Restin protein expression in non‐small cell lung cancer

Abstract Background Restin is a member of the melanoma‐associated antigen (MAGE) superfamily. Its expression has been reported to be up‐ or downregulated in cancer. Preclinical data suggest it is a tumor suppressor. In this study, we aimed to evaluate restin expression and prognostic value in non‐small cell lung cancer (NSCLC). Methods Restin expression was analyzed by immunohistochemistry in three tissue microarrays consisting of formalin‐fixed/paraffin‐embedded NSCLC specimens from 113 patients, represented in triplicate. Restin staining H‐score was the result of the staining intensity (0‐no, 1‐weak, 2‐moderate, and 3‐strong) multiplied by the percentage of stained tumor cells; it was defined as low if 1–100, moderate if 101–200, and strong if 201–300. Haverage‐score was the average H‐score in the triplicate. Restin Haverage‐scores were tested for correlations with clinical and pathological characteristics and patient outcome. Results Restin expression was localized to the cytoplasm, with nuclear enhancement, of 112/113 (99.1%) NSCLCs. Restin Haverage‐scores were 0 in 1/113 (0.88%), low in 15/113 (13.3%), moderate in 48/113 (42.5%), and strong in 49/113 (43.4%) NSCLCs. Restin Haverage‐scores did not correlate with NSCLC histological subtype, disease stage, recurrence/progression‐free, or overall survival. Conclusion Restin is moderately to strongly expressed in the majority of NSCLC tumors but its expression has no prognostic value in patients with NSCLC.