Abstract 1537: Prospective mutational characterization of Japanese patients with non-small cell lung cancer by next-generation sequencing
Authors: Kenmotsu Hirotsugu , Koh Yasuhiro , Serizawa Masakuni , Isaka Mitsuhiro , Maniwa Tomohiro , Murakami Haruyasu , Mori Keita , Endo Masahiro , Nakajima Takashi , Ohde Yasuhisa , Takahashi Toshiaki , Yamamoto Nobuyuki 
Published: May 2015

Background: Detection of tumor genetic alterations is critically needed for lung cancer clinic as well as for the development of molecular targeted therapeutics. Here we report the results of a broad spectrum of genetic alterations identified in Japanese patients with non-small cell lung cancer (NSCLC) by ultra-deep targeted sequencing.

Material and Methods: Highly multiplexed amplicon sequencing was performed using genomic DNA extracted from snap-frozen tumor specimens. TruSeq amplicon cancer panel was used for the detection of somatic mutations in 48 cancer related genes followed by ultra-deep sequencing (Illumina) at an average coverage of approximately 3,400x. ALK, ROS1 and RET translocations and EGFR, MET, PIK3CA, FGFR1 and FGFR2 amplifications were also detected by multiplex RT-PCR and quantitative PCR, respectively.

Results: Between July 2011 and March 2013, 279 consecutive patients were enrolled in this prospective study at Shizuoka Cancer Center: median age 69 years (range: 38-92); male 66%; never smoker 25.8%; histology: adenocarcinoma 70.6%, squamous cell carcinoma (SQ) 25.1%, others 4.3%; pathological stage: I 58.1%, II 22.6%, III 15.4%, IV 3.9%. TP53 mutation was most frequently detected (35.9%) in all patients, particularly in SQ (59.2%). Mutations in genes such as CTNNB1 (4.0%), SMAD4 (1.5%), GNAS (1.0%), STK11 (1.0%), HRAS (0.5%) and PTPN11 (0.5%) were also detected in addition to major mutations in genes such as EGFR (44.8%), KRAS (18.4%) and PIK3CA (4.5%) in adenocarcinoma. PIK3CA (19.7%), HRAS (2.8%), APC (1.4%), FGFR2 (1.4%), FGFR3 (1.4%) and SMAD4 (1.4%) mutations were identified in SQ and notably, 40.9% of SQ patients harbored concurrent gene mutations, suggesting the genetic complexity of this histological subset. In EGFR mutation, deletion in exon 19 (42.6%) and L858R point mutation in exon 21 (41.5%) were frequently observed. As for PIK3CA mutation, the majority (92.8% of all PIK3CA mutant SQ cases) was detected in exon 9 (residues E542 and E545) in SQ but in contrast, mutations in exon 1 and 20 (residues G106 and H1047, respectively) were more frequently detected (33.3% combined of all PIK3CA mutant adenocarcinoma cases) in adenocarcinoma.

Conclusions: We managed to detect a wide range of genetic alterations and to identify additional actionable mutations along with popular driver mutations in NSCLC by next-generation sequencing technology. These data should be incorporated into lung cancer clinic to implement personalized cancer medicine.

Citation Format: Hirotsugu Kenmotsu, Yasuhiro Koh, Masakuni Serizawa, Mitsuhiro Isaka, Tomohiro Maniwa, Haruyasu Murakami, Keita Mori, Masahiro Endo, Takashi Nakajima, Yasuhisa Ohde, Toshiaki Takahashi, Nobuyuki Yamamoto. Prospective mutational characterization of Japanese patients with non-small cell lung cancer by next-generation sequencing. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 1537. doi:10.1158/1538-7445.AM2014-1537