Does cancer change its name when it spreads to another organ?

No. When cancer spreads to a distant part of the body, it keeps the name of the original, or primary, cancer.

For example, breast cancer that spreads to the lung is called metastatic breast cancer, not lung cancer. It is treated as stage 4 breast cancer, not as lung cancer. This is because the cancer cells that spread still look and behave like the original cancer.

When doctors look at metastatic cancer cells under a microscope, the cells look like the cells of the primary cancer and not like the cells of the place where the metastatic cancer is found. That is how doctors can tell the cancer spread from somewhere else. Knowing the original type of cancer helps your health care team choose the treatment that is most likely to help.