Definition of Metastatic cancer to the lung:

Metastatic lung cancer is cancer that starts somewhere else in the body and spreads to the lungs.

See also: Lung cancer

Causes, incidence, and risk factors:

Metastatic tumors in the lungs are malignancies (cancers) that developed at other sites and spread via the blood stream to the lungs. Common tumors that metastasize to the lungs include breast cancer, colon cancer, prostate cancer, sarcoma, bladder cancer, neuroblastoma, and Wilm's tumor. However, almost any cancer has the capacity to spread to the lungs.