Lung adenocarcinoma (LUAD) has been described as the most common type of lung cancer among non-smokers. The aim of this study was to build a prognostic scoring model to identify survival risk of LUAD patients using survival analysis and to link patient characteristics to this disease for prognosis and needed treatments. Data from 131 non-smoking LUAD patients were included in the study with 13 variables: five clinicopathologic variables (age, tumor stage, tumor grade, metastasis status, lymph node metastasis status) and six IHC markers (RAD54B, BRCA1-RAD54B, FEN1(N)-RAD54B, PARP1-RAD54B, POLB, and POLB-TP53). Each investigated predictor was evaluated for their statistical significance using univariate Cox-Proportional Hazards (Cox PH) model. Furthermore, multiple Cox PH regression was used to generate a prognostic score model with the addition of a shrinkage factor to prevent overfitting. Prognostic information was evaluated using Likelihood Ratio Statistic (LR χ2) to derive the best score model available. Results of the study showed that only age, metastasis, lymph node metastasis, and IHC Pair BRCA1-RAD54B were included in the model given by: 

Score = 96.3*(1.305*Age(>65)+1.019*Meta+1.296*NodeMeta+0.799*(BRCA1-RAD54), 

with LR χ2=54.57 (p<0.0001). Patients were categorized as low risk-patients (S.50 =106.6 months) and high risk-patients (S.50 =27.8 months) using median splits and showed that survival rates were statistically different between the two categories. Overall, this study has seen the need to identify immunohistochemical markers in the advent of targeted therapy, as well as, patient specific treatments among non-smoking LUAD patients.