Positive tumour CD47 expression is an independent prognostic factor for recurrence in resected non-small cell lung cancer

Background Immunotherapy is a promising advance in oncology. Limited information exists regarding the interrelationship between CD47 expression and tumour-associated macrophage-related immuno-microenvironment in patients with non-small cell lung cancer (NSCLC). These factors may predict novel immunotherapy efficacy. Patients and methods CD47 and PD-L1 expression was retrospectively assessed in 191 resected NSCLC specimens via immunohistochemistry. Forty-six patients with pulmonary infectious diseases were enrolled as the control group. The infiltration of macrophages (M2 and M1) and CD8+ T-lymphocytes was evaluated via dual-immunofluorescence staining. Targeted DNA sequencing was performed on NSCLC specimens. Survival analysis was performed using the Cox model. Results Using 2+/3+ as a CD47 positive (CD47 pos ) expression cut-off, the prevalence of CD47 pos expression in NSCLC was 33.0% (63/191), significantly higher than in pulmonary infectious diseases. CD47 pos expression was significantly higher in female, non-smoking and adenocarcinoma patients (p=0.020, p<0.001 and p<0.001, respectively). Furthermore, CD47 pos expression was significantly correlated with epidermal growth factor receptor mutation (p<0.001). The expression of CD47 (H-score) in NSCLC was negatively correlated with tumour PD-L1 expression (p=0.0346) and tumour mutation burden (p=0.0107). CD47 pos expression was independently correlated with poor disease-free survival in patients with resected NSCLC in multivariate Cox regression analysis (p=0.035). Conclusion This study revealed the demographic, molecular and immuno-microenvironment characteristics of CD47 expression in NSCLC. We identified tumour CD47 pos expression as an independent prognostic factor for recurrence in resected NSCLC. Our findings illustrate the potential of anti-CD47 treatment in NSCLC.