AKT1 E17K mutation profiling in breast cancer: prevalence, concurrent oncogenic alterations, and blood-based detection

Table 3 Comparative mutation analysis using blood and tissue samples of the same patients

			AKT1 ^E17K			PIK3CA
			Cohort A	Cohort B	Cohort C	Cohort A	Cohort B
Total paired samples analyzed, n			94	50	35	71	50
Mismatched samples, pairs, n
	Tumor	Blood				-	-
	AKT1 WT	AKT1 ^E17K	0	0	0	-	-
	AKT1 ^E17K	AKT1 WT	31	1	1	-	-
	PIK3CA WT	PIK3CA mut	-	-	-	1	0
	PIK3CA mut	PIK3CA WT	-	-	-	16	0
	PIK3CA mut	PIK3CA mut	-	-	-	1	0
Total mismatched, pairs, n			31	1	1	18	0
Matched samples, pairs, n
	AKT1 WT	AKT1 WT	59	47	28	-	-
	AKT1 ^E17K	AKT1 ^E17K	4	2	6	-	-
	PIK3CA WT	PIK3CA WT	-	-	-	50	37
	PIK3CA mut	PIK3CA mut	-	-	-	5	13
Total matched, pairs, n			63	49	34	55	50
Concordance (%)			67.0	98.0	97.1	75.3^a	100
Mutation capture rate in ctDNA (%)			11.4	66.7	85.7	22.7	100

Cohort A: Analysis of AKT1 ^E17K mutations using BEAMing for fresh frozen tumor tissue samples and blood samples (serum), and analysis of PIK3CA mutations (H1047R, H1047L, E542K, E545K) using BEAMing for blood samples (serum) and next-generation sequencing for fresh frozen tumor tissue samples. Cohort B: Both AKT1 ^E17K and PIK3CA mutations (H1047R, H1047L, E542K, E545K) were determined in tissue (FFPE) and blood (plasma) using BEAMing. Cohort C: Analysis of AKT1 ^E17K using BEAMing for blood samples (plasma) and next-generation sequencing for tissue samples (FFPE). “Matched samples” indicates that the same result was obtained using tissue or blood samples. “Mismatched samples” indicates that different results were obtained using tissue and blood samples. ^aCalculation was based on total measured events (n = 73), as in one sample, two PIK3CA mutations were detected of which only one matched
Abbreviations: AKT1 v-akt murine thymoma viral oncogene, BEAMing Beads, Emulsions, Amplification, and Magnetics, FFPE formalin-fixed paraffin-embedded, mut mutant, WT wild type

ISSN: 1471-2407