Identification of Potential Prognostic and Predictive Immunological Biomarkers in Patients with Stage I and Stage III Non-Small Cell Lung Cancer (NSCLC): A Prospective Exploratory Study

SIMPLE SUMMARY: Over the last 5 years, immune checkpoint inhibitors (ICIs) are increasingly used in the treatment of non-small cell lung cancer (NSCLC) as either monotherapy or in combination with chemo- and/or radiotherapy. However, despite these advances, outcome still remains poor for most patients and there is still a lot of room to improve prognosis in these patients. To date, we have no tools that allow us to identify the patients that will benefit from chemo- and/or radiotherapy combined with immunotherapy, what treatment-induced immune changes can be expected, and what are the most optimal treatment combinations. Therefore, prognostic and predictive immunological biomarkers are urgently needed. This prospective exploratory study aimed to identify potential prognostic and predictive immune-related proteins that are associated with progression-free survival in patients with stage I/III NSCLC. The results of this trial provide a good starting point to implement blood-based immune profiling analyses in future clinical trials. ABSTRACT: Radiotherapy (RT) and chemotherapy can induce immune responses, but not much is known regarding treatment-induced immune changes in patients. This exploratory study aimed to identify potential prognostic and predictive immune-related proteins associated with progression-free survival (PFS) in patients with non-small cell lung cancer (NSCLC). In this prospective study, patients with stage I NSCLC treated with stereotactic body radiation therapy (n = 26) and patients with stage III NSCLC treated with concurrent chemoradiotherapy (n = 18) were included. Blood samples were collected before (v1), during (v2), and after RT (v3). In patients with stage I NSCLC, CD244 (HR: 10.2, 95% CI: 1.8–57.4) was identified as a negative prognostic biomarker. In patients with stage III NSCLC, CR2 and IFNGR2 were identified as positive prognostic biomarkers (CR2, HR: 0.00, 95% CI: 0.00–0.12; IFNGR2, HR: 0.04, 95% CI: 0.00–0.46). In addition, analysis of the treatment-induced changes of circulating protein levels over time (Δv2/v3−v1) also identified CXCL10 and IL-10 as negative predictive biomarkers (CXCL10, HR: 3.86, 95% CI: 1.0–14.7; IL-10, HR: 16.92 (2.74–104.36)), although serum-induced interferon (IFN) response was a positive prognostic. In conclusion, we identified several circulating immunogenic proteins that are correlated with PFS in patients with stage I and stage III NSCLC before and during treatment.