Secondary lung cancer. Light micrograph of a section through lung tissue showing a tumour (pink, centre right) due to the spread of cancer from the liver. The spread of a cancer from one site in the body to others is called metastasis. The primary cancer in this case was a hepatoma, a cancer of liver cells. Once a cancer has spread throughout the body, any treatment must be systemic. Removal of all tumours must be followed by chemo- and radiotherapy (drug and radiation treatment). The prognosis is poor for most systemic cancer. Magnification unknown.