What are the most common locations of metastases in colorectal cancer?
The liver is the most common site because the portal vein receives the majority of colonic venous drainage.
Other common sites include the lungs, adrenal glands, and osseous structures.
The rectum has dual venous drainage into the portal venous system (via the superior hemorrhoidal vein) and into the systemic venous system (via the middle and inferior hemorrhoidal veins to the inferior vena cava).
For this reason, rectal cancer has a predilection to lead to lung cancer metastases, sometimes without liver metastases.
