Abstract 1597: Real-world large-scale study kinase domain duplications across diverse tumor types in Chinese populations
Authors: Xu Chun-wei , Wang Wen-xian , Wang Xiao-jia , Zhu You-cai , Zhang Qu-xia , Fang Yong , Cai Xiu-yu , Chen Yu , Lin Li , Wang Hong , Fang Mei-yu , Zhang Yin-bin , Lan Shi-jie , Liu Xin , Pu Xing-xiang , Yu Zong-yang , Wan Bing , Li Jian-ying , Liang Xian-bin , Wang Li-ping , Zhuang Wu , Lin Ling , Chen Gang , Lv Tang-feng , Song Yong 
Published: August 2019

Background: Recently, kinase domain duplications (KDD) in BRAF, EGFR, MET and FGFR1 were reported, along with responses to tyrosine kinase inhibitors (TKI). However, its frequency and clinical outcomes in advanced cancer patients are larglely uncertain. We assessed the frequency of KDD across 14, 491 advanced cancers to reveal the landscape in a wide variety of subtypes.

Methods: A multicenter study in China was initiated from July 2013, and advanced cancer patients have been enrolled as of September 2018. We analyzed data from 14, 491 clinical advanced cancer cases, each of which had results from next-generation sequencing (NGS)-based 381 genes panel assay, analogous to the index patient.

Results: Of this entire cohort [6837 lung cancer (47.18%), 1894 breast cancer (13.07%), 1325 colorectal cancer (9.14%), 710 urinary system tumor (4.90%), 536 gynecological tumor (3.70%), 592 hepatobiliary cancer (4.09%), 221 gastric cancer (1.53%), 312 soft tissue sarcoma (2.15%), 260 head and neck cancer (1.79%) and 1804 others (12.45%)], 71 patients were identified with KDD, including EGFR (16), BRAF (12), MET (11), FGFR3 (8), RET (3), PDGFRA (3), ROS1 (3), FGFR1 (2), ERBB2 (2), SOX17 (2), ALK (2), KIT (1), NTRK1 (1), BAP1 (1), TMPRSS2 (1), ERBB4 (1), VHL (1), NTRK3 (1). KDD were seen in 0.39% (27/6837) of lung cancer [EGFR(9), BRAF (2), MET (6), FGFR3 (2), RET (1), PDGFRA (1), ROS1 (2), ERBB2 (1), ALK (1), NTRK1 (1), and ERBB4 (1)]; 0.21%(4/1894) of breast cancer [BRAF (1), FGFR3 (2), FGFR1 (1)]; 0.60%(8/1325) of colorectal cancer [EGFR (1), BRAF (3), FGFR3 (2), RET (1), ROS1 (1)]; 0.28%(2/710) of urinary system tumor [TMPRSS2(1), VHL (1)]; 0.19%(1/536) of gynecological tumor [SOX17 (1)]; 0.17%(1/592) of hepatobiliary cancer [EGFR (1)]; 0.45%(1/221) of gastric cancer [ERBB2 (1)]; 0.96%(3/312) of soft tissue sarcoma [EGFR (1), FGFR3 (1), PDGFRA (1)]; 0.77%(2/260) of head and neck cancer [BRAF (2)]; and 1.22%(22/1804) of others [EGFR (4), BRAF (4), MET (5), FGFR3 (1), RET (1), PDGFRA (1), FGFR1 (1), SOX17 (1), ALK (1), KIT (1), BAP1 (1), and NTRK3 (1)]; KDD possibly related to target resistance were seen in ERBB2 amplification gastric cancer and ALK-related NSCLC.

Conclusion: Diverse KDD are found across diverse tumor types and may underlie acquired resistance, and can benefit from matched targeted treatment. In addition, for short- or long-term responses to targeted treatment, we can use the NGS assay to explore differential gene alter in the future.

Citation Format: Chun-wei Xu, Wen-xian Wang, Xiao-jia Wang, You-cai Zhu, Qu-xia Zhang, Yong Fang, Xiu-yu Cai, Yu Chen, Li Lin, Hong Wang, Mei-yu Fang, Yin-bin Zhang, Shi-jie Lan, Xin Liu, Xing-xiang Pu, Zong-yang Yu, Bing Wan, Jian-ying Li, Xian-bin Liang, Li-ping Wang, Wu Zhuang, Ling Lin, Gang Chen, Tang-feng Lv, Yong Song. Real-world large-scale study kinase domain duplications across diverse tumor types in Chinese populations [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1597.