What does it mean for cancer cells to metastasize?

Metastasis refers to the process by which cancer cells break off from their original (primary) tumor and travel through the bloodstream or lymphatic system to establish new tumors in different parts of the body. This is a critical and defining characteristic of malignant tumors, which distinguishes them from benign tumors. When cancer cells metastasize, they can spread to various organs and tissues, complicating treatment and significantly affecting the prognosis of the patient.

This invasive capability is a hallmark of cancer progression, as it allows the disease to become systemic rather than localized. Understanding metastasis is essential in cancer biology and treatment strategies, as it informs approaches to prevent spread, manage secondary tumors, and improve patient outcomes. Other options, such as growing larger in their original location, engulfing other cells, or entering apoptosis, do not accurately describe the metastatic behavior of cancer cells.