['There is little information on the outcome of patients with retinoblastoma and tumor at the resection margin of the optic nerve.', 'Retrospective evaluation of three successive prospective protocols. Twenty-six consecutive patients were analyzed (International Staging System-IRSS-stage 2 = 21, stage 3 = 5) from three successive prospective protocols (1988-2006). Patients with stage 2 were enucleated upfront and those with stage 3 had neoadjuvant chemotherapy followed by enucleation and adjuvant therapy. Both groups received adjuvant chemotherapy and orbital radiotherapy after enucleation. Patients in protocol 1 received 1 year of the lower-dose chemotherapy regimen including cyclophosphamide, vincristine and doxorubicin along with intrathecal chemotherapy. Patients of protocols 2 and 3 received a more intense and shorter intravenous regimen including carboplatin and etoposide alternating with cyclophosphamide, idarubicin and vincristine with no intrathecal treatment. The components of protocol 2 and 3 were similar except for the dose of carboplatin which was 10% lower in protocol 3.', 'Thirteen were treated in protocol 1 and 13 in protocols 2 and 3. The probability of event-free survival was 0.70 at 5 years. Events included: CNS relapse = 3, second malignancies = 3, death in complete remission = 2. There were no significant differences in outcome between protocols or stages. Endocrinological disturbances related to the hypothalamus-hypophysis axis were evident in 6/8 patients evaluated. Severe orbital sequelae occurred in 12 cases.'] Does treatment result in patients with retinoblastoma and invasion to the cut end of the optic nerve?