Abstract 726: Copy number amplification of the PIK3CA gene is associated with poor prognosis in early-stage head and neck squamous cell carcinoma

Abstract

Abstract Background: Deregulation of the EGFR signaling pathway is one of the most frequently observed genetic abnormalities that drive cancer development. Mutations in downstream components of the EGFR signaling pathway, including KRAS, BRAF and PIK3CA, have been reported in numerous cancers. However, extensive mutation analysis of these genes in clinical samples has not been performed for head and neck squamous cell carcinoma (HNSCC). Patient and methods: We examined mutations and copy number alterations of KRAS, BRAF and PIK3CA in 115 clinical specimens of HNSCC obtained from surgically treated patients. Results: We identified three mutations in K-RAS and two mutations in PIK3CA. Copy number amplification was found in 42 cases (36.4%) for PIK3CA, 12 cases (10.4%) for K-RAS and nine cases (7.8%) for BRAF. Tumor recurrence and death occurred in 49 (42.6%) and in 22 (19.3 %) patients during the median follow-up of 723 days, respectively. Kaplan-Meier survival analysis revealed that in patients with early-stage carcinoma (Stages I-III), copy-number amplification of PIK3CA was drastically associated with cancer relapse. Conclusion: Copy number amplification of the PIK3CA is associated with poor prognosis in early-stage HNSCC. The PIK3CA copy number status will serve as a marker of poor prognosis in patients with HNSCC. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 726. doi:1538-7445.AM2012-726