Scientists Uncover How Cancer Metastasizes.(to the lymph nodes and lungs)

2001 FEB 15 - (NewsRx.com) -- Researchers have identified a mechanism by which breast cancer cells metastasize to the lymph nodes and lungs.

By blocking this path, the researchers believe it might be possible to prevent the spread of cancer cells from a primary tumor.

"We have identified a mechanism of breast cancer metastasis. I wouldn't say it's the mechanism because there may be several others," said Michael Detmar, MD, a dermatologist and principal investigator in the Cutaneous Biology Research Center (CBRC). "But this is certainly a major molecular mechanism of how breast cancer metastasizes to the lymph nodes."

The report was published from the Massachusetts General Hospital (MGH) CBRC in the February 2001 issue of Nature Medicine.

Although cancer cells are believed to enter the lymph nodes through the lymphatic system - a multipurpose tangle of vessels - little is known about how tumor cells get from the primary tumor into the lymphatic system. Detmar, Mihaela Skobe, PhD, a postdoctoral fellow, and their colleagues report that the tumorcells appear to be exiting the tumor through a home-grown system of lymphatic vessels-one expressly cultivated by the tumor.

What is surprising about the discovery is that lymphatic vessels were not thought to exist in tumors. Part of the problem, said Detmar, is that until recently there has been no effective means of visualizing lymphatic vessels. Using a new method for imaging lymphatic vessels, he and Skobe observed networks of lymphatic vessels deep inside breast tumor masses grown in mice. Upon closer inspection, the vessels appeared to be carrying tumor cells.

Most striking, the number of lymphatic vessels inside the tumor appeared to be highly correlated with the number of metastatic cells in the lymph nodes and lungs, suggesting that the lymphatic vessels were providing a conduit for the flow of metastatic tumor cells.