Objective: Lung cancer is the leading cause of cancer-related death worldwide. Treatment in locally advanced non-small cell lung cancer (NSCLC) is heterogeneous. The cure rates after complete surgical resections are not as good as expected. A better understanding of the biology of NSCLC might allow the selection of appropriate treatment. Only a few studies have been carried out on the prognostic value of xanthine oxidoreductase (XOR) and BRCA1 in lung cancer. Material and Methods: In this study, 35 patients with stage IIIA and stage IIIB of NSCLC were included. They were operated in Baskent Ankara and Adana hospitals and received neoadjuvant chemotherapy. The regular follow-up of all the patients was done in Baskent University Medical Oncology, Thoracic Surgery Department. The clinical and histopathological parameters (age, gender, stage, smoking history, performance status, and neoadjuvant chemotherapy), along with the immunohistochemical study of BRCA1 and XOR staining, were examined, and correlated with survival outcomes. Results: Median overall survival time was reported as 38.5 months, and 5-year survival rate was 33%. The presence of BRCA1 was positively associated with shorter overall survival in stage III lung cancer patients, who were followed up with the neoadjuvant platinum-based chemotherapy regime (p<0.05). There was no relation between XOR activity and overall survival outcomes. Conclusion: BRCA1-positive status might be prognostic in patients with Stage IIIA and IIIB of NSCLC.