Assessment of potential risk factors for breast cancer in a population in Southern Brazil
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The aim of this study is to assess potential risk factors for breast cancer in a population in Southern Brazil and build a multivariate logistic model using these factors for breast cancer risk prediction.
A total of 4242 women between 40 and 69 years of age without a history of breast cancer were selected at primary healthcare facilities in Porto Alegre and submitted to mammographic screening. They were evaluated for potential risk factors.
In all, 73 participants among the 4242 women had a breast cancer diagnosis during the follow-up of the project (10 years). The multivariate analysis considering all the patients aged 40–69 years showed that older age (OR 1.08, 95% CI 1.04–1.12), higher height (OR 1.04, 95% CI 1.01–1.09), and history of previous breast biopsy (OR 2.66, 95% CI 1.38–5.13) were associated with the development of breast cancer. Conversely, the number of pregnancies (OR 0.87, 95% CI 0.78–0.98) and use of hormone replacement therapy (OR 0.39, 95% CI 0.20–0.75) were considered a protective factor. Additionally, we performed an analysis separating the participants into groups of 40–49 and 50–69 years old, since a risk factor could have a specific behavior in these age groups. No additional risk factors were identified within these age brackets, and some factors lost statistical significance.
The risk prediction model indicates that the following variables should be assessed in this specific population: age, height, having had previous breast biopsies, number of pregnancies, and use of hormone replacement therapy. These findings may help to better understand the causal model of breast cancer in Southern Brazil.
KeywordsBreast cancer Risk factors Mortality Etiology Incidence
This study was funded by Brazilian Ministry of Health along with the Moinhos de Vento Hospital through the Program for Supporting the Institutional Development of the Public Health System (PROADI-SUS).
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflicts of interest.
Informed consent was obtained from all individual participants included in the study.
- 1.Breast cancer statistics | World Cancer Research Fund International. http://www.wcrf.org/int/cancer-facts-figures/data-specific-cancers/breast-cancer-statistics. Accessed 5 Sep 2017
- 2.INCA—Instituto Nacional de Câncer—Estimativa 2016. http://www.inca.gov.br/estimativa/2016/. Accessed 5 Sep 2017
- 3.Fact Sheets by Population. http://globocan.iarc.fr/Pages/fact_sheets_population.aspx. Accessed 13 Sep 2017
- 6.Breast Cancer Risk and Prevention. https://www.cancer.org/cancer/breast-cancer/risk-and-prevention.html. Accessed 5 Sep 2017
- 8.Associação Brasileira de Empresas de Pesquisa (ABEP) (2012) Critério de Classificação Econômica BrasilGoogle Scholar
- 9.WHO | Obesity and overweight. In: WHO. http://www.who.int/mediacentre/factsheets/fs311/en/. Accessed 7 Sep 2017
- 10.SAS (2016) SAS Institute Inc. 2016. SAS/STAT® 14.2 User’s Guide. Cary, NC: SAS Institute IncGoogle Scholar
- 11.U.S. Breast Cancer Statistics. In: Breastcancer.org. http://www.breastcancer.org/symptoms/understand_bc/statistics. Accessed 6 Sep 2017
- 12.National Breast and Ovarian Cancer Centre (2009) Breast cancer risk factors: a review of the evidence. National Breast and Ovarian Cancer Centre, Surry Hills, NSWGoogle Scholar
- 13.Cancer Statistics Review, 1975–2014—SEER Statistics. https://seer.cancer.gov/csr/1975_2014/. Accessed 22 Oct 2017
- 17.Freisling H, Arnold M, Soerjomataram I et al (2017) Comparison of general obesity and measures of body fat distribution in older adults in relation to cancer risk: meta-analysis of individual participant data of seven prospective cohorts in Europe. Br J Cancer 116:1486–1497. https://doi.org/10.1038/bjc.2017.106 CrossRefPubMedGoogle Scholar
- 23.Collaborative Group on Hormonal Factors in Breast Cancer (1997) Breast cancer and hormone replacement therapy: collaborative reanalysis of data from 51 epidemiological studies of 52,705 women with breast cancer and 108,411 women without breast cancer. Lancet Lond Engl 350:1047–1059CrossRefGoogle Scholar