Pre-enucleation chemo may increase risk of metastatic death

The authors retrospectively studied eyes with advanced retinoblastoma that underwent enucleation with or without previous chemotherapy. They sought to determine if chemotherapy before enucleation masks histologic features of extraocular extension, potentially endangering the child's life by subsequent undertreatment. They found that disease-specific survival (DSS) was lower for children with group E eyes, those with pre-enucleation chemotherapy and those that underwent enucleation longer than three months after diagnosis. They conclude that chemotherapy pre-enucleation in group E eyes, especially if enucleation took place longer than three months after diagnosis, downstaged pathologic evidence of extraocular extention and increased the risk of metastatic death from reduced surveillance and inappropriate management.

The study included 100 eyes with advanced retinoblastoma enucleated with or without primary chemotherapy at one hospital in Beijing. Chemotherapy varied from one to 12 cycles. Varying combinations of agents were used pre-enucleation, since treatment pre-enucleation was performed at different centers. The authors histopathologically classified eyes using pathological tumor-node-metastasis (pTNM) stage and recorded invasion into optic nerve, uvea and anterior chamber. They compared the treatment groups for pathologic stage using the Cochran-Armitage trend test and for DSS using the competing risks methods.

Children who received chemotherapy before enucleation had lower pTNM stage than primarily enucleated children (P = .01). Five patients who received pre-enucleation chemotherapy died as a result of extension into the brain or metastasis. No patients who underwent primary enucleation died. Among group E eyes, DSS was lower with pre-enucleation chemotherapy (n = 45) than with primary enucleation (n = 37; P = .01). Enucleation longer than three months after diagnosis was also associated with lower DSS (P < .001).

The study's results highlight the importance of adequate selection of patients who require chemoreduction versus those who would benefit from primary enucleation, as well as the histopathologic evaluation of any eye with retinoblastoma that undergoes enucleation.