British scientists measured the aluminum content inside of breast tissue to find a relation between breast cancer and deodorants. They found that there is a significantly higher portion in the outer regions of the breast that have the greatest exposure to antiperspirant. This recent study identified a specific distribution of aluminum in breast tissue which may be associated with breast cancer. Deodorants are mainly made up from aluminum salts that have been associated with cancer and other human diseases. Continuous usage of antiperspirants is likely responsible for the buildup of aluminum in the tissue of the underarm and nearby areas. Another explanation for the higher aluminum concentration would be that tumourous tissue acts as a sink for systemic aluminum. Experts say that there is still no proof that either deodorant or antiperspirant use increases the risk of developing breast cancer, because it is a very complex disease and the causes of cancer are unknown for most of women diagnosed with it.