Introduction
Some cancers are associated with genetic changes that may cause second cancers later on. Retinoblastoma in both eyes is one example. The treatments that cure some cancers also put young patients at varying degrees of risk for having second cancers later. As frightening as this may sound, these cancers occur only in a very small number of survivors (around 5%). It is also important to remember that these treatments cured the first cancer. If you are faced with a second cancer diagnosis, remember, you beat it the first time; there is no reason to think you will not be able to do it again.
Several classes of chemotherapy are associated with an increased risk of developing a secondary cancer or new leukemia. Drugs that may cause leukemia include the topoisomerase I inhibitors (etoposide and teniposide), the anthracyclines (doxorubicin, daunomycin, and idarubicin), and the alkylating agents (cyclophosphamide, busulfan, and melphalan). The overall risk of developing a secondary leukemia is quite small and most new leukemias develop within the first 5-10 years after completion of treatment. Second solid cancers, such as brain tumors, bone sarcomas, and breast cancers, are seen more commonly in areas of the body previously treated with radiation therapy. Second solid cancers tend to develop many years after treatment has ended, often 10 or more years after completion of treatment for the first cancer.
