Case-control study of lifetime physical activity and breast cancer risk

A population-based case-control study of 1,233 incident breast cancer cases and 1,237 controls was conducted in Alberta, Canada, in 1995-1997 to examine the effect of lifetime physical activity patterns on breast cancer risk. No associations between physical activity and breast cancer were found for premenopausal women. For postmenopausal women in the highest quartile (> or =161 metabolic equivalent (MET)-hours/week per year) versus the lowest quartile (<104.8 MET-hours/week per year) of lifetime total physical activity, the adjusted odds ratio was 0.70 (95% confidence interval (CI): 0.52, 0.94). When the risks associated with each type of activity were examined for postmenopausal women, household and occupational activity conferred the largest risk reductions (odds ratio (OR) = 0.57, 95% CI: 0.41, 0.79 and OR = 0.59, 95% CI: 0.44, 0.81, respectively, for highest vs. lowest quartiles of activity), while recreational activity was not associated with any risk reductions. For postmenopausal women, the authors found stronger risk reductions for those who were also nonsmokers (OR = 0.64, 95% CI: 0.46, 0.88), non-alcohol-drinkers (OR = 0.39, 95% CI: 0.11, 0.77), or nulliparous (OR = 0.22, 95% CI: 0.07, 0.70) when they compared the highest with the lowest quartile of lifetime total physical activity. This study provides evidence that lifetime total activity reduces risk of postmenopausal breast cancer.     

前列腺癌与生活行为方式病例对照研究

目的探讨前列腺癌与生活行为方式的病因学关系。方法选择在中山大学4所附属医院诊断的前列腺癌患者62例，选择良性前列腺增生、其他疾病患者各62例为对照（1：2配对），匹配条件为年龄组（±5岁）、性别、民族和居住地类型相同。调查以面谈为主，辅以病历记录，采用条件Logistic回归法分析数据。结果以前列腺增生为对照。吸烟量每天20支及以上者患前列腺癌的危险是不吸烟者的2．19（0．87～5．52）倍；年吸烟量达800支以上者患前列腺癌的危险是不吸烟者的2．08（0．81～12．679）倍。以其他病例为对照，日饮酒量超过100g（乙醇）者患前列腺癌的危险是不饮酒者的2．17（0．7～6．63）倍；饮酒年限达40年及以上者患前列腺癌的危险是不饮酒者的3．35（O．89～5．30）倍。体育锻炼频率每周少于5次增加前列腺癌的患病危险，OR〈3次／周=6．68（0．46-97．58），OR3-5次／周=8．48（1．37～52．61）。未发现饮茶与前列腺癌有统计学关联。结论吸烟是前列腺癌的危险因素，饮酒年限长者和缺乏锻炼者易患前列腺癌．     

Case-control study of physical activity and breast cancer risk among premenopausal women in Germany

Important aspects of the recognized inverse relation between physical activity and breast cancer risk are still under discussion. Data on physical activity from sports, occupational activity, household tasks, walking, and cycling by reported frequency, duration, and intensity during adolescence and young adulthood were collected in 1999-2000 from 360 premenopausal breast cancer cases and 886 controls who had previously participated in a German population-based case-control study. In multivariate conditional logistic regression, no association between total physical activity and premenopausal breast cancer was found in two age periods. For women who were active during both periods, the adjusted odds ratio was 0.83 (95% confidence interval: 0.60, 1.14). When both age periods were combined, higher quartiles of total physical activity compared with the lowest quartile showed adjusted odds ratios of 0.97, 0.68, and 0.94. Only the effect of moderately high physical activity was statistically significant. Analyses by type of activity revealed significant protective effects for women who reported the highest levels of cycling activities (adjusted odds ratio = 0.66, 95% confidence interval: 0.45, 0.97). These data do not suggest an inverse monotonic association between total physical activity and breast cancer risk in premenopausal women. The study prevalence of cycling and walking for transportation demonstrated that national habits need consideration in the exposure assessment.     

Lifetime occupational physical activity and prostate cancer risk

The authors compared the lifetime occupational physical activity of 452 prostate cancer cases identified through the population-based Hawaii Tumor Registry and 899 population controls interviewed from 1981 to 1983. Each job reported was classified into one of five levels of physical activity using published sources. Among men aged 70 years or older, a negative association was found between prostate cancer risk and proportion of life spent in jobs involving only sedentary or light work. Compared with men never employed in such jobs, men who spent more than 54% of their life in these jobs had an odds ratio of 0.5 (95% confidence interval 0.3-0.9). This negative association was dose-dependent, consistent across ethnic groups, and unrelated to socioeconomic status, dietary risk factors, or job-related chemical exposures. The findings for younger men were less clear, but not inconsistent with those for older men. Surprisingly, no association was found with years spent in moderately active or very active jobs in either age group. Although inconclusive, these results suggest that physical activity may be positively associated with the risk of prostate cancer, but this association is likely to be weak and indirect.     

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.     

Adulthood lifetime physical activity and breast cancer

BACKGROUND: Epidemiologic studies have shown that breast cancer risk is reduced 30% to 40% in highly physically active compared with inactive women. However, the effects of moderate activities, timing of activities, and intervening effects of other risk factors remain less clear. METHODS: We analyzed data on physical activity patterns in 2176 incident breast cancer cases and 2326 controls in a population-based breast cancer case-control study in Poland conducted in 2000-2003. Using unconditional logistic regression analyses, we calculated odds ratios (ORs) and 95% confidence intervals (CIs) associated with physical activity levels (measured by average metabolic equivalents of energy expenditure hours per week), controlling for potential confounders. RESULTS: Total adult lifetime activity reduced risk of breast cancer, with individuals in the highest quartile having an OR of 0.80 (CI = 0.67-0.96) compared with the lowest quartile. Reduced risks were most consistent for the highest quartiles of moderate-to-vigorous activities: moderate/vigorous recreational activities (OR = 0.74; CI = 0.62-0.89), outdoor activities (0.81; 0.68-0.97), heavy physical work (0.60; 0.42-0.87), and combined high intensity (metabolic equivalent >6.0) activities (0.75; 0.63-0.90). These relations were not modified by body mass index, menopausal status, or family history of breast cancer. Reductions in risk with moderate/vigorous recreational activities were stronger for larger tumors and those with nodal involvement. Women who increased their recreational activity in their 50s had significantly reduced risk, with those in the highest tertile of change being at a 27% lower risk. CONCLUSIONS: Leisure-time moderate-to-vigorous activities reduce breast cancer risk irrespective of underlying host characteristics.     

卵巢癌危险因素的病例对照研究

卵巢癌严重威胁妇女健康 ,其死亡率居妇科恶性肿瘤首位[1 ] 。近十几年来 ,我国卵巢癌的发病率呈逐年上升之趋势 ;而且 ,将近 80 %的上皮性卵巢癌确诊时已为Ⅲ、Ⅳ期[2 ] 。因而 ,有必要对我国卵巢癌的发病及其影响因素进行深一步的研究。1 .对象与方法 :(1 )研究对象 :病例选自 1 999年 3月至 2 0 0 1年 1 2月天津医科大学附属肿瘤医院及天津市中心妇产科医院住院患者 ,均被确诊为卵巢癌 ,共 1 0 2例。1 0 2名对照来自与病例居住地相同或相似的社区正常健康人 ,并且于病例确诊时随机选取。两组在年龄 (χ2 =4.373 ,P =0 .82 2 )、民族 (χ…     

胃癌危险因素病例对照研究

目的调查本溪地区胃癌发生危险因素，为胃癌防治提供科学依据。方法采用1：1配对病例对照研究方法，问卷调查2002年2月～2004年2月经病理组织学确诊的新发胃癌298例，对可疑致癌因素进行Logistic回归模型单因素和多因素分析，筛选与胃癌发生有关的危险因素。结果缺乏体育锻炼、精神压抑、吸烟量大、喜食烟熏食品、喜食重盐饮食、过量摄入动物肉类、幽门螺杆菌感染、胃溃疡、恶性肿瘤家族史是胃癌的危险因素，OR值依次为2．181，19．502，2．920，6．985，3．013，12．882，32．624，13．006，5．550。喜食香菇和蘑菇(OR=0．443)、喜食新鲜水果(OR=0．665)是胃癌的保护因素。结论本溪地区胃癌发生主要与幽门螺杆菌感染、精神压抑、胃溃疡史、过量摄入肉类、缺乏体育锻炼等因素有关，应开展幽门螺杆菌检测，提倡保持心理平衡，适当进行体育锻炼；经常进食香菇、蘑菇和新鲜水果，以有效预防胃癌。     

山东省大汶河流域食管癌发病影响因素分析

目的 探讨山东省大汶河流域食管癌发病的影响因素.方法 在山东省大汶河主干流域的宁阳县,采用1:1配对病例对照研究方法,对195例食管癌现患及其对照进行问卷调查.结果 多因素条件Logistic回归分析结果显示,干硬饮食(OR=5.850,95%CI=1.080~31.693)、吸自制烟(OR=16.158,95%CI=2.529~103.259)、每天饮酒量>500 ml(OR=11.513,95%CI=1.0625~124.837)、疾病家族史(OR=1.827,95%CI=1.016~3.285)及饮茶(OR=0.311,95%CI=0.148~0.652)等因素2组比较差异有统计学意义.结论 大汶河流域食管癌高发不仅与环境、饮食因素有关,而且与食管癌家族史有关,应进行深入的研究并采取相应的综合性防治措施.     

Case-control study of dietary patterns and endometrial cancer risk

Dietary patterns, rather than intakes of specific foods or nutrients, may influence risk of endometrial cancer (EC). This population-based case-control study in Canada (2002-2006) included incident EC cases (n = 506) from the Alberta Cancer Registry and controls frequency age-matched to cases (n = 981). Past-year dietary patterns were defined using factor analysis of food frequency questionnaire data. Logistic regression was used to estimate EC risk within quartiles of dietary patterns. Three patterns (sweets, meat, plants) explained 23% of the variance in the dietary data. In multivariable models, EC risk was significantly reduced by 30% for women in the highest quartile of the healthier plants pattern (OR = 0.70, 95% CI 0.50-0.98, P trend = 0.02). When stratified by body mass index (BMI; kg/m(2)), risk was further reduced among overweight or obese women with a BMI ≥25 (OR = 0.57, 95% CI 0.39-0.83; P trend = 0.004). EC was not associated with the less healthy sweets and meat patterns. However, risk was modestly, but not significantly, elevated for higher intakes of the meat pattern among overweight or obese women. A mostly plant-based dietary pattern may reduce EC risk. Recommendations for risk reduction should focus on maintaining a healthy weight and the role of diet should be studied further.     

宫内节育器与子宫内膜癌病例对照研究

目的探讨宫内节育器（IUD）使用与子宫内膜癌的关系。方法采用病例对照研究方法，调查上海市区1997年1月～2000年12月间确诊、年龄在30～69岁之间的子宫内膜癌患者（n=1204）和普通对照人群（n=1212）的一般情况、月经生育史、饮食、个人生活习惯、口服避孕药（OC）及宫内节育器使用情况、疾病及家族史等。采用非条件Logisfic回归模型分析宫内节育器使用与子宫内膜癌的关系。结果上海市区女性所使用的宫内节育器类型主要为金属环和V型塑料环。分别占使用者的68．1％和20．7％。与从未使用过宫内节育器的女性比较，使用者发生子宫内膜癌的危险性显著降低。调整后OR=0．57（95％CI=0．47～0．69），且随使用时间增加而降低。分层分析显示，在从未服用口服避孕药的女性中，曾使用IUD者发生子宫内膜癌的危险降低，OR=0．51（95％CI=0．41～0．64）。结论绝经前后女性使用宫内节育器可能会降低子宫内膜癌的风险。     

Case-control study of cancer risk in tetraethyl lead manufacturing

A case-control study was conducted to investigate the relative risk of cancer detection among Du Pont employees who worked in a tetraethyl lead (TEL) manufacturing area. The study's objective was to determine whether the employees' risk of developing or dying from cancer was associated with occupational exposure to TEL. All malignant neoplasms detected in the active and pensioned employee population during the period 1956–1987 were studied. TEL exposure was estimated by the following measures: ever employed in the TEL area, years of employment in TEL, TEL exposure rank, and the TEL cumulative exposure index. TEL manufacturing exposed employees to both organic and inorganic lead compounds. Because the underlying data did not permit the exposure assessment to distinguish between organic and inorganic lead, the TEL exposure measures reflect exposure to the TEL manufacturing process itself. The effects of latency, cigarette smoking habits, and exposures to other known or suspected carcinogens at the plant were also assessed. A strong association was observed between exposure to the TEL manufacturing process and rectal cancer (the odds ratio was 3.7 with 90% confidence limits of 1.3–10.2 for the analysis of ever/never exposed to TEL). An exposure-response relationship was noted with a fourfold elevation in the odds ratio at the high-very high cumulative exposure level. These patterns were even more pronounced after assuming a 10 year latency. Similar results were obtained for cancers of the sigmoid colon. These findings suggest that exposure to the TEL manufacturing process may have played a causal role in the colorectal cancer experience at the plant. This position is supported by the graded exposure-response relationships, the consistency of the results across exposure measures, the specificity of the health outcome (i.e., colorectal cancer), and the strength of the association. However, the evidence for causality is not compelling. This is the first report of an association between TEL manufacturing and colorectal cancer, and the evidence is compatible with a wide range of causal (i.e., indirect vs. direct acting; initiating vs. promoting) and noncausal (i.e., statistical and methodological bias; coincidence) interpretations. Am. J. Ind. Med. 31:28–35 © 1997 Wiley-Liss, Inc.     

Daily total physical activity level and total cancer risk in men and women: results from a large-scale population-based cohort study in Japan

The impact of total physical activity level on cancer risk has not been fully clarified, particularly in non-Western, relatively lean populations. The authors prospectively examined the association between daily total physical activity (using a metabolic equivalents/day score) and subsequent cancer risk in the Japan Public Health Center-based Prospective Study. A total of 79,771 general-population Japanese men and women aged 45-74 years who responded to a questionnaire in 1995-1999 were followed for total cancer incidence (4,334 cases) through 2004. Compared with subjects in the lowest quartile, increased daily physical activity was associated with a significantly decreased risk of cancer in both sexes. In men, hazard ratios for the second, third, and highest quartiles were 1.00 (95% confidence interval (CI): 0.90, 1.11), 0.96 (95% CI: 0.86, 1.07), and 0.87 (95% CI: 0.78, 0.96), respectively (p for trend = 0.005); in women, hazard ratios were 0.93 (95% CI: 0.82, 1.05), 0.84 (95% CI: 0.73, 0.96), and 0.84 (95% CI: 0.73, 0.97), respectively (p for trend = 0.007). The decreased risk was more clearly observed in women than in men, especially among the elderly and those who regularly engaged in leisure-time sports or physical exercise. By site, decreased risks were observed for cancers of the colon, liver, and pancreas in men and for cancer of the stomach in women. Increased daily physical activity may be beneficial in preventing cancer in a relatively lean population.     

Case-control study of occupation and cancer of the prostate in New Zealand.

A New Zealand Cancer Registry based case-control study involved 617 male patients with prostate cancer registered during 1979 and aged 20 years or more at the time of registration. Controls were also males chosen from the Cancer Registry with two controls per case, matched on age and year of registration. There was an elevated risk in the upper social class groupings. The data did not support the findings, from other countries, of elevated risks in agricultural workers (odds ratio = 1.08, 90% confidence limits 0.86-1.36). The only occupational groups showing elevated risks were sales and service workers (odds ratio = 1.29, 90% confidence limits 0.99-1.69) and teachers (odds ratio = 2.44, 90% confidence limits 1.05-5.70). The New Zealand data do not in general suggest that occupational factors--or lifestyle factors associated with occupation--are of major direct importance in the aetiology of prostate cancer.     

Recreational physical activity and endometrial cancer risk.

To investigate the association between recreational physical activity and endometrial cancer risk, a population-based case-control study was conducted in Washington State. The study included 822 incident cases of endometrial cancer diagnosed between 1985 and 1991 and 1,111 randomly selected population-based controls. Detailed information on recreational physical activities as well as other endometrial cancer risk factors was obtained in structured, in-person interviews. Unconditional logistic regression, adjusted for age, county, energy intake, unopposed estrogen use, income, and, in separate models, body mass index (kg/m(2)), was used to estimate the odds ratios and their 95% confidence intervals, relating endometrial cancer to each level of physical activity. A greater proportion of controls (49.3%) than cases (40.5%) reported doing regular exercise (compared with no exercise: adjusted odds ratio = 0.62, 95% confidence interval: 0.51, 0.76) in the 2-year period prior to diagnosis date. There was little evidence of a trend of decreasing risk with increasing duration or intensity of recreational physical activities. These results provide support for an association between the lack of recent recreational physical activity and endometrial cancer risk. However, the absence of a difference by duration or intensity levels and the inconsistent results from other studies suggest caution before interpreting this association as causal.     

安溪县食管癌发病影响因素病例对照调查

目的探讨福建省安溪县食管癌发病的影响因素，为食管癌高发区制定综合防制措施提供理论依据。方法采用1：1配对研究方法，对237例食管癌患者及与之在年龄、性别和居住地相匹配的非癌人群采用统一的调查表进行问卷调查。采用单因素及多因素条件Logistic分析方法分析安溪县食管癌发生的影响因素。结果食盐量(OR 3．704)、性格内向(OR13．511)、吸烟量(OR1．667)、一级亲属食管癌家族史(OR5．687)、病前10～20年前常食用油炸食品(OR2．577)、霉变红薯(OR4．803)、腌菜(OR2．285)是安溪县食管癌发生的危险因素；常饮茶(OR0．234)、饮用清洁水(OR0．142)、常吃豆制品(OR0．407)、水果(OR0．255)是保护因素。结论食管癌是一种由多种致癌因素引起疾病，即在环境危险因素和遗传因素的作用下发生，因此，对其应采取综合性的预防措施。     

Occupational physical activity and breast cancer risk in the upper Cape Cod cancer incidence study.

BACKGROUND: In several epidemiological studies, breast cancer risk has been reduced among women who reported high levels of occupational or leisure-time physical activity. We used data from a population-based case control study to evaluate the effect of occupational physical activity on breast cancer risk. METHODS: Two hundred-thirty three incident cases of breast cancer and 670 controls or their next of kin were interviewed for information on breast cancer risk factors and a complete job history. Physical activity level of jobs were classified using a Department of Labor rating scheme. We calculated adjusted odds ratios for light and medium/heavy activity jobs compared to sedentary jobs. RESULTS: Odds ratios for women who held medium/heavy jobs for less than 10 years and more than ten years were, respectively, 0.7 (95% CI = 0.4,1.3) and 1.7 (95% CI = 0.9,3.3). CONCLUSIONS: In these data there was no evidence that holding a job of medium/heavy activity reduced breast cancer risk. The study was limited by misclassification inherent in the occupational exposure scheme and by the lack of information on leisure time physical activity. The modest risk increase for subjects holding a medium/heavy job for at least 10 years probably represents either confounding or random variation.