men
The observed associations of fruit and vegetable consumption with the risk of colorectal cancer have been inconsistent. Therefore, we aimed to evaluate the association of fruit and vegetable consumption with the risk of colorectal cancer within Chinese men.
61,274 male participants aged 40 to 74 years were included. A validated food frequency questionnaire was administered to collect information on usual dietary intake, including 8 fruits and 38 vegetables commonly consumed by residents of Shanghai. Follow-up for diagnoses of colon or rectal cancer were available through December 31, 2010. Dietary intakes were analyzed both as categorical (quintiles) and continuous variables. Multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (95% CIs) were calculated for colorectal, colon, and rectal cancer using Cox proportional hazards models.
After 390,688 person-years of follow-up, 398 cases of colorectal cancer (236 colon and 162 rectal) were observed in the cohort. Fruit consumption was inversely associated with the risk of colorectal cancer (5th vs. 1st quintile HR: 0.67; 95% CI: 0.48, 0.95; P trend = 0.03), whereas vegetable intake was not significantly associated with risk. The associations for sub-groups of fruits and legumes, but not other vegetable categories, were generally inversely associated with the risk of colon and rectal cancer.
Fruit intake was generally inversely associated with the risk of colorectal cancer while vegetable consumption was largely unrelated to risk among middle aged and older Chinese men.
Colorectal cancer; fruits; vegetables; cohort study; Chinese men
Despite a proposed protective effect of fish intake on the risk of cardiovascular disease, epidemiologic evidence on fish intake and mortality is inconsistent. We investigated associations of fish intake, assessed through a validated food frequency questionnaire, with risks of total and cause-specific mortality in 2 prospective cohort studies of 134,296 Chinese men and women (1997–2009). Vital status and date and cause of death were ascertained through annual linkage to the Shanghai Vital Statistics Registry database and biennial home visits. Cox regression was used to calculate hazard ratios and corresponding 95% confidence intervals. After excluding the first year of observation, the analysis included 3,666 deaths among women and 2,170 deaths among men. Fish intake was inversely associated with risks of total, ischemic stroke, and diabetes mortality; the corresponding hazard ratios for the highest quintiles of intake compared with the lowest were 0.84 (95% confidence interval (CI): 0.76, 0.92), 0.63 (95% CI: 0.41, 0.94), and 0.61 (95% CI: 0.39, 0.95), respectively. No associations with cancer or ischemic heart disease mortality were observed. Further analyses suggested that the inverse associations with total, ischemic stroke, and diabetes mortality were primarily related to consumption of saltwater fish and intake of long-chain n-3 fatty acids. Overall, our findings support the postulated health benefits of fish consumption.
China; diet; fish intake; men; mortality; stroke; women
Calcium has been implicated in carcinogenesis and linked to the risk of several cancers in epidemiologic studies; however, few studies have investigated the association of calcium intake with lung cancer risk, particularly among non-smokers.
We evaluated the association of intakes of calcium and related minerals, assessed through a food frequency questionnaire, with lung cancer risk among 71,267 female non-smokers who were cancer free at baseline in the Shanghai Women's Health Study, a population-based, prospective cohort study. Multivariate Cox regression was used to calculate hazard ratios (HR) and 95% confidence intervals (CI).
During follow-up through December 2009 (median follow-up time: 11.2 years), 428 incident lung cancer cases accrued. The median intakes of dietary calcium, magnesium, and phosphorus were 441, 266, and 935 mg/day, respectively. Intakes of calcium, phosphorus, and the calcium-to-magnesium (Ca:Mg) ratio were inversely associated with lung cancer risk. The corresponding HRs (95% CIs) for the highest compared with the lowest quartile were 0.66 (0.48, 0.91) for calcium, 0.55 (0.36, 0.85) for phosphorus, and 0.62 (0.47, 0.82) for the Ca:Mg ratio. No association was observed for dietary magnesium intake or the use of calcium- or vitamin D-containing supplements.
Conclusions and Impact
Our study provides some of the first evidence suggesting a possible role for increasing dietary calcium intake in lung cancer prevention among female non-smokers, especially in populations with relatively low calcium intake.
calcium; dietary intake; lung cancer; women; non-smokers
Type 2 diabetes mellitus (T2DM) is a prevalent chronic disease worldwide. The prevalence of T2DM is increasing rapidly in China. Understanding the contribution of modifiable lifestyle factors on T2DM risk is imperative to prevent the development of T2DM in China.
We examined associations between lifestyle factors including physical activity, smoking and alcohol consumption with incidence of T2DM among middle-aged and elderly men in urban Shanghai. Information on socio-demographics, lifestyle habits, dietary habits, and disease history was collected via in-person interviews. Anthropometric measurements were taken. A total of 51 464 Chinese men aged 40–74 years free of T2DM, coronary heart disease (CHD), and stroke at baseline were included in the current study. Incident T2DM was identified through follow-up surveys conducted every 2–3 years. Cox proportional hazard analyses were conducted to evaluate associations between lifestyle risk factors and incidence of T2DM.
We documented 1304 new cases of T2DM during 276 929 person-years of follow-up (average: 5.4 years). Physical activity was inversely associated with T2DM risk. Daily living, commuting, and total physical activity METs had inverse negative dose-response relationships with T2DM (P-trend = 0.0033, 0.0022, and <0.0001, respectively). Regular participation in exercise or sports reduced T2DM risk (HR = 0.86, 95%CI: 0.76–0.98). Moderate alcohol intake (1–3 drinks/day) was inversely related to T2DM risk (HR = 0.80, 95%CI: 0.67–0.94). Cigarette smoking, on the other hand, was associated with increased T2DM risk; HRs were 1.25 (95%CI: 1.00–1.56) for smoking more than 20 cigarettes per day and 1.28 (95%CI: 1.04–1.57) for smoking more than 40 pack-years.
Physical activity and moderate alcohol intake are inversely associated with T2DM risk, whereas smoking was positively associated with T2DM risk among middle-age and elderly Chinese men. Preventive measures should be developed to focus on these modifiable lifestyle habits to reduce the upward trend of T2DM.
Nine previously reported associations between single nucleotide polymorphisms (SNPs) and breast cancer outcomes from the Shanghai Breast Cancer Study (Stage 1) were further evaluated in relation to disease-free survival (DFS) and overall survival (OS) among 5,192 additional breast cancer patients (Stage 2).
Hazard ratios (HR) and 95% confidence intervals (CI) were calculated by proportional hazards regression in models adjusted for age, disease stage, estrogen and progesterone receptor status, and treatment regimens.
Two SNPs had generally consistent results and significant associations with OS in combined analyses. Compared to women with MMP7 rs11225297 AA genotypes, OS was moderately better for women with AT genotypes (HR: 0.8, 95% CI: 0.7-1.0) and much better for women with TT genotypes (HR: 0.4, 95% CI: 0.2-0.8). Compared to women with MMP8 rs11225395 CC genotypes, OS was slightly better for women with CT genotypes (HR: 0.9, 95% CI: 0.7-1.1) and moderately better for women with TT genotypes (HR: 0.6, 95% CI: 0.4-0.9). Joint analysis showed significant dose-response relationships with increasing numbers of rare alleles for both OS (p<0.001) and DFS (p=0.001)
A functional variant in MMP8 and a SNP in high linkage disequilibrium with a functional variant in MMP7 were significantly associated with breast cancer survival in a large two-stage survival study among Chinese women. This supports the hypothesis that SNPs in MMP genes may influence breast cancer prognosis; additional research on these and other SNPs in genes important in metastasis, angiogenesis, and the regulation of the tumor microenvironment is warranted.
breast cancer; survival; genetic variants; replication; matrix metalloproteinases
Little is known about the association of circulating 25-hydroxyvitamin D (25[OH]D) and blood pressure (BP) parameters, and hypertension in non-Western populations that have not yet been exposed to foods fortified with vitamins and seldom use vitamin D supplements. A cross-sectional analysis of plasma 25(OH)D levels in association with BP measures was performed for 1460 participants (405 men and 1055 women, aged 40–75 years) of two large cohort studies in Shanghai. Multivariable linear and logistic regressions were conducted. Overall, the prevalence of vitamin D deficiency was 55.8% using NHANES/USA criteria and 29.9% using WHO criteria. The median plasma 25(OH)D level was 38.0 nmol/L for men and 33.6 nmol/L for women (P<0.01) among subjects who were not on antihypertensive drugs. Among men, BP parameters (systolic BP, diastolic BP, and MAP) were significantly and inversely associated with higher quintiles of 25(OH)D compared with the lowest quintile (Ptrend <0.05 for all). Vitamin D non-deficient status (WHO criteria) was inversely associated with hypertension (ORadj =0.29, 95% CI: 0.10–0.82). An inverse association was also found between hypertension and the highest quintile of 25(OH)D (ORadj =0.16, 95% CI: 0.04–0.65 for ≥50.6 nmol/L; Ptrend =0.02). Among women, no significant associations were found for BP parameters and hypertension. The present study shows that vitamin D deficiency is common among adults in urban China. Circulating 25(OH)D levels were inversely related to levels of individual BP parameters and hypertension among middle-aged and elderly men but not in women. More research is needed to investigate the potential gender differential associations.
Blood pressure parameters; Hypertension; 25(OH)D; Gender; China
Most epidemiological studies evaluating the association of fruit and vegetable intakes on lung cancer risk were conducted in North American and European countries. We investigated the association of intakes of fruits, vegetables, dietary vitamins A and C, and folate with lung cancer risk among 61,491 Chinese adult men who were recruited to the Shanghai Men's Health Study, a population-based, prospective cohort study. Baseline dietary intake was assessed through a validated food frequency questionnaire during in-home visits. Multivariate Cox regression was used to estimate hazard ratios (HR) and 95% confidence intervals (CI) of lung cancer risk associated with dietary intakes. During a median follow-up of 5.5 years, 359 incident lung cancer cases accrued after the first year of follow-up and 68.8% of them were current smokers. Intakes of green leafy vegetables, β-carotene-rich vegetables, watermelon, vitamin A, and carotenoids were inversely associated with lung cancer risk; the corresponding HR (95% CI) comparing the highest with the lowest quartiles were 0.72 (0.53–0.98), 0.69 (0.51–0.94), 0.65 (0.47–0.90), 0.63 (0.44–0.88), and 0.64 (0.46–0.88). Intake of all fruits and vegetables combined was marginally associated with lower risk. Our study suggests that the consumption of carotenoid-rich vegetables is inversely associated with lung cancer risk.
fruits; vegetables; carotenoids; dietary intake; lung cancer; epidemiological
Vitamin D deficiency has been consistently associated with obesity. However, it is unclear whether vitamin D deficiency is the cause or consequence of obesity. We investigated this question by evaluating the association between genetic variants in vitamin D metabolism pathway genes and obesity-related traits. Using directly genotyped and imputed data from a genome-wide association (GWA) study of 6,922 women aged 25–70 years, we examined the association of 198 SNPs in vitamin D pathway genes (CYP27A1, CYP27B1, CYP24A1, CYP2R1, GC, and VDR) with body mass index (BMI) and body weight. Per allele beta (β) estimates were calculated for this association using linear regression models, controlling for age, square of age, menopausal status, and sample sets. Overall, only two SNPs (rs2248359 in CYP24A1 and rs10832313 in CYP2R1) had a nominally significant association with BMI and weight (P=0.02 for both) with no variation observed by menopausal status, physical activity, or dietary energy intake. None of the SNPs examined in the VDR gene were associated with BMI or weight. Our findings suggest that common genetic variations in vitamin D pathway genes do not play a major role in obesity among Chinese women.
genetic variants; body mass index; body weight; obesity; vitamin D pathway; genome-wide association study; women; China
The authors evaluated the prognostic effects of obesity and weight change after breast cancer diagnosis. A total of 5042 breast cancer patients aged 20–75 were identified through the population-based Shanghai Cancer Registry approximately 6 months after cancer diagnosis and recruited into the study between 2002 and 2006. Participants were followed by in-person interviews supplemented by record linkage with the Shanghai Vital Statistics Registry database. Anthropometric measurements were taken and information on sociodemographic, clinical, and lifestyle factors was collected through in-person interviews. During the median follow-up of 46 months, 442 deaths and 534 relapses/breast cancer-specific deaths were documented. Women with body mass index (BMI) ≥30 at diagnosis had higher mortality than women with 18.5≤BMI<25; the multivariate adjusted hazard ratios (HRs) were 1.55 (95% confidence interval (95% CI): 1.10–2.17) for total mortality and 1.44 (95% CI: 1.02–2.03) for relapse/disease-specific mortality. Similar results were found for pre- and post-diagnostic obesity. Women who gained ≥5kg or lost >1kg had higher mortality than those who maintained their weight. No association was observed between waist-to-hip ratio and mortality. Our study suggests that obesity and weight change after diagnosis are inversely associated with breast cancer prognosis. Weight control is important among women with breast cancer.
Body mass index; central obesity; weight change; breast cancer; survival
Few data are available regarding depression among Asian breast cancer survivors.
We estimated the prevalence of depression and its correlates among 1400 participants of a population-based cohort study of women with stage 0–IV breast cancer in Shanghai, China. Through in-person interviews conducted at 6 months and 18 months post-diagnosis and review of medical charts, information on sociodemographic and clinical factors and quality of life (QOL) were collected. Depression was measured by the 20-item Center for Epidemiologic Studies Depression Scale 18 months after diagnosis.
Approximately 26% of participants had mild to severe depression and 13% fulfilled the criteria of clinical depression at 18 months post-diagnosis. Women with lower income were more likely to have depression than those with higher income (prevalence: 16.6% vs. 6.9% for mild depression and 17.1% vs. 5.5% for clinical depression, respectively). Depression was more common among women who were widowed (18.9%) or divorced/separated/single (16.4%) than those who were married (11.8%). Women with comorbidity were more likely to have clinical depression (17.3% vs 11.2%). Multivariate analysis showed that low income, marital status, comorbidity, and low QOL scores were independent predictors for depression. We did not find that prevalence of depression differed by menopausal status, estrogen or progesterone receptor status, disease stage, or cancer-related treatments.
Depression is common among Asian women with breast cancer. Routine screening and prevention of depression are warranted among women with breast cancer.
depression; breast cancer; prevalence; risk factor
In a population-based cohort study of 5014 women with stage 0–III breast cancer, we evaluated weight change patterns from diagnosis to 6, 18, and 36 months post-diagnosis. Patients were recruited to the study approximately 6 months after cancer diagnosis between 2002 and 2006 and followed through 36 months post-diagnosis. The medians of weight change from diagnosis to 6, 18, and 36 months post-diagnosis were 1.0 kg, 2.0 kg, and 1.0 kg, respectively. Approximately 26% of survivors gained ≥5% of their at-diagnosis body weight during the first 6 months after diagnosis, while 37% and 33% of women gained the same percentage of weight at 18 and 36 months post-diagnosis. More weight gain was observed among women who had a more advanced disease stage, were younger, had lower body mass index at diagnosis, were premenopausal, or received chemotherapy or radiotherapy during the first 6 months after cancer diagnosis. Multivariate analyses indicated that age at diagnosis, body size, comorbidity, and disease stage independently predicted weight gain from diagnosis to 36 months post-diagnosis. In summary, weight gain is common over the first 3 years after breast cancer diagnosis among Chinese women. More research is needed to investigate measures to prevent weight gain in breast cancer survivors.
weight change pattern; breast cancer; survivor; Chinese population
The effects of diet on breast cancer are controversial and whether the effects vary with hormone receptor status has not been well investigated. This study evaluated the associations of dietary factors with risk for breast cancer overall and by hormone receptor status of tumors among Chinese women.
The Shanghai Breast Cancer Study, a large, population-based, case-control study, enrolled 3,443 cases and 3,474 controls in 1996–1998 (phase I) and 2002–2004 (phase II); 2,676 cases had ER and PR data. Dietary intake was assessed using a validated, quantitative, food frequency questionnaire (FFQ). Odds ratios (ORs) and 95% confidence intervals (95% CI) were derived from multivariate, polychotomous, unconditional logistic regression models.
Total vegetable intake was inversely related to breast cancer risk, with an adjusted OR for the highest quintile of 0.80 (95% CI = 0.67–0.95; P trend=0.02). Reduced risk was also related to high intake of allium vegetables (P trend = 0.01) and fresh legumes (P trend = 0.0008). High intake of citrus fruits and rosaceae fruits were inversely associated with breast cancer risk (P trend = 0.003 and P trend = 0.004, respectively), although no consistent association was seen for total fruit intake. Elevated risk was observed for all types of meat and fish intake (all P trend <0.05), while intakes of eggs and milk were associated with a decreased risk of breast cancer (both P trend <0.05). There was little evidence that associations with dietary intakes varied across the four tumor subtypes or between ER+/PR+ and ER−/PR− tumors (P for heterogeneity >0.05).
Our results suggest that high intake of total vegetables, certain fruits, milk, and eggs may reduce the risk of breast cancer, while high consumption of animal-source foods may increase risk. The dietary associations did not appear to vary by ER/PR status.
Experimental and epidemiological evidence have suggested that chronic inflammation may play a critical role in endometrial carcinogenesis.
To investigate this hypothesis, a two-stage study was carried out to evaluate single nucleotide polymorphisms (SNPs) in inflammatory pathway genes in association with endometrial cancer risk. In stage 1, 64 candidate pathway genes were identified and 4,542 directly genotyped or imputed SNPs were analyzed among 832 endometrial cancer cases and 2,049 controls, using data from the Shanghai Endometrial Cancer Genetics Study. Linkage disequilibrium of stage 1 SNPs significantly associated with endometrial cancer (P<0.05) indicated that the majority of associations could be linked to one of 24 distinct loci. One SNP from each of the 24 loci was then selected for follow-up genotyping. Of these, 21 SNPs were successfully designed and genotyped in stage 2, which consisted of ten additional studies including 6,604 endometrial cancer cases and 8,511 controls.
Five of the 21 SNPs had significant allelic odds ratios and 95% confidence intervals as follows: FABP1, 0.92 (0.85-0.99); CXCL3, 1.16 (1.05-1.29); IL6, 1.08 (1.00-1.17); MSR1, 0.90 (0.82-0.98); and MMP9, 0.91 (0.87-0.97). Two of these polymorphisms were independently significant in the replication sample (rs352038 in CXCL3 and rs3918249 in MMP9). The association for the MMP9 polymorphism remained significant after Bonferroni correction and showed a significant association with endometrial cancer in both Asian- and European-ancestry samples.
These findings lend support to the hypothesis that genetic polymorphisms in genes involved in the inflammatory pathway may contribute to genetic susceptibility to endometrial cancer.
This study adds to the growing evidence that inflammation plays an important role in endometrial carcinogenesis.
endometrial cancer; inflammation; genetic risk variants; meta-analysis
Obesity is associated with circulating levels of adiponectin and leptin and endometrial cancer risk. Little is known about whether single nucleotide polymorphisms (SNPs) in the genes that encode adiponectin (ADIPOQ), leptin (LEP), adiponectin receptor 1 (ADIPOR1), adiponectin receptor 2 (ADIPOR2), and leptin receptor (LEPR) are associated with endometrial cancer.
We selected 87 tagging SNPs to capture common genetic variants in these five genes. These SNPs were evaluated in 1,028 endometrial cancer cases and 1,932 community controls recruited from Chinese women. Logistic regression models were used to estimate odds ratios (ORs) and 95% confidence intervals (95% CIs).
Three of the 10 SNPs evaluated in the ADIPOQ gene were significantly associated with reduced cancer risk. The OR for women homozygous for the minor allele (A/A) for rs3774262 was 0.68 (95% CI: 0.48-0.97) compared with women homozygous for the major allele (G/G). Similar results were found for SNPs rs1063539 and rs12629945 in ADIPOQ, which were in linkage disequilibrium with rs3774262. These associations became non-significant after Bonferroni correction was applied. Controls with the minor allele A at rs3774262 had lower weight, waist circumference, hip circumference, and BMI than controls with the major allele G (all P<0.05). Women homozygous for the minor allele (T/T) of rs2071045 in the LEP gene also had significantly lower risk (OR=0.70 (0.54-0.90)) than women homozygous for the major allele (C/C). No other SNPs in the LEP, ADIPOR1, ADIPOR2, or LEPR genes were found to be associated with cancer risk.
Although a chance finding cannot be ruled out, the consistency of findings for gene-endometrial cancer risk and gene-obesity measurements suggests that genetic polymorphisms in the ADIPOQ genes may play a role in endometrial cancer development.
adipokine; adiponectin; leptin; polymorphism; obesity; endometrial cancer
Only two genome-wide association studies (GWAS) have been conducted to date to identify potential markers for total mortality after diagnosis of breast cancer. Here we report the identification of two SNPs associated with total mortality from a two-stage GWAS conducted among 6,110 Shanghai-resident Chinese women with TNM stage I-IV breast cancer. The discovery stage included 1,950 patients and evaluated 613,031 common SNPs. The top 49 associations were evaluated in an independent replication stage of 4,160 Shanghai breast cancer patients. A consistent and highly significant association with total mortality was documented for SNPs rs3784099 and rs9934948. SNP rs3784099, located in the RAD51L1 gene, was associated with total morality in both the discovery stage (P=1.44×10−8) and replication stage (P=0.06; P-combined=1.17×10−7). Adjusted hazard ratios (HR) for total mortality were 1.41 (95%CI=1.18–1.68) for the AG genotype and 2.64 (95%CI=1.74–4.03) for the AA genotype, when compared with the GG genotype. The variant C allele of rs9934948, located on chromosome 16, was associated with a similarly elevated risk of total mortality (P-combined: 5.75×10−6). We also observed this association among 1,145 breast cancer patients of European-ancestry from the Nurses’ Health Study (NHS; P=0.006); the association was highly significant in a combined analysis of NHS and Chinese data (P=1.39×10−7). Similar associations were observed for these two SNPs with breast cancer-specific mortality. This study provides strong evidence suggesting that the RAD51L1 gene and a chromosome 16 locus influence breast cancer prognosis.
breast cancer; survival; genome-wide association study; Asian population; RAD51L1 gene
Genome-wide association studies (GWAS) have identified over 100 genetic loci for various cancers. However, only one is for endometrial cancer.
We conducted a three-stage GWAS including 8,492 endometrial cancer cases and 16,596 controls. After analyzing 585,963 SNPs in 832 cases and 2,682 controls (Stage 1) from the Shanghai Endometrial Cancer Genetics Study, we selected the top 106 SNPs for in silico replication among 1,265 cases and 5,190 controls from the Australian/British Endometrial Cancer GWAS (Stage 2). Nine SNPs showed results consistent in direction with Stage 1 with P<0.1. These 9 SNPs were investigated among 459 cases and 558 controls (Stage 3a) and 6 SNPs showed a direction of association consistent with Stages 1 and 2. These 6 SNPs, plus 2 additional SNPs selected based on linkage disequilibrium (LD) and P values in Stage 2, were investigated among 5,936 cases and 8,166 controls from an additional 11 studies (Stage 3b).
SNP rs1202524, near the CAPN9 gene on chromosome 1q42.2, showed a consistent association with endometrial cancer risk across all three stages, with odds ratios (OR) of 1.09 (95% CI: 1.03–1.16) for the A/G genotype and 1.17 (95% CI: 1.05–1.30) for the G/G genotype (P=1.6 × 10−4 in combined analyses of all samples). The association was stronger when limited to the endometrioid subtype, with ORs (95% CI) of 1.11 (1.04–1.18) and 1.21 (1.08–1.35), respectively (P=2.4 × 10−5).
Chromosome 1q42.2 may host an endometrial cancer susceptibility locus.
This study identified a potential genetic locus for endometrial cancer risk.
Obesity is a well-established risk factor for endometrial cancer, the most common gynecologic malignancy. Recent genome-wide association studies (GWAS) have identified multiple genetic markers for obesity. The authors evaluated the association of obesity-related single nucleotide polymorphisms (SNPs) with endometrial cancer using GWAS data from their recently completed study, the Shanghai Endometrial Cancer Genetics Study, which comprised 832 endometrial cancer cases and 2,049 controls (1996–2005). Thirty-five SNPs previously associated with obesity or body mass index (BMI; weight (kg)/height (m)2) at a minimum significance level of ≤5 × 10−7 in the US National Human Genome Research Institute's GWAS catalog (http://genome.gov/gwastudies) and representing 26 unique loci were evaluated by either direct genotyping or imputation. The authors found that for 22 of the 26 unique loci tested (84.6%), the BMI-associated risk variants were present at a higher frequency in cases than in population controls (P = 0.0003). Multiple regression analysis showed that 9 of 35 BMI-associated variants, representing 7 loci, were significantly associated (P ≤ 0.05) with the risk of endometrial cancer; for all but 1 SNP, the direction of association was consistent with that found for BMI. For consistent SNPs, the allelic odds ratios ranged from 1.15 to 1.29. These 7 loci are in the SEC16B/RASAL, TMEM18, MSRA, SOX6, MTCH2, FTO, and MC4R genes. The associations persisted after adjustment for BMI, suggesting that genetic markers of obesity provide value in addition to BMI in predicting endometrial cancer risk.
body mass index; endometrial neoplasms; genetics; genome-wide association study; obesity; risk factors
Previous studies evaluating the association of vitamin D related genetic variants with breast cancer risk have produced inconsistent results.
We evaluated the association between breast cancer risk and of 559 SNPs in 12 vitamin D-related genes, including 6 genes associated with circulating 25(OH)D level identified by recent genome-wide association studies (GWAS) using directly observed and imputed GWAS genotyping data from 2,919 breast cancer cases and 2,323 controls recruited in the Shanghai Breast Cancer Study (SBCS).
Of the studied SNPs, only rs12570116 in ACADSB, rs10902845 in C10orf88, rs4760658 in VDR, and rs6091822, rs8124792 and rs6097809 in CYP24A1 had a nominal association with breast cancer risk (P value <0.05 for all). None of these association persisted after adjustment for multiple comparisons. The most extensively studied SNPs including rs10735810, also known as rs2228570 (Fok1, VDR), rs1544410 (Bsm1, VDR), and rs2296241 (CYP24A1) were not associated with breast cancer risk. GWAS-identified genetic variants that were associated with 25(OH)D were also not related to breast cancer risk.
Our data suggest that genetic polymorphisms in vitamin D-related genes do not play a major role in breast cancer risk in Chinese women.
Although our study confirms previously documented breast cancer risk-factor associations, our null results suggest that common genetic variants in vitamin D genes and loci associated with control of vitamin D levels are not risk factors for breast cancer in Chinese women. Our data contributes to filling the gap in this field of research.
breast cancer; risk; polymorphisms; vitamin D pathway genes; 25(OH)D; GWAS
Etiologic differences between subtypes of breast cancer defined by estrogen receptor (ER) and progesterone receptor (PR) status are not well understood. The authors evaluated associations of hormone-related factors with breast cancer subtypes in a population-based case-control study involving 1,409 ER-positive (ER+)/PR-positive (PR+) cases, 712 ER-negative (ER−)/PR-negative (PR−) cases, 301 ER+/PR− cases, 254 ER−/PR+ cases, and 3,474 controls aged 20–70 years in Shanghai, China (phase I, 1996–1998; phase II, 2002–2005). Polytomous logistic regression and Wald tests for heterogeneity across subtypes were conducted. Breast cancer risks associated with age at menarche, age at menopause, breastfeeding, age at first livebirth, waist-to-hip ratio, and oral contraceptive use did not differ by hormone receptor status. Among postmenopausal women, higher parity (≥2 children vs. 1) was associated with reduced risk (odds ratio (OR) = 0.69, 95% confidence interval (CI): 0.52, 0.91) and higher body mass index (BMI; weight (kg)/height (m)2) with increased risk (highest quartile: OR = 2.40, 95% CI: 1.65, 3.47) of the ER+/PR+ subtype but was unrelated to the ER−/PR− subtype (for parity, Pheterogeneity = 0.02; for BMI, Pheterogeneity < 0.01). Hormone replacement therapy (OR = 2.25, 95% CI: 1.40, 3.62) and alcohol consumption (OR = 1.59, 95% CI: 1.01, 2.51) appeared to be preferentially associated with the ER+/PR− subtype. These findings indicate that BMI, parity, hormone replacement therapy, and alcohol consumption may play different roles in subtypes of breast cancer. More research is needed to better understand the etiology of 2 relatively rare subtypes, ER+/PR− tumors and ER−/PR+ tumors.
breast neoplasms; China; hormones; receptors, estrogen; receptors, progesterone; risk factors; women
Multiple genetic loci associated with obesity or body mass index (BMI) have been identified through genome-wide association studies conducted predominantly in populations of European ancestry. We conducted a meta-analysis of associations between BMI and approximately 2.4 million SNPs in 27,715 East Asians, followed by in silico and de novo replication in 37,691 and 17,642 additional East Asians, respectively. We identified ten BMI-associated loci at the genome-wide significance level (P<5.0×10−8), including seven previously identified loci (FTO, SEC16B, MC4R, GIPR/QPCTL, ADCY3/RBJ, BDNF, and MAP2K5) and three novel loci in or near the CDKAL1,PCSK1, and GP2 genes. Three additional loci nearly reached the genome-wide significance threshold, including two previously identified loci in the GNPDA2 and TFAP2B genes and a new locus near PAX6, which all had P<5.0×10−7. Findings from this study may shed light on new pathways involved in obesity and demonstrate the value of conducting genetic studies in non-European populations.
It has been suggested that exercise following breast cancer diagnosis is inversely associated with mortality. However, controversy exists regarding the causality of such associations. We evaluated associations of exercise after breast cancer diagnosis with total mortality and recurrence/disease-specific mortality after accounting for conditions that restrict exercise participation. The analysis included 4826 women with stage I–III breast cancer identified 6 months after diagnosis through the population-based Shanghai Cancer Registry and recruited into the study between 2002 and 2006. Exercise was assessed approximately 6, 18, and 36 months post-diagnosis and metabolic equivalent (MET) scores were derived. Information on medical history, cancer diagnosis, treatments, quality of life (QOL), anthropometrics, and lifestyles were obtained by in-person interviews at 6 months post-diagnosis. Medical charts were abstracted to verify clinical information. During the median follow-up of 4.3 years, 436 deaths and 450 recurrences/cancer-related deaths were documented. After adjustment for QOL, clinical prognostic factors, and other covariates, exercise during first 36 months post-diagnosis was inversely associated with total mortality and recurrence/disease-specific mortality with hazard ratios of 0.70 (95% confidence interval (CI): 0.56–0.88) and 0.60 (95% CI: 0.47–0.76), respectively. Significant dose-response relationships between total and recurrence/disease-specific mortality rates and exercise duration and MET scores were observed (all Ptrend<0.05). The exercise-mortality associations were not modified by menopausal status, comorbidity, QOL, or body size assessed approximately 6 months post-diagnosis. An interaction between disease stage and hormone receptor status and total mortality was noted. Our study suggests that exercise after breast cancer diagnosis may improve overall and disease-free survival.
breast cancer; exercise; quality of life; survival
The After Breast Cancer Pooling Project was established to examine the role of physical activity, adiposity, dietary factors, supplement use, and quality of life (QOL) in breast cancer prognosis. This paper presents pooled and harmonized data on post-diagnosis lifestyle factors, clinical prognostic factors, and breast cancer outcomes from four prospective cohorts of breast cancer survivors (three US-based and one from Shanghai, China) for 18,314 invasive breast cancer cases diagnosed between 1976 and 2006. Most participants were diagnosed with stage I-II breast cancer (84.7%). About 60% of breast tumors were estrogen receptor (ER)+/progesterone receptor (PR)+; 21% were ER−/PR−. Among 8,118 participants with information on HER-2 tumor status, 74.8% were HER-2− and 18.5% were HER-2+. At 1–2 years post-diagnosis (on average) 17.9% of participants were obese (BMI ≥30 kg/m2), 32.6% were overweight (BMI 25–29 kg/m2) and 59.9% met the 2008 Physical Activity Guidelines for Americans (≥ 2.5 hours per week of moderate activity). During follow-up (mean=8.4 years), 3,736 deaths (2,614 from breast cancer), and 3,564 recurrences have been documented. After accounting for differences in year of diagnosis and timing of post-diagnosis enrollment, five-year overall survival estimates were similar across cohorts. This pooling project of 18,000 breast cancer survivors enables the evaluation of associations of post-diagnosis lifestyle factors, QOL, and breast cancer outcomes with an adequate sample size for investigation of heterogeneity by hormone-receptor status and other clinical predictors. The project sets the stage for international collaborations for the investigation of modifiable predictors for breast cancer outcomes.
Breast neoplasm; Survival; Recurrence; Life style