Second malignant tumors in childhood cancer survivors.

Abstract

9573 Background: The risk of second malignancies is 3-6 times more in childhood cancer survivors. The 20 year cumulative risk of secondary malignancies in 14,193 chilhood cancer survivors followed for >5 years was 3.2% (Cancer 2005). Methods: 1,500 childhood cancer survivors treated between 1990-2010 in the Istanbul University, Oncology Institute were evaluated for second malignancies. Results: 16 second malignancies were identified in 15 childhood cancer survivors in a median time of 6 years. The 16 second malignancies were: 4 acute myeloblastic leukemias (AML), 2 malignant nerve sheath tumors (MNST), 8 sarcomas, 2 breast cancers. AML was diagnosed in 4 children in a median of 31 months (13-60 mo): The primary diagnosis were Ewing’s sarcoma, osteosarcoma, non-Hodgkin’s lymphoma and neuroblastoma. Two of these children had recieved multiple therapies for recurrences. Two children with a primary diagnosis of medulloblastoma and neuroblastoma developed MNST in the radiation field after 9 years. A Ewing sarcoma patient developed sarcoma after 6 years, an osteosarcoma patient developed breast cancer after 8 years, an ALL patient developed Ewing sarcoma after 3 years, a mesenchymal chondrosarcoma patient developed breast cancer after 11 and osteosarcoma after 16 years. These were not in the radiation field. A soft tissue sarcoma, and an osteosarcoma developed in two bilateral retinoblastoma patients both after 14 years, a sarcoma developed in a rabdomyosarcoma patient after 6 years and in a patient treated for nasopharyngeal carcinoma after 3.5 years all in the radiation field. An extremity osteosarcoma developed in another bilateral retinoblastoma patient after 4 years. The two patients that developed breast cancer and the six patients that developed sarcoma are alive. All others are dead of disease. Conclusions: The risk of secondary malignancies in our series is 1% and low in comparison to the literature. However, it has increased within years and may still increase as the follow-up time increases. Since, the risk of second malignancies is associated with the cumulative dose of some chemotherapeutics, the radiation dose/field, the use of minimal therapy that has the maximum efficacy according to the diagnosis, age, stage and risk of the patient is important.