Incidence of cervical cancer after several negative smear results by age 50: prospective observational study
BMJ 2009; 338 doi: https://doi.org/10.1136/bmj.b1354 (Published 24 April 2009) Cite this as: BMJ 2009;338:b1354
- Matejka Rebolj, scientific researcher1,
- Marjolein van Ballegooijen, associate professor of epidemiology1,
- Elsebeth Lynge, professor of epidemiology2,
- Caspar Looman, statistician1,
- Marie-Louise Essink-Bot, associate professor of epidemiology1,
- Rob Boer, professor of policy analysis1,
- Dik Habbema, professor of medical decision sciences1
- 1Erasmus MC, Department of Public Health, PO Box 2040, 3000 CA Rotterdam, Netherlands
- 2University of Copenhagen, Institute of Public Health, PO Box 2099, 1014 Copenhagen K, Denmark
- Correspondence to: M Rebolj m.rebolj{at}pubhealth.ku.dk
- Accepted 16 January 2009
Abstract
Objective To determine the incidence of cervical cancer after several negative cervical smear tests at different ages.
Design Prospective observational study of incidence of cervical cancer after the third consecutive negative result based on individual level data in a national registry of histopathology and cytopathology (PALGA).
Setting Netherlands, national data.
Population 218 847 women aged 45-54 and 445 382 aged 30-44 at the time of the third negative smear test.
Main outcome measures 10 year cumulative incidence of interval cervical cancer.
Results 105 women developed cervical cancer within 2 595 964 woman years at risk after the third negative result at age 30-44 and 42 within 1 278 532 woman years at risk after age 45-54. During follow-up, both age groups had similar levels of screening. After 10 years of follow-up, the cumulative incidence rate of cervical cancer was similar: 41/100 000 (95% confidence interval 33 to 51) in the younger group and 36/100 000 (24 to 52) in the older group (P=0.48). The cumulative incidence rate of cervical intraepithelial neoplasia grade I+ was twice as high in the younger than in the older group (P<0.001).
Conclusions The risk for cervical cancer after several negative smear results by age 50 is similar to the risk at younger ages. Even after several negative smear results, age is not a good discriminative factor for early cessation of cervical cancer screening.
Footnotes
Contributors: MvB, EL, DH, and MR designed the study. MvB and MR collected the data. MR and CL analysed the data. MR, MvB, and DH wrote the manuscript, which was critically revised by EL, CL, M-LE-B, and RB. All authors interpreted the data and decided to submit the manuscript for publication. MR and MvB are guarantors.
Funding: This study was financed by the Dutch National Institute for Public Health and the Environment (RIVM, grant No 3022/07 DG MS/CvB/NvN). The authors wrote the manuscript independent of the funder. The RIVM had no role in the design of the study, data collection, analysis and interpretation of the data, and the decision to submit the manuscript for publication.
Competing interests: The department of public health of the Erasmus MC received a grant from GSK, a manufacturer of an HPV vaccine, for research on the cost effectiveness of HPV vaccination in 2007 and 2008. This research and manuscript were neither funded nor supported by GSK. RB has been participating since 1989 in the screening research group at the department. He has been affiliated with RAND since 2000. Since 2007, he has been a director of evidence based strategies-disease modelling and economic evaluation at Pfizer, who develop and sell various drugs for cancer and other diseases. This research and manuscript were neither funded nor supported by Pfizer.
Ethical approval: Not required.
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