Schlafen 11 Expression in Patients With Small Cell Lung Cancer and Its Association With Clinical Outcomes

Abstract

ABSTRACT Background Schlafen 11 (SLFN‐11) has been identified as a sensitizer of tumor cells to DNA‐damaging agents. However, the relationship between SLFN‐11 expression and clinical outcomes in patients with small cell lung cancer (SCLC) remains unexplored. Thus, we aimed to evaluate the impact of SLFN‐11 expression on survival in patients with limited‐stage (LS) SCLC. Methods We conducted a retrospective review of data from patients pathologically diagnosed with LS‐SCLC post‐surgery between January 2008 and December 2018. SLFN‐11 expression was assessed using immunohistochemistry in tissue microarrays and scored using a histology (H)‐score (range: 0–300). Results Overall, 86 patients were included in the analysis with a median H‐score of 43 for SLFN‐11 expression. Among the patients, 44 had high SLFN‐11 expression (provisionally defined as H‐score ≥ 43). No significant differences in clinical profiles were observed between the two groups (high and low SLFN expression). The median survival durations were not reached (NR; 95% confidence interval [CI]: 65.1 months to NR) and 33.5 months (95% CI: 24.2 months to NR) for patients with high and low SLFN‐11 expression, respectively (hazard ratio [HR]: 0.40, 95% CI: 0.19–0.81; p = 0.012). Among patients who relapsed post‐surgery (n = 21), the median survival durations were 22.0 (95% CI: 7.6–44.9 months) and 8.1 (95% CI: 1.8–24.6 months) months in patients with high and low SLFN‐11 expression, respectively (HR: 0.22, 95% CI: 0.06–0.84; p = 0.026). Conclusions High SLFN‐11 expression is associated with relatively longer survival in patients with LS‐SCLC in both those undergoing surgery and those who have relapsed.

Keywords

• immunohistochemistry
• lung cancer
• Schlafen 11
• small cell lung cancer