Abstract 7667: Neutrophil to lymphocyte ratio (NLR) as an indicator of tumor immune status in non-small cell lung cancer

Abstract Background: Neutrophil to lymphocyte ratio (NLR) has been reported as a prognostic biomarker in non-small cell lung cancer (NSCLC), while its biological rationale has yet to be clarified. In cancer patients, inflammation and immune status plays crucial roles in tumor growth and the prognosis. While several studies have explored the relationship between NLR and inflammation, there are few reports on the relationship between NLR and immune status in the tumor microenvironment of cancer patient so far. The purpose of this study is to explore the potential utility of NLR as a surrogate biomarker for assessing the immune response to tumors. Methods: The medical records of NSCLC patients who underwent surgery at our institution in 2012 were retrospectively reviewed. The patients’ clinical information including age, sex, performance status, smoking history, histology, clinical stage (7th), and NLR, was obtained. NLR was calculated based on blood tests conducted within a month before surgery. Tumor immune status was evaluated by Immunohistochemical staining for CD3, CD8, and FOXP3 in their surgical specimens. The relationship between NLR, clinicopathology, and tumor immune status was examined. The survival curves were estimated using the Kaplan-Meier method and compared using the log-rank test. Blood cell counts and ratios between different groups were compared using nonpaired t test or Mann-Whitney U test, with a significance threshold set at p = 0.05. Results: A total of 120 patients were included. The 5-year overall survival rate (OS) in all 120 patients was 63.4%. The 5-year OS of the patients with lower NLR was significantly better than those with high NLR (low < 2.2 vs high ≥ 2.2; 70.1% vs 56.8%, p = 0.042). The 5-year OS of the patients with high density of CD3+ TILs was significantly better than that in patients with low density of CD3+ TILs (high ≥ 242 vs low < 242; 70% vs 56.8%, p = 0.019). The 5-year OS of the patients with high density of CD8+ TILs was significantly better than that in patients with low density of CD8+ TILs (high ≥ 112 vs low < 112; 72.4% vs 54.1%, p = 0.011). Conversely, the 5-year OS of the patients with low density of FOXP3+ TILs was significantly better than that in patients with high density of FOXP3+ TILs (high ≥ 7.5 vs low < 7.5; 46.2.% vs 79.6%, p = 0.0006). The number of CD3+ TILs had negative correlation with NLR (p = 0.005), while the number of CD8+ TILs and FOXP3+ TILs didn’t exhibit an association with NLR. Conclusion: Our results suggest that NLR might potentially reflect immune status in the tumor microenvironment, explaining its impact on the prognosis of NSCLC patients. While further research is needed, these findings may offer valuable insights for guiding treatment options. Citation Format: Ryo Yoshichika, Kazuma Iwata, Ken Suzawa, Yin Min Thu, Daisuke Mizuno, Tomoaki Higashihara, Naohiro Hayashi, Atsushi Matsuoka, Mao Yoshikawa, Fumiaki Mukohara, Kazuhiko Shien, Hiromasa Yamamoto, Shinichi Toyooka. Neutrophil to lymphocyte ratio (NLR) as an indicator of tumor immune status in non-small cell lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7667.