Abstract PO4-05-12: High expression of SLC9A2 is correlation with lymphatic metastasis and poor survival in breast cancer

Abstract Background: SLC9A2 encodes Na+/H+ exchanger 2 which is an essential solute carrier protein on the surface of multiple cells. The prediction potentials of SLC9A2 in lymphatic metastasis and survival were unknow but explored in this study of breast cancer. Methods: Expression of SLC9A2 was determined in breast cancers (n=127) using real time quantitative polymerase chain reaction. Transcript levels of this gene was analysed in the breast cancers for the implication in lymph node involvement and survival using Mann-Whitney test with SPSS (Version 27). The relation of prognosis was also analysed by Kaplan Meier plotter in breast cancer. Results: In lymph node positive breast cancer, the expression of SLC9A2 shown an increase trend than no metastasis (n=43, median=25.9, interquartile range IQR 0.9-215.4 vs. n=44, median=4.9, IQR 0.2-31.8, p=0.1213). SLC9A2 expression in TNM stage Ⅱ was significantly higher than stage Ⅰ (n=31, median=42, IQR 0-195 vs. n=47, median=3.3, IQR 0.2- 31.6, p=0.0267) and also showed in the pathological type of invasive ductal carcinoma (n=27, median=42, IQR 3- 550 vs. n=35, median=3.3, IQR 0.2-31.8, p=0.0223). Kaplan Meier plotter showed over survival of SLC9A2 high expression was significantly worse than SLC9A2 low expression (66 months vs. 123.6 months, Hazard Ratio HR=1.57 1.3-1.9, p=0.000), also found in estrogen receptor (ER) positive (63.8 months vs. 173.7 months, HR=2.19 1.6-3.01, p=0.000). In patients with tamoxifen therapy, SLC9A2 high expression also had poor survival comparing to low expression (HR=2.86 1.4-5.86, p=0.0026). Conclusions: High expression of SLC9A2 is correlation with lymph node metastasis and poor survival in breast cancer. SLC9A2 could be as a predictor for lymphatic involvement and survival and might be an indicator for detection of resistance to endocrine therapy. Citation Format: Binbin Cong, Xiaoshan Cao, Wen Jiang, Lin Ye. High expression of SLC9A2 is correlation with lymphatic metastasis and poor survival in breast cancer abstract. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO4-05-12.