When cancer leaves its original site, what is this called?

The term that describes when cancer leaves its original site and spreads to other parts of the body is classified as a secondary neoplasm. In cancer terminology, a secondary neoplasm refers to a new and distinct tumor that arises from the spread of the cancerous cells, as opposed to the primary tumor, which is the original site of the cancer.

When cancer cells detach from the primary tumor and migrate through the bloodstream or lymphatic system to establish a new tumor in a different organ or tissue, they are considered secondary neoplasms. This process illustrates the aggressive nature of cancer and its ability to invade other areas, making treatment more complex.

In contrast, primary growth refers specifically to the original tumor where the cancer began. Distant spread generally indicates the same concept of reaching far-off parts of the body but does not specifically refer to the tumor itself. A metastatic site, while related, emphasizes the location of the secondary neoplasm rather than naming the phenomenon of spreading itself. Hence, secondary neoplasm accurately encapsulates the process of cancer spreading to new sites in the body.