Waist-to-Hip Ratio and Breast Cancer Mortality Borugian, Marilyn J.; Sheps, Samuel B.; Kim-Sing, Charmaine ...
American journal of epidemiology,
11/2003, Letnik:
158, Številka:
10
Journal Article
Recenzirano
Odprti dostop
High insulin levels have been associated with increased risk of breast cancer and poorer survival after a breast cancer diagnosis. Waist-to-hip ratio (WHR) is a marker for insulin resistance and ...hyperinsulinemia. In this study, the authors tested the hypothesis that elevated WHR is directly related to breast cancer mortality. For identification of modifiable factors affecting survival, data were collected on 603 patients with incident breast cancer who visited the Vancouver Cancer Centre of the British Columbia Cancer Agency (Vancouver, British Columbia, Canada) in 1991–1992, including body measurements and information on demographic, medical, reproductive, and dietary factors. These patients were followed for up to 10 years. Cox proportional hazards regression models were used to relate the variables to breast cancer mortality (n = 112). After adjustment for age, body mass index, family history, estrogen receptor (ER) status, tumor stage at diagnosis, and systemic treatment (chemotherapy or tamoxifen), WHR was directly related to breast cancer mortality in postmenopausal women (for highest quartile vs. lowest, relative risk = 3.3, 95% confidence interval: 1.1, 10.4) but not in premenopausal women (relative risk = 1.2, 95% confidence interval: 0.4, 3.4). Stratification according to ER status showed that the increased mortality was restricted to ER-positive postmenopausal women. Elevated WHR was confirmed as a predictor of breast cancer mortality, with menopausal status and ER status at diagnosis found to be important modifiers of that relation.
A strategic partnership has been formed to establish a large prospective cohort for the study of the causes of cancer and other chronic diseases in Canada. This partnership, the Can - adian ...Partnership for Tomorrow Project, aims to develop a comprehensive, long-term, pan-Canadian health research platform with sufficient statistical power to examine the complex interplay of genetic and environmental factors that leads to the development of important chronic diseases in the Canadian population.7 The Canadian Partnership for Tomorrow Project comprises a confederation of provincial and regional cohorts (Table 2) in British Columbia, Alberta, Ontario, Quebec and Atlantic Canada (Nova Scotia, New Brunswick, Prince Edward Island, and Newfoundland and Labrador). The oper - ational objective is to enrol 250 000 to 300 000 Canadians aged 35-69 years by 2012, and enrolment is already under way. A number of task forces and working groups have been established to address issues related to ethics, privacy, har - monization, information technology, sample processing and definition of environmental exposures of interest (Figure 1). Contributors: All authors contributed to manuscript conception and design. Marilyn J. Borugian PhD, John McLaughlin PhD and Richard P. Gallagher MA contributed to writing the initial drafts of the article, revising the manuscript and responding to editors and reviewers. Paula Robson PhD, Isabel Fortier PhD, Louise Parker PhD, Bartha Maria Knoppers PhD, Karine Bédard, Sandra Sinclair, Vincent Ferretti PhD, Heather Whelan, David Hoskin PhD and John D. Potter MD PhD were involved in reviewing drafts and suggesting revisions. Isabel Fortier provided information about cohorts in other countries. Louise Parker provided input to responses to editors and reviewers. Bartha Maria Knoppers provided expert advice on ethical and governance issues. Vincent Ferretti provided information about information technology challenges. John D. Potter made suggestions about responses to editors and reviewers and provided information about other cohorts around the world. All authors approved the final version of the manuscript submitted for publication. From the Cancer Control Research Program (Borugian, Gallagher), British Columbia Cancer Agency and School of Population and Public Health, University of British Columbia, Vancouver, BC; Alberta Health Services - Cancer Care (Robson, Whelan), Edmonton, Alta.; School of Public Health (Robson), University of Alberta, Edmonton, Alta.; Public Population Project in Genomics (Fortier), Université de Montréal, Montréal, Que.; Cancer Care Nova Scotia (Parker), Dalhousie University, Halifax, NS; Population Studies and Surveillance (McLaughlin, Sinclair), Cancer Care Ontario, Toronto, Ont.; Dalla Lana School of Public Health (McLaughlin), University of Toronto, Toronto, Ont.; Centre of Genomics and Policy (Knoppers), McGill University, Montréal, Que.; CARTaGENE (Bédard), Université de Montréal, Montréal, Que.; Ontario Institute for Cancer Research (Ferretti), Toronto, Ont.; Capital District Health Authority and Dalhousie University (Hoskin), Halifax, NS; and Fred Hutchinson Cancer Research Center (Potter), Seattle, USA
High levels of insulin have been associated with increased risk of breast cancer, and poorer survival after diagnosis. Data
and sera were collected from 603 breast cancer patients, including ...information on diet and physical activity, medical history,
family history, demographic, and reproductive risk factors. These data were analyzed to test the hypothesis that excess insulin
and related factors are directly related to mortality after a diagnosis of breast cancer. The cohort was recruited from breast
cancer patients treated at the British Columbia Cancer Agency between July 1991 and December 1992. Questionnaire and medical
record data were collected at enrolment and outcomes were ascertained by linkage to the BC Cancer Registry after 10 years
of follow-up. The primary outcome of interest was breast cancer-specific mortality ( n = 112). Lifestyle data were analyzed using Cox proportional hazards regression models to relate risk factors to outcomes,
controlling for potential confounders, such as age and stage at diagnosis. Data for biological variables were analyzed as
a nested case-control study due to limited serum volumes, with at least one survivor from the same cohort as a control for
each breast cancer death, matched on stage and length of follow-up. High levels of insulin were associated with poorer survival
for postmenopausal women odds ratio, 1.9; 95% confidence interval (CI), 0.7-6.6, comparing highest to lowest tertile, P trend = 0.10, while high dietary fat intake was associated with poorer survival for premenopausal women (relative risk,
4.8; 95% CI, 1.3-18.1, comparing highest to lowest quartile). Higher dietary protein intake was associated with better survival
for all women (relative risk, 0.4; 95% CI, 0.2-0.8, comparing highest to lowest quartile).
Background: Leukemia is one of the most common potentially fatal illnesses in children, and its causes are not well understood. Although socioeconomic status (SES) has been related to leukemia in ...some studies, this apparent association may be attributable to ascertainment or participation bias. This study was undertaken to determine whether there is a difference in incidence of childhood leukemia for different levels of SES, as measured by neighborhood income, in an unselected population case group. Methods: All cases of childhood leukemia diagnosed in the years 1985-2001 were identified from population-based cancer registries in Canada. Postal codes for the place of residence at diagnosis were used to ascertain the census neighborhoods for cases. We constructed neighborhood-based income quintiles from census population data, and stratified the population at risk by sex and 5-year age groupings. Age-standardized incidence rates and 95% confidence intervals (CIs) were calculated. We used Poisson regression to compare incidence rate ratios (RRs) across income quintiles. Results: A slightly lower relative risk of childhood leukemia was observed in the poorest quintile compared with the richest (RR = 0.87; 95% CI = 0.80-0.95). The lower risk in the poorest quintile was restricted to acute lymphoid leukemia (0.86; 0.78-0.95) and was strengthened slightly by restriction to urban areas (0.83; 0.74-0.93). Conclusions: This analysis suggests that high SES is a true risk factor for childhood leukemia and that inconsistent results from other studies may be related to differences in case ascertainment or study participation.
Purpose: Mammographic breast density (BD) is associated with increased risk of breast cancer. This study asks which circulating metabolic and reproductive biomarkers are associated with BD, ...particularly dense breast area, in premenopausal women not taking exogenous hormones. Methods: In a cross-sectional study, 299 premenopausal women aged 40–49 completed questionnaires, provided a fasting blood sample, had height, weight, percentage body fat, waist and hip measurements taken, and attended a screening mammogram. Multivariate linear regression was used to calculate adjusted means for percentage BD, absolute dense and non-dense area, across categories of covariates, adjusted for day of menstrual cycle, age, parity, body mass index, percentage body fat, and ethnicity. Results: Fasting insulin levels were inversely associated, and insulin-like growth factor-binding protein 1 levels directly associated with percentage BD, but lost statistical significance after multivariate adjustment. Sex hormone-binding globulin levels were directly associated with percentage BD, still significant after multivariate adjustment (p = 0.03). A significant inverse does–response association was observed between progesterone levels and dense area (p < 0.01). Conclusions: Breast density in premenopausal women seems unrelated or inversely related to insulin resistance, levels of insulin-like growth factor 1 and its binding proteins, and levels of sex steroids; therefore, the mechanism by which radiodensity on a mammogram is related to breast cancer risk remains unclear.
In developed countries, women of higher socioeconomic status often have higher breast cancer incidence rates, compared with women of lower socioeconomic status.
Data were extracted from the Canadian ...Cancer Registry for the 229,955 cases of adult female invasive breast cancer diagnosed from 1992 through 2004. Postal code at diagnosis was used to determine neighbourhood income quintile. Breast cancer incidence was examined by year, region, age and neighbourhood income quintile. Census data for 1991 on children ever born and British Columbia data for 2006 on first-time attendance at mammography screening were analyzed by neighbourhood income quintile.
Residence in the lowest as opposed to the highest neighbourhood income quintile was associated with a 15% lower risk of being diagnosed with breast cancer. Higher income levels were associated with lower parity in 1991 and a higher prevalence of first-time screening mammography in British Columbia in 2006.
Canadian data support an association between the diagnosis of invasive breast cancer and neighbourhood income quintile. Parity and mammography screening may account for some differences in incidence.
To retrospectively assess the feasibility of an uninformed review process to evaluate interval breast cancers and to compare the number of false-negative cancers detected at uninformed review with ...the number detected at standard informed review.
Institutional review board approval was obtained for this retrospective study, and informed consent was waived. Mammograms showing interval cancer were included in the daily work of radiologists in a high-volume screening center. Each of three experienced radiologists read studies in the normal screening environment, without knowledge that identifiers had been changed to conceal the fact that studies were not current (ie, uninformed review). Results were compared with the standard review procedure, in which mammograms showing interval cancers were mixed with normal mammograms and read in a panel of 17-20 interval cancers per 80 normal studies by radiologists who were aware that they were participating in a review process (ie, informed review).
Of 21 interval cancers, six (29%) were interpreted as positive more often by the informed radiologists than by the uninformed radiologists. For 14 (67%) cancers, there was no difference in detection rate between the two groups, and one cancer (5%) was seen by one of the uninformed radiologists but by none of the informed radiologists. The screening environment review process was found to be feasible at the low volumes tested.
The number of false-negative cancers was higher in the informed review than in the uninformed review. This result suggests that bias exists with the informed review process.
The authors examined the relation between neighborhood income, as a measure of socioeconomic status, and childhood cancer. Incident cases of childhood solid tumor and lymphoma in 1985–2001 were ...identified from provincial cancer registries in Canada. Residential postal codes at the time of diagnosis were used to assign cases to census neighborhoods. Person-years at risk were determined from quintiles of population by neighborhood income, sex, and 5-year age group, constructed using census population data. Poisson regression was used to calculate incidence rate ratios across neighborhood income quintiles. Compared with the incidence rate in the richest income quintile, moderately lower rate ratios of 0.73 (95% confidence interval: 0.63, 0.86) and 0.84 (95% confidence interval: 0.69, 1.04) were observed, respectively, for carcinomas and renal tumors in the poorest income quintile. No association was found for other types of cancer. Although a potential relation between socioeconomic status and childhood cancer cannot be excluded, the overall pattern seems compatible with random variation.
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