Prostate cancer risk. Medical history, sexual, and hormonal factors

PURPOSE: Various medical conditions, infectious agents, sexual, and hormonal factors have been investigated in relation to prostate cancer risk. Given inconsistent results these factors were examined in this study.METHODS: This population-based case-control study was conducted in northeastern Ontario from 1995 to 1999. Cases (n = 760), aged 45 to 84 at the time of diagnosis, were identified through the Ontario Cancer Registry and diagnosed between January 1995 and December 1998. Controls (n = 1,634) were age-frequency matched and were selected from the northeastern Ontario population using published telephone listings. Mail and telephone questionnaires were used for data collection. Logistic regression was used to investigate risk associated with: 1) particular medical conditions and 2) hormonal and sexual factors. Cases were subdivided into those with symptoms of prostate disease and those with few or no such symptoms.RESULTS: Symptomatic cases who reported a history of venereal disease (age-adjusted odds ratio (OR) = 2.11, 95% confidence interval (CI) 1.18-3.80) and vasectomy (age-adjusted OR = 1.49, 95% CI 1.14-1.95) were at significantly increased risk of prostate cancer. Asymptomatic cases who reported a check-up at least once a year were at increased risk (age-adjusted OR = 1.46, 95% CI 1.08-1.98). Asymptomatic and symptomatic cases who reported a history of prostate cancer in a first degree relative were at increased risk (age-adjusted OR = 2.41, 95% CI 1.64-3.54; age-adjusted OR = 3.18, 95% CI 2.28-4.45, respectively). Symptomatic cases with a history of urinary tract infection were at non-significantly increased risk (age-adjusted OR = 1.31, 95% CI 0.98-1.76). Heart disease, mumps, allergies, and height were generally not associated with prostate cancer.CONCLUSIONS: A history of venereal disease, family history of prostate cancer, and vasectomy were positively associated with prostate cancer. Further investigation of selected medical conditions, sexual, and hormonal factors in prostate cancer development is warranted.     

环境和遗传因素与广东前列腺癌关系的病例对照研究

目的 探索我国南方前列腺癌发生与环境危险因素及基因多态性的关系.方法 采用以医院为基础的1:1匹配病例-对照设计,以病理确诊的前列腺癌住院患者为病例,其他疾病住院患者为对照.共完成142对病例和对照的问卷调查,采集85例病例和82例对照的血样.采用聚合酶链反应(PCR)、限制性片段长度多态性聚合酶链反应(PCR-RFLP)检测外周血细胞色素P450家族1A1(CYP1A1)、家族17(CYP17)和雄激素受体(AR)的基因型.应用条件logistic回归模型进行多因素分析.结果 与对照相比,首次遗精年龄小于18岁(OR=2.90,95%CI值:1.76～4.80)、首次性生活年龄≤24岁(OR=2.38,95%C/值:1.14～4.96)、35岁前每周性生活频率高(OR=1.80,95%CI值:1.19～2.70)、有肿瘤家族史(OR=2.70,95%C/值:1.31～5.58)、每天摄人猪肉(OR=2.27,95%C/值:1.38～3.70)是前列腺癌发生的危险因素,而吃水果多和喝绿茶是保护因素,OR值分别为0.25(95%C/值:0.08～0.75)和0.52(95%C/值:0.28～0.96).基因多态性分析发现携带CYP17A1/A2基因型与A1/A1相比,OR值为1.78(95%C/值:0.70～4.53),A2/A2基因型OR值为2.57(95%CI值:0.91～7.25),提示该基因多态性A2突变型与前列腺癌发生有关.在遗传与环境因素交互作用分析中发现遗精年龄早、癌家族史与CYP17基因多态性存在交互作用,OR值分别为13.35(95%C/值:1.58～113.00)和4.01(95%C/值:1.22～13.17).结论 性生活史、饮食、癌家族史与前列腺癌发生相关联.CYP17基因型的突变可能是前列腺癌发生的危险因素,提示遗传与环境因素共同在前列腺癌发生中起作用.     

Aggregation of ovarian cancer with breast, ovarian, colorectal, and prostate cancer in first-degree relatives

Epidemiologic studies have demonstrated a tendency for common cancers to aggregate in families. The authors investigated the effects of family history of cancer at multiple sites, including the breast, ovary, colorectum, and prostate, on ovarian cancer risk among 607 controls and 558 ovarian cases in Hawaii and Los Angeles, California, in 1993-1999. A family history of cancer of the breast, ovary, colorectum, or prostate in first-degree relatives was associated with an increased risk of ovarian cancer (odds ratio (OR)=1.7, 95% confidence interval (CI): 1.1, 2.6; OR=3.2, 95% CI: 1.3, 7.9; OR=1.5, 95% CI: 0.9, 2.5; and OR=1.6, 95% CI: 1.0, 2.8, respectively). A greater risk of ovarian cancer was observed for women with parents rather than siblings with a history of breast or prostate cancer and for women with parental colorectal cancer diagnosed at an early age, suggesting a genetic predisposition among these women. The risk of nonmucinous tumors, but not mucinous tumors, was positively associated with a family history of cancer. No significant interaction effects on risk existed between oral contraceptive pill use or pregnancy and family history of breast and/or ovarian cancer. Study findings suggest that ovarian cancer aggregates with several common cancers in family members.     

Salivary gland cancer: an exploratory analysis of dietary factors

This study was an exploratory analysis of dietary and other risk factors for primary salivary gland cancer in a population-based case-control study in Ontario, Canada. Cases were men and women diagnosed between 1995 and 1996 with a first primary cancer of the salivary gland, identified through the Ontario Cancer Registry. Controls were an age-matched random sample of the population of Ontario, identified through property assessment files. Cases (n = 91) and controls (n = 1897) completed a self-administered questionnaire with information on diet, smoking, height and weight, and other lifestyle and socio-demographic factors. Multivariate logistic regression was used to estimate odds ratios (ORs) and corresponding 95% confidence intervals (CIs). Among dietary variables, high relative to low intakes of alcohol (OR: 1.26; 95% CI: 0.68-2.35), fruits (OR: 1.26; 95% CI: 0.68-2.33), sweets (OR: 1.66; 95% CI: 0.85-3.25), dairy (OR: 1.41; 95% CI: 0.77-2.58), and starchy foods (OR: 1.78; 95% CI: 0.96-3.3) were associated with non-statistically significant increased risk of salivary gland cancer; whereas vegetables and meats were linked with non-statistically significant decreased risks of the disease. Among non-diet factors, male sex, obese BMI, exposure to occupational radiation, family history of cancer, and household income were suggestive of increased disease risk. Future work with larger numbers of cases are needed to further explore these associations.     

Lifestyle and anthropometric risk factors for prostate cancer in a cohort of Iowa men

PURPOSE: Several lines of evidence suggest that prostate cancer has a hormonal etiology. We evaluated factors known to modulate the endocrine system, including alcohol and tobacco use, physical activity, and obesity as risk factors for prostate cancer. METHODS: Cancer-free controls who participated in a population-based case-control study from 1986-1989 (81% response rate) were followed through 1995 for cancer incidence by linkage to the Iowa Cancer Registry; 101 incident prostate cancers were identified. RESULTS: Compared with non-users of alcohol, men who consumed <22 grams alcohol per week (relative risk [RR] = 1.1; 95% Confidence Interval [CI] 0.6-2.1), 22-96 grams alcohol per week (RR = 2.6; 95% CI 1.4-4. 6) and >96 grams alcohol per week (RR = 3.1; 95% CI 1.5-6.3) were at increased risk of prostate cancer after adjustment for age, family history of prostate cancer, body mass index, total energy, and intake of carbohydrate, linoleic acid, lycopene, retinol, and red meat (p for trend < 0.0001). The respective RRs were similar when assessing type of alcohol consumed (beer, wine or liquor) or when well-differentiated, localized tumors were excluded. Body mass index was only weakly and positively associated with prostate cancer after adjustment for age, but this association strengthened after multivariate adjustment and exclusion of well-differentiated, localized tumors. For the latter tumors, men with a BMI of 24.1-26.6 kg/m(2) and >26.6 kg/m(2) were at elevated risk compared to men with a BMI <24.1 kg/m(2). Tobacco use (cigarettes, cigar/pipe, chewing tobacco and snuff use), height, weight, and both leisure and occupational physical activity were not associated with risk of prostate cancer in this cohort. CONCLUSIONS: These data suggest that in white men obesity is a risk factor for more clinically significant prostate cancer and confirm limited previous reports showing that alcohol consumption is positively associated with prostate cancer and that this risk is not limited to any specific type of alcohol.     

Serum phospholipid fatty acids and prostate cancer risk: results from the prostate cancer prevention trial

Inflammation may be involved in prostate cancer development and progression. This study examined the associations between inflammation-related phospholipid fatty acids and the 7-year-period prevalence of prostate cancer in a nested case-control analysis of participants, aged 55-84 years, in the Prostate Cancer Prevention Trial during 1994-2003. Cases (n = 1,658) were frequency matched to controls (n = 1,803) on age, treatment, and prostate cancer family history. Phospholipid fatty acids were extracted from serum, and concentrations of ω-3, ω-6, and trans-fatty acids (TFAs) were expressed as proportions of the total. Logistic regression models estimated odds ratios and 95% confidence intervals of associations of fatty acids with prostate cancer by grade. No fatty acids were associated with low-grade prostate cancer risk. Docosahexaenoic acid was positively associated with high-grade disease (quartile 4 vs. 1: odds ratio (OR) = 2.50, 95% confidence interval (CI): 1.34, 4.65); TFA 18:1 and TFA 18:2 were linearly and inversely associated with risk of high-grade prostate cancer (quartile 4 vs. 1: TFA 18:1, OR = 0.55, 95% CI: 0.30, 0.98; TFA 18:2, OR = 0.48, 95% CI: 0.27, 0.84). The study findings are contrary to those expected from the pro- and antiinflammatory effects of these fatty acids and suggest a greater complexity of effects of these nutrients with regard to prostate cancer risk.     

武汉市前列腺癌的流行病学研究

前列腺癌是欧美国家男性的主要死亡原因，我国还没有全面的发病率和死亡统计资料。为了解我国前列腺癌的流行情况，在武汉市１９９０～１９９２年前列腺癌的发病及死亡报告的基础上，收集了１９９０～１９９５年住院治疗的１０２例前列腺癌现患病例进行了１１配比的病例对照研究。结果显示：武汉市前列腺癌的发病率和死亡率分别为１．３７／１０万和０．７５／１０万，世界人口年平均标化发病率和死亡率分别为１．１０／１０万和０．６６／１０万。泌尿系统病史〔ＯＲ＝５．４２，９５％可信区间（ＣＩ）＝１．５６～１８．８３〕、子女数超过３个（ＯＲ＝２．４３，９５％ＣＩ＝１．１７～５．０２）、青壮年期每周性交超过３次（ＯＲ＝３．３８，９５％ＣＩ＝１．５１～７．５８）、滥用药物（ＯＲ＝４．１１，９５％ＣＩ＝１．６５～１０．２５）、体质指数高（ＯＲ＝２．５８，９５％ＣＩ＝１．３０～５．１１）等是前列腺癌的危险因素，而体力劳动（ＯＲ＝０．３５，９５％ＣＩ＝０．１７～０．７１）、初次遗精年龄晚于１８岁（ＯＲ＝０．２０，９５％ＣＩ＝０．０８～０．５２）等是其保护性因素。     

History of diabetes mellitus and risk of prostate cancer in physicians

Some studies have suggested that diabetes mellitus may decrease the risk of prostate cancer because of lower insulin levels. To further investigate the relation between diabetes and prostate cancer, a nested case-control study was conducted within the US Physicians' Health Study. Cases (n = 1,110) had been diagnosed with prostate cancer, confirmed on medical record review, during follow-up in 1982-1995. Controls (n = 1,110) were selected randomly from men free of prostate cancer and were matched on age and date of randomization. Information on personal history of diabetes and other diseases, lifestyle habits, and body weight/height was self-reported. Logistic regression analysis showed that the odds ratio for prostate cancer was 0.64 (95% confidence interval (CI): 0.43, 0.95) for men with diabetes, relative to those without the disease, after adjustment for potential confounders. Odds ratio estimates were 0.63 (95% CI: 0.35, 1.14), 0.77 (95% CI: 0.35, 1.72), 0.59 (95% CI: 0.21, 1.66), and 0.59 (95% CI: 0.27, 1.27) for diabetes diagnosed 1-5, 6-10, 11-15, and > or = 16 years prior to prostate cancer diagnosis (p for trend < 0.05). Adjusted odds ratios were 1.44 (95% CI: 0.34, 6.17) for stage A prostate cancer and 0.48 (95% CI: 0.28, 0.83) for stages B-D. Results suggest that history of diabetes may be associated with a decreased risk of prostate cancer, especially late-stage tumors.     

Antioxidants, carotenoids, and risk of rectal cancer

Numerous properties suggest that antioxidants and carotenoids may be valuable chemopreventive agents. A population-based case-control study of 952 rectal cancer cases and 1,205 controls from Northern California and Utah was conducted between September 1997 and February 2002. Detailed diet history, medical history, and lifestyle factors interviews were conducted. Dietary antioxidants were not associated with rectal cancer risk in men. For women, relative to the highest level of intake, low intake of dietary lycopene (odds ratio (OR) = 1.7, 95% confidence interval (CI): 1.0, 2.8) or vitamin E (OR = 2.2, 95% CI: 1.1, 4.3) was associated with an increased risk of rectal cancer. Alpha-, beta-, and gamma-tocopherol were associated with an approximate twofold increased risk of rectal cancer in women. Associations were stronger for women aged > or = 60 years for vitamin E and tocopherols (alpha-tocopherol OR = 3.6, 95% CI: 1.4, 9.4; gamma-tocopherol OR = 5.3, 95% CI: 2.1, 13.2; delta-tocopherol OR = 1.9, 95% CI: 0.9, 4.0), except for beta-tocopherol, for which risk increased twofold for all women. Associations differed by estrogen status for beta-carotene, lycopene, and vitamin E. These results suggest that vitamin E and lycopene may modestly reduce the risk of rectal cancer in women.     

Obesity before age 30 years and risk of advanced prostate cancer

Adult obesity has shown little association with prostate cancer risk, but obesity at younger ages may be associated with reduced risk. In 1997-2000, the relation between obesity before age 30 years and incident advanced prostate cancer was investigated in a population-based case-control study of African-American and White men (568 cases, 544 controls) in California. Unconditional logistic regression was used to estimate odds ratios and 95% confidence intervals, adjusted for age, race, family history of prostate cancer, and saturated fat intake. Measures of obesity for age 10 years tended to be inversely associated with prostate cancer (odds ratio (OR) = 0.79, 95% confidence interval (CI): 0.46, 1.38 for selecting the "obese" pictogram and OR = 0.76, 95% CI: 0.52, 1.11 for reporting being heavier than peers). The decreased risk was more pronounced at ages 20-29 years (OR = 0.53, 95% CI: 0.28, 1.00 for the "obese" drawing, OR = 0.59, 95% CI: 0.40, 0.88 for being heavier than peers, and OR = 0.40, 95% CI: 0.20, 0.81 for body mass index > or =30 kg/m(2)). In addition, both "obese" and small waist size at ages 20-29 years showed inverse trends. This research implicating early-life body size in prostate cancer development helps to elucidate causal mechanisms, such as altered sex hormone profiles during critical developmental periods, potentially involved in development of the disease.     

Occupational risk factors for prostate cancer

BACKGROUND: Occupational risk factors for prostate cancer have been investigated with inconsistent findings. METHODS: This was a population-based case-control study of men in Northeastern Ontario, Canada. Cases (n = 760) were from the Ontario Cancer Registry, 50 to 84 years old, and diagnosed with prostate cancer between 1995 and 1998. Age-frequency matched controls (n = 1,632) were obtained from telephone listings. A questionnaire yielded information on occupational history and self-reported exposures to a list of occupational hazards. Exposures to these hazards were assessed by an occupational hygienist. RESULTS: An odds ratio estimate (OR) of 1.21 (95 percent confidence interval (% CI) 1.01, 1.46) was found for employment in trades, transport and equipment operators and related occupations, possibly related to exposure to whole-body vibration (OR = 1.38, 95% CI 1.07, 1.78). For the highest quartile of lifetime cumulative workplace physical activity an OR of 1.33 (95% CI 1.02, 1.74) was found. No statistically significant associations were found for any other occupational category or exposure. CONCLUSIONS: This study does not provide strong evidence for significant occupational risk factors for prostate cancer. However, whole-body vibration exposures, as well as physical activity, may be worth pursuing in future occupational studies.     

嘉兴市农村人群高血压危险因素研究

目的通过流行病学研究,探索嘉兴市农村高血压的主要危险因素。方法选择塘汇乡和南湖乡年龄在25~74周岁常住居民进行问卷调查(包括一般情况、生活方式和行为、家族史、计划生育、病史等)、体格检查(血压测量、身高体重测量)和实验室检查(血糖、血脂检测)。用Logistic回归综合分析各因素与高血压的关系。结果高血压危险因素有饮酒、肥胖、高胆固醇、高甘油三酯和年龄,OR值分别为2.175、1.999、2.922、1.66、1.086,95%可信区间分别为1.64~2.886、1.645~2.43、1.398~6.107、1.217~2.265、1.073~1.1;收入高和主食增加是保护因素,OR值分别为0.809、0.797,95%可信区间分别为0.669~0.979、0.64~0.992。结论年龄是嘉兴市农村人群高血压危险因素,高血压患病率男女均随着年龄而递增;家庭经济收入影响高血压患病率,家庭经济收入低者高血压患病率相对高;饮酒和超重增加高血压患病的危险性;家庭史不是本地区农村人群高血压患病的主要危险因素;近5年主食减少者高血压患病率显著高于主食增加者;血脂高者高血压患病率也高。     

Education,income, occupational status and health risk behaviour

Aim Socio-economic status is associated with a variety of health-related behaviours. In our study, we determined the independent effects of income, educational attainment and occupational status on overweight, smoking and physical activity in the German population. Subjects and methods The German National Health Interview and Examination Survey is a representative sample of the German adult population and includes 7,124 men and women. Prevalences of obesity, smoking and physical inactivity stratified for education, income and occupational status were calculated. Multiple logistic regression models were used to estimate the odds ratios (OR) and 95% confidence intervals (CI) for education, income, occupational status and health-related behaviour, adjusted for age and gender. Results Health risk behaviours were more prevalent in subjects with lower education, income or occupational status. After mutual adjustment, education, income and occupation were independently associated with physical inactivity. Low education was strongly associated with both obesity (OR: 2.58, 95% CI: 1.99–3.34) and smoking (OR: 2.09, 95% CI: 1.71–2.54). Low income was associated with smoking (OR: 1.40, 95% CI: 1.07–1.83), but not with obesity, and low occupational status was associated with obesity (OR: 1.42, 95% CI: 1.05–1.92), but not with smoking. High income or occupation could not compensate for the impact of low education on obesity and smoking. Conclusion Low socio-economic status is associated with health risk behaviours. Concerning obesity and smoking, education was more important than income or occupational status. Public health programmes to reduce these risk factors should focus on early-life health education.     

Predictor factors for childhood obesity in a Spanish case-control study

OBJECTIVE: The aim of this study was to identify and characterize factors associated with childhood obesity risk related to lifestyle and perinatal life influences (dietary pattern, physical activity, family history of obesity, breast-feeding, sedentary behavior, and birth weight) in a case-control study design. METHODS: Cases were 185 obese (body mass index >97th percentile) children and adolescents (6-18 y old) from the Navarra region of Spain and control subjects were matched by sex and age. Anthropometric data were collected, and a personal interview about lifestyle parameters (dietary patterns, physical activity, family history of obesity, breast-feeding and sedentary behaviors) was performed with each participant. Conditional logistic regression was used to identify predictive factors of obesity. RESULTS: Leisure time physical activity proved to be a protector factor against obesity (odds ratio [OR] 0.94, 95% confidence interval [CI] 0.92-0.96), whereas family history of obesity (OR 4.18, 95% CI 2.20-8.62), watching television (OR 2.02, 95% CI 1.09-3.77), and sugar-sweetened beverage consumption (OR 1.74, 95% CI 1.05-2.89) were associated with a higher obesity risk. CONCLUSION: Our results suggest that leisure time physical activity, family history of obesity, watching television, and sugar-sweetened beverage consumption are important predictive variables for childhood obesity, whereas other factors including breast-feeding, birth weight, and time spent sleeping did not appear to play an important role in the development of childhood obesity.     

Case-control study of lifetime total physical activity and prostate cancer risk

A population-based case-control study of physical activity and prostate cancer risk was conducted in Alberta, Canada, between 1997 and 2000. A total of 988 incident, histologically confirmed cases of stage T2 or greater prostate cancer were frequency matched to 1,063 population controls. The Lifetime Total Physical Activity Questionnaire was used to measure occupational, household, and recreational activity levels from childhood until diagnosis. Multivariable logistic regression analyses were conducted. No association for total lifetime physical activity and prostate cancer risk was found (odds ratio (OR) for > or =203 vs. <115 metabolic equivalent-hours/week/year=0.87, 95% confidence interval (CI): 0.65, 1.17). By type of activity, the risks were decreased for occupational (OR=0.90, 95% CI: 0.66, 1.22) and recreational (OR=0.80, 95% CI: 0.61, 1.05) activity but were increased for household (OR=1.36, 95% CI: 1.05, 1.76) activity when comparing the highest and lowest quartiles. For activity performed at different age periods throughout life, activity done during the first 18 years of life (OR=0.78, 95% CI: 0.59, 1.04) decreased risk. When activity was examined by intensity of activity (i.e., low, <3; moderate, 3-6; and vigorous, >6 metabolic equivalents), vigorous activity decreased prostate cancer risk (OR=0.70, 95% CI: 0.54, 0.92). This study provides inconsistent evidence for the association between physical activity and prostate cancer risk.     

A prospective study of physical activity and risk of prostate cancer in US physicians

BACKGROUND: Exercise can suppress androgen production and may thus decrease the risk of prostate cancer. However, findings from epidemiological studies assessing physical activity and risk of prostate cancer are inconsistent. METHODS: We prospectively examined the association between physical activity and prostate cancer risk in the Physicians' Health Study (PHS), a randomized trial of low-dose aspirin and beta-carotene among 22,071 men aged 40-84 without self-reported myocardial infarction, stroke and cancer. At baseline in 1982, men were asked about the frequency of exercise vigorous enough to work up a sweat. Physical activity was assessed in a similar fashion again at 36 months of follow-up. RESULTS: During 11.1 years of follow-up (258 779 person-years), 982 cases of prostate cancer occurred and were confirmed by medical record review. After adjustment for potential confounding factors (including age, height, randomized treatment assignment, smoking status, alcohol intake, use of multivitamins, history of diabetes, history of hypertension and history of high cholesterol), the relative risks for prostate cancer associated with exercise vigorous enough to work up a sweat were 1.0 (referent) for frequency less than once per week, 1.02 (95% CI: 0.82-1.26) for once per week, 1.07 (95% CI: 0.90-1.27) for 2-4 times per week, and 1.11 (95% CI: 0.90-1.36) for 5+ times per week. Across all subgroups of men categorized by age, body mass index, smoking status, alcohol intake, use of multivitamins, history of diabetes, history of hypertension and history of high cholesterol, there were no significant associations between frequency of exercise vigorous enough to work up a sweat and prostate cancer risk. After excluding cases of prostate cancer that occurred during the first 36 months of follow-up, again, there was no significant association. Combining physical activity assessments at baseline and at 36 months also yielded no significant association with prostate cancer risk. CONCLUSIONS: These observational data from the Physicians' Health Study do not support the hypothesis that increased physical activity reduces the risk of prostate cancer.     

Energy intake, body mass index, physical activity, and the colorectal adenoma-carcinoma sequence

Little is known about the precise relationship between energy intake, overweight, sedentary lifestyle, and steps in the colorectal adenoma-carcinoma pathway. We studied these parameters within a case-control study. Patients with adenomas < 10 mm (n = 154) or > 10 mm (n = 208) were compared with polyp-free controls (n = 426) for determining factors associated with adenoma formation, i.e., observed for small and large adenomas, or with adenoma growth only. Colorectal cancer cases (n = 171) were compared with population controls (n = 309) to determine factors specific to the final stage, cancer. Exercise reduced the risk of cancer [odds ratio (OR) = 0.3, 95% confidence interval (CI) = 0.2-0.5 for high vs. low physical activity] but had little influence on adenomas. High energy intake increased the risk of cancer [OR for 5th vs. 1st quintile (OR5) = 1.6, 95% CI = 0.9-2.9, p = 0.02], but not of adenomas. High body mass index (BMI) significantly increased the risk of large adenomas (OR5 = 2.1, 95% CI = 1.2-3.5, p = 0.02 and OR5 = 1.7, 95% CI = 1.0-3.1, p = 0.25) for large and small adenomas vs. polyp-free controls. Neither height nor weight nor BMI influenced the risk of cancer. Results were unmodified when controlling for dietary risk factors and family history. Energy intake, a sedentary lifestyle, and high BMI were independently associated with a high risk of cancer itself or large adenomas, which indicates an effect on promotion of colorectal tumors. These findings suggest that preventive advice regarding these factors should be provided, even late in life, to decrease the risk of colorectal cancer.     

Sociodemographic status, stress, and risk of prostate cancer. A prospective cohort study

PURPOSE: The social gradient in prostate cancer incidence observed in several studies may be a result of differential access to prostate cancer screening. We aim to assess if socioeconomic status, stress, and marital status are associated with prostate cancer risk in a population with free access to health care. METHODS: The 5,496 men who participated in the Copenhagen City Heart Study were asked about their income, educational level, stress level, and marital status during 1981-1983. These men were prospectively followed up in the Danish Cancer Registry until the end of 2002 and fewer than 0.1 % were lost to follow-up. RESULTS: During follow-up, 157 men were diagnosed with prostate cancer. Neither high income (HR = 1.17, 95% confidence interval [CI]: 0.78-1.76) nor high education (HR = 1.22; 95% CI: 0.76-1.96) were associated with risk of prostate cancer. There were also no differences in prostate cancer risk according to stress (HR = 0.99; 95% CI: 0.90-1.09) or marital status. CONCLUSION: In a racially homogeneous population of Caucasians with free access to health care, we found no evidence of a relation between sociodemographic variables or stress and subsequent risk of prostate cancer.     

Salivary Gland Cancer: An Exploratory Analysis of Dietary Factors

This study was an exploratory analysis of dietary and other risk factors for primary salivary gland cancer in a population-based case-control study in Ontario, Canada. Cases were men and women diagnosed between 1995 and 1996 with a first primary cancer of the salivary gland, identified through the Ontario Cancer Registry. Controls were an age-matched random sample of the population of Ontario, identified through property assessment files. Cases ( n = 91) and controls ( n = 1897) completed a self-administered questionnaire with information on diet, smoking, height and weight, and other lifestyle and socio-demographic factors. Multivariate logistic regression was used to estimate odds ratios (ORs) and corresponding 95% confidence intervals (CIs). Among dietary variables, high relative to low intakes of alcohol (OR: 1.26; 95% CI: 0.68–2.35), fruits (OR: 1.26; 95% CI: 0.68–2.33), sweets (OR: 1.66; 95% CI: 0.85–3.25), dairy (OR: 1.41; 95% CI: 0.77–2.58), and starchy foods (OR: 1.78; 95% CI: 0.96–3.3) were associated with non-statistically significant increased risk of salivary gland cancer; whereas vegetables and meats were linked with non-statistically significant decreased risks of the disease. Among non-diet factors, male sex, obese BMI, exposure to occupational radiation, family history of cancer, and household income were suggestive of increased disease risk. Future work with larger numbers of cases are needed to further explore these associations.     

Risk factors of type 2 diabetes among Korean adults: The 2001 Korean national health and nutrition examination survey

This study aimed to identify risk factors for type 2 diabetes (T2D) in Korea, a rapidly changing country. Data of 5,132 adults aged 20-85 were used from the 2001 Korean Health and Nutrition Examination Survey. Multiple logistic regression was carried out to identify risk factors for T2D. Three models were specified: (i) socioeconomic and demographic factors (model 1: age, gender, education, poverty income ratio, employment), (ii) behavioral risk factors and covariates (model 2: obesity, physical activity, smoking, alcohol drinking, dietary quality, family history of T2D, co-morbidity) and (iii) socioeconomic, demographic, and behavioral factors (model 3). The prevalence of T2D was 7.4%. Less education (OR 1.41, 95% CI 1.08-1.84), age (OR 2.19, 95% CI 1.56-3.08 in 40-59 yrs, OR 4.05, 95% CI 2.76-5.95 in 60 yrs + comparing to 20-39 yrs) and abdominal obesity (OR 2.24, 95% CI 1.79-2.82) were risk factors for T2D even after controlling for other factors simultaneously. There was a significant association of T2D with ever smoking (OR 1.34, 95% CI 1.06-1.67). The relationship of age with T2D was modified by gender in model 1 and the relationship of smoking with T2D was modified by obesity in model 2. Less educated, older, obese or ever smokers were more likely to have T2D. Gender mediated the relationship of age, and obesity mediated the relationship of smoking, with T2D. Intervention programs for T2D in Korea should take the interactions among risk factors into account.