Final answer:
Metastasis is the process where cancer cells travel from the original tumor to new locations in the body to form new tumors, called metastases. This typically has a worse prognosis and can involve organs such as the brain, lungs, bones, and liver.
Step-by-step explanation:
When cancer cells travel from the original location or primary tumor to a new location in the body, this process is called metastasis. The new cancers that form at these distant sites are referred to as metastases. Cancer can spread through three main ways: local spread, via the lymphatic system, or through the bloodstream.
Metastasis happens when cancer cells enter the bloodstream, allowing them to be carried throughout the body and potentially start new tumors elsewhere. These new tumor sites are often found in organs like the brain, lungs, bones, and liver, and this stage of cancer often has a more challenging prognosis.