Changes in cervical cancer incidence following the introduction of organized screening in italy
Menée à partir des données des registres italiens des cancers portant sur 3 557 femmes atteintes d'un cancer invasif du col de l'utérus diagnostiqué entre 1995 et 2008 (âge au diagnostic : entre 25 et 74 ans), cette étude évalue l'effet d'un programme de dépistage organisé sur l'incidence de la maladie et son stade au diagnostic
Objective : To quantify the impact of organized cervical screening programs (OCSPs) on the incidence of invasive cervical cancer (ICC), comparing rates before and after OCSP activation.
Methods : This population-based investigation, using individual data from cancer registries and OCSPs, included 3557 women diagnosed with ICC at age 25–74 years in 1995–2008. The year of OCSP full-activation was defined as the year when at least 40% of target women had been invited. Incidence rate ratios (IRRs) with 95% confidence intervals (95% CIs) were calculated as the ratios between age-standardized incidence rates observed in periods after OCSP full-activation vs those observed in the preceding quinquennium.
Results : ICC incidence rates diminished with time since OCSPs' full-activation: after 6–8 years, the IRR was 0.75 (95% CI: 0.67–0.85). The reduction was higher for stages IB–IV (IRR = 0.68, 95% CI: 0.58–0.80), squamous cell ICCs (IRR = 0.74, 95% CI: 0.64–0.84), and particularly evident among women aged 45–74 years. Conversely, incidence rates of micro-invasive (stage IA) ICCs increased, though not significantly, among women aged 25–44 years (IRR = 1.34, 95% CI: 0.91–1.96). Following OCSP full-activation, micro-invasive ICCs were mainly and increasingly diagnosed within OCSPs (up to 72%).
Conclusion(s) : Within a few years from activation, organized screening positively impacted the already low ICC incidence in Italy and favored down-staging.
Preventive Medicine , résumé, 2014