Metastasis is the spread of cancer from its place of origin to another organ of the body. For example, breast cancer can metastasize to the lungs, liver or bones. Cancer cells can leave the tumor in the breast, enter the blood stream or lymphatic system and circulate in the blood to the lungs where they settle and time can grow to form another tumor, called secondary.
This tumor is not considered lung cancer as it is formed by breast cancer cells. This tumor is called metastatic tumor or secondary breast tumor.
It has been found that all types of cancer can metastasize.
They are not known for sure the causes of metastasis. It is known, moreover, that metastasize, cancer cells must undergo certain changes.
For example, healthy cells typically do not leave the body to which they belong or migrate to other organs.
The risk that a primary tumor metastasizes increases with time. That is, the more you delay in treating the primary tumor, the greater the possibility that tumor cells migrate to other organs and form more tumors. Clinical experience suggests that it is more difficult to cure or control cancer with metastatic cancer without metastases.
For this reason periodic health checks including cancer screening is recommended. Ask your doctor what tests you recommended.
It has been observed that cancers tend to spread in certain organs rather than others.The most common sites of metastases are the lungs, bones and liver.
Metastatic tumors may exhibit symptoms sometimes, but sometimes not. If there are symptoms, they depend on the organ where the tumor is growing. For example
The presence of these symptoms does not indicate that there is necessarily cancer, but if the problem persists for several days consult your doctor immediately.
Metastatic tumors are treated using the same types of therapies used to treat primary tumors.
Treatment depends on several factors
National Cancer Institute, Cancer Metastatic, http://www.cancer.gov/espanol/recursos/hojas-informativas/tipos/metastatico-respuestas (accessed on September 29, 2015)