Peripheral NK cells identified as the predictor of response in extensive-stage small cell lung cancer patients treated with first-line immunotherapy plus chemotherapy.

PURPOSE: Although immunotherapy improves outcomes in extensive-stage small-cell lung cancer (ES-SCLC), the search for biomarkers predicting treatment success is crucial. Natural killer (NK) cells are potential indicators in various cancers, however, their precise role in ES-SCLC prognosis remains unclear. METHODS: In this retrospective study, 33 patients with ES-SCLC treated with first-line immuno-chemotherapy were enrolled. The peripheral NK cell percentage and its longitudinal dynamics were analyzed using flow cytometry. Progression-free survival (PFS) and overall survival (OS) were calculated as hazard ratio (HR) and compared statistically. RESULTS: The median PFS was better in the group with normal baseline NK cell levels than the low group (7.0 vs. 4.6 months; HR = 0.17; 95% CI 0.07-0.41; P < 0.0001), but there was no association with OS (14.9 vs. 10.3 months; HR = 0.55; 95% CI 0.23-1.31; P = 0.171). Furthermore, the NK cell% for 95.0% of patients increased after immunochemotherapy in the clinical response group (P = 0.0047), which led to a better median PFS (6.3 vs. 2.1 months; HR = 0.23; 95% CI 0.05-0.98; P < 0.0001) and OS (14.9 vs. 5.9 months; HR = 0.20; 95% CI 0.04-1.02; P < 0.0001). Similar trends were observed with NK cell% changes up to disease progression, improving PFS (6.5 vs. 4.3; HR = 0.41; 95% CI 0.12-0.92; P = 0.0049) and OS (17.4 vs. 9.7; HR = 0.42; 95% CI 0.17-1.02; P < 0.0001). CONCLUSION: In patients with ES-SCLC, the percentage and changes in peripheral NK cells can predict the response to combined immunotherapy and chemotherapy.

Effect of immune checkpoint inhibitors at different treatment time periods on prognosis of patients with extensive-stage small-cell lung cancer.

BACKGROUND: The application of immune checkpoint inhibitors (ICIs) in treating patients with extensive-stage small-cell lung cancer (ES-SCLC) has brought us new hope, but the real-world outcome is relatively lacking. Our aim was to investigate the clinical use, efficacy, and survival benefit of ICIs in ES-SCLC from real-world data analysis. METHODS: A retrospective analysis of ES-SCLC patients was conducted between 2012 and 2022. Progression-free survival (PFS) and overall survival (OS) were assessed between groups to evaluate the value of ICIs at different lines of treatment. PFS1 was defined as the duration from initial therapy to disease progression or death. PFS2 was defined as the duration from the first disease progression to the second disease progression or death. RESULTS: One hundred and eighty patients with ES-SCLC were included. We performed landmark analysis, which showed that compared to the second-line and subsequent-lines ICIs-combined therapy group (2SL-ICIs) and non-ICIs group, the first-line ICIs-combined therapy group (1L-ICIs) prolonged OS and PFS1. There was a trend toward prolonged OS in the 2SL-ICIs group than in the non-ICIs group, but the significance threshold was not met (median OS 11.94 months vs. 11.10 months, P = 0.14). A longer PFS2 was present in the 2SL-ICIs group than in the non-ICIs group (median PFS2 4.13 months vs. 2.60 months, P < 0.001). CONCLUSION: First-line ICIs plus chemotherapy should be applied in clinical practice. If patients did not use ICIs plus chemotherapy in first-line therapy, the use of ICIs in the second line or subsequent lines of treatment could prolong PFS2.