Risk factors for extraocular relapse following enucleation after failure of chemoreduction in retinoblastoma.

OBJECTIVE

To assess the outcome and determine risk factors for extraocular relapse in patients with retinoblastoma who had been enucleated after failure of chemoreduction.

METHODS

Retrospective study (1995-2002) at three institutions. Pathological risk factors (PRF) were defined as invasion of the anterior segment, choroid, post-laminar optic nerve, subarachnoid space, or sclera according to the local pathology report. Extraocular relapse was defined as an event.

RESULTS

One hundred twenty-two patients were included (17 had bilateral enucleation). Chemoreduction included vincristine, carboplatin, and etoposide (n=80, 65.6%), vincristine, and carboplatin (n=17, 13.9%), or carboplatin (n=25, 20.5%). Thirty-five also received external beam radiotherapy (28.7%). PRF included: 39 with choroidal involvement, 9 with anterior segment, 9 with scleral, and 2 with post-laminar optic nerve with subarachnoid invasion. Adjuvant chemotherapy was given to eight patients (6.5%) because of scleral invasion. Four patients had an extraocular relapse after enucleation, two of whom survive after intensive treatment including stem cell rescue. Five-year probability of event-free survival is 0.96. Only scleral invasion and bilateral enucleation were significantly associated with extraocular relapse.

CONCLUSIONS

The risk of extraocular relapse is low after enucleation following failure of chemoreduction. Patients who underwent bilateral enucleation and those with scleral invasion are at higher risk of extraocular relapse.