Predictive value of CD73 expression for the efficacy of immune checkpoint inhibitors in NSCLC.

Background CD73 induces the dephosphorylation of adenosine monophosphate converting it to adenosine, enabling malignancies to escape from immune surveillance. Although CD73 overexpression has been reported to be a poor prognostic factor in several malignancies including non-small cell lung cancer (NSCLC), its predictive relevance in NSCLC patients receiving immune checkpoint inhibitors is unknown. The present research was conducted to investigate the prognostic significance of CD73 expression in NSCLC patients receiving immune checkpoint inhibitors (ICIs). Methods We screened 91 patients with advanced or recurrent NSCLC who received immune checkpoint inhibitors. CD73 expression was evaluated immunohistochemically using tissue specimens obtained just before treatment with ICIs. Results Analysis of progression-free survival (PFS) and overall survival (OS) in relation to several levels of CD73 expression (1%, 10%, 30%, and 50%) showed that both tended to be more favorable as expression of CD73 increased. PFS and OS were longer for patients in whom at least 50% of the tumor cells expressed CD73 than for those in whom EGFR mutation, immune checkpoint inhibitors were significantly more effective in those with high CD73 expression, whereas CD73 expression did not significantly affect the efficacy in patients with EGFR mutation-negative NSCLC. Furthermore, CD73 expression was predictive factor for the PFS independent of PD-L1 expression in patients with EGFR mutation. Conclusions High CD73 expression may predict a favorable response to ICIs in NSCLC patients, especially those harboring EGFR mutations. Key points Significant findings of the study: In patients who were positive for EGFR mutation, immune checkpoint inhibitors (ICIs) were significantly more effective in those with high CD73 expression, whereas CD73 expression did not significantly affect the efficacy in patients with EGFR mutation-negative NSCLC. What this study adds: High CD73 expression may predict a favorable response to immune checkpoint inhibitors in NSCLC patients, especially those harboring EGFR mutations.