Table 2.
Subgroup analysis of saliva testing for cancer diagnosis based on different covariates.
| Number of study units | DOR (95% CI) | I2 (%) | AUC (95% CI) | Sensitivity (95% CI) | Specificity (95% CI) | PLR (95% CI) | NLR (95% CI) | |
|---|---|---|---|---|---|---|---|---|
| All | 155 | 13.42 (12.28–15.96) | 61.81 | 0.85 (0.84–0.87) | 0.76 (0.74–0.77) | 0.76 (0.75–0.77) | 3.22 (2.92–3.55) | 0.31 (0.28–0.34) |
| Saliva fraction | ||||||||
| Whole | 12 | 15.90 (9.91–25.50) | 9.24 | 0.86 (0.84–0.88) | 0.76 (0.66–0.83) | 0.85 (0.74–0.91) | 3.46 (2.30–5.21) | 0.27 (0.20–0.38) |
| Supernatant | 129 | 13.11 (10.85–15.85) | 64.76 | 0.84 (0.83–0.85) | 0.77 (0.74–0.79) | 0.77 (0.75–0.79) | 3.20 (2.89–3.55) | 0.31 (0.28–0.34) |
| Pellet | 3 | 13.97 (3.25–60.02) | 64.73 | 0.85 (0.78–0.91) | 0.90 (0.76–0.96) | 0.64 (0.42–0.81) | 2.40 (1.39–4.15) | 0.20 (0.08–0.47) |
| Type of saliva | ||||||||
| Stimulated | 30 | 10.83 (8.04–15.60) | 44.62 | 0.85 (0.84–0.86) | 0.80 (0.75–0.84) | 0.71 (0.63–0.78) | 2.59 (2.12–3.16) | 0.30 (0.25–0.36) |
| Unstimulated | 114 | 14.33 (11.68–17.57) | 65.15 | 0.83 (0.81–0.84) | 0.77 (0.74–0.79) | 0.77 (0.75–0.78) | 3.39(3.05–3.78) | 0.31 (0.28–0.35) |
| Anatomic tumour location | ||||||||
| Pancreatic | 29 | 15.86 (10.03–25.08) | 59.15 | 0.87 (0.83–0.92) | 0.81 (0.78–0.84) | 0.71 (0.68–0.74) | 3.32 (2.48–4.44) | 0.28 (0.33–0.34) |
| Oesophageal | 11 | 11.50 (8.03–16.599 | 0 | 0.84 (0.81–0.87) | 0.76 (0.72–0.80) | 0.73 (0.68–0.78) | 2.71 (2.26–3.26) | 0.34 (0.29–0.40) |
| Gastric | 5 | 88.22 (18.71–416.07) | 63.57 | 0.96 (0.91–1) | 0.91 (0.86–0.95) | 0.89 (0.83–0.93) | 7.31 (3.16–16.88) | 0.10 (0.03–0.31) |
| Lung | 27 | 18.20 (14.07–25.53) | 30.41 | 0.88 (0.86–0.90) | 0.76 (0.73–0.79) | 0.81 (0.78–0.83) | 4.20 (3.68–4.79) | 0.27 (0.33–0.31) |
| Ovarian | 11 | 14.21 (7.24–27.89) | 50.93 | 0.86 (0.80–0.92) | 0.75 (0.69–0.80) | 0.77 (0.73–0.81) | 3.24 (2.13–4.93) | 0.34 (0.23–0.50) |
| Breast | 71 | 10.40 (8.24–13.13) | 64.21 | 0.83 (0.81–0.85) | 0.73 (0.71–0.74) | 0.74 (0.72–0.76) | 2.88 (2.56–3.24) | 0.35 (0.31–0.39) |
| Sample size | ||||||||
| <50 | 24 | 15.60 (10.31–23.93) | 0 | 0.85 (0.83–0.87) | 0.71 (0.63–0.79) | 0.83 (0.77–0.88) | 3.76 (2.83–5.01) | 0.34 (0.26–0.45) |
| >50 | 131 | 13.14 (10.91–15.82) | 65.69 | 0.85 (0.78–0.91) | 0.78 (0.75–0.80) | 0.76 (0.73–0.79) | 3.15 (2.85–3.48) | 0.31 (0.28–0.34) |
| Type of biomarker | ||||||||
| Proteomic | 49 | 13.44 (10.43–17.31) | 41.13 | 0.85 (0.84–0.87) | 0.78 (0.74–0.81) | 0.77 (0.73–0.80) | 3.34 (2.90–3.85) | 0.30 (0.26–0.34) |
| Epigenomic | 35 | 11.56 (8.56–15.62) | 35.15 | 0.84 (0.83–0.86) | 0.78 (0.73–0.82) | 0.75 (0.68–0.82) | 2.83 (2.27–3.52) | 0.31 (0.26–0.37) |
| Metabolomic | 30 | 8.45 (5.91–12.08) | 71.99 | 0.81 (0.79–0.83) | 0.70 (0.66–0.74) | 0.74 (0.69–0.78) | 2.65 (2.20–3.20) | 0.40 (0.35–0.47) |
| Transcriptomic | 24 | 21.85 (13.31–35.88) | 66.25 | 0.89 (0.87–0.91) | 0.82 (0.74–0.88) | 0.76 (0.71–0.81) | 3.76 (2.91–4.87) | 0.22 (0.15–0.31) |
| Microbiome | 13 | 14.61 (8.32–25.64) | 27.21 | 0.86 (0.84–0.89) | 0.77 (0.63–0.87) | 0.78 (0.65–0.87) | 3.84 (2.46–5.99) | 0.36 (0.25–0.52) |
| Genomic | 3 | 87.89 (11.05–699.02) | 68.94 | 0.96 (0.93–0.99) | 0.69 (0.56–0.80) | 0.81 (0.70–0.88) | 10.96 (1.20–100.36) | 0.11 (0.02–0.69) |
| Type of control | ||||||||
| HC | 125 | 12.98 (10.79–15.62) | 61.69 | 0.87 (0.86–0.88) | 0.76 (0.75–0.78) | 0.76 (0.74–0.79) | 3.17 (2.71–3.51) | 0.32 (0.29–0.35) |
| BC | 11 | 24.88 (11.18–55.40) | 57.46 | 0.92 (0.89–0.94) | 0.85 (0.76–0.92) | 0.76 (0.59–0.87) | 4.72 (2.80–7.97) | 0.26 (0.17–0.39) |
| NCCs | 9 | 11.97 (6.31–22.73) | 63.78 | 0.88 (0.85–0.92) | 0.62 (0.51–0.72) | 0.74 (0.80–0.92) | 2.80 (1.96–3.98) | 0.29 (0.21–0.39) |
CI: confidence interval; PLR: positive likelihood ratio; NLR: negative likelihood ratio; DOR: diagnostic odds ratio; AUC: area under the ROC curve, HC: healthy controls; BC: benign controls; NCCs: non-cancer controls.