Objective The objective of this study was to study whether women surgically treated for cervical intraepithelial neoplasia (CIN) have increased mortality later in life. We also wanted to study whether pregnancy beyond 22 weeks post-treatment affects the risk.
Design Register-based retrospective cohort study from Finland.
Setting National data of the Hospital Discharge Register and the Cause-of-Death Register during 1986–2003.
Population A total of 25 827 women who had surgical treatment for CIN during 1986–2003.
Methods We calculated standardised mortality ratios (SMRs) by dividing the numbers of observed deaths (until 31 December 2006) by the numbers of expected deaths.
Main outcome measures SMRs for different causes-of-death groups.
Results The overall mortality increased by 17% after treatment for CIN, including increased risk of dying from all diseases and medical conditions (SMR 1.13, 95% CI 1.01–1.26), cancers (SMR 1.09, 95% CI 0.91–1.27) and injury deaths (SMR 1.31, 95% CI 1.03–1.58). As expected, the mortality from cervical cancer was high (SMR 7.69, 95% CI 4.23–11.15). Women who had delivered post-treatment tended to have decreased overall mortality (SMR 0.78, 95% CI 0.52–1.04) and decreased disease mortality (SMR 0.63, 95% CI 0.37–0.90). However, the mortality rate was significantly increased for women who had subsequent preterm delivery (SMR 2.51, 95% CI 1.24–3.78). In this subgroup, there was a tendency of increased mortality from diseases of the circulatory system, alcohol-related causes and injury deaths.
Conclusions Mortality rate was increased after surgical treatment for CIN. However, women who had delivered post-treatment had decreased overall disease mortality rate. Subsequent preterm delivery may be a risk marker for increased long-term mortality.