Abstract 2267: Efficacy of pemetrexed-based chemotherapy in patients with NSCLC harboring KRAS mutations

Abstract

Abstract [Background] Biomarkers like epidermal growth factor receptor (EGFR) gene mutations or anaplastic lymphoma kinase (ALK) rearrangement have been discovered in lung cancer, leading to targeted therapies developed in non-small cell lung cancer (NSCLC). Several oncogenes have been reported to be negative biomarkers for response to tyrosine kinase inhibitors (TKIs), for example, NSCLC with KRAS mutations are resistant to EGFR-TKIs. A preclinical study showed that KRAS mutant lung cancer cells were sensitive to pemetrexed, while a retrospective study reported that pemetrexed-based chemotherapy didn't show a favorable outcomes in patients with KRAS mutant NSCLC. We, therefore, studied efficacy of pemetrexed-based chemotherapy in patients with NSCLC, and compared the efficacy between KRAS and wild-type NSCLC. [Methods] We retrospectively studied the medical records of patients diagnosed with NSCLC between 2013 to 2015. Genomic DNA (gDNA) was extracted from FFPE tissue samples (QIAamp DNA FFPE Tissue Kit, QIAGEN). KRAS mutations were evaluated using Ion Torrent NGS systems (Ion PGM, Thermo Fischer Scientific) or PCR-rSSO. AmpliSeq Colon and Lung Cancer Research Panel v2 was used in the present study. We used Ion Reporter software for next-generation sequencing data analysis. [Results] We analyzed the data of 226 patients with NSCLC and successfully extracted gDNA from 94 tissue samples. Among them, mutation analysis by Ion PGM system was performed in 48 samples and PCR-rSSO in 46 samples. We will report response rate and progression free survival in the patients treated with pemetrexed-based chemotherapy. Citation Format: Shunsuke Okumura, Takaaki Sasaki, Shin-ichi Chiba, Masatoshi Sado, Naoyuki Miyokawa, Hiroshi Funakoshi, Yoshinobu Ohsaki. Efficacy of pemetrexed-based chemotherapy in patients with NSCLC harboring KRAS mutations. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2267.