Occasionally you may hear stories about people who are diagnosed with “secondary cancer” after they already went through cancer treatment.
These stories are frightening, but secondary cancers are very rare, said Dr. Bilal Naqvi, a Marshfield Clinic oncologist/hematologist.
If you’re surprised, that might be because the term secondary cancer often is misused.
Secondary cancer vs. metastasis
“Secondary cancer is a cancer that develops as a complication from treatment for a previous cancer,” Naqvi said. “A tumor caused by radiation is an example of a secondary cancer.”
It often is confused with metastasis, which means the spread of cancer to a different part of the body. Metastatic cancer is referred to by the same name as the primary cancer. For example, breast cancer that has spread to the lung is called metastatic breast cancer, not lung cancer or secondary breast cancer.
It is possible to have a second type of cancer that is neither metastatic nor caused by cancer treatment. Genetics, aging and exposure to cancer-causing agents increase your risk of developing a second cancer.
Types of secondary cancer
Although secondary cancers are very rare, the most frequently seen type is sarcoma, a type of bone or soft tissue cancer that can be caused by radiation.
“These tumors are rare and getting even less common because radiation technology is improving,” Naqvi said. “The type of radiation machines used today reduces patients’ risk of developing secondary cancer.”
Cancers caused by chemotherapy are even more rare. Certain chemotherapy drugs called alkylating agents increase the risk of developing leukemia.
Am I at risk?
The type and dose of treatment you receive affects your risk for developing secondary cancer. Alkylating chemotherapy agents increase your risk, as well as high dose radiation over large areas of the body. Secondary cancers tend to be more common among survivors of childhood cancer, but are still rare.
Unfortunately, patients can’t reduce their risk for secondary cancer through lifestyle changes. Your treating physician can explain more about your risk based on the type of cancer treatment you have received.