Abstract P5-06-30: Identification of novel single nucleotide polymorphisms located in MAP3K1 and ABCB1 genes as markers for poor overall survival in early-stage hormone receptor-positive breast cancer using next-generation sequencing
Authors: Kuo Sung-Hsin , Yang Shi-Yi , Lin Po-Han , Chen Chen-Hsin , Yang Hsin-Chou , Hsu Chih-Yuan , Huang Chiun-Sheng 
Published: March 2020

Abstract
Background: We previously revealed that single nucleotide polymorphisms (SNPs) of CYP19A1, MAP3K1 rs889312, and ABCB1 rs2032582 were associated with overall survival (OS) in early-stage hormone receptor (HR)-positive breast cancer patients. Previous studies also showed that FGFR2 rs1219468 and TOX3 rs8051542 influenced OS in early-stage breast cancer patients. In this study, we assessed whether undiscovered SNPs of CYP19A1, MAP3K1, ABCB1, FGFR2, and TOX3 are associated with clinical outcome of patients with early-stage HR-positive breast cancer.
Patients and Methods: We used next-generation sequencing (NGS) methods to explore unidentified SNPs of CYP19A1, MAP3K1, ABCB1, FGFR2, and TOX3 in 80 patients who had HR+, T1 to T2, and N0 to N1 breast cancer and had matched clinicopathological features and clinical outcomes (experimental cohort). The mapping selected SNPs identified from NGS were located in different chromosomes, such as chromosome 5 (MAP3K), 7 (ABCB1), 10 (FGFR2), 15 (CYP19A1), and 16 (TOX3), were analyzed. The multivariate-adjusted hazard ratio (aHR) of OS associated with the individual genotypes of the experimental cohort was assessed after adjusting for age, tumor size, tumor grade, HER2 status, menopausal status, and chemotherapy using Cox regression analyses. We further correlated identified significant novel SNPs with disease-free survival (DFS) and OS in 195 patients with HR-positive, T1-T2, and N0-1 breast cancer (validation cohort) using stepwise selection multiple Cox model analyses.
Results: Through target region re-sequencing, we identified 69 novel SNPs, including 18 CYP19A1 SNPs, 16 MAP3K SNPs, 18 ABCB1 SNPs, 12 FGFR2 SNPs, and 5 TOX3 SNPs in the experimental cohort (n = 80). After multivariate-adjusted analyzing, FGFR2 rs2981460(C/C) (p = 0.0115), and MAP3K1 rs3822625 (A/A) (p = 0.0475), rs702689
(G/G) (p = 0.0312), rs832567 (C/C) (p = 0.0312), and rs9687226 (C/C) (p = 0.0475), and ABCB1 rs2032582 (T/T+T/C) (p = 0.0061) were significantly associated with the poorer OS of the experimental cohort. In a validated cohort (n =195) (Table 1), we found that MAP3K1 rs702689 (G/G) was significantly associated with poorer DFS (aHR = 2.3; 95% confidence interval [CI] = 1.1 to 5.1; p = 0.03) and OS (aHR = 4.9; 95% CI = 1.3 to 18.7; p = 0.02). In addition, MAP3K1 rs832567 (C/C) was significantly associated with poorer DFS (aHR = 2.5; 95% CI = 1.1 to 5.5; p = 0.02) and OS (aHR = 5.4; 95% CI = 1.4 to 21.6; p = 0.02). In premenopausal women of validation cohort (n = 108), ABCB1 rs2032582 (T/T+T/C) was significantly associated with a poor OS (aHR = 62.3; 95% CI = 2.0 to 1911.7; p = 0.02).
Conclusions: Our results indicate that 3 novel SNPs, MAP3K1 rs702689, MAP3K1 rs832567, and ABCB1 rs2032582, may affect the prognosis of early-stage HR-positive breast cancer. Further validation of these SNPs in a large series of patients with early-stage HR-positive breast cancer who received adjuvant endocrine therapy alone is warranted.
Table 1. The Associations of Hormone Receptor-Positive Breast Cancer Patients with Various Genotypes in multiple Cox model (validation cohort)Disease-free survivalOverall survivalGenotypeaHR (95%CI)PaHR (95%CI)PTotal (n = 195)FGFR2_ rs2981460 (C/C vs.C/T+T/T)0.4 (0.1-1.8)0.220.6 (0.1-5.4)0.68MAP3K1_ rs3822625 (A/A vs. G/A+GG)2.0 (0.7-5.3)0.192.7 (0.6-12.9)0.20MAP3K1_ rs702689 (G/G vs. A/A+A/G)2.3 (1.1-5.1)0.034.9 (1.3-18.7)0.02MAP3K1_rs832567 (C/C vs. A/A+A/C)2.5 (1.1-5.5)0.025.4 (1.4-21.6)0.02MAP3K1_rs9687226 (C/C vs. T/T+T/C)2.0 (0.7-5.3)0.192.7 (0.6-12.9)0.20Premenopausal (n=108)ABCB1_rs2032582 (T/T+T/C vs. C/C)2.0 (0.8-5.0)0.1562.3 (2.0-1911.7)0.02aHR: adjusted by age, estrogen receptor and progesterone receptor status, number of lymph nodes, menopausal status, adjuvant chemotherapy, lymphovascular invasion, and tumor size.
Citation Format: Sung-Hsin Kuo, Shi-Yi Yang, Po-Han Lin, Chen-Hsin Chen, Hsin-Chou Yang, Chih-Yuan Hsu, Chiun-Sheng Huang. Identification of novel single nucleotide polymorphisms located in MAP3K1 and ABCB1 genes as markers for poor overall survival in early-stage hormone receptor-positive breast cancer using next-generation sequencing [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P5-06-30.