PAEA Surgery End Of Rotation (EOR) Practice Exam

Where is the most common site of distal metastases in colorectal cancer?

1. Lungs

2. Brain

3. Liver

4. Bone

The correct answer is: Liver

The liver is the most common site of distal metastases in colorectal cancer due to the pattern of blood flow in the body. Colorectal cancer cells can spread through the portal circulation, which drains blood from the gastrointestinal tract directly to the liver. This anatomical relationship means that any cancerous cells shed from a primary colorectal tumor are likely to first travel to the liver, making it a prime location for metastatic disease. While other sites like the lungs and bones are also potential locations for metastases, they occur less frequently compared to the liver in the context of colorectal cancer. The brain, although it can also be a site of metastasis in many cancers, is not a typical site for colorectal cancer, confirming that although metastasis can happen in various areas, the liver holds the highest prevalence for colorectal metastasis. The distinct preference of colorectal cancer for the liver is a key point in understanding the disease's progression and associated management strategies.