Screening-detection history of women with cervical cancer : an Italian Collaborative Study

Introduction. Organized cervical screening programs (CSPs) are more effective in reducing the burden of invasive cervical cancer (ICC) than opportunistic screening. CSPs have been extensively introduced in Italy. Objectives. To depict screening-detection history within CSPs of women with ICC in Italy, and to evaluate association between such a history and women/ICC characteristics, for identifying potential flaws of CSPs. Materials and Methods. Screening history of women diagnosed with ICC in areas covered by Cancer Registries (CRs) and CSPs was retrieved by merging CRs and CSPs databases. Screen-Detected (SD) women were those with a positive Pap smear within a CSP, otherwise they were considered Non-Screen-Detected (NSD). Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated by logistic regression model adjusted for age. Results. Among 3473 women, aged 25-74 years and belonging to CSPs target population between 1995 and 2008, 32.3% had SD ICC and 67.7% had NSD ICC. Among 2350 NSD women, 27.7% were ‘not invited’, 55.2% were ‘non compliant’, and 17.1% had a last ‘negative Pap smear’ within a CSP (58.0% of them had this Pap smear <3.5 years before diagnosis). NSD status was directly associated with increasing age at diagnosis (OR=1.02, 95%CI 1.01-1.03 for each year); residence in Center (OR=1.4, 95%CI 1.2-1.7) or South/Islands (OR=7.8, 95%CI 4.2-14.5), as compared to North Italy; being born abroad compared to Italy (OR=1.6, 95%CI 1.3-2.1); high ICC stage (OR=8.7 for FIGO III-IV vs. IA-IA1), and non-squamous cells ICC histology (OR=1.5, 95%CI 1.3-1.8 vs. squamous). Discussion and Conclusions. This population-based study found that 68% of women with ICC were NSD - i.e., diagnosed outside CPSs - mainly because of non compliance to CSP invitation. These women had advanced stages of the disease, with relevant negative effects on prognosis. The findings also showed a very high geographic heterogeneity, only partly due to the very recent activation of CSPs in some Italian areas.