Ali Rezaeian,1Zahra Amirkhani,2,*
1. Medical Student, Student Research Committee, Larestan University of Medical Sciences, Larestan, Iran. 2. Assistant Professor, Student Research Committee, Larestan University of Medical Sciences, Larestan, Iran.
Introduction: Retinoblastoma (RB) is an intraocular tumor with hereditary and diffuse forms. The disease develops from retinal cones, which have special properties that make them sensitive to tumorigenesis. The genetic implications for more than 97% of all RB cases are the inactivation of the RB1 gene. The original work, which explained the inheritance of retinoblastoma but also failed to explain the concept of tumor-suppressing genes, was originally published by Knudson in its original article from 1971. The two-stroke Knudson model suggested that an RB1 allele was found in all lost cells or a genetic mutation, thus initiating Tumorigenesis. More than 10 years after Knudson was discovered, the RB1 gene was the first tumor suppressor gene to be identified and simulated. 8000 new cases of this growing retinal eye malignancy are diagnosed worldwide every year. The original gene is responsible for RB1 retinoblastoma and holds a wide range of pathogenic variants. Retinoblastoma is the most common primary malignancy within the eyes in children and is found almost exclusively in young children. Most cases are diagnosed before the age of 5 and account for 3% of all childhood cancers. Previous studies showed significant differences in the incidence of retinoblastoma based on gender, ethnicity and infection due to poor hygiene. However, newer studies deny the importance of such differences, treating retinoblastoma worldwide as a similar outbreak.
Methods: We conducted an extensive search across electronic databases, including PubMed, MEDLINE, Embase, Google Scholar, and ResearchGate, and explored the available English-language literature. The MeSH terms were " Retinoblastoma " OR "RB1 "; " Genetic testing ";" ophthalmology". The articles included in this review adhere to the following criteria: they encompass studies solely focused on progress in comprehending and novel treatment approaches, and they are studies conducted in the English language within the last decades.
Results: Retinoblastoma screening involves various tests to detect the symptoms of the disease. Among its cases are leukocoria (sometimes referred to as "cat eye reflex"), which can be detected despite a white reflection in photographs or a red reflex test. A simpler approach is in detecting the use of mobile phones for the same purpose in which, such an application exists in the form of an application called "White eye Detector" developed by Brian Shaw. Screening by an ophthalmologist is essential in children with a positive family history of retinoblastoma. Children and sibling’s patients with the disease require regular screening examinations in childhood unless genetic testing is performed to rule out a gene mutation in which case the risk is similar to that of the general population. The onset of each tumor requires a set of genetic deviations that regulate their basic cellular functions.
Conclusion: These genetic and epigenetic changes allow cells to escape their homeostatic controls and allow them to multiply outside their natural niche. This is mainly due to disruptions in the simultaneous regulation of various signal transmission paths such as Rb, p53, Wnt, Ras-ERK. That may affect the oncogenic properties of retinoblastoma through multiple mechanisms, including obtaining stem cell-like phenotype, epithelial–mesenchymal transition (EMT) activation. From another point of view, in this article, we will examine the treatment and its treatment practices, and it should be noted that retinoblastoma is a cancer that can be treated if diagnosed at the right time. Involvement of structures beyond the retina should be considered as they have the potential to progress rapidly as metastases. Treatment of retinoblastoma is often complex and involves decisions that must be made based on a number of factors, including the size of the tumor in different axes, the age of the patient, the risk of secondary metastasis, previous attempts made in chemotherapy, the toxicity of the chemotherapy agent in the subject and the laterality of the tumor. Treatments include Enucleation, Intravitreal chemotherapy (IVitC), Intra‐arterial (IAC) chemotherapy, Thermotherapy, Cryotherapy, and External beam radiation (EBR). In the Enucleation procedure, complete removal of the eye that is affected by the tumor or surgical incision is called anoclination. This is the least conservative management and is therefore reserved for items that would otherwise not be able to help. Or, for example, in the IVitC pathway, modern MicroCutter techniques can be used to prescribe chemotherapy agents, and success can be achieved with acceptable levels of toxicity. The choice of drugs included melphalan, topotecan hydrochloride, carboplatin and methotrexate in this administration pathway.