O uso da quimioterapia no tratamento do retinoblastoma: Avaliação retrospectiva

Purpose: Retrospective uncontrolled series of consecutive patients with retinoblastoma considering: 1-tumor features on computed tomography, 2-proportion of patients with optic nerve invasion in pathology studies of enucleated eyes and 3-results after chemotherapy. Methods: The authors revised the charts of 11 consecutive patients diagnosed with retinoblastoma between Febuary/98 and September/99, treated at the Departments of Pediatric Oncology and Ophthalmology. Seven cases who received chemotherapy with vincristine sulfate, etoposide and carboplatin (VEC) were selected for this study to evaluate tumor presentation (response to chemotherapy and patient survival). Results: The seven studied patients were diagnosed between the ages of 15 and 38 months (mean =25.7 months), 3 being unilateral, 3 bilateral and 1 trilateral (with pinealoblastoma). All patients were treated with VEC protocol administered in 2 to 5 cycles, and divided in to 2 groups: Group1- Patients treated with primary chemotherapy to obtain tumor reduction and preservation of one of the eyes (5 patients); Group2- Patients treated with aggressive chemotherapy for extraocular disease (2 patients). Of the 5 patients treated with primary chemotherapy (4 subsequently enucleated due to eye filling tumor), 4 achieved some tumor reduction, however 2 of them had only an initial tumor response and died on average 10 months later, one was chemoresistant. Patients with bilateral tumor were also treated with external beam radiation treatment (EBRT) of the eye containing the smaller tumor. The average follow-up period after primary chemotherapy was 12.4 months. The two patients submitted to primary enucleation and adjuvant chemotherapy (Group 2) had brain metastasis and died on average 4.5 months later regardless of treatment. Conclusion: This study revealed that: 1-retinoblastoma is a disease of late diagnosis and advanced clinical presentation in our area. 2-The percentage of enucleations with free optic nerve margins was only 50% of the cases. 3-The chemotherapy protocol using VEC associated either with radiotherapy or enucleation provided satisfactory tumor reduction and increased survival in patients with advanced disease but did not change the lethal outcome when brain metastasis and optic nerve invasion were present. Randomized studies will be necessary to determine efficacy and complications of these new chemotherapy protocols. Abbreviations: VEC- vincristine sulfate 1.5mg/m², etoposide 100 mg/m², carboplatin 360mg/m².