Abstract 2372: Predictive markers in patients with non-small cell lung cancer with pemetrexed treatment.

Abstract

Abstract Background: This study is desiged to evaluate biomarkers that are correlated with the efficacy of pemetrexed in patients with non-small-cell lung cancer (NSCLC). Methods: Patients with stage III or IV NSCLC who received pemetrexed monotherapy after failure of one or more chemotherapy regimen between January 2003 and August 2011 were included. Polymorphism of reduced folate carrier gene (SLC19A, rs1051298), 5,10-methylenetetrahydroflate reductase (MTHFR, rs1801133) and thymidylate synthase (TS, rs45445694, rs16430) gene were analyzed by PCR and direct sequencing method using peripheral blood. Results: Total 123 patients were included. The median age was 61 years (range 35-82). Fifty eight (47.2%) patients were female. Predominant histology was adenocarcinoma (92.7%). Metastatic diseases were 114 (80.5%) patients. Patients received one or more lines of systemic therapy before pemetrexed therapy, one line in 53 (43.1%) patients, two in 51(41.5%), three in 14 (11.02%), and four in 4 (3.3%). Median 4 cycles of chemotherapy were given (range 1-44). Response rate was 22.7% (CR, n=2, PR, n=26) and stable disease was detected in 54 patients (43.9%). Median follow up duration was 28.7months (range 4.07-84.33months). Median progression free survival (PFS) was 4.2 months (95% CI: 2.9-5.6) and median overall survival (OS) was 18.9 months (95% CI: 13.3-24.6). Clinical factors like, sex, histology of tumor (adenocarcinoma vs, nonadenocarcinoma), differentiation, smoking status and EGFR mutation status (active mutation vs. other mutation vs. wild type) did not have any significant difference on response and PFS. Only polymorphisms of TS promoter enhancer region (TSER) were related with PFS. 2R/2R repeat in the TSER (2R/2R vs 2R/3R, 3R/3R 1.0m vs 4.3m, p<0.01) and CC homozygote variant in second repeat of the 3R allele (CC vs GC, GG 2.8m vs 5.0m, p=0.04) had poor PFS. All polymorphism did not have effect on response rate and overall survival. Conclusions: This study suggests that polymorphisms of TSER associated PFS in pemetrexed treatment. Further prospective studies will be needed to validate these polymorphism as a useful biomarker of pemetrexed treatment in NSCLC patients. Citation Format: Hiun S. Chae, Yoon Ho Ko, Eun Kyoung Jeon, Sook Hee Hong, Jeong-Oh Kim, Seung Joon Kim, Kyo Young Lee, Young Kyoon Kim, HoonKyo Kim, Seok young Park, In Sook Woo, Jin Hyoung Kang. Predictive markers in patients with non-small cell lung cancer with pemetrexed treatment. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2372. doi:10.1158/1538-7445.AM2013-2372