Chemoreduction for retinoblastoma may prevent intracranial neuroblastic malignancy (trilateral retinoblastoma).

OBJECTIVE To evaluate whether neoadjuvant intravenous chemotherapy (chemoreduction) for retinoblastoma reduces the risk for associated intracranial neuroblastic tumor (trilateral retinoblastoma). DESIGN Retrospective consecutive case series. PARTICIPANTS Two hundred fourteen consecutive children with newly diagnosed retinoblastoma treated at a major ocular oncology center from January 1, 1995, to July 1, 1999. MAIN OUTCOME MEASURE Development of associated intracranial neuroblastic tumor (trilateral retinoblastoma). RESULTS During the 54-month study period, 142 patients (66%) received chemoreduction (consisting of vincristine sulfate, etoposide phosphate, and carboplatin therapy) as part of their treatment strategy (chemoreduction group), whereas 72 (34%) were treated with nonchemoreduction methods (nonchemoreduction group). In the chemoreduction group, no associated intracranial neuroblastic tumor developed during the mean 47-month follow-up. Based on a recent meta-analysis of the prevalence of trilateral retinoblastoma, we would have expected the intracranial tumor to develop in 5 to 15 patients with hereditary retinoblastoma. This lack of associated trilateral retinoblastoma in the chemoreduction group was significantly less than expected using binomial distribution (P<.001). In the nonchemoreduction group, associated intracranial tumor (pinealoblastoma) developed in 1 patient, a finding consistent with the expected frequency. CONCLUSION Chemoreduction protects against the highly fatal associated intracranial neuroblastic tumor (trilateral retinoblastoma). This observation is especially important in children with bilateral or familial retinoblastoma who are at greatest risk for this brain tumor.