Scientists Find Key Player In Cancer's Spread

A protein called VEGF-A, already known to stimulate the growth of blood vessels associated with tumors, may also help tumors spread cancer to lymph nodes, according to a new study. In research with mice, scientists from Massachusetts General Hospital (MGH) and the Swiss Federal Institute of Technology found VEGF-A promotes development of lymphatic vessels that can deliver cancer cells to lymph nodes and actually pave the way for tumor spread. "This observation is our most surprising and exciting finding. It's a new twist to the 'seed-and-soil' hypothesis, which postulates that distinct cancer types preferentially metastasize to organs that are optimally suited for them. Our results indicate that the 'seeds' can actively modify the 'soil' and prepare it for later metastatic arrival," study senior author Dr. Michael Detmar, of the MGH Cutaneous Biology Research Center, said in a prepared statement. It was previously believed that the movement of tumor cells by the lymphatic system was a more passive process. "Our findings reveal that tumor cells, even after they have metastasized to the lymph nodes, can very actively induce the growth of the very channels that will enable transport to other nodes and organs," Detmar said. The process identified in this study could offer a promising target for the development of new treatments to prevent the further spread of metastatic cancer. The findings appear in the April Journal of Experimental Medicine.