Abstract 125P
Background
There occurs huge heterogeneity in clinical outcomes for epidermal growth factor receptor (EGFR) mutated non-small cell lung cancer (NSCLC) patients treated with EGFR -tyrosine kinase inhibitors (EGFR-TKIs). The purpose of this study was to indicate bio-markers in tumor immune microenvironment (TIME) predicting the prognosis of these patients after EGFR-TKIs treatment.
Methods
Using the multiplexed immunofluorescence staining methods, formalin-fixed, paraffin-embedded tumor tissues of previously untreated NSCLC patients were sequentially stained with anti-CD4, CD8, FoxP3, CD68, and CD163 antibodies. Most of the patients taking EGFR-TKIs were followed up with imaging examination every 3 months. Correlation of histochemistry score (H-score) of each marker with progression free survival (PFS) and overall survival (OS) were analyzed.
Results
The 36 patients treated with EGFR-TKIs were followed up until May 2020, and 1 patient had withdrawn without PFS or OS data. The median follow-up period was 18.9 months (range 5.0∼52.9 months). By the end of follow up, 28 patients (77.78%) had progressed, and 16 patients (44.44%) had died. The median PFS was 9.13 months, so we used the receiver operating characteristic curves (ROC) and calculated the area under curve (AUC) predicting 9-month PFS rates to decide the best cut off value for each biomarker. The AUC of CD4-H-score was 0.7100 (95% CI: 0.5270, 0.8930), while AUCs of the other markers were all less than 0.55. We then set 7.43 as the cut-off value for CD4-H-score, because of the best sensitivity and specificity as 75% and 73.33%, respectively. Patients with CD4-H-score more than 7.43 achieved significantly better PFS (10.57 vs. 5.83 months, p=0.0355) . Median OS of patients with CD4-H-score no more than 7.43 was 18.93 months, while median OS of those with CD4-H-score >7.43 hasn’t been achieved (p=0.0396).
Conclusions
Low CD4+ lymphocytes in tumor tissues predicted poor PFS and OS in EGFR-TKIs treated NSCLC patients, and may help to select patients needing new treatment strategies.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
Yan-juan Zhu.
Funding
Guangzhou Municipal Science and Technology Bureau, China (201604020017); Science and Technology Planning Project of Guangdong Province (2014A020221046, 2014A020221113, 2017B030314166).
Disclosure
All authors have declared no conflicts of interest.