Stage I includes: cT1, cT2, cT3, cN0, cM0, Any H. cT1: Intraretinal tumor(s) with subretinal fluid 5 mm or less from the base of any tumor. cT2: Intraocular tumor(s) with retinal detachment, vitreous seeding, or subretinal seeding. cT3: Advanced intraocular tumor(s). cN0: No regional lymph node involvement. cM0: No signs or symptoms of intracranial or distant metastasis. HX: Unknown or insufficient evidence of a constitutional RB1 gene mutation. H0: Normal RB1 alleles in blood tested with demonstrated high-sensitivity assays. H1: Bilateral retinoblastoma, retinoblastoma with an intracranial primitive neuroectodermal tumor (i.e., trilateral retinoblastoma), patient with family history of retinoblastoma, or molecular definition of a constitutional RB1 gene mutation. (AJCC 8th ed.) [from
NCI]