First-time postmenopausal bleeding as a clinical marker of long-term cancer risk: A Danish Nationwide Cohort Study

Background Data on long-term risk of cancer after a postmenopausal bleeding diagnosis are sparse. Methods We used Danish medical registries to conduct a population-based cohort study of women with a first hospital-diagnosed postmenopausal bleeding during 1995–2013. We computed the absolute risk of cancer and the standardised incidence ratio (SIR) comparing the observed cancer incidence with that expected in the general population. Results Among 43,756 women with postmenopausal bleeding, the absolute 1- and 5-year risk of endometrial cancer were 4.66% and 5.18%, respectively. The SIR of endometrial cancer was elevated during 0–3 months (SIR = 330.36 (95% CI: 315.43–345.81)), 3–12 months (SIR = 11.39 (95% CI: 9.79–13.17)), 1–5 years (SIR = 2.55 (95% CI: 2.19–2.94)) and >5 years of follow-up (SIR = 1.63 (95% CI: 1.40–1.90)). All selected gynaecological and urological, gastrointestinal and haematological cancers had elevated 0–3 months SIRs. Beyond 1 year of follow-up the SIRs of ovarian and bladder cancer remained elevated with a 1–5-year SIR of 2.15 (95% CI: 1.71–2.65) and 1.45 (95% CI: 1.14–1.80), respectively. Conclusions In the Danish population, women with a first hospital-diagnosed postmenopausal bleeding have an increased 0–3 months risk of gynaecological, urological, gastrointestinal and haematological cancers. The SIR of endometrial, ovarian and bladder cancer remained elevated for several years.