Document Type : Original Article
Authors
1
MSc, Center for Healthcare Data Modeling, School of public health, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
2
Prof, Center for Healthcare Data Modeling, Dept of Biostatistics and Epidemiology, School of public health, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
3
Associate Prof, Dept of Internal Medicine, School of Medicine, Shahid Sadoughi General Hospital, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
4
Prof, Dept of Oral and Maxillofacial Radiology, School of Dentistry, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
5
MSc Student, Dept of Ergonomics, School of Public Health, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
Abstract
Introduction: The identification of risk factors for breast cancer has an important role in examining the status of cancer care system. Therefore, the present study was conducted to determine the relationship between reproductive factors and breast cancer in women aged 35 to 70 years based on the data from the first phase of Shahedyeh Cohort Study (SCS) in Yazd province.
Materials and Methods: This descriptive, cross-sectional study was conducted using the data from the first phase of SCS in Yazd province in 2015-2017. In this study, 4820 women aged 35 to 70 years were investigated, including 25 (0.6%) with a history of breast cancer and 4795 (99.4%) without any history of breast cancer. The data used in this study included demographic and reproductive histories of the women. The data were analyzed using Chi-square, t-test, and logistic regression.
Results: The results showed that breastfeeding for less than 11 months increases the chance of breast cancer by 2.78 times, hormone therapy after menopause by 2.07 times, the onset age of menopause ≥46 by 1.71 times, having a history of abortion by 1.63 times, taking contraceptive pills by 1.59 times, age at menarche ≤13 by 1.49 times, and being overweight and obesity by 1.45 times.
Conclusion: According to the results, breastfeeding for less than 11 months, hormone therapy after menopause, the onset age of menopause after 46 years, and taking contraceptive pills were the most important risk factors for breast cancer.
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