Introduction/Background*ECCCs are non-endometrioid (type II) cancers. Representing 3% of uterine malignancies, ECCCs are not hormonally-driven, but aggressive – with high rates of LVSI, metastases and extra-pelvic relapse. Five-year survival is 60%. Latest European guidance (2020) recommends primary surgery – incorporating sentinel or pelvic lymph node dissection (PLND); but omitting omentectomy in stage I disease. Excluding those with tumour confined to endometrium, adjuvant chemo-radiation is recommended.

Methodology All patients treated for ECCC in a large cancer centre between 2009-2019 were identified and data collected retrospectively.

Result(s)*17 patients were identified, representing <2% uterine malignancies treated. Mean age was 68.6years and BMI 26.8kg/m2. 82.4% (n=14) presented with post-menopausal bleeding and 11.7% (n=2) were diabetic.

All patients underwent primary surgery (total hysterectomy and bilateral salpingo-oophrectomy). 94.1% (n=16) had PLND and omental biopsy. All were grade 3; 70.6% (n=12) LVSI positive; and endometrial hyperplasia co-existed in 1 case. 76.5% were stage 1; 5.9% stage II; and 17.6% stage III. 94.1% (n=16) received adjuvant treatment: vault brachytherapy in 58.8%; reserving chemotherapy for stage III.

17.6% (n=3) recurred: on average 22.3months from surgery and most often (66.7%) upper abdominally. All patients with relapse were high grade with LVSI; and 2/3 stage III. 5-year survival was 75% overall; 66.7% in advanced disease.

Conclusion*In keeping with literature, our experience suggests ECCC is rare and not associated with obesity, diabetes, endometrial hyperplasia or omental disease. High grade, LVSI and advanced stage appear to be risk factors for upper abdominal recurrence. Whilst our stage III survival data is as expected, relatively favourable overall figures likely reflect the high proportion of early stage disease captured. Latest guidance may encourage more sentinel nodes, less omental surgery, and a switch from vault brachytherapy to wider administration of chemo-radiotherapy for ECCC.