What does metastasis refer to?

Metastasis specifically refers to the transfer of disease, particularly cancer, from the primary site of origin to distant parts of the body. In the context of cancer, this process involves tumor cells breaking away from the original tumor, traveling through the bloodstream or lymphatic system, and establishing secondary tumors in other organs or tissues. This ability to spread is a hallmark of malignant tumors and significantly impacts the prognosis and treatment strategies for patients. Understanding metastasis is crucial in informing treatment plans, as it indicates the extent of the disease and helps in predicting outcomes.

The other options do not relate to the definition of metastasis. Healing a wound pertains to tissue repair, the growth of new hair follicles refers to hair regeneration, and the contraction of blood vessels deals with vascular responses. All these processes are vital in their respective contexts but are unrelated to the concept of metastasis in disease progression.