Breast cancer, which is caused by rapid and abnormal growth of cells in the breast, is a complex disease in which many factors can be involved. Some factors such as age, family history, genetics and gender are not under the control of the individual. However, a person can control other factors such as smoking, physical activity, proper weight and diet to prevent breast cancer. Some researchers believe that diet can be responsible for 30-40% of all cancers. This study raises an interesting point in research to identify breast cancer risk by focusing on estrogen- or progesterone-enhancing chemicals. However, without in vivo studies, it is premature to attempt to make a definitive connection. A multifaceted approach is necessary to fully understand the role that chemicals play in the development of breast cancer. According to Dr. Truss, this should include all data from cell studies, animal studies, and human observations. The human body is [also] very complex, and studying one piece of the puzzle individually may be very different than what happens when all the pieces are put together, said Dr. Lauren Truss. Dr. Gramley added: "Even if the findings are interesting, we can't take it and apply it to humans." Evaluating the effects of these chemicals on humans is still challenging and most of them have not been studied enough. So we expect more care to be taken in interpreting observations of chemically induced changes in breast tissue, Rudel said. A new cell culture study joins the list of research investigating the link between environmental chemicals and breast cancer. Although this is a bold and premature claim, the paper overlaps with what experts currently believe. A new study suggests that certain synthetic chemicals can increase the risk of breast cancer by stimulating hormones.