What describes the process of metastasis?

The process of metastasis specifically involves the movement of cancer cells from the original (primary) tumor to distant sites in the body. This is a complex process that allows cancer to spread beyond its initial location, often making treatment more challenging and unfavorable for the patient.

During metastasis, cancer cells detach from the primary tumor, invade surrounding tissues, enter the bloodstream or lymphatic system, and eventually settle in another part of the body, where they can begin to grow into new tumors. This characteristic of cancer is a critical concern in oncology, as the presence of metastatic disease indicates more advanced cancer and often dictates the treatment approach.

The other options relate to different aspects of cancer behavior but do not accurately define metastasis. For example, spreading within the same tissue refers more to local invasion or growth of the tumor rather than its spread to distant sites. Invasion of neighboring non-cancerous cells describes how a tumor may affect its immediate environment but does not encompass the broader concept of distant metastasis. Repair of damaged tissue following surgery is unrelated to cancer progression and signifies healing processes rather than the behavior of cancer cells.