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50 years of screening in the Nordic countries: quantifying the effects on cervical cancer incidence.

Vaccarella S, Franceschi S, Engholm G, Lönnberg S, Khan S, Bray F - Br. J. Cancer (2014)

Bottom Line: Nordic countries' data offer a unique possibility to evaluate the long-term benefit of cervical cancer screening in a context of increasing risk of human papillomavirus infection.In the absence of screening, projected incidence rates for 2006-2010 in Nordic countries would have been between 3 and 5 times higher than observed rates.Over 60,000 cases or between 41 and 49% of the expected cases of cervical cancer may have been prevented by the introduction of screening in the late 1960s and early 1970s.

View Article: PubMed Central - PubMed

Affiliation: International Agency for Research on Cancer, 150 cours Albert Thomas, 69372 Lyon cedex 08, France.

ABSTRACT

Background: Nordic countries' data offer a unique possibility to evaluate the long-term benefit of cervical cancer screening in a context of increasing risk of human papillomavirus infection.

Methods: Ad hoc-refined age-period-cohort models were applied to the last 50-year incidence data from Denmark, Finland, Norway and Sweden to project expected cervical cancer cases in a no-screening scenario.

Results: In the absence of screening, projected incidence rates for 2006-2010 in Nordic countries would have been between 3 and 5 times higher than observed rates. Over 60,000 cases or between 41 and 49% of the expected cases of cervical cancer may have been prevented by the introduction of screening in the late 1960s and early 1970s.

Conclusions: Our study suggests that screening programmes might have prevented a HPV-driven epidemic of cervical cancer in Nordic countries. According to extrapolations from cohort effects, cervical cancer incidence rates in the Nordic countries would have been otherwise comparable to the highest incidence rates currently detected in low-income countries.

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Related in: MedlinePlus

Effect of age, period and cohort on observed and projected ASRs of incident cervical cancer. Age-standardised rates (ASRs) are plotted by period. Age effects and ASRs are shown on a rate per 100 000 scale; cohort and period effects are on a relative risk scale. Reference points for period and cohort rate ratios are marked. Under a scenario without screening activities, period effects are forced to assume a constant value over time (dot-dashed lines). The projected ASRs corresponding to period effects constant over time, but age and cohort effects as estimated by the model, are also shown (dashed thick lines).
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fig1: Effect of age, period and cohort on observed and projected ASRs of incident cervical cancer. Age-standardised rates (ASRs) are plotted by period. Age effects and ASRs are shown on a rate per 100 000 scale; cohort and period effects are on a relative risk scale. Reference points for period and cohort rate ratios are marked. Under a scenario without screening activities, period effects are forced to assume a constant value over time (dot-dashed lines). The projected ASRs corresponding to period effects constant over time, but age and cohort effects as estimated by the model, are also shown (dashed thick lines).

Mentions: According to our projections of a no-screening scenario, cervical cancer incidence rates between 1961 and 2010 would have increased in Denmark and Norway and remained stable in Sweden. In Finland, declines would have been substantially smaller than those observed. Projected incidence rates in 2006–2010 would have been ∼threefold higher than those observed in Finland, Norway and Sweden and fivefold higher in Denmark. Cervical cancer incidence rates in Denmark and Norway in 2006–2010 would have, therefore, been 102 (observed: 19) and 63 (observed: 19) per 100 000, respectively (Table 1 and Figure 1), that is, comparable to the highest rates observed in sub-Saharan countries (Ferlay et al. 2010). Rates in Finland and Sweden would have been 22 (observed: 8) and 40 (observed: 14) per 100 000, respectively (Table 1 and Figure 1), that is, comparable to the highest rates observed in Eastern Europe, Latin America and Asia (Ferlay et al. 2010). Table 1 also shows the projections relative to the average yearly number of cervical cancer cases that have been prevented by screening in 2006–2010 (from 202 in Finland to 1239 in Denmark). Overall in the Nordic countries, over 60 000 cases or between 41 and 49% of the expected cases of cervical cancer may have been prevented by the introduction of screening in the late 1960s and early 1970s.


50 years of screening in the Nordic countries: quantifying the effects on cervical cancer incidence.

Vaccarella S, Franceschi S, Engholm G, Lönnberg S, Khan S, Bray F - Br. J. Cancer (2014)

Effect of age, period and cohort on observed and projected ASRs of incident cervical cancer. Age-standardised rates (ASRs) are plotted by period. Age effects and ASRs are shown on a rate per 100 000 scale; cohort and period effects are on a relative risk scale. Reference points for period and cohort rate ratios are marked. Under a scenario without screening activities, period effects are forced to assume a constant value over time (dot-dashed lines). The projected ASRs corresponding to period effects constant over time, but age and cohort effects as estimated by the model, are also shown (dashed thick lines).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4150271&req=5

fig1: Effect of age, period and cohort on observed and projected ASRs of incident cervical cancer. Age-standardised rates (ASRs) are plotted by period. Age effects and ASRs are shown on a rate per 100 000 scale; cohort and period effects are on a relative risk scale. Reference points for period and cohort rate ratios are marked. Under a scenario without screening activities, period effects are forced to assume a constant value over time (dot-dashed lines). The projected ASRs corresponding to period effects constant over time, but age and cohort effects as estimated by the model, are also shown (dashed thick lines).
Mentions: According to our projections of a no-screening scenario, cervical cancer incidence rates between 1961 and 2010 would have increased in Denmark and Norway and remained stable in Sweden. In Finland, declines would have been substantially smaller than those observed. Projected incidence rates in 2006–2010 would have been ∼threefold higher than those observed in Finland, Norway and Sweden and fivefold higher in Denmark. Cervical cancer incidence rates in Denmark and Norway in 2006–2010 would have, therefore, been 102 (observed: 19) and 63 (observed: 19) per 100 000, respectively (Table 1 and Figure 1), that is, comparable to the highest rates observed in sub-Saharan countries (Ferlay et al. 2010). Rates in Finland and Sweden would have been 22 (observed: 8) and 40 (observed: 14) per 100 000, respectively (Table 1 and Figure 1), that is, comparable to the highest rates observed in Eastern Europe, Latin America and Asia (Ferlay et al. 2010). Table 1 also shows the projections relative to the average yearly number of cervical cancer cases that have been prevented by screening in 2006–2010 (from 202 in Finland to 1239 in Denmark). Overall in the Nordic countries, over 60 000 cases or between 41 and 49% of the expected cases of cervical cancer may have been prevented by the introduction of screening in the late 1960s and early 1970s.

Bottom Line: Nordic countries' data offer a unique possibility to evaluate the long-term benefit of cervical cancer screening in a context of increasing risk of human papillomavirus infection.In the absence of screening, projected incidence rates for 2006-2010 in Nordic countries would have been between 3 and 5 times higher than observed rates.Over 60,000 cases or between 41 and 49% of the expected cases of cervical cancer may have been prevented by the introduction of screening in the late 1960s and early 1970s.

View Article: PubMed Central - PubMed

Affiliation: International Agency for Research on Cancer, 150 cours Albert Thomas, 69372 Lyon cedex 08, France.

ABSTRACT

Background: Nordic countries' data offer a unique possibility to evaluate the long-term benefit of cervical cancer screening in a context of increasing risk of human papillomavirus infection.

Methods: Ad hoc-refined age-period-cohort models were applied to the last 50-year incidence data from Denmark, Finland, Norway and Sweden to project expected cervical cancer cases in a no-screening scenario.

Results: In the absence of screening, projected incidence rates for 2006-2010 in Nordic countries would have been between 3 and 5 times higher than observed rates. Over 60,000 cases or between 41 and 49% of the expected cases of cervical cancer may have been prevented by the introduction of screening in the late 1960s and early 1970s.

Conclusions: Our study suggests that screening programmes might have prevented a HPV-driven epidemic of cervical cancer in Nordic countries. According to extrapolations from cohort effects, cervical cancer incidence rates in the Nordic countries would have been otherwise comparable to the highest incidence rates currently detected in low-income countries.

Show MeSH
Related in: MedlinePlus