Molecular spectrum of PIK3CA gene mutations in patients with nonsmall-cell lung cancer in Turkey.

Aims: The aim of the present study was to obtain the first data for the phosphatidylinositol-4,5-bisphosphate 3-kinase (PIK3CA) mutation frequency among nonsmall-cell lung cancer (NSCLC) patients in Turkey. All exons of the PIK3CA gene were investigated by sequence analysis in 40 NSCLC tumor tissue samples.

Results: The 1634A>C mutation, which has previously been identified in many cancers including NSCLC, was identified in three tumor tissue samples in the present study. Interestingly, a second mutation (1658_1659delGTinsC) was also identified in these patients. The concurrence of these two mutations has been reported as the Cowden syndrome, which is known to be a cancer predisposition syndrome. This finding is important since it may be an indicator of the underlying cancer predisposition syndrome in NSCLC patients. Moreover, four novel mutations were identified in the present study. However, in vitro studies are required to evaluate the effects of these mutations on kinase activation.

Conclusions: The high frequency of PIK3CA mutations exerts important clinical implications for targeted therapy. This finding indicates that therapeutic agents targeting the phosphatidylinositol 3-kinase (PI3K) would be beneficial in the NSCLC subpopulation.