BACKGROUND: Endometrial cancer is mainly dependent on oestrogen exposure. Preeclampsia has shown to reduce oestrogen levels hence preeclampsia may affect later endometrial cancer risk.

METHODS: We conducted a case-control study of 523 Danish women with endometrial cancer and 52 299controls during 1978-2010. The association between preeclampsia and later endometrial cancer was evaluated overall and according to preeclampsia onset and type of endometrial cancer in conditional logistic regression models.

RESULTS: We observed no overall association between preeclampsia and endometrial cancer risk (OR=1.11 (95% CI 0.68-1.81)). This was true for all endometrial cancer subtypes. In an analysis of preeclampsia onset, however, we report a markedly increased risk of endometrial cancer following early-onset preeclampsia (OR=2.64 (95% CI 1.29-5.38)).

CONCLUSIONS: Although we report no obvious association between preeclampsia and endometrial cancer, studying the subset of early-onset preeclampsia may prove fruitful in further understanding the aetiology of endometrial cancer.