Abstract Introduction: To date, the role of immunotherapy with check point inhibitors and/or vaccines in the treatment of breast cancer (BC) is still debating, and the main focus of immunotherapy in BC is on triple negative subtype as a target population in many ongoing clinical trials. Translational research into identifying predictive and prognostic immune biomarkers is of particular clinical relevance, but, there are currently no definite prognostic and predictive immune biomarkers in BC, especially in triple negative breast cancer(TNBC). We investigated the expression profiles of immune genes in patients with TNBC to identify the prognostic value of immune genes in search of clinical implications. Methods : We investigated expression profiles of 770 pan-cancer immune related genes using the nCounter mRNA expression assay (NanoString®) from paraffin-embedded tumor tissues in 200 patients diagnosed as TNBC who received curative surgery at Samsung Medical Center from 2000 to 2004. We analyzed the relationship between stage adjusted level of gene expressions and patients' survival outcomes using Cox regression model. Results: Of 770 genes, 186 genes were selected from univariate analysis with clinical stage adjustment. In multivariate analysis using Cox regression, expressions of CD1B, CD45, CD53, CT45A1, GTF3C1, IL11RA, IL1RN, LRRN3, MAPK1, NEFL, PRKCE, SPACA3 and RANKL were associated with distant recurrence free survival (p<0.05, respectively). Among these 13 genes, expression of MAPK1, NEFL, CD45, SPACA3 and RANKL were correlated with favorable outcome in terms of distant recurrence free survival (p<0.05, respectively). In terms of overall survival, C3, IL1RL1, IL1RN, IL7 and PRKCE were associated with poor prognosis (p<0.05, respectively) and expression of SAA1 CXCL9 and RANKL resulted in favorable outcome (p<0.05, respectively). Table 1ParameterParameter EstimateStandard Errorp-valueHazard Ratio95% Confidence Interval(a) distant recurrence free survival Stage2.487350.680570.000312.0293.169, 45.661CD1B1.141910.2753<.00013.1331.826, 5.374CD531.531650.34851<.00014.6262.336, 9.159CT45A10.426110.134210.00151.5311.177, 1.992GTF3C11.193110.579720.03963.2971.059, 10.271IL11RA1.671120.461750.00035.3182.151, 13.146IL1RN0.980280.24657<.00012.6651.644, 4.321LRRN31.424170.28742<.00014.1542.365, 7.297MAPK1-0.542740.258240.03560.5810.35, 0.964NEFL-1.12170.335610.00080.3260.169, 0.629PRKCE2.378340.49659<.000110.7874.076, 28.549CD45-2.736780.43154<.00010.0650.028, 0.151SPACA3-0.745930.272270.00610.4740.278, 0.809RANKL-1.288920.2976<.00010.2760.154, 0.494(b) overall survival Stage1.359280.497810.00633.8931.468, 10.329C30.329830.150350.02831.3911.036, 1.867CXCL9-0.379190.100680.00020.6840.562, 0.834IL1RL10.679360.262940.00981.9731.178, 3.303IL1RN0.437130.172370.01121.5481.104, 2.171IL70.507280.206250.01391.6611.109, 2.488PRKCE0.835340.272910.00222.3061.35, 3.936SAA1-0.564250.13449<.00010.5690.437, 0.74RANKL-0.604990.234510.00990.5460.345, 0.865 Conclusion: High expression of IL1RN, PRKCE were associated with short distant recurrence free survival and overall survival in patients with TNBCs who received curative surgery. In contrast, RANKL expression resulted in prolonged distant recurrence free survival and overall survival. Citation Format: Kim J-Y, Jung HH, Lim JE, Cho EY, Lee SK, Yu JH, Lee JE, Kim SW, Nam SJ, Park YH, Ahn JS, Im Y-H. Prognostication of immune related gene expression in patients with triple negative breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P4-08-30.