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Screening-preventable cervical cancer risks: Evidence from a nationwide audit in Sweden

Andrae, Bengt; Kemetli, Levent; Sparen, Pär; Silfverdal, Lena; Strander, Björn; Ryd, Walter; Dillner, Joakim LU and Törnberg, Sven (2008) In Journal of the National Cancer Institute 100(9). p.622-629
Abstract
Background The effectiveness of cervical cancer screening programs differs widely in different populations. The reasons for these differences are unclear. Routine and comprehensive audits have been proposed as an ethically required component of screening. We performed a nationwide audit of the effectiveness of the Swedish cervical cancer screening program. Methods We identified all invasive cervical cancer cases that were diagnosed in Sweden from January 1, 1999, through December 31, 2001, and had been reported to the Swedish Cancer Registry (n = 1230 cases). We verified the diagnoses by histopathologic rereview and matched each case subject to five (population-based) age-matched control subjects who were identified from the National... (More)
Background The effectiveness of cervical cancer screening programs differs widely in different populations. The reasons for these differences are unclear. Routine and comprehensive audits have been proposed as an ethically required component of screening. We performed a nationwide audit of the effectiveness of the Swedish cervical cancer screening program. Methods We identified all invasive cervical cancer cases that were diagnosed in Sweden from January 1, 1999, through December 31, 2001, and had been reported to the Swedish Cancer Registry (n = 1230 cases). We verified the diagnoses by histopathologic rereview and matched each case subject to five (population-based) age-matched control subjects who were identified from the National Population Register. The Pap smear screening histories for case and control subjects were reviewed for a 6-year period using the National Cervical Cancer Screening Register, which contains data on essentially all relevant cytological and histological diagnoses in Sweden. Odds ratios (ORs), and their 95% confidence intervals (CIs), of cervical cancer according to screening history were calculated in conditional logistic regression models. All statistical tests were two-sided. Results Women who had not had a Pap smear within the recommended screening interval had higher risk of cervical cancer than women who had been screened (OR = 2.52, 95% CI = 2.19 to 2.91). This risk was similarly increased for all age groups (P-homogeneity = .96). The risk for nonsquamous cell cervical cancers (OR = 1.59, 95% CI = 1.20 to 2.11) was also increased. Women who had not had a Pap smear within the recommended screening interval had a particularly high risk of advanced cancers (OR = 4.82, 95% CI = 3.61 to 6.44). Among women who had been screened within the recommended interval, those with abnormal Pap smears had a higher risk of cervical cancer than those with normal smears (OR = 7.55, 95% CI = 5.88 to 9.69) and constituted 11.5% of all women with cervical cancer. Conclusions Nonadherence to screening intervals was the major reason for cervical cancer morbidity. The screening program was equally effective for women of all ages and was also effective against nonsquamous cancers. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Journal of the National Cancer Institute
volume
100
issue
9
pages
622 - 629
publisher
Oxford University Press
external identifiers
  • wos:000255757200010
  • scopus:44049097019
ISSN
1460-2105
DOI
10.1093/jnci/djn099
language
English
LU publication?
yes
id
650affeb-4c3a-4878-b711-42fcca618d4b (old id 1203638)
date added to LUP
2008-09-17 10:04:31
date last changed
2017-11-12 03:47:11
@article{650affeb-4c3a-4878-b711-42fcca618d4b,
  abstract     = {Background The effectiveness of cervical cancer screening programs differs widely in different populations. The reasons for these differences are unclear. Routine and comprehensive audits have been proposed as an ethically required component of screening. We performed a nationwide audit of the effectiveness of the Swedish cervical cancer screening program. Methods We identified all invasive cervical cancer cases that were diagnosed in Sweden from January 1, 1999, through December 31, 2001, and had been reported to the Swedish Cancer Registry (n = 1230 cases). We verified the diagnoses by histopathologic rereview and matched each case subject to five (population-based) age-matched control subjects who were identified from the National Population Register. The Pap smear screening histories for case and control subjects were reviewed for a 6-year period using the National Cervical Cancer Screening Register, which contains data on essentially all relevant cytological and histological diagnoses in Sweden. Odds ratios (ORs), and their 95% confidence intervals (CIs), of cervical cancer according to screening history were calculated in conditional logistic regression models. All statistical tests were two-sided. Results Women who had not had a Pap smear within the recommended screening interval had higher risk of cervical cancer than women who had been screened (OR = 2.52, 95% CI = 2.19 to 2.91). This risk was similarly increased for all age groups (P-homogeneity = .96). The risk for nonsquamous cell cervical cancers (OR = 1.59, 95% CI = 1.20 to 2.11) was also increased. Women who had not had a Pap smear within the recommended screening interval had a particularly high risk of advanced cancers (OR = 4.82, 95% CI = 3.61 to 6.44). Among women who had been screened within the recommended interval, those with abnormal Pap smears had a higher risk of cervical cancer than those with normal smears (OR = 7.55, 95% CI = 5.88 to 9.69) and constituted 11.5% of all women with cervical cancer. Conclusions Nonadherence to screening intervals was the major reason for cervical cancer morbidity. The screening program was equally effective for women of all ages and was also effective against nonsquamous cancers.},
  author       = {Andrae, Bengt and Kemetli, Levent and Sparen, Pär and Silfverdal, Lena and Strander, Björn and Ryd, Walter and Dillner, Joakim and Törnberg, Sven},
  issn         = {1460-2105},
  language     = {eng},
  number       = {9},
  pages        = {622--629},
  publisher    = {Oxford University Press},
  series       = {Journal of the National Cancer Institute},
  title        = {Screening-preventable cervical cancer risks: Evidence from a nationwide audit in Sweden},
  url          = {http://dx.doi.org/10.1093/jnci/djn099},
  volume       = {100},
  year         = {2008},
}