Table 2.
Incidence (per 100 000 person-years) of cervical carcinoma in situ (CIS) and invasive cancer (ICC) among 10 123 cytologically normal women by type-specific human papillomavirus (HPV) infections at baseline and second examinations*
| Cohort with baseline examination (n = 10 123) |
Cohort with both baseline and second examinations (n = 6666) |
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| Baseline HPV infection |
Genotype-specific persistence |
Acquisition† |
Clearance |
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| HPV type | No. of women | No. of cancers (ICC/CIS) | Incidence (10−5)§ | HR (95% CI) | P‖ | No. of women | No. of cancers (ICC/CIS) | Incidence (10−5)§ | HR (95% CI) | P‖ | No. of women | No. of cancers (ICC/CIS) | No. of women | No. of cancers (ICC/CIS) | Ratio of persistence vs baseline infection ‡ |
| HPV negative | 8780 | 20 (9/11) | 15.7 | 1.0 (referent) | 5396 | 7 | 9.9 | 1.0 (referent) | |||||||
| Carcinogenic types¶ | |||||||||||||||
| Any carcinogenic type | 784 | 41 (24/17) | 370.8 | 23.8 (14.0 to 40.7) | <.001 | 205 | 21 | 838.3 | 85.1 (36.2 to 200.3) | <.001 | 300 | 5 | 345 | 5 | 3.4 |
| 16 | 139 | 13 (9/4) | 675.5 | 43.6 (21.7 to 87.6) | <.001 | 21 | 5 | 2204.6 | 216.7 (68.7 to 683.3) | <.001 | 48 | 0 | 64 | 1 | 5.0 |
| 52 | 189 | 10 (4/6) | 376.9 | 24.3 (11.4 to 51.8) | <.001 | 74 | 6 | 676.9 | 69.5 (23.3 to 206.79) | <.001 | 54 | 2 | 56 | 0 | 2.9 |
| 58 | 85 | 9 (7/2) | 766.5 | 49.4 (22.5 to 108.5) | <.001 | 32 | 4 | 1045.8 | 105.1 (30.7 to 358.9) | <.001 | 30 | 0 | 22 | 0 | 2.1 |
| 18 | 145 | 7 (5/2) | 338.1 | 21.7 (9.2 to 51.3) | <.001 | 23 | 2 | 688.5 | 68.3 (14.2 to 328.4) | <.001 | 43 | 1 | 66 | 1 | 3.1 |
| 31 | 48 | 6 (4/2) | 888.2 | 56.9 (22.9 to 141.8) | <.001 | 16 | 3 | 1545.6 | 156.3 (40.4 to 604.9) | <.001 | 14 | 0 | 14 | 0 | 2.7 |
| 33 | 94 | 4 (2/2) | 292.0 | 18.6 (6.3 to 54.3) | <.001 | 14 | 4 | 2189.4 | 221.3 (64.8 to 756.1) | <.001 | 21 | 1 | 54 | 0 | 11.9 |
| 56 | 86 | 4 (2/2) | 327.1 | 21.1 (7.2 to 61.7) | <.001 | 9 | 3 | 2601.9 | 269.6 (69.7 to 1043.6) | <.001 | 38 | 0 | 44 | 1 | 12.8 |
| 35 | 36 | 3 (2/1) | 598.9 | 38.9 (11.6 to 130.9) | <.001 | 5 | 1 | 1529.1 | 151.1 (18.6 to 1228.1) | <.001 | 11 | 0 | 18 | 2 | 3.9 |
| 39 | 84 | 2 (2/0) | 166.6 | 10.7 (2.5 to 45.9) | .001 | 21 | 2 | 725.7 | 73.9 (15.4 to 356.1) | <.001 | 29 | 0 | 32 | 0 | 6.9 |
| 45 | 48 | 2 (2/0) | 293.6 | 18.9 (4.4 to 81.2) | <.001 | 6 | 1 | 1322.8 | 134.5 (16.5 to 1094.0) | <.001 | 23 | 1 | 27 | 0 | 7.1 |
| 51 | 64 | 2 (1/1) | 215.0 | 13.7(3.2 to 58.5) | <.001 | 12 | 2 | 1282.1 | 132.8 (25.6 to 639.4) | <.001 | 25 | 0 | 31 | 0 | 9.7 |
| 59 | 69 | 0 | 0.0 | 0.0# | 4 | 0 | 0.0 | 0.0# | 8 | 0 | 11 | 0 | — | ||
| Probably or possibly carcinogenic types** | |||||||||||||||
| Any probably or possible carcinogenic type | 281 | 8 (4/4) | 204.7 | 13.3 (5.8 to 30.1) | <.001 | 70 | 5 | 560.5 | 57.3 (18.2 to 180.5) | <.001 | 118 | 2 | 105 | 0 | 4.3 |
| 68 | 55 | 2 (1/1) | 264.1 | 17.2 (4.0 to 73.6) | <.001 | 13 | 1 | 577.0 | 57.4 (7.1 to 466.7) | <.001 | 23 | 0 | 22 | 0 | 3.3 |
| 53 | 97 | 4 (2/2) | 293.35 | 19.0 (6.5 to 55.6) | <.001 | 22 | 2 | 748.8 | 75.7 (15.7 to 364.5) | <.001 | 39 | 1 | 29 | 0 | 4.0 |
| 70 | 84 | 3 (2/1) | 259.8 | 17.0 (5.1 to 57.3) | <.001 | 26 | 3 | 900.1 | 91.3 (23.6 to 353.2) | <.001 | 25 | 1 | 28 | 0 | 5.4 |
| 67 | 27 | 1 (1/0) | 258.2 | 16.3 (2.2 to 121.6) | .006 | 3 | 1 | 2512.6 | 252.8 (31.1 to 2056.4) | <.001 | 6 | 0 | 12 | 0 | 15.5 |
| 82 | 19 | 1 (1/0) | 374.3 | 24.4 (3.3 to 182.0) | .002 | 7 | 1 | 1132.5 | 116.4 (14.3 to 947.6) | <.001 | 13 | 0 | 9 | 0 | 4.8 |
| 26 | 11 | 0 | 0.0 | 0.0# | 3 | 0 | 0.0 | 0.0# | 8 | 0 | 6 | 0 | — | ||
Some women were infected with more than one HPV type. There were 6667 initially normal women who participated in the second visit; among them, 38 cervical cancers occurred after the second visit. One cancer that occurred between the two visits was excluded from the analysis of 2-year persistence. Only 3456 initially normal women participated in the baseline visit and 29 of them developed cervical cancer (Figure 1).
Acquisition of given type indicated that the woman was negative for the given type at baseline.
The ratio is the quotient of hazard ratio of persistent infection divided by hazard ratio of baseline infection from the given type.
Incidence rate: per 100 000 person-years.
Hazard ratios (HRs) and their 95% confidence intervals (CIs) were estimated using Cox proportional hazard models. All statistical tests were two-sided.
Carcinogenic types include HPV16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, and 59.
There was no incident cancer for calculation of 95% confidence intervals.
Probably or possibly carcinogenic types include HPV68 and HPV26, 53, 66, 67, 70, 73, and 82 (without any carcinogenic type[s], as listed above).