Introduction/Background Approximately 15% of women who present with post-menopausal bleeding (PMB) are diagnosed with proliferative endometrium. It is not currently thought to be precancerous, however is part of the spectrum of changes seen with persistent unopposed oestrogen stimulation. (1,2)

There is little high quality evidence regarding long term outcomes on these women.

We performed a retrospective cohort study to investigate the long term outcomes and the chance of development into malignancy.

Methodology 411 women aged over 55 years where identified from the Northern Ireland histopathology records with a diagnosis of proliferative endometrium from January 2008 until December 2014 (follow up until December 2022)

Electronic records where used to obtain patient information.

Data collected included age, BMI, further PMB, further histopathology, progression to malignancy.

Results Overall population

- N = 411

- Age range :55 – 86 (Mean : 58)

- BMI range : 17 – 78 (Mean : 30)

PMB population

- 325/411 presented with PMB

- 8/325 (2.5%) where later diagnosed with endometrial cancer (EC).

- Mean BMI : 37.8

- Mean age : 58

- Mean time to progression : 52 months

- An additional 11 (3.3%) had complex endometrial hyperplasia found on a subsequent sample

Women with BMI >30 with proliferative endometrium :

Over twice likely to have recurrent PMB episodes than women with BMI <30 (OR 2.1 95% CI 1.46–3.03, p =0.00001)

Nearly nine times as likely to develop EC in the future (OD 8.9, 95% CI 2.02 - 38.11, p = 0.004).

Conclusion 2.5% of women with proliferative endometrium went on to develop EC. This is in keeping with the population background rate. Increased BMI independently increases the risk of repeat PMB episodes, increasing clinical workload, as well as increasing the risk of developing EC. This is in keeping with known research.

This indicates that proliferative endometrium independently is not a precursor to developing EC, however future prospective studies are needed to confirm this.

Disclosures Nil.