UNASSIGNED: @entity8497 and @entity817 mutational status has become mandatory to treat @entity1 with metastatic @entity320 . Mutation-specific immunohistochemistry (IHC) can help analyze challenging @entity5 samples. We report our experience integrating NRASQ61R (SP174) and BRAFV600E (VE1) IHC in routine practice in a @entity5 molecular genetic platform. All samples screened for @entity817 and @entity8497 mutations during the year 2014 were analyzed by IHC and pyrosequencing, with an independent analysis of the 2 methods. Cases with first-line discordant results benefited from a complementary second-round IHC and next-generation sequencing (NGS) with a final interpretation taking into account the results of pyrosequencing, IHC, NGS, and quantification of the @entity5 cells. We analyzed 111 consecutive @entity406 -fixed and @entity982 -embedded @entity320 samples from 101 @entity1 . Twenty-two and 11 samples were concordant for BRAFV600E and NRASQ61R mutations, respectively. Second-round analyses of 9 discordant and 1 molecularly inconclusive samples allowed conclusion in 4 further mutated samples (2 BRAFV600E and 2 NRASQ61R). A sample remained NRASQ61R IHC negative but NRASQ61R mutated with molecular methods. Overall, BRAFV600 and NRASQ61 mutation frequencies were 31.7% and 30.7%, respectively. When compared to molecular results, the sensitivity and specificity of IHC were 100% for BRAFV600E IHC and 92.3% and 98.9% for NRASQ61R IHC, respectively. IHC interpretation required a more stringent cutoff for BRAFV600E IHC than NRASQ61R to minimize false results. We conclude that NRASQ61R and BRAFV600E IHC coupled with NGS allow detection of mutations in @entity320 challenging samples.

Dual NRASQ61R and BRAFV600E mutation-specific immunohistochemistry completes molecular screening in XXXX samples in a routine practice.

@entity1 :: ('9606', 'Species') :: ['patients'] @entity5 :: ('MESH:D009369', 'Disease') :: ['tumor', 'cancer'] @entity406 :: ('MESH:D005557', 'Chemical') :: ['formalin'] @entity982 :: ('MESH:D010232', 'Chemical') :: ['paraffin'] @entity8497 :: ('4893', 'Gene') :: ['NRAS'] @entity817 :: ('673', 'Gene') :: ['BRAF'] @entity320 :: ('MESH:D008545', 'Disease') :: ['melanoma', 'melanomas']
@entity320 :: (MESH:D008545,Disease) :: ['melanoma']
