The term adenocarcinoma is a descriptive term for how the cancer cells look when viewed under a microscope.
Adenocarcinomas are cancer cells that appear to form glands.
Colon cancer is nearly always classified as adenocarcinoma. The term metastatic indicates that the cancer has spread to other areas of the body. When detected in its early stages, treatment of colon cancer by surgical removal is highly successful. Unfortunately, once colon cancer is metastatic, it's almost always incurable. Treatment may shrink the tumor and perhaps relieve symptoms but not eradicate it.