Second primary tumors in retinoblastoma

Advances in the diagnosis and treatment of retinoblastoma have vastly improved patient outcomes. In developed countries, the most common cause of death in patients with heritable retinoblastoma is now a second primary tumor occurring in retinoblastoma survivors; many of these second primaries can be avoided by the reduced use of radiation. Mesenchymal tumors including primitive neuroectodermal tumors, bone and soft tissue sarcomas, leiomyomas, lipomas, cutaneous melanomas, and gliomas are the most common types of the second primary tumors in retinoblastoma survivors. Osteogenic sarcoma is the most common type of second primary tumor particularly in younger patients. Widespread use of systemic chemotherapy only started in the mid-1990s, so it is still too early to know its long-term risk of second primary tumors. Ophthalmic arterial chemotherapy has been widely used for only a few years and, while a major goal of this therapy is to reduce systemic exposure to chemotherapy, a significant amount of radiation exposure to the orbit is required for the fluoroscopy needed to cannulate the ophthalmic artery. Thus, it will be many years before we know the long-term risk of ocular tumors associated with ophthalmic arterial chemotherapy. Regardless of the therapy used to treat intraocular retinoblastoma, it is important to provide lifelong surveillance for second primary tumors that may arise in the orbit and elsewhere in patients with germline retinoblastoma.