Trilateral retinoblastoma: a meta-analysis of hereditary retinoblastoma associated with primary ectopic intracranial retinoblastoma.

PURPOSE: To obtain refined knowledge regarding trilateral retinoblastoma (TRb), which is a syndrome that consists of hereditary retinoblastoma associated with an intracranial neuroblastic tumor.
MATERIALS AND METHODS: Using a systematic literature review, we contacted authors to obtain missing information. Data from 106 children were used in a meta-analysis including frequency distributions and Kaplan-Meier survival curves.
RESULTS: TRb showed no sex predilection. Median age at diagnosis of retinoblastoma was 5 months (range, 0 to 29 months); age at diagnosis was younger among 47 children (47%) with familial retinoblastoma compared with age at diagnosis among 52 children (53%) with sporadic retinoblastoma (2 v 6.5 months, P <.0001). TRb usually affected the second or third generation with retinoblastoma. Median time from retinoblastoma to TRb was 21 months (range, 6 months before to 141 months after); time to TRb was longer for 78 (77%) pineal tumors compared with 23 (23%) suprasellar tumors (32 v 6.5 months, P <.0001). The size (27 v 32 mm, P =.57) and prognosis (survival of 9 v 8 months, P =.91) of pineal and suprasellar tumors were similar. TRb was detected earlier (1 v 22 months, P =.0007) and the child survived longer if neuroimaging was routinely performed (16 v 8 months, P =.001), but age at death was similar (36 v 37 months, P =.98). Cumulative 5-year survival (which was likely to indicate cure) was 27% (v 0%) if screening was undertaken. All children whose TRb exceeded 15 mm in size died.
CONCLUSION: The family history, age at diagnosis, and laterality of retinoblastoma in children with TRb resembled that of ordinary hereditary retinoblastoma. Suprasellar TRb were diagnosed earlier, and may arise earlier, than pineal TRb. Screening by neuroimaging could improve the cure rate if cases of TRb were detected when tumors were 15 mm or smaller in size.