Cervical cancer mortality in Norway according to screening attendance and age

Introduction: The association between cervical cancer screening and reduction of cervical cancer has been dealt with in much research. However, little has been pub-lished on the association between screening and cervical cancer mortality. We as-sessed cervical cancer deaths according to screening history, histopathology, and age among women in, under, and above screening age. Material and methods: In this nationwide, registry- based case–control study from Norway, we included 817 cervical cancer deaths in women diagnosed with cervical cancer in the period 1998–2009. We matched each case with 10 population- based controls free from cervical cancer, obtained by density- based sampling. Odds ratios (ORs) with 95% confidence intervals (CIs) for the association between screening attendance and cervical cancer mortality were estimated using conditional logistic regression models. Results: Of all fatal cervical cancers, 35% were diagnosed among women over screening age and altogether, 83% were either in age groups not covered by the screening program or in non-attenders of screening age. The estimated risk reduction associated with a cytology test in the preceding 3.5 years was 80% in screening age 25–69 years (OR 0.20; 95% CI 0.16–0.24) with the largest reduction in squamous cell carcinomas (84%) but also a substantial estimated risk reduction of 65% for adenocarcinomas. The associated risk reduction was strongest in women aged 45–69 years, with ORs in the range 0.09–0.18, compared with ORs 0.42–1.35 in women aged 25–39 years. Conclusions: To reduce the mortality of cervical cancer, screening programs should focus on increasing adherence to the program, as half of all the fatal cases were in the non-attender group. Further assessments regarding the potential preventive impact of extending screening to women over the current screening age should be considered.