Residential proximity to agricultural pesticide use and incidence of breast cancer in the California Teachers Study cohort

We examined the association between residential proximity to agricultural pesticide use and breast cancer incidence among members of the California Teachers Study cohort, a large study of professional school employees with extensive information on breast cancer risk factors, followed for cancer incidence since 1995. We identified 1552 invasive breast cancer cases, diagnosed between 1996 and 1999, among 114,835 cohort members. We used California Pesticide Use Reporting data to select pesticides for analysis based on use volume, carcinogenic potential, and exposure potential; a Geographic Information System was used to estimate pesticide applications within a half-mile radius of subjects' residences. We applied Cox proportional hazard models to estimate hazard rate ratios (HR) for selected pesticides, adjusting for age, race, and socioeconomic status. We saw no association between residential proximity to recent agricultural pesticide use and invasive breast cancer incidence. HR estimates for the highest compared to the lowest exposure categories for groups of agents were as follows: probable or likely carcinogens (1.07, 95% confidence interval (CI): 0.86-1.32), possible or suggestive carcinogens (1.06, 95% CI: 0.87-1.29), mammary carcinogens (1.15, 95% CI: 0.90-1.48), and endocrine disruptors (1.03, 95% CI: 0.86-1.25). HR estimates for other groups and individual pesticides did not differ from unity, nor was there a trend for any groupings of or individual pesticides examined. Stratifying by menopausal status or family history of breast cancer did not substantially affect our results. Our analyses suggest that breast cancer incidence is not elevated in areas of recent, high agricultural pesticide use in California.     

Pesticide use and breast cancer risk among farmers' wives in the agricultural health study

The authors examined the association between pesticide use and breast cancer incidence among farmers' wives in a large prospective cohort study in Iowa and North Carolina. Participants were 30,454 women with no history of breast cancer prior to cohort enrollment in 1993-1997. Information on pesticide use and other information was obtained by self-administered questionnaire at enrollment from the women and their husbands. Through 2000, 309 incident breast cancer cases were identified via population-based cancer registries. Rate ratios were calculated for individual pesticides using Poisson regression, controlling for confounding factors. Breast cancer standardized incidence ratios were 0.87 (95% confidence interval: 0.74, 1.02) for women who reported ever applying pesticides and 1.05 (95% confidence interval: 0.89, 1.24) for women who reported never applying pesticides. There was some evidence of increased risk associated with use of 2,4,5-trichloro-phenoxypropionic acid (2,4,5-TP) and possibly use of dieldrin, captan, and 2,4,5-trichlorophenoxyacetic acid (2,4,5-TP), but small numbers of cases among those who had personally used the pesticides precluded firm conclusions. The authors found no clear association of breast cancer risk with farm size or washing of clothes worn during pesticide application, but risk was modestly elevated among women whose homes were closest to areas of pesticide application. Further follow-up of this cohort should help clarify the relation between pesticide exposure and breast cancer risk.     

Household and occupational exposure to pesticides and risk of breast cancer

The association between breast cancer in women and the use of household or occupational pesticides was examined in a population-based case-control study. This study was conducted in Western Australia in 2009–2011and included 1,789 controls and 1,205 cases. Information on household pesticide exposure was collected from questionnaires. For occupational pesticide exposure, job-specific modules (JSMs) were used. To evaluate potential recall bias, we stratified the analysis by belief about whether pesticides contribute to breast cancer. Unconditional logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs). Women’s exposures to pesticides in households and workplaces were not related to increased risk of breast cancer (OR?=?1.10; CI: 0.86–1.37) and (OR?=?0.77; CI: 0.45–1.32), respectively. The prevalence of occupational exposure to pesticides among women in our study was low. In the stratified analyses, the odd ratios associated with household pesticide use were similar among participants who believed pesticides increased breast cancer risk and those who did not. The results of our study did not show associations between breast cancer and household or occupational exposure to pesticides.     

Maternal age,anthropometrics and pregnancy oestriol

It has been hypothesised that oestrogen exposure in utero influences the risk for breast cancer in adult life. Although several studies report associations between breast cancer and maternal factors associated with birthweight of the offspring - a marker for antenatal oestriol exposure - little is known about the relations between maternal oestrogen levels and these factors per se. We therefore analysed the association between oestriol levels in 188 women in the 17th, 25th, 33rd and 37th weeks of pregnancy, and maternal age, prepregnancy weight, height and pregnancy weight gain.Both maternal prepregnancy body mass index and maternal height were, after controlling for infant birthweight, independently and inversely associated with oestriol levels (P = 0.0021 and P = 0.0006 respectively). We found no association between maternal age or pregnancy weight gain and pregnancy oestriol levels. These findings suggest that the previously reported associations between maternal age and maternal pregnancy weight gain and the offsprings risk of breast cancer are due to factors other than antenatal exposure to oestriol.     

Association between residence on Cape Cod, Massachusetts, and breast cancer

PURPOSE: Massachusetts cancer registry and case-control data suggest that breast cancer incidence is elevated on Cape Cod relative to other parts of the state. We examined the association between length of residence on Cape Cod and breast cancer, since residential history could be acting as a surrogate for unidentified environmental risk factors. METHODS: We computed odds ratios (OR) and 95% confidence limits (CL) for 1121 cases occurring between 1988 and 1995 on Cape Cod and 992 controls, according to categories of residence time on Cape Cod, after adjusting for age, family history, parity and age at first live or stillbirth, education, body mass index, and breast cancer history. RESULTS: Breast cancer risk was elevated among women living on Cape Cod 5 or more years with a peak occurring in the 25 to less than 30 year category (adjusted OR=1.72; 95% CL, 1.12, 2.64). Adjusting for confounding strengthened the associations. Odds ratios did not increase monotonically over categories of longer residence. CONCLUSIONS: Our results suggest that longer residence on Cape Cod is associated with elevated breast cancer risk, however inconsistency in the pattern of association limits conclusions that might be drawn about it. Suspected environmental exposures include pesticides and drinking water contaminated by industrial, agricultural, and residential land use.     

Spatial modeling of dengue and socio-environmental indicators in the city of Rio de Janeiro, Brazil

This study analyzed the spatial distribution of dengue in Rio de Janeiro, Brazil, in 2006, and associations between the incidence per 100,000 inhabitants and socio-environmental variables. The study analyzed reported dengue cases among the city's inhabitants, rainfall, Breteau index (for Aedes aegypti and Aedes albopictus), Gini index, and social development index. We conducted mapping and used the global Moran index to measure the indicators' spatial autocorrelation, which was positive for all variables. The generalized linear model showed a direct association between dengue incidence and rainfall, one-month rainfall time lag, Gini index, and Breteau index for A. albopictus. The conditional autoregressive model (CAR) showed a direct association with rainfall for four months of the year, rain time lag in July, and Gini index in February. The results demonstrate the importance of socio-environmental variables in the dynamics of dengue transmission and the relevance for the development of dengue control strategies.     

Dietary carbohydrate intake is not associated with the breast cancer incidence rate ratio in postmenopausal Danish women

Although many case-control studies have suggested positive associations between carbohydrate intake and breast cancer incidence rates in both pre- and postmenopausal women, there is limited information available from cohort studies. We examined the effect of the intake of different carbohydrates, the glycemic index, and the glycemic load on breast cancer incidence in postmenopausal women taking into consideration tumor estrogen receptor status. Postmenopausal women (n = 23,870; aged 50-65 y) participated in the "Diet, Cancer, and Health" study, and provided information about diet and established risk factors for breast cancer. During follow-up, we identified 634 incidents of breast cancer. Associations between carbohydrate intake and breast cancer incidence were analyzed using Cox's regression models. There was no association for intake of glucose, fructose, sucrose, maltose, lactose, or starch and breast cancer incidence rate, and no association for glycemic index or glycemic load after adjusting for confounding factors. Intake of different carbohydrates was not associated with breast cancer incidence rates for either estrogen receptor positive (ER+) or (ER-) breast cancer. Similarly, glycemic index and glycemic load were not associated with ER+ breast cancer after adjusting for confounding factors. A borderline significant positive association between glycemic index and (ER-) breast cancer was observed (P = 0.05). In conclusion, we found no clear associations between intake of different carbohydrates, total carbohydrate intake, glycemic index, or glycemic load and breast cancer incidence in postmenopausal women. Furthermore, when ER+ and ER- breast cancer cases were analyzed separately, no clear associations were observed.     

Does stage at diagnosis influence the observed relationship between socioeconomic status and breast cancer incidence, case-fatality, and mortality?

Historically, lower socioeconomic status (SES) has been reported to be associated with decreased breast cancer incidence and mortality and increased case-fatality, although recent trends in breast cancer screening and treatment may alter these relationships. This study assessed the associations between SES and breast cancer incidence, case-fatality, and mortality by stage of disease at diagnosis using recent data in the United States. Breast cancer incidence and survival data from the Surveillance, Epidemiology, and End Results (SEER) tumor registry for black and white women aged 55 and above were linked to county level SES and population data based on place of residence. Poisson regression was used to calculate age-adjusted relative rates associated with SES levels and breast cancer incidence, case-fatality, and mortality. As SES decreased, localized breast cancer incidence rates decreased, while incidence rates of distant disease increased. Five-year localized and regional breast cancer case-fatality rates increased as SES decreased. Localized breast cancer mortality rates decreased as SES declined, whereas regional breast cancer mortality rates tended to increase. These results confirm some previously reported findings and suggest that associations between lower SES and lower localized breast cancer mortality rates are influenced mainly by underlying associations between SES and localized breast cancer incidence, whereas regional breast cancer mortality rates appear to reflect the underlying association between SES and regional case-fatality rates.     

Socioeconomic inequality of cancer mortality in the United States: a spatial data mining approach

Background  

The objective of this study was to demonstrate the use of an association rule mining approach to discover associations between selected socioeconomic variables and the four most leading causes of cancer mortality in the United States. An association rule mining algorithm was applied to extract associations between the 1988–1992 cancer mortality rates for colorectal, lung, breast, and prostate cancers defined at the Health Service Area level and selected socioeconomic variables from the 1990 United States census. Geographic information system technology was used to integrate these data which were defined at different spatial resolutions, and to visualize and analyze the results from the association rule mining process.     

Local clustering in breast,lung and colorectal cancer in Long Island,New York

Background  

Analyses of spatial disease patterns usually employ a univariate approach that uses one technique to identify disease clusters. Because different methods are sensitive to different aspects of spatial pattern, an approach employing a battery of techniques is expected to describe geographic variation in human health more fully. This two-part study employs a multi-method approach to elucidate geographic variation in cancer incidence in Long Island, New York, and to evaluate spatial association with air-borne toxics. This first paper uses the local Moran statistic to identify cancer hotspots and spatial outliers. We evaluated the geographic distributions of breast cancer in females and colorectal and lung cancer in males and females in Nassau, Queens, and Suffolk counties, New York, USA. We calculated standardized morbidity ratios (SMR values) from New York State Department of Health (NYSDOH) data.