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.