Retinoblastoma: concerning its initiation and treatment

Abstract

Retinoblastoma (RB) is the most common intraocular cancer of infancy and childhood. This cancer is initiated by mutation on RB1, the tumor suppressor gene that is responsible for the regulation of both cell cycle and gnome stability in retinal cells. Patients with a constitutional mutation on RB1 can be inherited. RB occurs approximately 1 in every 15 000-20 000 live births. The worldwide mortality for this cancer is about 5%-11%. However, this rate rises to about 40%-70% in developing countries due to a delay in diagnosis. A wide variety of options are available for the treatment, but often a combination of therapies is adopted to optimize individualized care.

Keywords: epidemiology; leukocoria; medical management; retinoblastoma; retinoblastomal gene.

Figure 1. RB and G1/S regulation

A: Classical pathway of RB and G1/S transition. Small cell cycle inhibitors of the INK4 and CIP/KIP families inhibit the activity of Cyclin/Cdk complexes, which consequently maintain the activity of RB by preventing it from being phosphorylated. Unphosphorylated RB would bind E2F family proteins and block their activities as transfactors; B: Beyond the classical pathway, RB also controls the cell cycle by blocking the degradation of the p27 small cell cycle inhibitor.