ICAM-1 expression in patients with advanced non-small cell lung cancer treated with radiotherapy

Purpose: To investigate the possible clinical relevance of ICAM-1 molecule in patients with advanced non-small cell lung cancer (NSCLC) treated with radiotherapy. Methods: The expression of ICAM-1 was examined immunohistochemically on tissue specimens of 62 patients with pathologically confirmed NCSLC. The median age at diagnosis was 62 years (range 49-84) with a male predominance (87.8%). All patients had stage III disease at presentation. The median follow up was 15.5 months (range 7-44). Obtained expression data were weighted against clinical and pathological parameters. Results: Thirty-seven patients (60%) had no ICAM-1 staining, 16 patients (26%) had weak staining, while 6 patients (10%) expressed moderate staining and only 3 patients (5%) showed strong ICAM-1 staining. Moderate and high expressions were mostly observed in adenocarcinomas and undifferentiated carcinomas (n=8), that are considered more aggressive than squamous cell carcinoma (n=1). The median overall survival (OS) was 15 months (range 11-20). There seemed to exist an inverse association between ICAM-1 expression and OS, since there was a trend in median survival in favor of no ICAM-1 expression (p=0.083). Moreover, in patients with no ICAM-1 expression, there was observed a statistically significant difference in OS, favoring the squamous cell subtype (p=0.006). Nevertheless, ICAM-1 expression did not confer any statistical significance regarding smoking status (p=0.128), metastatic potential (p=0.574) as well as with the site of metastasis (p=0.964). Conclusion: Our findings may serve as a helping resource for further investigations of ICAM-1 as a molecular marker that could characterize treatment response and survival of tumor subpopulations.