Second Primary Malignant Neoplasms in Survivors of Retinoblastoma in a Single Ocular Oncology Practice.

Introduction: A retrospective review of patients treated for retinoblastoma who developed a non-pineoblastoma second primary malignant neoplasm (SPMN) was performed.

Methods: The demographics, clinical features and treatments for retinoblastoma, pathologic types of non-pineoblastoma second primary malignant neoplasm (SPMN), intervals between the retinoblastoma diagnosis and treatment and diagnosis of non-pineoblastoma SPMN, treatment provided for the SPMN, and the survival outcomes of the patients were evaluated.

Results: Of 550 patients treated initially for retinoblastoma, this series used the 15 (2.7) that developed a non-pineoblastoma SPMN, 14 of which (93.3%) had been treated for bilateral retinoblastoma. All patients had carried a germline mutations in the RB1 gene. The median time from retinoblastoma diagnosis to SPMN diagnosis was 19.0 years (extremes 3.4 and 39.4 years). Six of the fifteen patients died during the follow-up of their SPMN. The median interval between initial retinoblastoma diagnosis and death in the 6 patients who died of their SPMN was 18.8 years (extremes 6.2 and 34.6 years) and between diagnosis of the SPMN and death was 1.2 years (extremes 0.25 and 4 years).

Discussion: Of the patients who had been treated with External Beam Radiotherapy (EBRT), 13 developed a SPMN within the previously irradiated field.