Survival of retinoblastoma in less-developed countries impact of socioeconomic and health-related indicators.

BACKGROUND: The survival of retinoblastoma in less-developed countries (LDCs) and the impact of socioeconomic variables on survival are not widely available in the literature. METHODS: A systematic review of publications from LDCs was performed. Articles were from multiple databases and written in seven languages. Results were correlated with socioeconomic indicators. Lower-income countries (LICs) and middle-income countries (MICs) were included in our analyses. RESULTS: An analysis of 164 publications including 14,800 patients from 48 LDCs was performed. Twenty-six per cent of the papers were written in languages other than English. Estimated survival in LICs was 40% (range, 23-70%); in lower MICs, 77% (range, 60-92%) and in upper MICs, 79% (range, 54-93%; p = 0.001).Significant differences were also found in the occurrence of metastasis: in LICs, 32% (range, 12-45); in lower MICs, 12% (range, 3-31) and in upper MICs, 9.5% (range, 3-24; p = 0.04). On multivariate analysis, physician density and human development index were significantly associated with survival and metastasis. Maternal mortality rate and per capita health expenditure were significantly associated with treatment refusal. CONCLUSIONS: Important information from LDCs is not always available in English or in major databases. Indicators of socioeconomic development and maternal and infant health were related with outcome.

Multidrug resistant proteins: P-glycoprotein and lung resistance protein expression in retinoblastoma.

BACKGROUND/AIM: Retinoblastoma is the commonest primary intraocular tumour in children. Chemotherapy now plays a big part in the treatment of these tumours. There is not much information about the role of the multidrug resistance proteins (MDR)-P-glycoprotein (P-gp) and vault protein lung resistance protein (LRP)-in retinoblastoma. The authors investigated the expression of P-gp and LRP in retinoblastoma and correlated them clinicopathologically. METHODS: Among 60 retinoblastomas, 40 tumours were not subjected to preoperative or postoperative chemotherapy and 20 tumours were subjected to postoperative chemotherapy. In this cohort 27 tumours had no invasion and 33 tumours had invasion of choroid, optic nerve, and orbit. P-gp and LRP expression were studied by immunohistochemistry. Immunoanalysis was done semiquantitatively. RESULTS: Among the 60 tumours P-gp was expressed in 23 (38%) tumours and LRP was expressed in 35 (58%). P-gp was expressed in 11/27 (40%) tumours with no invasion and in 12/33 (36%) tumours with invasion. LRP was expressed in 15/27 (55%) tumours with no invasion and in 20/33 (60%) tumours with invasion. Both P-gp and LRP were negative in three tumours with invasion, which had later developed bone marrow metastasis. There was no correlation between P-gp and LRP expression with invasion, differentiation and laterality of the tumours and response to treatment. CONCLUSION: Retinoblastoma expresses P-gp and LRP intrinsically before chemotherapy and none of these proteins predicted the response to chemotherapy. Thus, further studies are needed to understand the significance of the expression of the P-gp and LRP proteins in retinoblastoma.