Final answer:
Metastasis is the process by which cancer cells from a primary tumor spread to distant sites in the body. It is a characteristic of malignant tumors and is one of the hallmarks of cancer.
Step-by-step explanation:
In relation to cancer, metastasis means systemic invasion. Metastasis is the process by which cancer cells from a primary tumor spread to distant sites in the body through the bloodstream or lymphatic system. It is a characteristic of malignant tumors and is one of the hallmarks of cancer.