Diagnostic application of PIK3CA mutation analysis in Chinese esophageal cancer patients.

[esophageal carcinoma]

The PIK 3 CA gene mutation was found to associate with prognosis and might affect molecular targeted therapy in esophageal carcinoma (EC ). The aim of this study is to compare different methods for analyzing the PIK 3 CA gene mutation in EC .Genomic DNA was extracted from 106 surgically resected EC patient tissues . The PIK 3 CA mutation status (exons 9 and 20 ) were screened by mutant-enrich liquid chip (ME -Liquidchip ), Sanger sequencing , and pyrosequencing . And all samples with mutations were independently reassessed using amplification refractory mutation system (ARMS ) methods again .PIK 3 CA mutation rates were identified as 11 .3 % (12 /106 ) by ME -Liquidchip . 10 mutations occurred in exon 9 and 2 in exon 20 , including G 1624 A :E 542 K (n = 4 ), G 1633 A :E 545 K (n = 6 ) and A 3140 G :H 1047 R (n = 2 ). The results were further verified by ARMS methods . Among these 12 cases characterized for PIK 3 CA mutation , however , only 7 and 6 cases were identified by Sanger sequencing (6 .6 %,7 /106 ) and pyrosequencing (5 .7 %,6 /106 ), respectively .Sanger sequencing and pyrosequencing are less sensitive and are not efficiently applicable to the detection of PIK 3 CA mutation in EC samples . Choosing between ME -Liquidchip and ARMS will depend on laboratory facilities and expertise .The virtual slide (s ) for this article can be found here : http ://www .diagnosticpathology .diagnomx .eu /vs /13000 _2014 _153 .