Reply

We thank Abramson and associates for their comments regarding our report and welcome the opportunity to clarify our conclusions. In our study, only 1 of 252 patients that had received systemic chemotherapy developed pineoblastoma, while 3 of 156 patients, who did not receive chemotherapy, developed pineoblastoma. Abramson and associates correctly point out that only patients with the genetic form of retinoblastoma are at risk for pineoblastoma and hence only they should be included in the analysis, a fact that we well recognize. However, we wish to point out that their interpretation of our study data is not accurate. In our study, there were 193 bilateral retinoblastoma patients and among the 215 unilateral retinoblastoma patients, 22 were confirmed as having a germline mutation. Therefore, there were 215 patients with the genetic form of retinoblastoma, placing them at risk for the development of pineoblastoma. In this group, 1 of 180 patients that received chemotherapy developed pineoblastoma and 3 of 35 patients that did not receive chemotherapy developed pineoblastoma, and this difference is statistically significant (P = .014).