Table 1. Summary of the detection of HPV types and positivity rate in normal and CRC samples relative to the different selected articles.
| Studied Population | Technique used for the viral genome detection | Target gene | Identified strain | Most prevalent identified strain | No. of normal samples screened | No. of normal samples positive for HPV | Percentage positivity of HPV for normal samples | No. of adjacent or benign samples screened | No. of adjacent or benign samples positive for HPV |
Percentage positivity of HPV for adjacent or benign samples | No. of total screened CRC samples | No. of colorectal cancer samples positive for HPV | Percentage positivity of HPV for colorectal cancer | References |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| United States | PCR | L1 | 16, 18 | -- | 0 | 0 | 0% | 0 | 0 | 0% | 50 | 0 | 0% | [11] |
| PCR | L1 | 6, 11, 16, 18, 33 | -- | 24 | 2 | 8% | 21 | 8 | 38% | 38 | 13 | 32% | [33] | |
| Nested PCR | L1, E6 | 16, 18, 45 | 16 | 10 | 0 | 0% | 0 | 0 | 0% | 55 | 28 | 51% | [21] | |
| PCR | L1 | -- | -- | 0 | 0 | 0% | 30 | 0 | 0% | 73 | 0 | 0% | [26] | |
| Real-time PCR | E6, E7 | 16, 18. 31, 33, 45 | -- | 250 | 0 | 0% | 254 | 0 | 0% | 0 | 0 | 0% | [22] | |
| Immunohistochemistry | -- | -- | -- | 0 | 0 | 0% | 0 | 0 | 0% | 11 | 9 | 82% | [51] | |
| Real-time PCR | L1, E7 | 16 | 16 | 0 | 0 | 0% | 0 | 0 | 0% | 555 | 11 | 2% | [64] | |
| China | PCR | E6, E7 | 6, 11, 16, 18 | 16 | 0 | 0 | 0% | 37 | 11 | 29.7% | 70 | 37 | 52.9% | [24] |
| PCR | L1 | 6, 11, 18 33 | 6, 33 | 16 | 0 | 0% | 10 | 1 | 10% | 46 | 20 | 43.47% | [49] | |
| PCR | L1 | 16 | 16 | 0 | 0 | 0% | 32 | 1 | 3.1% | 32 | 7 | 21.9% | [47] | |
| PCR | E7 | 16 | 16 | 0 | 0 | 0% | 82 | 4 | 4.87% | 82 | 42 | 51.21% | [48] | |
| PCR | L1 | 16, 18, 51, 59 | 16 | 32 | 0 | 0% | 0 | 0 | 0% | 96 | 28 | 29.1% | [29] | |
| PCR | L1 | -- | -- | 0 | 0 | 0% | 75 | 0 | 0% | 75 | 55 | 73% | [42] | |
| Gene chip technology and immunohistochemistry | -- | 6, 11, 16, 18, 31, 33, 35, 39, 42, 43, 44, 45, 51, 52, 53, 56, 58, 59, 66, 68, 73, 83 and MM4, | 16 | 0 | 0 | 0% | 100 | 29 | 29% | 95 | 46 | 48.4% | [53] | |
| Immunohistochemistry | -- | 6, 11, 16, 18, 31, 33, 42, 51, 52, 56, 58 | -- | 0 | 0 | 0% | 47 | 0 | 0% | 47 | 15 | 31.9% | [56] | |
| India | PCR | L1 | 16, 18 | 18 | 0 | 0 | 0% | 30 | 6 | 20% | 93 | 34 | 36.5% | [27] |
| Iran | PCR | L1 | 16, 18 | 18 | 0 | 0 | 0% | 0 | 0 | 0% | 60 | 21 | 35% | [37] |
| PCR | L1 | -- | -- | 50 | 0 | 0% | 8 | 0 | 0% | 42 | 0 | 0% | [43] | |
| PCR | L1 | -- | -- | 0 | 0 | 0% | 0 | 0 | 0% | 100 | 1 | 1% | [80] | |
| Nested PCR | L1 | 11, 18, 31, 45 | 18 | 80 | 1 | 1.25% | 0 | 0 | 0% | 80 | 5 | 6.25% | [39] | |
| Nested PCR | L1 | -- | -- | 0 | 0 | 0% | 60 | 0 | 0% | 70 | 0 | 0% | [17] | |
| Nested PCR | L1, E6, E7 | 16, 18 | 16 | 0 | 0 | 0% | 0 | 0 | 0% | 38 | 12 | 31.5% | [75] | |
| PCR | L1, E6 | 16, 18 | 16 | 70 | 0 | 0% | 70 | 4 | 5.7% | 70 | 2 | 2.85% | [30] | |
| Qualitative real-time PCR | L1 | 51, 56, 16, 31, 33, 8, 39, 45 | 51, 56 | 0 | 0 | 0% | 0 | 0 | 0% | 84 | 19 | 22.6% | [79] | |
| Hungary | PCR and Southern blotting | -- | -- | 16 | 0 | 0 | 0% | 0 | 0 | 0% | 1 | 1 | 100% | [13] |
| Poland | PCR | -- | -- | -- | -- | -- | 28% | -- | -- | 56% | -- | -- | 67% | [35] |
| PCR | E6, E7 | -- | -- | 0 | 0 | 0% | 0 | 0 | 0% | 186 | 0 | 0% | [59] | |
| Real-time PCR | L1 | -- | -- | 0 | 0 | 0% | 10 | 0 | 0% | 40 | 0 | 0% | [41] | |
| PCR | -- | 16, 18 | 16 | 0 | 0 | 0% | 0 | 0 | 0% | 50 | 10 | 20% | [74] | |
| Real-time PCR | 6, 11, 16, 18 | 11 | -- | 0 | 0 | 0% | 23 | 16 | 69.56% | 1 | 1 | 100% | [54] | |
| Nested PCR | L1, E6 | 16, 18 | 16 | 0 | 0 | 0% | 0 | 0 | 0% | 120 | 3 | 2.5% | [20] | |
| Turkey | PCR | L1 | 6, 11, 16, 18, 33 | 18, 33 | 0 | 0 | 0% | 0 | 0 | 0% | 53 | 43 | 81.2% | [65] |
| Nested PCR | L1 | -- | 16 | 0 | 0 | 0% | 22 | 1 | 4.5% | 100 | 4 | 4% | [34] | |
| PCR | -- | -- | 18, 33 | 0 | 0 | 0% | 56 | 18 | 32% | 56 | 46 | 82.14% | [40] | |
| PCR | L1 | -- | -- | 0 | 0 | 0% | 49 | 0 | 0% | 106 | 0 | 0% | [46] | |
| PCR | L1 | -- | 16,18 | 0 | 0 | 0% | 0 | 0 | 0% | 93 | 3 | 3.2% | [18] | |
| Italy | PCR | L1, E6, E7 | 6, 11, 16, 18, 31, 33, 43, 56, 58, 66 | 18 | 0 | 0 | 0% | 0 | 0 | 0% | 66 | 22 | 33.3% | [71] |
| PCR | L1 | 16, 18, 33, 58 | 58 | 0 | 0 | 0% | 57 | 5 | 8.8% | 57 | 9 | 15.8% | [44] | |
| PCR | E2, E4, E5, E6, E7 | 6, 16, 26, 39, 53 | 16 | 0 | 0 | 0% | 0 | 0 | 0% | 65 | 11 | 16.9% | [77] | |
| Greece | Immunohistochemistry | L1 | 1, 6, 11, 16, 18 31 | 16,18 | 0 | 0 | 0% | 0 | 0 | 0% | 60 | 16 | 26.6% | [36] |
| Belgium | PCR | L1, E6 | 6, 11, 16, 18, 31, 35, 39, 42, 43, 44, 45, 51, 52, 66 | 16 | 0 | 0 | 0% | 0 | 0 | 0% | 232 | 33 | 14.2% | [8] |
| France | Real-time PCR | E6, E7 | 6, 11, 26, 40, 43, 44, 53, 54, 66, 70, 71, 73, 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 68, 69, 82 | -- | 0 | 0 | 0% | 217 | 0 | 0% | 217 | 0 | 0% | [45] |
| Brazil | Nested PCR | L1, E6, E7 | 16, 18, 31 | 16 | 72 | 14 | 19.4% | 72 | 36 | 50% | 72 | 46 | 63.9% | [25] |
| PCR | L1 | 6, 11, 16, 18, 31, 33, 34, 35, 39, 40, 42, 43, 44, 45, 51, 52, 54, 56 58 | 16 | 0 | 0 | 0% | 65 | 5 | 7.7% | 79 | 36 | 45.5% | [55] | |
| PCR | L1 | 16, 18, 26, 31, 33, 35, 39, 45, 51, 52, 53, 56, 58, 59, 66, 68, 70, 73, 82, 6, 11, 40, 40, 42, 43, 44, 54, 61, 62, 67, 81, 83, 89 | 16 | 0 | 0 | 0% | 105 | 0 | 0% | 92 | 12 | 13% | [52] | |
| Cuba | PCR | E6, E7 | 16, 18, 31, 33, 45, 52, 58 | 16 | 0 | 0 | 0% | 21 | 0 | 0% | 42 | 15 | 35.7% | [57] |
| Taiwan | PCR and Southern blotting | -- | 18 | 18 | 19 | 16 | 84% | 0 | 0 | 0% | 19 | 10 | 53% | [28] |
| Nested PCR | L1, E6 | 16 | 16 | 0 | 0 | 0% | 0 | 0 | 0% | 69 | 11 | 16% | [67] | |
| Egypt | Nested PCR and in situ hybridisation | -- | 16,18 | 18 | 0 | 0 | 0% | 40 | 10 | 25% | 40 | 6 | 15% | [58] |
| Israel | PCR | L1 | -- | -- | 0 | 0 | 0% | 30 | 0 | 0% | 106 | 0 | 0% | [26] |
| Australia | In situ hybridisation | -- | 6, 11, 16, 18 | -- | 0 | 0 | 0% | 0 | 0 | 0% | 9 | 0 | 0% | [12] |
| Spain | PCR | L1 | -- | -- | 0 | 0 | 0% | 30 | 0 | 0% | 100 | 0 | 0% | [26] |
| Puerto Rico | Nested PCR | L1, E2 | 16 | 16 | 36 | 1 | 2.8% | 0 | 0 | 0% | 45 | 19 | 42% | [19] |
| Argentina | Nested PCR | L1 | 6, 16, 18, 33 | 16 | 0 | 0 | 0% | 30 | 10 | 33% | 54 | 40 | 74% | [38] |
| PCR | L1 | 16, 18, 31, 33 | -- | 0 | 0 | 0% | 0 | 0 | 0% | 7 | 0 | 0% | [23] | |
| Nested PCR | L1 | 16, 18, 31, 66 | 16 | 0 | 0 | 0% | 0 | 0 | 0% | 75 | 33 | 44% | [84] | |
| Portugal | Real-time PCR | E7 | 16 | -- | 0 | 0 | 0% | 0 | 0 | 0% | 144 | 0 | 0% | [32] |
| Bosnia and Herzegovina | PCR | E6 | 16, 18, 31, 35, 39, 45, 51, 52, 56 | 16 | 0 | 0 | 0% | 0 | 0 | 0% | 106 | 85 | 80% | [72] |
| PCR | E6 | 16, 18, 31, 35, 45, 51, 52 | 16 | 0 | 0 | 0% | 0 | 0 | 0% | 106 | 53 | 50% | [94] |
|
| Syria | PCR | E6, E7, L1 | 16, 18, 31, 33, 35 | 16, 33, 18, 35, 31 | 0 | 0 | 0% | 0 | 0 | 0% | 78 | 42 | 53.8% | [70] |
| Immunohistochemistry | E6, E7, L1 | 16, 18, 31, 33, 35, 45, 51, 52 58. | -- | 0 | 0 | 0% | 0 | 0 | 0% | 102 | 37 | 36.2% | [31] | |
| Czechoslovakia | Southern blotting | -- | 2, 6, 16, 18 | -- | 0 | 0 | 0% | 10 | 0 | 0% | 13 | 0 | 0% | [50] |
PCR = Polymerase chain reaction.