Definition:
A secondary cancer can refer either to a second primary cancer, or to cancer that has spread from one part of the body to another (metastatic cancer).
For example, if someone has a primary breast cancer, a secondary cancer in her lung could be either a new lung cancer (primary lung cancer), or due to spread of her breast cancer to her lungs (breast cancer metastatic to the lungs).
In some cases, the treatment for a primary cancer (such as chemotherapy or radiation therapy), can cause cell damage that predisposes an individual to a secondary cancer.
