Cancer metastasis is the process by which cancer cells spread from the original tumor to other parts of the body. This occurs when cancer cells break away from the primary tumor, travel through the bloodstream or lymphatic system, and form new tumors in distant organs or tissues. Metastasis can complicate treatment and significantly affect a patient's prognosis. The ability of cancer cells to metastasize varies among different types of cancers. Factors such as the tumor's characteristics and the body's immune response play a role in how easily cancer spreads. Understanding metastasis is crucial for developing effective therapies and improving patient outcomes.