Abstract 4574: Genomic copy number variations characterize prognosis of oropharyngeal squamous cell carcinoma, including p16 positive subset, after surgery-based treatment

Abstract

Abstract Background High-risk human papillomavirus (HPV)-related (+) oropharyngeal squamous cell carcinoma (OSCC) exhibits unique clinical and molecular characteristics, compared to HPV-unrelated - OSCCs. As different patterns of genomic instability is expected in HPV-driven carcinogenesis, we questioned if patterns of genomic copy number variations (CNVs) differ depending on HPV association, and predict prognosis, after surgery-based treatment for OSCCs in Korean population. Methods Fifty-eight OSCCs patients, who underwent surgery-based treatment and followed for 42 months on median, were enrolled. HPV status was determined by p16 immunohistochemistry (IHC), and HPV DNA PCR. Genome-wide CNV analysis was performed using array-based comparative genomic hybridization of genomic DNA from paraffin-embedded specimen. Clinical association and survival analyses were followed. Results p16 predicted the overall survival (HR = 0.27, CI: 0.39-0.80, p = 0.0006), better than HPV DNA PCR (HR = 0.83, CI: 0.66-1.29, p = 0.64) or smoking history (HR = 2.18, CI: 0.92-5.18, p = 0.071). In overall, number of CNVs did not significantly differed between p16+/- groups. However, 30 locus showed different CNV pattern between these groups. PRDM2 was amplified only in p16+ group, while EGFR and 11q13.3 was more amplified in p16- patients. Loss of FGF18 lead to worse prognosis, and gain of CDK10 and RAD18 was linked to better prognosis in all patients. Amplification of HRAS and loss of KDR lead to better OS in p16+ group. Conclusions After surgery-based treatment, p16+ OSCCs exhibits different CNV patterns at some loci, compared with p16- counterpart. Specific patterns of CNVs do predict better survival, especially in p16+ OSCCs. In the future, clinical trials should stratify patients based on these patterns to apply escalated treatment to obtain better survival. Citation Format: Yuh-S. Jung, Arang Rhie, Jong-Il Kim, Jin Soo Lee, Junsun Ryu, Weon Seo Park. Genomic copy number variations characterize prognosis of oropharyngeal squamous cell carcinoma, including p16 positive subset, after surgery-based treatment. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4574. doi:10.1158/1538-7445.AM2015-4574