Retinoblastoma

Abstract

Retinoblastoma (RB) is the most common malignant eye tumor in children, arising from retinal cells. Although it is considered a rare disease in terms of newly diagnosed cases, it accounts for approximately 2 % of all childhood malignancies and up to 12 % of malignancies occurring within the first year of life. It is an embryonal tumor of young children, characterized by aggressive growth and fatal outcomes if left untreated. 95 % of cases are diagnosed by the age of 5, with a median age at diagnosis of 18 months. It most commonly presents with leukocoria and strabismus. Retinal tumors arise due to biallelic mutations of the tumor suppressor gene RB1 located on the long arm of chromosome 13. RB can be bilateral (30 - 40 %) or unilateral (60 - 70 %). Bilateral RB is always inherited and tends to occur at an earlier age than unilateral cases. Over the past few decades, there has been a shift in treatment approaches. Traditional radiation therapy for the orbit and, in some cases, enucleation have largely been replaced by systemic, intraarterial, and intravitreal chemotherapy combined with local disease control methods such as laser photocoagulation, thermotherapy, and cryotherapy. There is a significant disparity in diagnosis timing, level of medical care, and treatment outcomes between socioeconomically developed and underdeveloped countries. For example, the survival rate in Africa is as low as 30 %, whereas in Europe, the USA, and Canada it reaches 95 - 98 %. In Croatia, an initiative has been proposed to introduce early detection of RB in neonates using the Bruckner test. It is a simple yet highly effective screening method that induces the reflex with a direct ophthalmoscope. The plan is to implement it in maternity hospitals or conducted by primary pediatricians. This review article presents the main characteristics of the disease, focusing on challenges in treatment, genetics, and genetic counseling, and the ongoing search for new biomarkers associated with disease progression.