Why breast cancer often spreads to lungs revealed

Researchers have why breast cancer often spreads or metastasizes to the lung.

In this paper, the researchers developed an innovative ex vivo (outside the living organism) model system that simulates different organ environments.

They observed that breast CSCs have a particular propensity for migrating towards and growing in the lung, and they identified specific interactions between breast CSCs and lung-derived proteins that could be disrupted to reduce the metastatic behavior of breast cancer.

Alison Allan, PhD, a scientist at Western University and the Lawson Health Research Institute said that in metastasis, there's a theory called the seed and soil hypothesis.

"Analogous to a dandelion, when it goes to seed, the seeds blow all over the place. But they don't necessarily grow everywhere they land; they grow only in congenial soil that has the right nutrients that support growth of seeds in a foreign environment. In the situation of metastasis, the tumor cells ('seeds') have some inherent factors that determine their aggressiveness and ability to metastasize, while the different organs ('soil') are believed to provide important factors that attract tumor cells to particular organs and help support their survival and growth into metastatic tumors," explains Allan, an associate professor in the Departments of Oncology, and Anatomy and Cell Biology at Western's Schulich School of Medicine and Dentistry.

"A lot of research has been done on the cancer cells because they're easy to study, but not a lot has gone into understanding the 'soil factor.' We've uncovered some specific proteins that are produced in the lung that seem to interact with cancer stem cells, making the lungs a congenial place for cancer cells to grow."

The paper has been published online in the journal Neoplasia.