Surprise route found for spread of breast cancer

Cancer cells are thought to enter the lymph nodes through the lymphatic system — a multipurpose welter of vessels — but how the cells actually make their way out of a primary tumor and into the lymphatic system has been an enduring puzzle. Massachusetts General Hospital researchers reported recently that they have identified a new — and surprising — mechanism by which breast cancer cells may metastasize to the lymph nodes. Mihaela Skobe, Michael Detmar, and their colleagues report that the tumor cells appear to be leaving the tumor through a homegrown system of lymphatic vessels — one expressly cultivated by the tumor. By blocking this growth, the researchers say, it may be possible to prevent the spread of cancer cells from a primary tumor.