[Retinoblastoma update]

Abstract

Retinoblastoma is the most common intraocular malignancy of infancy with an incidence of 1/15,000 births. Sixty percent of retinoblastomas are unilateral, with a median age at diagnosis of 2 years, and in most cases they are not hereditary. Retinoblastoma is bilateral in 40% of cases, with an earlier median age at diagnosis of 1 year. All bilateral and multifocal unilateral forms are hereditary and are part of a genetic cancer predisposition syndrome. All children with a bilateral or familial form, and 10-15% of children with a unilateral form, constitutionally carry an RB1 gene mutation. The two most frequent symptoms at diagnosis are leukocoria and strabismus. Diagnosis is made by fundoscopy, with ultrasound and magnetic resonance imaging (MRI) contributing both to diagnosis and assessment of the extension of the disease. Treatment of patients with retinoblastoma must take into account the various aspects of the disease (unilateral/bilateral, size, location), the risks for vision, and the possible hereditary nature of the disease. The main prognostic aspects are still early detection and adapted coverage by a multidisciplinary, highly specialized team. Enucleation is still often necessary in unilateral disease; the decision for adjuvant treatment is made according to the histological risk factors. The most important recent therapeutic advances concern conservative treatment, which is proposed for at least one of the two eyes in most bilateral cases: laser alone or in combination with chemotherapy, cryotherapy, or brachytherapy. Recently, the development of new conservative techniques of treatment, such as intra-arterial selective chemotherapy perfusion and intravitreal injections, aims at preserving visual function in these children and decreasing the number of enucleations and the need for external beam radiotherapy. The vital prognosis related to retinoblastoma is now excellent in industrialized countries, but long-term survival is still related to the development of secondary tumors, mainly secondary sarcoma. Retinoblastoma requires multidisciplinary care as well as a long-term specialized follow-up. Early counseling of patients and their family concerning the risk of transmission of the disease and the risk of development of secondary tumors is necessary.