Environmental Exposure and Breast Cancer Among Young Women in Rio De Janeiro, Brazil

Abstract

Increasing breast cancer rates among young women (<40 years old) have been reported by the population-based cancer registries in Brazil. A case series study was carried out in Rio de Janeiro aiming to obtain epidemiological information allowing the generation of hypotheses to be further evaluated in analytical studies. One hundred and ten women 20–35 years old diagnosed with breast cancer were interviewed to determine the role environment plays in patients cased upon residential location. A comprehensive questionnaire including personal information (medical and lifestyle antecedents, reproductive history, family history of cancer, chemical and radiation exposure) was employed, and the obtained data were further compared with data provided by controls (women without cancer). An unconditional logistic regression was further employed to ascertain the respective odds ratios (OR) and their 95% confidence intervals (CI). Seventy-one percent of cancer cases were sporadic breast cancer, and familial aggregation (first degree relatives) was observed in just 3.5% (5.5% including second-degree relatives). Forty (51.3%) of the cancer cases were reported to have resided at a distance of less than 20 m from an electrical power transformer. Bivariate analysis revealed OR = 5.62 (95% CI 2.63–12) for residential use of pesticides during adulthood, OR = 2.15 (95% CI 1.22–3.77) for dental diagnostic x-rays, and OR= 1.53 (95% 0.77–3.04) for living nearby an electrical power transformer. Further multivariate analysis showed an adjusted OR = 3.5 (95% CI 1.11–11.0) for residential use of pesticides, and an adjusted OR = 2 (95% CI 1.24–3.23) for dental diagnostic x-rays during adulthood. The observed results highlight the importance of exploring the contribution of selected environmental agents possibly involved in breast carcinogenesis among young women.

Notes

This study was supported by the Brazilian National Research Council (CNPq), grant 307645/2004-5. Rosalina Koifman and Sergio Koifman are sponsored by research grants from the Brazilian National Research Council-CNPq and the State of Rio de Janeiro Research Council (FAPERJ). Sergio Koifman is an Irving J. Selikoff International Scholar of the Mount Sinai School of Medicine. His work was supported in part by award D43TW00640 from the Fogarty International Center. The presented content is solely the responsibility of the authors and does not necessarily represent the official views of the Fogarty International Center or the National Institutes of Health.