Time trends in the incidence of hysterectomy-corrected overall, type 1 and type 2 endometrial cancer in Denmark 1978-2014.

OBJECTIVE

To investigate time trends in the incidence of overall, type 1 and type 2 endometrial cancer in Denmark 1978-2014, correcting for hysterectomy.

METHODS

Based on the Danish Cancer Registry and the Danish National Patient Registry we calculated hysterectomy-corrected incidence rates of overall, type 1 and type 2 endometrial cancer. Separate analyses for women <55years (defined as pre- and perimenopausal age) and women aged ≥55years (defined as postmenopausal age) and analyses allowing for different time trends before and after the study period midyear 1996 were performed. Log-linear Poisson models were used to estimate annual percentage change (APC) in incidence with 95% confidence intervals (CI).

RESULTS

The overall incidence of endometrial cancer decreased slightly from 1978 to 1995, but in the last two decades of the study period the incidence has been stable (APC=0.16; 95% CI: -0.19; 0.50). In the study period (1978-2014) type 1 endometrial cancer incidence decreased slightly (APC=-0.67; 95% CI:-0.83; -0.52), whereas the incidence of type 2 endometrial cancer increased substantially (APC=4.85; 95% CI: 4.47; 5.23). The decrease in type 1 endometrial cancer was most pronounced before 1996 in women younger than 55 years (APC=-2.79; 95% CI: -3.65; -1.91), while the largest increase in type 2 endometrial cancer was observed after 1996 (APC=6.42; 95% CI: 5.72; 7.12).

CONCLUSIONS

Over a period of more than 35 years, the incidence of type 1 endometrial cancer decreased, mainly in pre- and perimenopausal women, while type 2 endometrial cancer incidence increased.