Researchers at Johns Hopkins University knew that breast cancer cells can grow so densely that they end up starved for oxygen. They discovered that a protein responsible for cell survival in low oxygen can trigger the spread of cancer cells into the lymphatic system in a mouse model of breast cancer.
The scientists say treating the mice with either digoxin, which blocks the protein, or imatinib, a cancer drug, reduced tumor size by 78 percent and reduced the spread to lymph nodes by 94 percent, although the researchers emphasized that more work must be done to determine whether these drugs will be effective in treating breast cancer patients.
The invasion of cancer cells into the lymph vessels that connect the breast to surrounding lymph nodes is the first step leading to mestastasis or the spread of cancer throughout the body. Metastasis is the primary cause of breast cancer deaths.
Results of the study are in the Proceedings of the National Academy of Sciences Online