Researchers at Wills Eye Hospital have found that frontline intravenous chemotherapy remains an important globe salvage therapy for retinoblastoma, the most common ocular cancer in young children. Less advanced cases avoided enucleation or external beam therapy, with minimal change up to 20 years following treatment.1
The study assessed 964 eyes of 554 patients, classified into the five groups based on the International Classification of Retinoblastoma:1,2
- Group A: retinoblastoma less than or equal to 3mm
- Group B: retinoblastoma great than 3mm with a macular location or minor subretinal fluid
- Group C: retinoblastoma with localized seeds
- Group D: retinoblastoma with diffuse seeds
- Group E: massive retinoblastoma necessitating enucleation
The researcher identified more advanced groups with older mean age at presentation: eight months (group A), seven months (group B), 10 months (group C), 11 months (group D) and 15 months (group E). By outcomes, the less advanced groups demonstrated greater tumor control by year two with frontline intravenous chemotherapy (96%, 91%, 91%, 71% and 32%, respectively), and with minimal change up to 20 years. To salvage the globe, additional intra-arterial chemo or plaque radiotherapy was necessary by year two for 5% (group A), 26% (group B), 28% (group C), 27% (group D) and 19% (group E), with little follow-up treatment up to 20 years.1
Analyzing clinical features, the more advanced group demonstrated greater mean tumor diameter (3.2mm in group A and 16.4mm in group E) and thickness (2.0mm in group A and 9.3mm in group E). The advanced group also had greater frequency of vitreous seeds in one or more quadrants—0% in group A compared with 57% in group E—and subretinal seeds (0% in group A and 54% in group E). Pinealoblastoma, metastasis and death were infrequent.2
Frontline treatment with intravenous chemotherapy (with additional treatment when necessary) can provide complete tumor control for most in groups A, B, C and D—and even 32% of those in group E, with the hope of efficacy lasting for up to 20 years, the researchers concluded in their paper.
1. Shields CL, Bas Z, Tadepalli S, et al. Long-term (20-year) real-world outcomes of intravenous chemotherapy (chemoreduction) for retinoblastoma in 964 eyes of 554 patients at a single center. Br J Ophthalmol. February 12, 2020. [Epub ahead of print].
2. Shields CL, Mashayekhi A, Au AK, et al. The International Classification of Retinoblastoma predicts chemoreduction success. Ophthalmology. 2006;113(12):2276-80.