Trends in incidence and mortality risk for acromegaly in Norway: a cohort study

Recent data have shown a decreasing overall mortality in acromegaly over the last decades. However, cancer incidence and cancer-related mortality still appear to be increased. Our aim was to obtain updated epidemiological data from Norway in a clinically well-defined cohort with complete register-based follow-up.

Patients diagnosed with acromegaly from South-Eastern Norway between 1999-2019 (n = 262) and age and sex matched population controls (1:100) were included (n = 26,200). Mortality and cancer data were obtained from the Norwegian Cause of Death and Cancer Registry. Mortality and cancer incidence were compared by Kaplan-Meier analyses and Cox regression; we report hazard ratios (HRs) with 95% confidence intervals (95% CI).

Median age at diagnosis was 48.0 years (interquartile range (IQR): 37.6-58.0). Mean annual acromegaly incidence rate was 4.7 (95% CI 4.2-5.3) cases/10⁶ person-years, and the point prevalence (2019) was 83 (95% CI 72.6-93.5) cases/10⁶ persons. Overall mortality was not increased in acromegaly, HR 0.8 (95% CI 0.5-1.4), cancer-specific and cardiovascular-specific mortality was also not increased (HR: 0.7 (95% CI 0.3-1.8) and 0.8 (95% CI: 0.3-2.5) respectively). The HR for all cancers was 1.45 (1.0-2.1; p = 0.052).

In this large cohort study, covering the period 1999-2019, patients were treated with individualized multimodal management. Mortality was not increased compared to the general population and comparable with recent registry studies from the Nordic countries and Europe. Overall cancer risk was slightly, but not significantly increased in the patients.