Metastatic tumors are cancerous tumors that have spread from one location to another. For example, if a person has lung cancer and it spreads to his or her liver, that would be a metastasis of the cancer, and the resulting tumor would be considered a metastatic tumor. These kinds of tumors are often much more dangerous than the original tumor, partly because they may appear in more lethal areas of the body, and partly because they’re a signal that the cancer has entered a more dangerous phase.
Once a person begins to develop metastatic tumors, it is often much more difficult to treat the cancer, and the five-year survival rates generally worsen. Metastatic tumors are generally treated in the same ways as any other kind of cancer tumors. This would include things like chemotherapy, for example. In some cases, treatments may sometimes be more aggressive and urgent because of the greater danger the tumors can represent.
The process that creates metastatic tumors involves a change in the nature of the cancer. Many cancers can eventually reach a point where cells can break off and enter the blood stream. Once that happens, they will travel through the body and sometimes establish themselves elsewhere, gradually forming new tumors. These tumors often form in clusters, so instead of a single tumor, a person may have a large number that pop up somewhere.
A common area for metastatic tumors to form is in lymph nodes that are close to the site of the original cancer tumor. Other than that, they can potentially form anywhere, but most cancer types have particular areas where spreading is more common. Sometimes these locations can be related to the distance on the body from the original cancer location, and sometimes they have more to do with blood pathways or other things.
Many dangerous cancers originally form in places that aren’t actually deadly. For example, a tumor in the breast isn’t lethal all by itself. These kinds of cancer only become dangerous when metastatic tumors begin to form. The length of time this takes to happen can be extremely variable. Sometimes metastatic tumors may form almost immediately, and sometimes it can take many years. This variation can also be partly dependent on the variety of cancer and certain particular things about the tumor.
It is not all that unusual for doctors to find metastatic tumors first before ever discovering the original cancer. Generally speaking, it is important for doctors to know if the cancer tumor is metastatic or not, so they will usually perform a biopsy to test this. When looking under a microscope, it is usually easy for doctors to tell if the tumor in question is made of the same kind of tissue as the area where it appeared, and this can help determine a treatment approach.