Progress on development and application of the diet-related inflammatory index in cancer epidemiological studies / 中华流行病学杂志

Cancer is a major public health problem worldwide, causing an more serious burden of disease. Inflammation is considered a predisposing factor for cancer with close relationship with its incidence. In recent years, the public and epidemiologists has paid more attention to the association between nutrition and cancer and other chronic diseases in the perspective of inflammation. This paper summarizes the development and application of the diet-related inflammatory index in cancer epidemiological studies based on the literature retrieval of common diet-related inflammatory index. Firstly, we highlight the common diet-related inflammatory indices and their construction methods, such as the Dietary Inflammatory Index, a literature-derived diet-related inflammatory index, and the Empirical Dietary Inflammatory Index, an empirically derived diet-related inflammatory index, and so on. Secondly, the epidemiological research progress on the commonly used diet-related inflammatory indices is briefly introduced. Finally, the advantages and disadvantages of the two types of this inflammatory indices are also briefly described for the purpose of providing reference for nutrition epidemiological studies of cancer and other chronic diseases in China.

Statistical methods for relative risk estimation and applications in case-cohort study / 中华流行病学杂志

Objective: To systematically introduce the design of case-cohort study and the statistical methods of relative risk estimation and their application in the design. Methods: First, we introduced the basic principles of case-cohort study design. Secondly, Prentice's method, Self-Prentice method and Barlow method were described in the weighted Cox proportional hazard regression models in detail, finally, the data from the Shanghai Women's Health Study were used as an example to analyze the association between obesity and liver cancer incidence in the full cohort and case-cohort sample, and the results of parameters from each method were compared. Results: Significant association was observed between obesity and risk for liver cancer incidence in women in both the full cohort and the case-cohort sample. In the Cox proportional hazard regression model, the partial regression coefficients of the full cohort and the case-cohort sample fluctuated with the adjustment of confounding factors, but the hazard ratio estimates of them were close. There was a difference in the standard error of the partial regression coefficient between the full cohort and the case-cohort sample. The standard error of the partial regression coefficient of the case-cohort sample was larger than that of the full cohort, resulting in a wider 95% confidence interval of the relative risk. In the weighted Cox proportional hazard regression model, the standard error of the partial regression coefficient of Prentice's method was closer to the parameter estimates from full cohort than Self-Prentice method and Barlow method, and the 95% confidence interval of hazard ratio was closer to that of the full cohort. Conclusions: Case-cohort design could yield parameter results closer to the full cohort by collecting and analyzing data from sub-cohort members and patients with the disease, and reduce sample size and improve research efficiency. The results suggested that Prentice's method would be preferred in case-cohort design.

Dietary antioxidants and common cancers： evidence from epidemiological studies / 上海预防医学

Cancer causes a considerable disease burden in countries all over the world. Numerous epidemiological evidences suggest that dietary antioxidants are closely related to the incidence， mortality and prognosis of cancer. For example， many antioxidants in fresh vegetables， fruits and legumes have beneficial effects in preventing some common cancers and improving patient survival. Based on our relevant research experience and reported studies from home and abroad， this paper summarizes the results of various epidemiological studies on the association between dietary antioxidants and cancer. Healthy diet education should be conducted in general population for cancer prevention and control.

Diabetes Medication Use in Association with Survival among Patients of Breast, Colorectal, Lung, or Gastric Cancer / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: Studies suggest that regular use of metformin may decrease cancer mortality. We investigated the association between diabetes medication use and cancer survival. MATERIALS AND METHODS: The current study includes 633 breast, 890 colorectal, 824 lung, and 543 gastric cancer cases identified from participants of two population-based cohort studies in Shanghai. Information on diabetes medication use was obtained by linking to electronic medical records. The associations between diabetes medication use (metformin, sulfonylureas, and insulin) and overall and cancer-specific survival were evaluated using time-dependent Cox proportional hazards models. RESULTS: After adjustment for clinical characteristics and treatment factors, use of metformin was associated with better overall survival among colorectal cancer patients (hazards ratio [HR], 0.55; 95% confidence interval [CI], 0.34 to 0.88) and for all four types of cancer combined (HR, 0.75; 95% CI, 0.57 to 0.98). Ever use of insulin was associated with worse survival for all cancer types combined (HR, 1.89; 95% CI, 1.57 to 2.29) and for the four cancer types individually. Similar associations were seen for diabetic patients. Sulfonylureas use was associated with worse overall survival for breast or gastric cancer (HR, 2.87; 95% CI, 1.22 to 6.80 and HR, 2.05; 95% CI, 1.09 to 3.84, respectively) among diabetic patients. Similar association patterns were observed between diabetes medication use and cancer-specific survival. CONCLUSION: Metformin was associated with improved survival among colorectal cancer cases, while insulin use was associated with worse survival among patients of four major cancers. Further investigation on the topic is needed given the potential translational impact of these findings.

Lifestyle-related factors and cancer incidence in men: a public health assessment based on a 'healthy lifestyle score' / 中华流行病学杂志

Objective To evaluate the effects of combined lifestyle-related factors and risk of cancer incidence among adult men in urban Shanghai.Methods Information was obtained from 60 817 men in the Shanghai Men' s Health Study (2002-2006) program and 2033 incident cancers who were confirmed at the end of 2009.A healthy lifestyle score (HLS) system was developed,based on five lifestyle-related factors,and participants were scored one point for each of the healthy behaviour:never smoked,alcohol intake less than 1 drink/day,under normal weight range (18.5-27.9 kg/m2),physical activity (≥ 54 Met-hours/week),fruit and vegetable intake ≥451 g/day,the else would score as zero.The total score would range from zero to five.Cox regression model was used to evaluate the associations between combined lifestyle-related factors and the cancer incidence.Results Compared to men having scores as zero or one,the hazard ratios (95％ confidence intervals) for men with two,three,four,five health behaviour scores were 0.77 (95％CI:0.66,0.90),0.67 (95％CI:0.58,0.78),0.56(95％ CI:0.47,0.65),0.51 (95％ CI:0.42,0.62),respectively.The population attributable risks for cancer incidence was 10.4％ for those having scores less than 3 items.Conclusion Never smoked,moderate alcohol intake,maintaining normal weight,being physically fit,and having enough daily fruit and vegetable intake were associated with lower risk of total cancer incidence in men.Our data showed that healthy lifestyle could significantly benefit the public health programs of the population.

ABO blood type is associated with endometrial cancer risk in Chinese women / 癌症

ABO blood type has been associated with risk of several malignancies. However, results are not consistent. In this population-based case-control study including 1204 incident endometrial cancer cases and 1212 population controls, we examined the association of self-reported serologic blood type with endometrial cancer risk using a logistic regression model. Women with endometrial cancer were more likely to have blood type A. Compared to women with blood type O, the adjusted odds ratios for endometrial cancer were 1.00 [95% confidence interval (CI), 0.79-1.28] for type B, 1.24 (95% CI, 0.90-1.69) for type AB, and 1.50 (95% CI, 1.19-1.90) for type A. A significant dose-response relationship was observed for cancer risk and level of antigen A (P for trend = 0.0003). The positive association of blood type A with cancer risk was observed regardless of menopausal status, body mass index, oral contraceptive use, or family cancer history. Our results suggest that ABO blood type may be involved in the development of endometrial cancer.

Association of a single nucleotide polymorphism at 6q25.1,rs2046210, with endometrial cancer risk among Chinese women / 癌症

A recent genome-wide association study identified a new susceptibility locus for breast cancer, rs2046210, which is a single nucleotide polymorphism (SNP) located upstream of the estrogen receptor α(ESR1) gene on chromosome 6q25.1. Given that endometrial cancer shares many risk factors with breast cancer and both are related to estrogen exposure and that rs2046210 is in close proximity to the ESR1 gene, we evaluated the association of SNP rs2046210 with endometrial cancer risk among 953 cases and 947 controls in a population-based, case-control study conducted in Shanghai, China. Logistic regression models were used to derive odds ratios (ORs) and 95% confidence intervals (95% CIs) after adjusting for potential confounders. We found that the A allele of rs2046210, linked to an increased risk of breast cancer, was associated with increased but not statistically significant risk of endometrial cancer (OR = 1.16, 95% CI = 0.96-1.41 for the GA and AA genotypes compared with the GG genotype); the association was stronger among post-menopausal women (OR = 1.28, 95% CI = 1.00-1.65). The association tended to be stronger among women with higher or longer estrogen exposure than among women with relatively lower or shorter exposure to estrogen. Our study suggests that rs2046210 may play a role in the etiology of endometrial cancer. Additional studies are needed to confirm our findings.

Total fluid intake, urination frequency and risk of bladder cancer: a population-based case-control study in urban Shanghai / 中华流行病学杂志

Objective To evaluate the association between total fluid intake and the time of urination per day and the risk of bladder cancer. Methods A population-based case-control study was conducted in urban Shanghai, China, during January 1996 to December 1998. The study included 608 incident cases of bladder cancer and 607 age- and sex-matched controls. Unconditional logistic regression models were used to estimate the odds ratios(ORs)and their corresponding 95%confidence intervals(95%CIs)for bladder cancer associated with frequency of urination, after adjusted for age, gender, smoking status, history of occupation with high risk, history of bladder infections, body mass index and other confounding factors. The level of statistical significance was set at 0.05(two-sided). Results No significant trend was observed for the association between total fluid intake, time of nighttime urination and the risk of bladder cancer. Increasing time of urination during daytime was associated with decreased risk of bladder cancer(P for trend=0.014). ORs(95%CIs)for subjects who voided 4 times, 5 times and 6 or more times per day[0.72(0.49-1.05),0.60(0.41-0.87)and 0.62(0.43-0.90), respectively], when compared with those with less than 4times per day after adjustment of confounding factors. Data showed that smokers and nonsmokers who voided at least 6 times per day had the ORs of 0.72(95%CI: 0.45-1.15)and 0.46(95%CI:0.25-0.87)when compared to their counterparts who voided 3 times or less per day during the daytime. Subjects who urinated at least 6 times per day and consumed more than 1500 ml of total fluid per day experienced a significant 57% reduction in risk compared to subjects who urinated 3 times or less and consumed less than 750 ml of total daily fluid intake. Conclusion Increased urination frequency and total fluid intake, especially among those who never smoked might be associated with a reduced risk of bladder cancer.

Epidemiological prospective studies on physical activities and the risk of colon cancer: a Meta-analysis / 中华流行病学杂志

Objective To explore the relationship between physical activity(PA) and the risk of colon cancer. Methods Cohort studies on physical activity and risk of colon cancer were identified by searching MEDLINE, EMBASE, Chinese Bio-medicine and Chinese Wanfang databases from January 1979 to December 2009. Results from the individual studies were synthetically combined in our study. Inverse variance weighting was used in fixed effects model and the random effects estimate was based on the DerSimonian-Laird method. Variance-weighted least squares method was used for trend test of summarized dose-response data. Results A total of 28 studies were included in our analysis. An inverse association between physical activities and the risk of colon cancer was observed with the relative risks (RR) as 0.75 [95% confidence interval (CI): 0.66-0.86] in males and 0.85(95%CI: 0.76-0.95)in females, respectively. However, the findings from those documents with high quality showed significant and borderline significant associations between PA and colon cancer in both males (RR=0.74, 95% CI: 0.61-0.90) and females (RR=0.99, 95% CI: 0.95-1.02). Meanwhile, the dose-response trend was not observed either in males (P=0.142) or in females (P=0.417). For men, the pooled RRs differed by subsites were 0.62(95%CI:0.45-0.85) and 0.74 (95%CI:0.56-0.99)for highest level PA, compared with lowest level PA in proximal colon and distal colon cancer,respectively. For women, the pooled RRs were 0.84 (95%CI: 0.69-1.01 ) in proximal colon and 0.75(95%CI: 0.53-1.05)in distal colon cancer, respectively. Conclusion These results added to the evidence for the protective effects in colon cancer among men and women.

Epidemiological characteristics of obesity and its relation to chronic diseases among middle aged and elderly men / 中华流行病学杂志

Objective To investigate the epidemiological characteristics of obesity and how they related to chronic diseases among middle aged and elderly men in urban Shanghai.Methods A cross-sectional analysis was conducted using data from a baseline survey from an on-going cohort study of 61 500 men between 40-74 of age in urban Shanghai.Study subjects were recruited from 8 communities of an urban district in Shanghai during 2002 to 2006.General obesity was measured by body mass index (BMI≥28) and,central obesity by waist to hip ratio (WHR≥0.9).Unconditional logistic regression model was used to estimate the odds ratio and 95% confidence interval of chronic diseases associated with obesity after adjustment for potential confounding factors.Results The aged-adjusted prevalence rates of overweight,overall obesity and central obesity were 36.8%,7.7% and 49.7% respectively.In this population,66.7% subjects had ever been diagnosed with one or more kinds of chronic diseases,in which hypertension ranked first with an age-adjusted prevalence rate of 26.5%.After mutual adjustment for WHR and BMI,obesity (BMI≥28) appeared to be associated with increased prevalence rates of hypertension,coronary heart disease,gallstone,urinary tract calculus and stroke comparing to men having normal BMI (18.5≤BMI＜24) with ORs ranged from 1.16 to 3.13.However,to the lowest quartile,the ORs associated with the highest WHR were between 1.20 and 1.69 for these 5 diseases.All P values for trend tests were less than 0.05.WHR was positively associated with diabetes,with OR as 2.40 (95% CI:2.14-2.70) for the highest quartile comparing to the lowest quartile.BMI was unrelated to the diabetes prevalence.Prevalence of chronic obstructive pulmonary disease decreased with increasing BMI,but increased with WHR.The corresponding OR was 0.87 (95% CI:0.77-0.98)for the obese men compared to those with normal BMI while 1.26(95%CI:1.14-1.40) for the subjects with the highest WHR comparing to those with the lowest WHR.Conclusion The prevalence rates of hypertension,gallstone,urinary tract calculus,cardiovascular and cerebrovascular diseases were higher in obesity men.Central obesity seemed to be related to high prevalence of diabetes.

A meta-analysis of cohort studies on the association between diabetes and the risk of primary liver cancer / 中华预防医学杂志

<p><b>OBJECTIVE</b>To investigate the association between diabetes and risks of primary liver cancer.</p><p><b>METHODS</b>A Meta-analysis was performed to estimate the pooled relative risk (RR) to evaluate the relationship between diabetes and the risk of primary liver cancer from cohort studies, which were identified by searching in Medline, Chinese CNKI and Wanfang databases from January 1989 to February 2010. A total of 28 publications were found according to this method. Adjusted RRs and their corresponding 95% confidence intervals (95%CI) were calculated by using the fixed-effect and random-effect model in our analysis. We also conducted a number of sub-groups analysis stratified by some important variables, such as source, gender, region and quality of study.</p><p><b>RESULTS</b>A total of 3800 cases of liver cancer and 3 672 248 study subjects from 14 prospective cohorts were included in our analysis. The pooled RR of primary liver cancer was 3.33 (95%CI: 1.82 - 6.10) for persons with diabetes when compared to subjects without diabetes. The results showed a significant association between diabetes and the risk of primary liver cancer based on these cohort studies. Subgroup analysis indicated that the pooled RRs for diabetes were 3.76 (95%CI: 1.69 - 8.38) in the population-based cohorts and 2.41 (1.34 - 4.32) in the hospital-based cohorts. In terms of the sex groups, the pooled RRs for diabetes were 2.32 (95%CI: 1.70 - 3.17) for males and 1.63 (95%CI: 1.08 - 2.47) for females, respectively.</p><p><b>CONCLUSION</b>As one of independent risk factors, diabetes was associated with an increased risk of primary liver cancer.</p>

Time trend analysis of incidence rate for nasopharyngeal carcinoma in urban Shanghai YANG / 中华流行病学杂志

Objective To explore the secular trend of incidence for nasopharyngeal carcinoma (NPC) in urban Shanghai during 1973-2005. Methods The incidence data from the population-based cancer registries in Shanghai was used in our analysis. We calculated the crude incidence rates, age-adjusted incidence rates, trucated rates and cumulative rates of NPC. The annual percentage change (APC) was used as an estimate of the secular trend. Results Over 33 years, a total of 7889 incident NPC cases in urban Shanghai were registered for 5555 males and 2334 females, respectively. The incidence of NPC had remained stable in males during the period (APC=-0.250%, P= 0.340), but a decreasing trend was observed in females with an average reduction of -1.577% (P=0.000) per year. During the period of 1973-1976 to 2001-2005, the crude incidence rates changed from 4.56 to 6.18 and from 3.96 to 2.41 per 100 000 in males and females, and the age-adjusted rates from 4.12 to 3.96 and from 2.18 to 3.42 per 100 000 in males and females, respectively. Conclusion From 1973 to 2005, the incidence of NPC was stable in males while having a decline in females, indicating that further epidemioiogical study and prevention for NPC should be addressed.

Incidence trends of colorectal cancer in urban Shanghai, 1973 - 2005 / 中华预防医学杂志

<p><b>OBJECTIVE</b>To explore the time trends of colorectal cancer incidence rates in urban Shanghai from 1973 to 2005.</p><p><b>METHODS</b>Data on the incidence rates of colorectal cancer were obtained from a population-based cancer registry in Shanghai. A total of 32 962 colon cancer patients and 24 662 rectal cancer patients were registered. Population estimation were based on periodic censuses, with age- and sex-specific annual estimates derived for the remaining years. The rates were adjusted to the world standard population by using the direct method. Annul percent changes (APCs) in rates were estimated by means of a linear regression of the logarithm of the respective rates on calendar, weighted by the number of incidence cases.</p><p><b>RESULTS</b>The incidence rates of colorectal cancer increased steadily during 1973 to 2005, the age-adjusted incidence rates of colon cancer increased from 6.09 and 5.70 to 14.70 and 14.35 per 100 000 in male and female respectively. The APCs were 3.03% (t = 14.77, P < 0.01) and 3.21% (t = 22.15, P < 0.01). The rates of rectal cancer increased from 7.68 and 6.51 to 11.45 and 8.28 per 100 000 in male and female respectively. The APCs were 1.34% (t = 7.28, P < 0.01) and 0.93% (t = 7.34, P < 0.01). The top APCs for colon and rectal cancer in female were 5.86% and 2.79% at age above 85 and in male those were 4.64% and 2.38% at age of 80-. The APCs of colon cancer were greater than those of rectal cancer at the groups above 45 years old. The average ages when diagnosed were delayed from 57 - 60 to 66 - 70 during these 33 years. The average diagnosed ages of colon cancer were later than those of rectal cancer slightly (from 2003 to 2005, the onset age of male colon cancer: 68.61 +/- 12.17, male rectal cancer: 66.81 +/- 12.62, t = 4.90, P < 0.01; female colon cancer: 69.20 +/- 12.13, female rectal cancer: 67.75 +/- 12.54, t = 3.81, P < 0.01).</p><p><b>CONCLUSION</b>The incidence rates of colorectal cancer increased steadily during 1973 to 2005, especially for colon cancer. Further research is needed to identify the causes resulting in these changes.</p>

A case-control study on genetic polymorphism of CYP17 MspA(1)I and its association with endometrial cancer risk / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To assess whether the polymorphisms of CYP17 MspA(1)I are associated with the susceptibility of endometrial cancer.</p><p><b>METHODS</b>The allelic discrimination of the CYP17A1 gene polymorphisms were assessed with the ABI PRISM 7900 Sequence Detection Systems using TaqMan genotyping assay. Unconditional logistic regression was applied to assess odds ratio and 95% CI and evaluate the association between different genotypes and endometrial cancer development.</p><p><b>RESULTS</b>The frequencies of wild-type, heterozygote and homozygote for the CYP17 MspA(1)I in control women in Shanghai were 17.8%, 49.3% and 32.9%, respectively. No significant difference was found in the distribution of various genotypes of CYP17 MspA(1)I between patients and controls. Pregnancy was associated with reduced risk of endometrial cancer in pre-menopausal women with A2 allele, OR = 0.66, 95% CI: 0.44 approximately 0.99. In post-menopausal women with A2 allele, more pregnancies ( > 2) and shorter time of menstruation ( < or = 32 yrs) were associated with reduced risk of endometrial cancer.</p><p><b>CONCLUSION</b>No significant relationship was found between CYP17 MspA(1)I genotypes and endometrial cancer risk.</p>

Green tea consumption and the risk of endometrial cancer: a population-based case-control study in urban Shanghai / 中华流行病学杂志

<p><b>OBJECTIVE</b>To assess the effect of tea consumption on the risk of endometrial cancer.</p><p><b>METHODS</b>In a population based case-control study conducted in urban Shanghai, face-to-face interviews were completed for 995 incidence cases aged 30 - 69 from January 1997 to December 2002 and 1087 controls that frequency-matched to cases on age. Unconditional logistic model was used for analysis.</p><p><b>RESULTS</b>An inverse association was observed in tea drinking and endometrial cancer risk. Compared to non-tea drinkers, regular tea drinkers had reduced risk of endometrial cancer (OR = 0.74; 95% CI: 0.54 - 1.01) in premenopausal women. Green tea had a protective effect on endometrial cancer among non-smoking or non-alcohol drinking women (OR = 0.77, P = 0.0199) and the ORs reduced with the increasing concentration of tea being served (P for trend = 0.0493). The multivariate ORs for drinking green tea < 7 times/week and >or= 7 times/week were 0.90 (95% CI: 0.53 - 1.54) and 0.76 (95% CI: 0.60 - 0.95) with the trend test of P = 0.0163.</p><p><b>CONCLUSION</b>Tea drinking, with green tea in particurlar, seemed to have weak but inverse association with endometrial cancer risk, but this effect of protection might only limit to premenopausal women.</p>

Methods for time trend analysis of cancer incidence rates / 中华流行病学杂志

<p><b>OBJECTIVE</b>To introduce statistical methods of time trend analysis on cancer rates.</p><p><b>METHODS</b>Cancer incidence data collected by the Shanghai Cancer Registry during 1991 to 1999 was used in the analysis to calculate the crude and age-adjusted rates, percent changes (PCs) and annual percent changes (APCs). APCs were estimated by a linear regression of the logarithm on the incidence rates during the nine years. It also introduced a method for partitioning a linear trend in age-adjusted rates into site-specific contributions to the overall floating trend. 95% confidence intervals for the APCs and contributions were described in the paper.</p><p><b>RESULTS</b>A decreasing rates were observed for cancers of stomach and esophagus among both men and women in urban Shanghai from 1991 to 1999. The increasing rates among men would include cancers of colon, rectum, gall bladder, pancreas, prostate, urinary bladder, kidney and leukemia. The rates of cancers among women increased for colon, rectum, lung, breast, gall bladder, endometrium, ovary, urinary bladder and kidney. The changes of above cancers over time were statistically significant (P < 0.05 or P < 0.01), but rates for other cancer sites changed little. The APCs (weighted method) and contributions for the cancers of stomach, esophagus, colon, rectum and prostate were -2.99% and -65.72%, -2.90% and -17.07%, 12.30% and 21.46%, 2.94% and 18.62%, and 3.11% and 15.09% among men, and -6.05% and -39.55%, -1.08% and -35.19%, 2.81% and 28.64%, and 3.69% and 15.70% for the cancers of stomach, esophagus, breast and colon in women, respectively.</p><p><b>CONCLUSION</b>APC, and related statistics could be used to describe and analyze the time trend of cancer rates rather than PC or/and graphical method alone.</p>