Phytochemical effects of soy isoflavones consumption on urinary estrogen levels in premenopausal and postmenopausal women with breast cancer
Breast cancer is the first of the top ten malignancies in Iraq. The benefits of consuming soy foods for hormone-positive breast cancer women are controversial. This study aimed to evaluate the effects of soy isoflavones on urinary estrogens levels and to investigate the association between urinary estrogens and urinary isoflavones in premenopausal (PreM) and postmenopausal (PostM) women with hormone-positive breast cancer treated with anti-estrogens. A randomized, interventional comparison study was carried out on 120 Iraqi women with hormonal-positive and HR2 Negative breast cancer. Participants were asked to fill out a questionnaire and to get urine samples. All participants were given (½ cup of soymilk daily) for one month and (one cup of soymilk daily) for another month. The fasted morning urine samples were collected monthly for urinary isoflavones and estrogens HPLC analysis. The mean estradiol level in PreM was significantly higher than in PostM, but after low and high doses of soymilk, it was much lower in PreM than in PostM women. While the mean estrone concentrations at low dose of soymilk were higher in PreM than in PostM women, but after high dose soymilk lower in PreM than in PostM women. Estrone level has biphasic non-significant change after isoflavone intake. Estrodail and Didazain level in PreM is lower than in PostM women after soy intake. Genstaine levels in PreM are higher than in PostM beyond soy intake. Patients who experience low urinary estradiol levels on soy food have less tendency to disease progression.