Reactive oxygen species modulator 1 (Romo1) overexpression is an independent predictor of poor survival in NSCLC patients who undergo surgical resection

Objectives: Reactive oxygen species modulator 1 (Romo1) is a novel protein that plays an important role in intracellular reactive oxygen species generation. Romo1 is overexpressed in most cancer cell lines and related to invasiveness and chemoresistance in vitro. However, little information is available on its clinical implications. We investigated the association between Romo1 expression and the clinical outcomes of non-small cell lung cancer (NSCLC) patients who underwent surgical resection. Materials and methods: Romo1 protein expressions were evaluated immunohistochemically in resected tumor specimens. Survival analyses for overall population (n = 110) and early-stage patients (n=97) were performed according to clinical parameters including level of Romo1 expression. Results: Multivariate analyses showed that high Romo1 expression in tumor tissues was significantly associated with short disease-free survival (hazard ratio [HR]=3.16, 95% confidence interval [CI]: 1.21-8.22), and with short overall survival (HR=3.22, 95% CI: 1.02-10.21). Stronger associations were observed between Romo1 expression and disease-free survival (HR=3.69, 95% CI: 1.39-9.97) and overall survival (HR=4.21, 95% CI: 1.12-14.67) in stage I and II patients than in the overall population. Romo1 expression was not associated with any clinical parameter including age, gender, smoking status, stage, differentiation, or tumor histology. Conclusions: Increased Romo1 expression in surgically resected NSCLC was found to be significantly associated with early recurrence and poor survival. Romo1 overexpression could be a potential adverse prognostic marker in this setting.