May 3, 2002

Lymphatic vessels surrounding tumors are key to cancer spread

MGH scientists have discovered that metastasis, or spreading, of cancer cells depends upon lymphatic vessels at the edges of tumors, not those within the tumor itself, as had been speculated. The results, which will appear in Science magazine, were published April 25 on the Science Express website at www.sciencexpress.org.

The lymphatic system plays an important role in immune function but may act as a conduit through which cancer cells spread. Previous studies have identified lymphatic structures within tumors, but those vessels have not appeared to be functional. The MGH researchers now have shown that only collapsed lymphatic structures reside within a tumor mass and there are no functional vessels.

"These findings suggest new strategies for cancer treatment," says Rakesh Jain, PhD, (right) of MGH Radiation Oncology. "Lymphatics at the tumor periphery are sufficient to carry cancer cells to other parts of the body, so these structures should be the targets of therapy." The MGH scientists have been conducting studies with a protein that stimulates the formation of lymphatic vessels and also promotes blood vessel formation in some tumors. They hope that hindering both blood vessel and lymphatic vessel formation may effectively block tumor metastasis.

The other members of this MGH research team are first author Timothy Padera; Ananth Kadambi, PhD; Emmanuelle di Tomaso, PhD; Carla Mouta Carreira, PhD; Edward Brown, PhD; Yves Boucher, PhD; Noah Choi, MD; Douglas Mathisen, MD; John Wain, MD; Eugene Mark, MD; and Lance Munn, PhD.