Analytical methods | |||
|---|---|---|---|
| Comparative study | #1 | #2 | |
| Chromatography | GC | GC | |
| Ion source | EI | EI | |
| Positive/Negative mode | – | – | |
| Mass analyzer | Q-TOF | Q-TOF | |
| Identification level | – | – | |
Sample information | |||
|---|---|---|---|
| Comparative study | #1 | #2 | |
| Country | Spain | Spain | |
| Specimen | exhaled breath | exhaled breath | |
| Marker function | diagnosis | diagnosis | |
| Participants(Case) | Cancer type | squamous cell carcinoma, adenocarcinoma, large cell carcinoma, NSCLC, SCLC | squamous cell carcinoma, adenocarcinoma, large cell carcinoma, NSCLC, SCLC |
| Stage | – | – | |
| Number | 48 | 48 | |
| Gender (M,F) | 45, 3 | 45, 3 | |
| Mean age (range) (M,F) | 63 ± 7 | 63 ± 7 | |
| Smoking status | – | – | |
| Participants(Control) | Type | healthy | at-risk controls |
| Number | 61.0 | 130.0 | |
| Gender (M,F) | 53, 8 | 107, 23 | |
| Mean age (range) (M,F) | 60 ± 9 | 61±8 | |
| Smoking status | non-smoker | former, active smokers | |
Data processing and metabolite identification | |
|---|---|
| Data processing software | Mass Profiler Professional (Angilent), Quantitative Analysis (Angilent) |
| Database search | NIST 11, KEGG |
Statistics and concentration information | |
|---|---|
| Differential analysis method | unpaired t-test, Fisher's exact, Mann–Whitney tests |
| Classification method | Support-vector machine, ROC curve analysis |
| Survival analysis method | – |
| Metabolite | Comparative study | Author-emphasized biomarkers | Mean concentration (case) | Mean concentration (control) | Fold change (case/control) | P-value | FDR | VIP |
|---|---|---|---|---|---|---|---|---|
| triethyl citrate | – | V | – | – | 4.70161367619487 | 0.009728 | – | – |
| monostearin | – | V | – | – | 6.09723858597765 | 0.003911 | – | – |
| monopalmitin | – | V | – | – | 6.19059466259437 | 0.003899 | – | – |
| benzoic acid 4-ethoxy-ethyl ester | – | V | – | – | 0.333703795329639 | 0.003489 | – | – |
| n-Hexadecylindane | – | – | – | – | 3.87058330523011 | 0.002707 | – | – |
| 13-heptadecyn-1-ol | – | – | – | – | 2.71283255037964 | 0.002017 | – | – |
| p-cresol | – | – | – | – | 0.116253011950669 | 0.0009 | – | – |
| n-Hexadecylindane | – | – | – | – | 3.5195207701501 | 0.000481 | – | – |
| indole | – | – | – | – | 0.145867461115403 | 0.000351 | – | – |
| squalene | – | V | – | – | 5.39295127783398 | 0.000212 | – | – |
| monostearin | – | V | – | – | 8.10376310015794 | 0.000107 | – | – |
| 11-eicosenamide | – | V | – | – | 4.47618604280698 | 0.0000313 | – | – |
| Metabolite | Comparative study | Author-emphasized biomarkers | Cutoff value | AUROC (95%CI) | Sensitivity (%) | Specificity (%) | Accuracy (%) |
|---|---|---|---|---|---|---|---|
| triethyl citrate | – | V | – | – | – | – | – |
| monostearin | – | V | – | – | – | – | – |
| monopalmitin | – | V | – | – | – | – | – |
| benzoic acid 4-ethoxy-ethyl ester | – | V | – | – | – | – | – |
| n-Hexadecylindane | – | – | – | – | – | – | – |
| 13-heptadecyn-1-ol | – | – | – | – | – | – | – |
| p-cresol | – | – | – | – | – | – | – |
| n-Hexadecylindane | – | – | – | – | – | – | – |
| indole | – | – | – | – | – | – | – |
| squalene | – | V | – | – | – | – | – |
| monostearin | – | V | – | – | – | – | – |
| 11-eicosenamide | – | V | – | – | – | – | – |