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.