Retinoblastoma in Mongolia: Clinical characteristics and survival from 1987 to 2014

BACKGROUND/PURPOSE: This study aims to describe the clinical characteristics and treatment outcome of retinoblastoma in Mongolian children. METHODS: Data of all children diagnosed with retinoblastoma at the National Center for Maternal and Child Health of Mongolia from 1987 to January 2014 were reviewed retrospectively. The ICRB classification was used. Survival characteristics of the cohort were analyzed. RESULTS: Retinoblastoma was diagnosed in 79 eyes of 64 cases during the study period. Median age of diagnosis was 24.5 ± 15.8 months. There were no differences in sex ratio, and 15 cases (23%) were bilateral. Forty-three (67%) patients were from rural areas. The more frequent clinical presentations were leukocoria in 50 (78%) patients, strabismus in 24 (38%) patients, and glaucoma in 21 (33%) patients. Sixty-one (95%) patients were diagnosed with Classification D or worse when presented to us. Due to late diagnosis in the majority of cases, unilateral and bilateral enucleations were performed in 48 (61%) eyes and 24 (30%) eyes, respectively; exenteration was done in three (4%) eyes. Fifty-two (81%) patients received chemotherapy and 13 (8.3%) patients underwent external beam radiation after enucleation. At the time of last follow-up, 52 (81%) patients were alive, five (8%) patients were dead, and seven (11%) patients had lost to follow-up or unknown vital status. The mean follow-up period was 121.5 months (range, 12–360 months). In five cases with immunohistochemistry analysis in the eye specimen, neuron-specific enolase-, Ki-67 protein-, and B-cell lymphoma 2-positive cells were found in all five (100%) cases and Rb protein was detected in three (60%) cases. CONCLUSION: Retinoblastoma in Mongolia is frequently diagnosed at late stages and has a poor outcome. These data show the importance of early pediatric eye examinations and better treatment of retino-blastoma in children younger than 3 years in Mongolia.