Metastasis is a critical aspect of oncogenesis and is responsible for the majority of cancer-related deaths. It involves the spread of cancer cells from the original tumor site to distant organs. Key steps in metastasis include:
1. Invasion: Cancer cells penetrate surrounding tissues. 2. Intravasation: Cancer cells enter the bloodstream or lymphatic system. 3. Circulation: Cancer cells travel through the bloodstream or lymphatic system. 4. Extravasation: Cancer cells exit the bloodstream or lymphatic system into new tissues. 5. Colonization: Cancer cells establish new tumors in distant organs.
