Mortality in a long-term follow-up after treatment of CIN.

After treatment of the cervical intraepithelial neoplasia (CIN) cervical cancer incidence remains elevated at least for 20 years. Whether the overall or cervical cancer mortality after treatment of CIN is elevated is unknown. The aim of this study was to determine the long-term survival and cause-specific mortality among women treated for CIN. The study population consisted of 7,104 women treated for CIN between 1974 and 2001 and 35,437 individually matched controls. The follow-up of mortality was based on nationwide registries and closed at death, emigration or December 31, 2005. The possible differences in mortality were assessed using Cox proportional hazard model. With follow-up time of approximately 630,000 woman-years, overall 2,781 deaths were observed, 530 among women treated for CIN and 2,251 among reference population (HR 1.1, 95% CI 1.0-1.3). Mortality from any cancer (HR 1.4, 95% CI 1.2-1.7), lung cancer (HR 2.7, 95% CI 1.8-4.1) and HPV-related anogenital cancer (HR 3.1, 95% CI 1.1-8.6) was higher among CIN patients, but mortality from cervical cancer was not (HR 1.0, 95% CI 0.3-4.0). Elevated cervical cancer incidence after treatment of CIN, documented earlier, did not predict elevation in cervical cancer mortality. This suggests high effectiveness of CIN management. Most of the excess mortality observed among CIN patients was due to increased risk of other cancers. These long-term mortality patterns should be considered when planning and evaluating the management of CIN lesions and related cervical or other cancer prevention activity.