Table 2.
Description of biomarkers of the 23 selected studies in this systematic review.
| Frequency * | Percentage | |
|---|---|---|
| Biological sample | ||
| Histologic tumor tissue | 19 | 82.5 |
| Cytologic tumor tissue | 1 | 4.4 |
| Histologic and cytologic tumor tissue | 1 | 4.4 |
| Peripheral blood | 2 | 8.7 |
| Total | 23 | 100 |
| Quantification methods | ||
| Next generation sequencing or microarray | 1 | 3 |
| Real time quantitative PCR | 9 | 27.3 |
| Immunohistochemical staining | 13 | 39.4 |
| In situ hybridization (ISH) or fluorescent ISH (FISH) | 7 | 21.2 |
| Western blot or antibodies | 3 | 9.1 |
| Total ** | 33 | 100 |
| Type of molecular biomarkers | ||
| DNA | 9 | 25 |
| RNA | 7 | 19.4 |
| Protein | 20 | 55.6 |
| Total ** | 36 | 100 |
| Biomarkers list | ||
| p16 | 11 | 33.4 |
| HPV DNA | 7 | 21.2 |
| HPV RNA | 1 | 3 |
| Circulating HPV protein | 1 | 3 |
| EBV DNA/RNA | 4 | 12.2 |
| p53/p53 antibodies | 2 | 6.1 |
| Genetic panel assay | 2 | 6.1 |
| Ceramides (n = 4) | 1 | 3 |
| Salivary mRNA | 1 | 3 |
| VEGF | 1 | 3 |
| Rb | 1 | 3 |
| GATA 3 | 1 | 3 |
| Total ** | 33 | 100 |
* Frequency corresponds to number of papers. ** Some papers studied more than one biomarker; for this reason, the total is higher than 23 for the type of molecular biomarkers and quantification methods.