Secondary cancers

In very rare cases, part of your breast cancer treatment can cause you to get a different cancer in a different part of your body, usually many years later. This is called a secondary cancer.

Secondary cancers are very rare, and your doctors will help make sure the risk of a secondary cancer is much smaller than the benefit of your breast cancer treatment. Still, it’s reasonable to have concerns about secondary cancers. Talk with your providers about any questions or concerns so they can help you understand the level of risk.

What causes secondary cancers?

Some breast cancer treatments that can increase your risk of a secondary cancer are:

• Radiation therapy. Radiation can damage bone marrow, the fatty tissue inside your bones that makes blood cells. This can increase your risk for blood cancers such as myelodysplasia or leukemia. Radiation may also cause an increased risk of solid tumors, which usually develop in or near the radiated areas.
• Chemotherapy. Chemotherapy also causes an increased risk of blood cancers. Chemotherapy medicines that may increase the risk of leukemia include, but are not limited, to:
  • carboplatin (Paraplatin)
  • cisplatin (Platinol)
  • cyclophosphamide (Cytoxan)
  • doxorubicin (Adriamycin)
  • epirubicin (Ellence)
  • liposomal doxorubicin HCI liposome injection (Doxil)
• Hormonal therapy. Tamoxifen slightly increases the risk of developing uterine cancer, mostly in women over age 50.