Epidemiology, Clinical Management, and Genetic Counseling of Retinoblastoma in Vietnam

Vietnam is a low- to middle-income ASEAN country with a population of about 98 million people. Annually, there are 1.5 million newborns, and the number of new cases of RB is about 80–100 patients/year, 75–80% of which have unilateral tumors, while 20–25% have bilateral tumors. The incidence did not differ by sex, ethnicity, or geographical area. The average age of diagnosis of bilateral RB was 20.9 ± 16.7 months and of unilateral RB was 25.6 ± 16.6 months. The majority of children present with leukocoria (60%) and/or strabismus (12–20%). Due to limited knowledge, poor economy, and lack of diagnostic facilities, up to 80% of patients have a delayed treatment of about 1 month later than standard. However, the number of cases of extra orbital RB has decreased to only 0.15%, and there are no untreated deaths. The 5-year survival rate reached 92.5%. The success of conservative treatment is increasing, as are the benefits of advanced treatment methods including IViC and IAC. Even preserving the eyeball in patients in group E is 20%, previously 0%. Unfortunately, 79.6% of the affected eyes still had to be removed. Genetic testing and counseling for affected families with RB has grown in recent decades. Test methods include Sanger sequencing, MLPA, and next-generation gene sequencing. The gene mutation spectrum including minor mutations and large deletion mutations of the RB1 gene is constantly being updated by geneticists. Prenatal diagnosis has been also applied accurately and effectively to some families where one parent carries the disease gene. Along with socioeconomic development, RB management and treatment have improved significantly in Vietnam over the years. However, there are still some difficulties and inadequacies that need to be overcome in order to better treat patients.