Clinical significance of calcium‐binding protein S100A8 and S100A9 expression in non‐small cell lung cancer

BACKGROUND: The purpose of this study was to evaluate the correlation between calcium‐binding protein S100A8 and S100A9 expression in non‐small cell lung cancer (NSCLC) and patients’ clinical features. METHODS: Fifty‐two NSCLC patients who underwent surgery at Zhejiang Hospital from February 2014 to January 2016 were included in this study. Calcium‐binding protein S100A8 and S100A9 expression patterns in cancer and para‐cancer tissues were examined by immunohistochemistry assay. The correlation between calcium‐binding protein S100A8 and S100A9 expression patterns and NSCLC patients’ clinical characteristics, including age, gender, tumor node metastasis stage, and pathology type, were evaluated. RESULTS: S100A8 and S100A9 were generally expressed on the cytoplasm and nucleus of NSCLC cells, mainly located in the cytoplasm, stained with brown particles, and distributed evenly. The positive expression rates of S100A8 and S100A9 in cancer tissues were 71.2% and 76.9%, respectively, which were significantly higher than in para‐cancer tissues at 11.5% and 19.2%, respectively, with statistical significance (P < 0.05). S100A8 and S100A9 positive expression was associated with tumor differentiation degree (P < 0.05) but were not correlated with age, gender, smoking history, tumor diameter, pathology type, tumor node metastasis stage, or pleural effusion (P (all) > 0.05). CONCLUSION: S100A8 and S100A9 positive expression in cancer tissues was significantly higher than in para‐cancer tissues and was correlated with tumor differentiation, which may be a potential marker for poor prognosis.