Prevalence of four risk factors in 1490 cases of invasive cervical cancer included in the IARC multicentre case–control study12 and approximately 800 cases included in the IBSCC tested for human papillomavirus (HPV) DNA in 1995 and 1999
| Study 1 Multicentric | Study 2 IBSCC (1995) | Study 3 IBSCC (1999) | ||||
|---|---|---|---|---|---|---|
| Presence of risk factor | N | % | N | % | N | % |
| *The total number in the column is not 806 because of missing values in some of the variables. References: study 1, Muñoz et al (2000)32; study 2, Bosch et al (1995)34; study 3, Walboomers et al (1999).216 | ||||||
| HPV, HPV DNA positive; OC, duration of use of hormonal contraceptives >6 years; Preg, ≥5 pregnancies (live or still born); Smk, smoker (ever). IARC, International Agency for Research on Cancer; IBSCC, international biological study on cervical cancer. | ||||||
| HPV | 341 | 22.9 | 186 | 23.1 | 186 | 23.1 |
| HPV + OC | 54 | 3.6 | 25 | 3.1 | 25 | 3.1 |
| HPV + Smk | 115 | 7.7 | 96 | 11.9 | 978 | 12.0 |
| HPV + Preg | 587 | 39.4 | 302 | 37.5 | 322 | 40.0 |
| HPV + OC + Smk | 20 | 1.3 | 25 | 3.1 | 28 | 3.5 |
| HPV + OC + Preg | 72 | 4.8 | 14 | 1.7 | 16 | 2.0 |
| HPV + Smk + Preg | 223 | 15.0 | 82 | 10.2 | 88 | 10.9 |
| HPV + OC + Smk + Preg | 21 | 1.4 | 7 | 0.9 | 7 | 0.9 |
| OC | 2 | 0.1 | 0 | 0 | 0 | 0 |
| OC + Smk | 0 | 0 | 3 | 0.4 | 0 | 0 |
| OC + Preg | 0 | 0 | 2 | 0.2 | 0 | 0 |
| OC + Smk + Preg | 0 | 0 | 0 | 0 | 0 | 0 |
| Smk | 8 | 0.5 | 1 | 0.1 | 0 | 0 |
| Smk + Preg | 9 | 0.6 | 6 | 0.7 | 0 | 0 |
| Preg | 15 | 1.0 | 21 | 2.61 | 1 | 0.1 |
| None of the four | 23 | 1.5 | 25 | 3.1 | 2 | 0.2 |
| Total number of cases | 1490 | 100 | 806* | 100 | 806* | 100 |