Effectiveness of cervical screening with age: population based case-control study of prospectively recorded data

Abstract

Objective To study the effect of cervical screening on incidence of cervical cancer as a function of age with particular focus on women screened under the age of 25. Design Population based case-control study with prospectively recorded data on cervical screening. Setting Selected centres in the United Kingdom. Participants 4012 women aged 20-69 with invasive cancer diagnosed in participating centres and two controls per case individually matched on age and area of residence. Main outcome measures Odds ratios for strength of association between cervical cancer and screening at particular ages. Results There is no evidence that screening women aged 22-24 reduced the incidence of cervical cancer at ages 25-29 (odds ratio 1.11, 95% confidence interval 0.83 to 1.50). Similar results were seen for cancers restricted to squamous carcinoma or FIGO (International Federation of Gynaecology and Obstetrics) stage IB or worse, but the numbers are insufficient to provide narrow confidence intervals. Screening was associated with a 60% reduction of cancers in women aged 40, increasing to 80% at age 64. Screening was particularly effective in preventing advanced stage cancers. Conclusions Cervical screening in women aged 20-24 has little or no impact on rates of invasive cervical cancer up to age 30. Some uncertainly still exists regarding its impact on advanced stage tumours in women under age 30. By contrast, screening older women leads to a substantial reduction in incidence of and mortality from cervical cancer. These data should help policy makers balance the impact of screening on cancer rates against its harms, such as overtreatment of lesions with little invasive potential.

Mortality audit of the Finnish cervical cancer screening program

“…2,3,11 This study indicates that also when using mortality as outcome, screening in younger ages (below 40) has less impact than in older women. Because of a small number of deaths among invited women, it was not possible to estimate ORs for the associations of screening participation in the individual 5-year age categories.…”

“…Similarly, a case-control study from the UK found screening to be less effective in women aged 20-34 and that the efficacy decreases with decreasing age even within this age range. 3 By contrast, a Swedish audit found screening to be equally effective in preventing cancer diagnosed in the ages 21-29 and 30-65. 4 To our knowledge no mortality based effectiveness studies have yet addressed this issue.…”

“…1 However, recent research suggests that screening may not be equally effective in all age-groups currently targeted by screening programmes. 2,3 In a case-control evaluation of the Finnish program, no effect on the risk of cancer in the following 5-year interval was found after participation at the age of 25-29. 2 Risk reductions increased with increasing age up to 40, and remained fairly constant thereafter.…”

Age Criteria for Cervical Screening in England: Qualitative Study of Women’s Views

“…Recent evidence supports the conclusion that cervical screening in women aged 20-24 is substantially less effective in preventing cancer than screening in older women (Sasieni et al 2009), not least because changes in the young cervix are normal, and unnecessary treatment in response to putative abnormal features could interfere with fertility (Arbyn et al 2008). Nonetheless, the decision to begin routine screening at 25 rather than 20 has been much debated, and in May 2009 an ‗extraordinary meeting' of the Advisory Committee on Cervical Screening (ACCS) was asked to make recommendations to government ministers about whether the age 25 start date was still the right policy.…”

Impacto da capacitação dos profissionais de saúde sobre o rastreamento do câncer do colo do útero em unidades básicas de saúde

“…Sasieni et al 22 mostraram que o rastreamento em mulheres com idade entre 20 e 24 anos teve pequeno ou nenhum impacto sobre as taxas de câncer cervical invasivo. Em contraste, o rastreamento em mulheres idosas obteve uma substancial redução na incidência e mortalidade em decorrência do CCU.…”