Rectal cancer commonly metastasizes to which organ?

Rectal cancer commonly metastasizes to the liver due to the vascular connection between the rectum and the hepatic circulation. The blood from the rectum drains into the inferior mesenteric vein, which ultimately merges with the splenic vein to form the portal vein. This portal vein carries blood directly to the liver, making it a likely site for metastatic spread.

The liver is often the first organ to be affected by metastases from colorectal cancers because of its unique blood supply and filtration function. Once cancer cells enter the bloodstream, they can easily lodge in the liver, leading to secondary tumor growth. As a result, monitoring liver function and screening for liver metastases are crucial parts of the management of patients with rectal cancer.