MYCN Amplification in RB1-Inactivated Retinoblastoma: Association With High-Risk Features.

All 10 tumors exhibited alterations in at least one RB1 allele (RB1 -/- or RB1 +/- ).

The RB1 mutation spectrum and overall genomic copy number changes were similar between MYCN-amplified and MYCN-nonamplified retinoblastomas.

Age at diagnosis did not differ significantly between the two groups (p = 0.21); however, secondary glaucoma, massive choroidal, and scleral invasion occurred more often in MYCN-amplified retinoblastomas (p = 0.038, p = 0.03, and p = 0.04, respectively).