The risk of some types of breast cancer could be modified by the increased phytoestrogens found in dietary soy, claims a new research study.
The research has benn conducted by Anne Weaver, a graduate student at the University at Buffalo and research apprentice at Roswell Park Cancer Institute and colleagues.
"This study was unique in that we looked at specific subtypes of breast cancer, and found a suggestion that menopausal status may play a role in risk," said Weaver.
Weaver and colleagues evaluated 683 women with breast cancer and compared them with 611 healthy women.
Those women with the highest isoflavone intake had an approximately 30 percent decreased risk of having an invasive breast tumor, and an approximately 60 percent decreased risk of having a grade 1 tumor.
Observations by menopausal status revealed that among premenopausal women, the highest intake of isoflavones had a 30 percent decreased risk of stage I disease, a 70 percent decreased risk of having a tumor larger than 2 cm, and a 60 percent decreased risk of having stage 2 breast cancer.
Like most dietary studies, Weaver said these findings are not definitive and need to be considered in the context of further follow-up and confirmation.
"Still, we definitely saw a reduction that deserves further investigation," she concluded.
The study was presented at the Ninth Annual AACR Frontiers in Cancer Prevention Research Conference.