Alcohol Consumption as a Risk Factor for Breast Cancer Development: A Case-Control Study in Brazil

Document Type: Research Articles

Authors

1 The Brazilian Society of Mastoloy from Rio de Janeiro – Rio de Janeiro (RJ), Brazil.

2 Post Graduate Program of Mastology, Pontifícia Universidade Católica do Rio de Janeiro (PUC-RJ), Rio de Janeiro (RJ), Brazil.

3 Department of Gynecology, Universidade Federal de São Paulo (UNIFESP), São Paulo, Brazil.

4 Research Center, Instituto Nacional de Câncer (INCA), Rio de Janeiro, Brazil.

5 Post Graduate Program in Neurology, Universidade Federal do Estado do Rio de Janeiro (UNIRIO), Rio de Janeiro, Brazil.

Abstract

Background: Alcohol consumption is a well-established risk factor for breast cancer, but the evidence is mostly
from developed countries. Brazil is going through a rapid demographic expansion, and studies of this relationship are
also needed in such unexplored settings. Methods: We assessed the relationship between alcohol consumption and
breast cancer risk among 1,506 Brazilian women (406 cases and 1,100 controls). Regression models were used to
calculate odds ratios (OR) and 95% confidence intervals (CI). All statistical tests were two-tailed. Results: The mean
age of the 1,506 women was 42.0 (standard deviation, ±15.0) years. There was a significant association between breast
cancer and age, body mass index, age at menarche, menstrual flow and menstrual cycle. Multivariate analysis showed
an increased risk of invasive breast cancer in regular alcohol consumers (years old: OR 3.9; 95% CI 1.2–13.4) compared with abstainers or occasional drinkers. Women with a regular alcohol
intake for 10 years or more who were less than 50 years old had a threefold higher risk of developing breast cancer
(OR 3.0; 95% CI 1.2–7.6). Conclusion: Regular alcohol consumption increases the risk of breast cancer mainly among
women less than 50 years old.

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