Case-control Study On The Association Of Sex Steriod Hormone Levels With The Risk Of Breast Cancer

Objective: The purpose of the study is to explore the association of sex steroid hormone levels with risk of breast cancer, the study on the risk factors of breast cancer and evaluation on the relationship between sex steroid hormone levels and breast cancer risk has important significance on the sex steroid hormone levels of breast cancer, in order to breast cancer prevention and treatment and provide a theoretical basis.Methods: A hospital-based case-control study, which has conducted between Jan, 2013 and Jan, 2015 in urban Yan’an, was carried out to assess the relationship between sex steroid hormone and risk of breast cancer. Subjects were divided into the breast cancer and control group according to their disease status. And the study period was divided into follicle phase, luteal phase and postmenopausal period according to their menstrual status and menstrual cycle. A total 72 newly incident and histologically confirmed breast cancer were obtained in final analyzed, included 15 in follicle phase, 22 in luteal phase and 35 in postmenopausal period. And 93 healthy controls were enrolled into final study, included 20 in follicle phase, 31 in luteal phase and 42 in postmenopausal period. Software SPSS 22.0 was applied to analyze the difference of conventional risk factors and sex hormone levels among different groups. Conventional risk factors were studied with univariate and multivariate analysis by unconditional Logistic regression analysis and to evaluate the associations of breast cancer risk with sex hormone levels. All statistical tests were two-sides.Results: 1) By unconditional Logistic regression analysis with univariate, our study suggested that older at first live birth, with breast benign disease history, higher body mass index(BMI) value and higher education extent were the risk factors of breast cancer in premenopausal women. Besides, older at menopause, with breast benign disease history, and higher BMI value were the risk factors of breast cancer in postmenopausal women. On the contrary, older at menarche could effectively decrease the risk of breast cancer among pre- and post-menopausal women.2) By unconditional Logistic regression analysis with multivariate, we observed that with breast benign disease history and higher BMI value were the risk factors of breast cancer in pre- and post-menopausal women. Besides, older at first live birth and higher education extent were the risk factors of breast cancer in premenopausal women, and older at menopause was the risk factors of breast cancer in postmenopausal women. On the contrary, older at menarche could effectively decrease the risk of breast cancer among pre- and post-menopausal women.3) We observed that levels of testosterone in postmenopausal women was significantly higher than the healthy controls(P=0.010). By unconditional Logistic regression analysis, increased risks of breast cancer were positively associated with elevated concentration of testosterone for highest versus lowest quartile in follicle phase and postmenopausal period. Increased risks of breast cancer were positively associated with elevated concentration of testosterone in postmenopausal women(Ptrend=0.027).4)The levels of estrodiol in follicle phase and luteal phase was significantly higher than the healthy controls(P=0.010, 0.030). Increased risks of breast cancer were positively associated with elevated concentration of estrodiol for highest versus lowest quartile in follicle phase, luteal phase and postmenopausal period. Increased risks of breast cancer were positively associated with elevated concentration of estrodiol in follicle phase, luteal phase and postmenopausal(Ptrend=0.032, 0.039, 0.041).5)The levels of progesterone in luteal phase was significantly higher than the healthy controls(P=0.005). Increased risks of breast cancer were positively associated with elevated concentration of progesterone for highest versus lowest quartile in luteal phase. Increased risks of breast cancer were positively associated with elevated concentration of progesterone in luteal phase(Ptrend=0.011).Conclusion: Our study investigated the risk factors of breast cancer in Yan’an, Shaanxi, evaluated the associations of sex hormone levels with breast cancer risk. 1) We observed that older at menarche was the protective factors of breast cancer in pre- and post-menopausal women. 2) Besides, older at first live birth, with breast benign disease history, with family history of breast cancer, higher BMI value and higher education extent were the risk factors of breast cancer in premenopausal women. 3) And older at menopause, with breast benign disease history, with family history of breast cancer and higher BMI value were the risk factors of breast cancer in postmenopausal women. 4) Increased risks of breast cancer were positively associated with elevated concentration of testosterone in postmenopausal women. 5) Increased risks of breast cancer were positively associated with elevated concentration of estrodiol in follicle phase and luteal phase. 6) Increased risks of breast cancer were positively associated with and elevated concentration of progesterone in luteal phase.