Differential expression of immune-regulatory proteins C5AR1, CLEC4A and NLRP3 on peripheral blood mononuclear cells in early-stage non-small cell lung cancer patients.

Changes in gene expression profiling of peripheral blood mononuclear cells (PBMC) appear to represent the host's response to the cancer cells via paracrine signaling. We speculated that protein expression on circulating T-lymphocytes represent T-lymphocyte trafficking before infiltration into the tumor microenvironment. The possibility of using protein expression on circulating T-lymphocytes as a biomarker to discriminate early-stage non-small cell lung cancer (NSCLC) was explored. Four independent PBMC gene expression microarray datasets (GSE12771, GSE13255, GSE20189 and GSE3934) were analyzed. We selected C5AR1, CLEC4A and NLRP3 based on their significant protein expression in tumor-infiltrating lymphocytes, but not in normal lymphoid tissue. A validation study using automated flow cytometry was conducted in 141 study participants including 76 treatment-naive early-stage non-small cell lung cancer patients (NSCLC), 12 individuals with non-malignant pulmonary diseases, and 53 healthy individuals. Median ratios of C5AR1, CLEC4A and NLRP3 specific antibody staining to CD3 positive cells in early-stage NSCLC patients compared to healthy controls were 0.014 [0-0.37] vs. 0.01 [0-0.07, p = 0.13], 0.03 [0-0.87] vs. 0.02 [0-0.13, p = 0.10] and 0.19 [0-0.60] vs. 0.09 [0.02-0.31, p < 0.0001], respectively. Median fluorescence intensity (MFI) of CD3+C5AR1+, CD3+CLEC4A+ and CD3+NLRP3+ expression in early-stage NSCLC patients compared to healthy volunteers was 185 [64.2-4801] vs. 107.5 [27-229, p < 0.0001], 91.2 [42.4-2355] vs. 71.25 [46.2-103, p = 0.0005], and 1585 [478-5224] vs. 758.5 [318-1976, p < 0.0001], respectively. NLRP3:CD3 ratio, CD3+C5AR1+, CD3+CLEC4A+ and CD3+NLRP3+ MFI were significantly higher in early-stage NSCLC than healthy volunteers with an area under the ROC curve of 0.69-0.76. The CD3+NLRP3+ MFI provided the most distinguishable expression at 71.5% sensitivity and 70% specificity. Furthermore, CD3+NLRP3+ MFI potentially discriminated between early-stage NSCLC from malignant-mimic inflammation and infection pulmonary disease. Further validation in various pulmonary inflammatory disease might be warranted. Our proof-of-principle findings strengthen the hypothesis that malignancies generate distinctive protein expression fingerprints on circulating T-lymphocytes.

Prognostic factors in completely resected lymph-node-negative pulmonary adenocarcinoma.

Background: Lymph node involvement is one of the important prognostic factors for early-stage lung cancer. However, in lymph node-negative (N0) lung cancer the recurrent rate may be as high as 30%. We aimed to study potential prognostic factors including clinicopathological factors and epidermal growth factor receptor (EGFR) mutation status in this lung cancer population. Methods: We retrospectively reviewed the medical records and pathological examinations of patients with completely resected N0 pulmonary adenocarcinoma treated in our institute between 2009 and 2016. We used Cobas® test to determine EGFR mutation status. Recurrence-free survival (RFS) was analyzed by univariable and multivariable Cox regression analyses. Results: We recruited 220 patients with median duration of follow up 5 years. Majority of these patients were in stage I (80%) and did not receive adjuvant therapy (86%). There were 53% with EGFR mutations which comprised of exon 19 deletion 51% and L858R 43%. Recurrence occurred in 64 out of 220 patients (29%). The median time to recurrence was 2.1 years. Statistically significant prognostic factors in both univariate and multivariate analyses included tumor size ≥4 centimeter (cm) (HR: 1.94; 95% CI: 1.03-3.67), visceral pleural invasion (HR: 2.53; 95% CI: 1.34-4.79), tumor necrosis (HR: 2.45; 95% CI: 1.13-5.31) and bronchial resection margin <2 cm (HR: 1.96; 95% CI: 1.10-3.51). However, presence of sensitizing EGFR mutation was not found to be a significant prognostic factor (HR: 1.20; 95% CI: 0.66-2.18; P=0.56). Conclusions: In N0 surgically resected lung adenocarcinoma, there were significant pathological prognostic factors including tumor 4 cm or more, visceral pleural invasion, tumor necrosis and bronchial resection margin less than 2 cm. Mutation of EGFR is not a significant prognostic factor to determine the risk of recurrence in this population and their risks shall be determined by the other poor prognostic factors.