It appears that cancer that started in the colon has probably punched through the colon wall and spread to the liver. Calcification on the liver generally indicates calcium has formed in areas affected by past infection or injury, typically to protect the area from further damage.
A malignant tumor with liver calcification may require advanced or invasive treatment. Surgery to remove a mass or radiation therapy may be an option for calcification on the liver caused by a malignant tumor. A follow-up course of chemotherapy may also be prescribed.
Basically, the colon cancer has metastasized; spread to the liver.