Retinoblastoma’s (RB) clinical high-risk features can help clinicians predict the presence of high-risk pathology in eyes with advanced intraocular RB following primary enucleation, according to research published in Ophthalmology. The study referred to the clinical features defined by the American Joint Committee on Cancer (AJCC) cT-categories and AJCC-Ophthalmic Oncology Task Force (AJCC-OOTF) Size Groups.
A total of 18 ophthalmic oncology centers in 13 countries contributed evaluations of eyes that underwent enucleation as primary treatment for AJCC cT3 RB (and cT2 RB, for comparison). Patients were enrolled between January 2001 and December 2013.
The researchers defined high-risk pathology as the AJCC RB categories pT3 and pT4 and tumor size per the AJCC-OOTF Size Groups was defined as proportion of globe volume involved (1-3) or the growth pattern (4) (1 for <50%, 2 for >50% but <2/3, 3 for >2/3, and 4 for diffuse infiltrating retinoblastoma).
A total of 942 eyes with RB were treated by primary enucleation. Of these, 478 eyes were categorized as cT3, with 282 (30%) having high-risk pathology; while 464 eyes were categorized as cT2, with 84 (18.1%) having high-risk pathology.
The researchers found that both the cT subcategories and AJCC-OOTF Size Groups were associated with high-risk pathology (P <.001 for both). Using logistic regression analysis, they demonstrated that cT3c (iris neovascularization with glaucoma; OR 2.3; P =.002), cT3d (intraocular hemorrhage; OR 2.5; P =.002), and cT3e (aseptic orbital cellulitis; OR 3.3; P =.019) were predictive factors for high-risk pathology compared with cT2a. They also showed that Size Group 3 (>2/3 globe volume; OR, 3.3; P <.001) and 4 (diffuse infiltrative RB; OR, 4.1; P <.001) were the best predictive factors for high-risk pathology compared with Size Group 1 and 2 combined (<2/3 globe volume).
“AJCC RB staging clinical cT3c-e subcategories (glaucoma, intraocular hemorrhage, and aseptic orbital cellulitis, respectively) as well as the AJCC-OOTF Size Groups 3 (tumor >2/3 globe volume) and 4 (diffuse infiltrative RB) both allowed stratification of clinical risk factors that can be used to predict the presence of high-risk pathology and thus facilitate treatment decisions,” researchers explain.
Limitations of the study included the retrospective design and lack of certain clinical data fields in the registry, particularly for pars plana and ciliary body involvement.
Tomar AS, Finger PT, Gallie B, et al. High-risk pathology based on presenting features in advanced intraocular retinoblastoma: a multicenter, international data-sharing AJCC study Ophthalmol. Published online April 15, 2022. doi:10.1016/j.ophtha.2022.04.006