Detection of EGFR T790M mutation using liquid biopsy for non-small cell lung cancer: Utility of droplet digital polymerase chain reaction vs. cobas real-time polymerase chain reaction.

BACKGROUND: Digital platforms for mutation detection yield higher sensitivity than non-digital platforms but lack universal positive cut-off values that correlate with the outcome of osimertinib treatment. This study determined compared droplet digital polymerase chain reaction (ddPCR) to the standard cobas assay for epithelial growth factor receptor (EGFR) T790M mutation detection in patients with non-small cell lung cancer. METHODS: Study patients had EGFR-mutant tumours with disease progression on first/second generation EGFR tyrosine kinase inhibitors, and osimertinib treatment after T790M mutation detection. T790M status was tested by cobas assay using liquid biopsy, and only by ddPCR if an EGFR mutation was identified but T790M was negative. Clinical efficacy of osimertinib was compared between patients with T790M detected by cobas vs. only by ddPCR. A positive cut-off value for ddPCR was determined by assessing efficacy with osimertinib. RESULTS: 61 patients had tumors with an acquired T790M mutation, 38 detected by cobas and an additional 23 only by ddPCR. The median progression-free survival (PFS) for the cobas- and ddPCR-positive groups was 9.5 and 7.8 months, respectively (p=0.43). For ddPCR, a fractional abundance (FA) of 0.1% was used as a cut-off value. The median PFS of patients with FA ≥0.1% and <0.1% was 8.3 and 4.6 months, respectively (p=0.08). FA ≥0.1% was independently associated with a longer PFS. CONCLUSION: Using ddPCR to follow up the cobas assay yielded more cases (38% of total) with a T790M mutation. A cut-off value of FA ≥0.1% identified patients who responded as well to osimertinib as those identified by cobas assay. This sequential approach should detect additional patients who might benefit from osimertinib treatment.

Trauma Hybrid Operating Room (THOR) shortened procedure time in abdominopelvic trauma patients requiring surgery and interventional radiology procedures.

INTRODUCTION: Abdominopelvic injuries are common, and bleeding occurring in both cavities requires various bleeding control techniques i.e., laparotomy, angiographic embolization (AE), and orthopedic fixation. Hence, the use of Trauma Hybrid Operating Room (THOR) in abdominopelvic injuries has theoretical advantages including rapid bleeding control and minimizing patient transportation. The objective of the present study is to evaluate the impact of THOR in abdominopelvic injuries. METHOD: A pre-post intervention study of abdominopelvic injury patients requiring both surgery and interventional radiology (IR) procedures for bleeding control from January 2015 to May 2020 was conducted. The patients were divided into 2 groups, pre-THOR group (received surgery in OR and scheduled for IR procedures in a separate IR suite, before December 2017) and THOR group (received all procedures in THOR, after December 2017). The primary outcomes were procedure time (including transit time in the pre-THOR group) and mortality. RESULTS: Ninety-one abdominopelvic trauma patients were identified during the study period, 56 patients in pre-THOR group and 35 patients in THOR group. Distribution of injuries was similar in both groups (59 abdominal injuries, 25 pelvic fractures, and 7 combined injuries). The bleeding-control interventions in both groups were 79 laparotomies, 10 preperitoneal pelvic packings, 12 pelvic fixations, 45 liver AEs, and 21 pelvic AEs. THOR group underwent significantly less thoracotomy (1 vs. 11, p = 0.036), more resuscitative endovascular balloon occlusion of the aorta (REBOA, 0 vs. 5, p = 0.014), and more pelvic AE (13 vs. 9, p = 0.043). The procedure time was significantly shorter in THOR group (153 min vs. 238 min, p = 0.030). Excluding the transit time in the pre-THOR group, procedure time was not significantly different (153 vs. 154 min, p = 0.872). Both groups had similar mortality rates of 34%, but the mortality due to exsanguination was significantly lower in THOR group (11% vs. 34%, p = 0.026). CONCLUSIONS: THOR eliminated transit time, resulting in shorter procedure time in abdominopelvic trauma patients requiring bleeding-control intervention. Although overall mortality reduction could not be demonstrated, the mortality due to exsanguination was reduced in THOR group.

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.