The temporal and age-dependent patterns of hysterectomy-corrected cervical cancer incidence rates in Denmark: a population-based cohort study

Introduction: Hysterectomy is a common gynecological procedure; however, the incidence of total and subtotal hysterectomy varies across countries, by age, and over time. As only women with an intact cervix are at risk of cervical cancer, failing to remove hysterectomized women from the denominator may underestimate the cervical cancer incidence. We aimed to describe the temporal and age-dependent patterns of cervical cancer incidence in Denmark before and after correction for hysterectomy. Material and methods: Using data from national registries we calculated uncorrected and hysterectomy-corrected cervical cancer incidence rates among women ≥20 years during 2000–11. Hysterectomy-corrected rates were calculated by subtracting post-hysterectomy person-years from the denominator. Results: The overall uncorrected cervical cancer incidence rate was 17.8/100 000 person-years (95% CI 17.3–18.3). After correction for hysterectomy, the rate increased by 8.4% to 19.3/100 000 person-years (95% CI 18.8–19.9). The highest uncorrected incidence was seen in women aged 35–39 years, peaking at 24.4/100 000 person-years, whereas the highest hysterectomy-corrected cervical cancer incidence rate was observed in women aged 75–79 years (29.4/100 000 person-years). Over time, women ≥60 years had the highest hysterectomy-corrected cervical cancer incidence. Conclusions: Correcting for hysterectomy incidence resulted in a higher cervical cancer incidence and a shift in the peak incidence from age 35–39 years to age 75–79 years. Over time, women ≥60 years were at the highest risk of cervical cancer. Given the high incidence in women >60–65 years, when women are eligible to exit screening, a revision of the screening guidelines may be warranted.