Retinoblastoma with low risk for extraocular relapse.

OBJECTIVE: To define a subgroup of patients with retino-blastoma and low risk of extraocular relapse through histopathological and clinical variables.

PATIENTS AND METHODS: Inclusion criteria consisted of stage I (intraocular disease), stage IIb1 (without concomitant choroid and/or scleral invasion), and nonenucleated patients (according to the Grabowski-Abramson classification). A total of 112 consecutive patients admitted to Hospital JP Garrahan from 1987 to 1997 were evaluable. Treatment included enucleation or local therapy and no chemotherapy.

RESULTS: Forty-one patients had stage Ia (intraretinal), 8 stage Ib (prelaminar optic nerve invasion), 40 stage Ic (uveal invasion), and 12 stage IIb1 (postlaminar optic nerve invasion and cut end free of tumor). Eleven patients had neither eye enucleated. Median follow-up was 60 months. Only two events occurred: one patient had progressive disease in the contralateral globe and died of CNS metastasis and another had an orbital relapse that was successfully treated. Both had choroidal invasion. Five-year pEFS and pOS were 0.97 and 0.98, respectively. Neither length of the optic nerve stump, tumor size, anterior chamber invasion, degree of differentiation, nor degree of ocular coat invasion correlated with increased risk of metastasis.

CONCLUSIONS: A subset of patients with retinoblastoma with low risk of relapse can be determined using histopathological evaluation of the invasion of ocular coats. Adjuvant chemotherapy is not warranted for patients with intraretinal extension and prelaminar optic nerve invasion. It is also probable that those patients with isolated choroidal invasion and those with postlaminar optic nerve extension with surgical margins clear of tumor do not need chemotherapy.