Abstract
Purpose :
To evaluate the likelihood of germline mutation in patients presenting with solitary retinoblastoma, based on tumor location at presentation.
Methods :
Retrospective analysis of 482 consecutive patients with solitary, unilateral, unifocal retinoblastoma for likelihood of germline mutation (family history of retinoblastoma and/or genetic testing germline Rb1 mutation present and/or development of additional new tumors) based on overall tumor location at presentation (macular vs. extramacular).
Results :
Of the overall group (n=482 consecutive patients) with solitary retinoblastoma, macular tumors at presentation were more likely to have a smaller basal diameter (12.5 mm vs. 18.9 mm, p<0.001) and thinner (6.1 mm vs. 10.7 mm, p<0.001) than extramacular tumors. Patients with tumors located in the macula were more likely to have a family history of retinoblastoma (13% vs. 2%, OR=4.89 [1.85–12.97], p<0.001) and to develop new tumors (10% vs. 4%, OR=3.17 [1.27–7.93], p=0.014) compared to patients with tumor located outside the macula at presentation. There was no statistically significant difference in genetic testing for Rb1 mutation (25% vs. 16%, p=0.078) or likelihood of germline mutation (23% vs. 14%, p=0.066).
Conclusions :
Patients with solitary unilateral macular retinoblastoma are more likely to express phenotypic outcomes of germline retinoblastoma, such as development of new tumors and family history of retinoblastoma, while trending toward increased risk of possessing germline Rb1 mutation.
This is a 2021 ARVO Annual Meeting abstract.