SDPS-11 IMPACT OF MOLECULAR MARKERS USING FISH TECHNIQUE ON GOS/SURVIVAL IN HIGH GRADE GLIOMAS IN INDIAN SCENARIO

AIMS: Molecular markers (MGMT, IDH and 1p/19q, MIB-1 index, TP53) are used for present day diagnosis of high-grade glial tumours. This study evaluates outcome parameters [e.g., GOS, progression free (PFS) and overall survival(OS)] in treated high grade gliomas in Indian context using FISH technique for molecular characterisation. MATERIALS AND METHODS: This study used FISH techniques for IDH, MGMT and other IHC markers prospectively on 10 patients with high-grade gliomas, after safe maximal resection. Outcomes were noted for PFS and OS. A GOS of 1-3 (considered unfavourable); 4-5 (favourable), was documented at every 3-monthly follow-up for 2 years. The standardised detection of IDH (by FISH) and methylation profiles of tumours is the strength of the study. RESULTS: Most (80%) patients had a GOS > 13 post operatively, and none were less than 9. There was no statistically significant effect of gender, extent of resection or tumour location. IDH-1 positivity was recorded in 10%, MGMT methylation in 40%, intermediate to low MIB-1 index in 83.3%. TP53 mutations were noted in 30% cohort who had adverse outcome. The median PFS was 8.60 months. Mean survival was 12.70 months, with no molecular marker having statistically significant effects on PFS or OS. GOS of 13-15 conferred the best OS in contrast to GOS of 9-12 (16.2 months versus 7.5 months); (p = 0.001). CONCLUSION: GOS is an easy-to-use, validated scoring system with broad applicability and high reproducibility as a quantitative benchmark for clinical assessment. Since IHC lacks standardisation, FISH, despite being costlier, was used as a diagnostic benchmark. Further research on the impact of genomic profiling, extent of resection, especially in geriatric age groups is needed, to formulate an algorithm for optimal management.