Twenty-year trends of primary liver cancer incidence rates in an urban Chinese population.

The objective of this study was to describe trends in the incidence rates of primary liver cancer in a geographically defined Chinese population. Primary liver cancer cases (N=13 685) were diagnosed between 1981 and 2000 and identified by the Tianjin Cancer Registry. Age-adjusted and age-specific incidence rates were examined in both males and females.

Misclassification in a matched case-control study with variable matching ratio: application to a study of c-erbB-2 overexpression and breast cancer.

We provide a simple analytic correction for risk factor misclassification in a matched case-control study with variable numbers of controls per case. The method is an extension of existing methodology, and involves estimating the corrected proportions of controls and cases in risk factor categories within each matched set. These estimates are then used to calculate the Mantel-Haenszel odds ratio estimate corrected for misclassification.

Occurrence of cervical infection with multiple human papillomavirus types is associated with age and cytologic abnormalities.

Background: Few aspects of the occurrence of infections with multiple HPV types have been described. Since the immunity conferred by vaccines is type-specific, the epidemiology of such coinfections needs to be addressed.

Goal: The goal of the study was to document the prevalence and incidence of infection with multiple HPV types and the distribution of HPV types in coinfections.

Glycemic load, carbohydrate intake, and risk of colorectal cancer in women: a prospective cohort study.

Mounting evidence suggests that high circulating levels of insulin might be associated with increased colorectal cancer risk. The glycemic effects of diets high in refined starch may increase colorectal cancer risk by affecting insulin and/or insulin-like growth factor-I levels. We examined the association between dietary intake and colorectal cancer risk in a cohort of 49 124 women participating in a randomized, controlled trial of screening for breast cancer in Canada.

Changes in survival patterns in urban Chinese patients with liver cancer.

Aim: To examine the survival patterns and determinants of primary liver cancer in a geographically defined Chinese population.

Methods: Primary liver cancer cases (n=13 685) diagnosed between 1981 and 2000 were identified by the Tianjin Cancer Registry. Age-adjusted and age-specific incidence rates were examined in both males and females.

Cigarette smoking and the risk of invasive epithelial ovarian cancer in a prospective cohort study.

Few cohort studies have examined the association between cigarette smoking and ovarian cancer risk, either overall, or by histological subtype. In relation to the latter, it has been suggested that mucinous ovarian tumours may be aetiologically unrelated to the other types of epithelial tumours and that their respective associations with cigarette smoking may differ. We examined the association between smoking and ovarian cancer risk using data from participants in a randomised controlled trial of screening for breast cancer involving 89,835 women aged 40-59 years at recruitment.

Fish consumption and breast cancer risk.

The omega-3 fatty acids, especially long-chain eicosapentaenoic acid (20:5n-3) and docosahexaenoic (22:6n-3) contained in "fatty" fish, have consistently been shown to retard the growth of breast cancer in vitro and in animal experiments. In contrast, studies of the association between fish consumption and breast cancer risk in human populations have not consistently shown inverse associations. However, previous studies have not considered the specific types of fish consumed.

Intakes of fish and marine fatty acids and the risks of cancers of the breast and prostate and of other hormone-related cancers: a review of the epidemiologic evidence.

Marine fatty acids, particularly the long-chain eicosapentaenoic and docosahexaenoic acids, have been consistently shown to inhibit the proliferation of breast and prostate cancer cell lines in vitro and to reduce the risk and progression of these tumors in animal experiments. However, whether a high consumption of marine fatty acids can reduce the risk of these cancers or other hormone-dependent cancers in human populations is unclear. Focusing primarily on the results of cohort and case-control studies, we reviewed the current epidemiologic literature on the intake of fish and marine fatty acids in relation to the major hormone-dependent cancers.

Calibration of the dietary questionnaire for the Canadian Study of Diet, Lifestyle and Health cohort.

Objective: For proper interpretation of results from epidemiological studies that use food-frequency questionnaires (FFQs), it is necessary to know the relationship between reported intakes from the FFQ and true usual intake. In this paper, we report a calibration study conducted to investigate the performance of the FFQ used in a cohort study, the Canadian Study of Diet, Lifestyle and Health.

Methods: Over a 1-year period, 151 men and 159 women completed a full set of questionnaires including a self-administered baseline FFQ, three 24-hour diet recalls administered by telephone, and a second FFQ self-administered subsequently.

Evidence-based policy recommendations on cancer screening and prevention.

Ideally, practice guidelines for cancer prevention should reflect the available empirical evidence. Although the most persuasive arguments for the efficacy of an intervention come from randomized controlled trials (RCTs), such studies are not always feasible because of ethical or logistical reasons. The advent of evidence-based medicine has underscored the need for consortia of researchers specialized in reviewing the biomedical literature on a systematic basis, ranking studies according to their design, quality, and generalizability of results.

Viral load as a predictor of the risk of cervical intraepithelial neoplasia.

HPV infections are believed to be a necessary cause of cervical cancer. Viral burden, as a surrogate indicator for persistence, may help predict risk of subsequent SIL. We used results of HPV test and cytology data repeated every 4-6 months in 2,081 women participating in a longitudinal study of the natural history of HPV infection and cervical neoplasia in São Paulo, Brazil.

Insulin-like growth factor (IGF)-I, IGF-binding protein-3 and colorectal adenomas in Japanese men.

Several epidemiological studies have found that high levels of plasma insulin-like growth factor (IGF)-I and low levels of IGF-binding protein (IGFBP)-3 are related to an increased risk of colorectal cancer or late-stage adenomas. We examined the relation of body mass index, fasting and 2-h postload plasma glucose levels and plasma concentrations of IGF-I and IGFBP-3 to colorectal adenomas in middle-aged Japanese men. The study subjects comprised 157 cases of histologically diagnosed colorectal adenomas and 311 controls with normal colonoscopy or non-polyp benign lesions in a consecutive series of 803 men receiving a preretirement health examination at two hospitals of the Self Defense Forces (SDF).

Alcohol, tobacco and breast cancer--collaborative reanalysis of individual data from 53 epidemiological studies, including 58,515 women with breast cancer and 95,067 women without the disease.

Alcohol and tobacco consumption are closely correlated and published results on their association with breast cancer have not always allowed adequately for confounding between these exposures. Over 80% of the relevant information worldwide on alcohol and tobacco consumption and breast cancer were collated, checked and analysed centrally. Analyses included 58,515 women with invasive breast cancer and 95,067 controls from 53 studies.

Dietary carotenoid intake and colorectal cancer risk.

Several studies have found inverse associations between fruit and vegetable consumption and colorectal cancer risk, suggesting the potential etiological importance of carotenoids (and other phytochemicals) contained in these foods. However, only one study (a case-control study) has examined the association between dietary carotenoids other than beta-carotene and colorectal cancer risk. In the study reported here, we examined the relationships between dietary intakes of beta-carotene, alpha-carotene, lycopene, lutein, and beta-cryptoxanthin and colorectal cancer risk in a large cohort study of Canadian women.

Dietary fat and risk of lung cancer in a pooled analysis of prospective studies.

Lung cancer rates are highest in countries with the greatest fat intakes. In several case-control studies, positive associations have been observed between lung cancer and intakes of total and saturated fat, particularly among nonsmokers. We analyzed the association between fat and cholesterol intakes and lung cancer risk in eight prospective cohort studies that met predefined criteria.

Cigarette smoking and the risk of breast cancer in women: a review of the literature.

Animal experiments and in vitro studies have shown that compounds found in tobacco smoke, such as polycyclic hydrocarbons, aromatic amines, and N-nitrosamines, may induce mammary tumors. The findings of smoking-specific DNA adducts and p53 gene mutations in the breast tissue of smokers also support the biological plausibility of a positive association between cigarette smoking and breast cancer, as does the detection of carcinogenic activity in breast fluid. However, epidemiological studies conducted over the past few decades have variably shown positive, inverse, or null associations.

Dietary carotenoids and risk of breast cancer.

Background: Many studies of fruit and vegetable consumption showed inverse associations with breast cancer risk, suggesting the potential importance of carotenoids (and other phytochemicals) contained in these foods. To date, however, only one prospective cohort study has examined dietary carotenoids other than beta-carotene in relation to breast cancer risk.

Objective: Our aim was to examine the relations between dietary intakes of beta-carotene, alpha-carotene, beta-cryptoxanthin, lycopene, and lutein + zeaxanthin and breast cancer risk in a large cohort study of Canadian women.

The development of a questionnaire to assess past year physical activity in a multi-ethnic/racial urban population.

Objectives: Describe the development of a questionnaire to assess past year physical activity, including activities of daily living, in a multi-ethnic/racial cohort. Describe energy expenditure (EE) patterns in the sample used for questionnaire development.

Methods: 24-hour activity recalls were collected from a convenience sample (N = 367) at four New York City health agencies (October 1999-February 2000).

Does the method of Helicobacter pylori detection influence the association with gastric cancer risk?

Background: The exact role of Helicobacter pylori as a causative agent of gastric cancer is still under debate. The aim of this study was to determine how the use of different diagnostic methods for detection of H. pylori influences the measures of prevalence of the infection and thus the association with risk of gastric adenocarcinoma.

Cigarette smoking and breast cancer risk: a long latency period?

The association between cigarette smoking and breast cancer risk remains unclear. Few studies have examined cigarette smoking of very long duration as there may not have been a sufficient number of long-term smokers in studies conducted before the 1980s. Therefore, we examined the association between smoking and breast cancer risk using data from participants in a randomized controlled trial of screening for breast cancer involving 89,835 women aged 40-59 years at recruitment and with up to 40 years of smoking duration at that time.

Anthropometric and behavioral correlates of insulin-like growth factor I and insulin-like growth factor binding protein 3 in middle-aged Japanese men.

High levels of plasma insulin-like growth factor I (IGF-I) and low levels of insulin-like growth factor binding protein 3 (IGFBP-3) have been related to increased risk of several cancers. Little is known about the behavioral determinants of these biologic markers. The authors examined the relation of anthropometric and behavioral factors to plasma concentrations of IGF-I and IGFBP-3 in a cross-sectional study of 616 Japanese men aged 45-55 years in 1995-1996.

Cigarette smoking and the risk of endometrial cancer.

Epidemiological studies have shown that cigarette smoking is associated with a reduced risk of endometrial cancer, in contrast to the increased risks observed with many other non-respiratory-tract cancers, including those of the bladder, pancreas, and cervix uteri. Some studies of endometrial cancer suggest that the inverse association with smoking is limited to certain groups of women, such as those who are postmenopausal or those taking hormone-replacement therapy. The biological mechanisms that might underlie this association remain unclear, although several have been proposed, including an antioestrogenic effect of cigarette smoking on circulating oestrogen concentrations, a reduction in relative bodyweight, and an earlier age at menopause.

Polymorphisms of the human leukocyte antigen DRB1 and DQB1 genes and the natural history of human papillomavirus infection.

This study investigated, through cohort analysis, whether HLA-DRB1 and -DQB1 variability is related to human papillomavirus (HPV) infection prevalence and persistence. HLA-DRB1 and -DQB1 genes were typed in 620 samples from the Ludwig-McGill cohort. HPV positivity was tested in specimens collected every 4 months during the first year of follow-up.

Obesity and colorectal cancer risk in women.

Background: Several large studies of obesity and colorectal cancer risk have found no association among women but a reasonably consistent positive association among men. In women, a positive association that is stronger among, or limited to, those who are premenopausal has been suggested by studies that stratified analyses by age, although no previous study has examined the association by menopausal status.

Methods: We used proportional hazards analyses to estimate hazard ratios relating obesity to colorectal cancer risk among 89,835 women aged 40-59 years at recruitment into the Canadian National Breast Screening Study, a multicentre randomised controlled trial of mammography screening for breast cancer.