PAEA Surgery End Of Rotation (EOR) Practice Exam

Which organ is the most common site for liver metastases?

1. Liver

2. Brain

3. Lungs

4. Bone

The correct answer is: Lungs

The correct choice highlights that the lungs are the most common site for liver metastases due to their extensive blood supply and the nature of the venous drainage from the liver. When cancers originate in other parts of the body, they can spread through the bloodstream. The most frequent primary cancers that lead to liver metastases include colorectal, breast, and lung cancers, among others. The lungs are strategically positioned as a key site for metastasis because of the way blood circulates – when cancer cells enter the venous system from the primary tumor, they can travel to the lungs before reaching the liver. Additionally, the pathways of circulation and filtration through the pulmonary vasculature allow for the deposition of metastatic cells. This understanding clarifies why metastases to the liver are ultimately a common feature of systemic cancers, with the lungs serving as a notable initial site of dissemination. Therefore, recognizing the lungs as the most frequent site for liver metastases aids in understanding tumor behavior and patterns in oncology, as well as in planning appropriate diagnostic and therapeutic approaches.