Methods
The authors performed a retrospective chart review of all patients in the Augsburger ocular oncology practice with a history of retinoblastoma who developed a SPMN between 1975 and 2022. A SPMN was defined as a histopathologically distinct solid malignant neoplasm that occurred after the onset of the primary retinoblastoma. The study was performed with the approval of the Institutional Review Board of the University of Cincinnati College of Medicine for retrospective analysis of deidentified clinical information contained in the charts of patients evaluated in the practice and generated as part of standard patient care.
The authors abstracted the following information from the charts: demographic information, family history of retinoblastoma, features of the affected eye(s), therapeutic interventions for retinoblastoma, the interval between initial diagnosis of retinoblastoma and detection-diagnosis of the SPMN, age at diagnosis of the SPMN, pathologic type of SPMN, location of the SPMN, treatment provided for the SPMN, duration of follow-up after retinoblastoma diagnosis and after SPMN diagnosis and treatment, and life status of the patient through most recent follow-up. Because genetic testing was not available for all patients, hereditary disease was defined by bilateral disease, a positive family history, and/or a germline RB1 mutation detected on chromosomal/DNA analysis. Non-hereditary disease was defined by unifocal, unilateral disease, negative family history of RB, and/or chromosomal/DNA analysis that showed no evidence of a germlineRB1 mutation. Since radiation field size data was not available for most patients in this series, SPMNs occurring in the head/neck region were defined as “in the field” whereas those occurring in the body or extremities were defined as “out of the field” of radiation.
The cases in this series fell into two discrete groups: Group 1 consisted of patients whose baseline diagnostic evaluation was performed and at least some of their initial retinoblastoma treatment was provided in the Augsburger ocular oncology practice and collaborating pediatric oncology practice, and Group 2 consisted of patients whose baseline diagnostic evaluation was performed and retinoblastoma treatment was provided at an outside center prior to referral to the Augsburger ocular oncology practice. For Group 1, we could determine both the baseline prognostic group (for ocular preservation) of the intraocular retinoblastoma of each affected eye (using both the Reese-Ellsworth7 and Murphree [ABCDE]8 classification systems) and the baseline stage of the retinoblastoma (using the AJCC tumor-node-metastasis [TNM] staging system, 2017 version9). For Group 2, this information was generally not available (i.e., not provided by the outside center where the patient’s baseline diagnostic evaluation had been performed) and could not be determined from records of the baseline evaluation obtained from those centers.
Statistical analysis was performed using Microsoft Excel (Microsoft Corp, Redmond, WA). Continuous numeric variables were described using the median and extreme values. Categorial variables were described using numerical counts and percentages.